KR20220042212A - Methods, corresponding granular materials and kits, devices, and uses for producing articles for use in the foundry industry - Google Patents

Abstract

The present invention relates to a method for producing an article for use in the foundry industry, wherein the article is selected from the group consisting of pourable additives, solid pourable additives, inorganic binders, and granular materials for producing a molding material mixture. . The present invention also relates to a corresponding granular material comprising particulate amorphous silica, and a kit for producing an inorganic binder. The invention also relates to an apparatus for carrying out the process according to the invention and to the corresponding use of particulate amorphous silica, and the corresponding use of granular material.

Description

Methods, corresponding granular materials and kits, devices, and uses for producing articles for use in the foundry industry

The present invention relates to a process for producing an article for use in the foundry industry, selected from the group consisting of pourable additives, solid pourable additives, inorganic binders and granular materials for the production of molding material mixtures. Further details of the process of the present invention will be apparent from the appended claims and the description which follows. The invention further relates to a corresponding granular material comprising particulate amorphous silicon dioxide. The invention further relates to a kit for the production of an inorganic binder. The invention also relates to an apparatus for carrying out the process of the invention. The present invention further relates to a corresponding use of particulate amorphous silicon dioxide. The invention further relates to a corresponding use of the granular material. Each detail will become apparent from the appended claims and the description that follows.

Casting in lost molds is a widely used process to produce components with a near-net shape. After casting, the mold is broken and the cast part is removed. The roast mold is a casting mold, and thus an engraving; It contains the cavity to be cast created in the final cast part. The inner contour of the future cast part is formed by the core. In the production of casting molds, a model of a casting part to be manufactured forms a cavity in the molding material.

Unlike the sand casting method, where the casting mold (lost mold) is destroyed after casting to remove the cast part, a metallic permanent mold, for example made from cast iron or steel, is reused for the next casting after the cast part has been removed. can be It is also possible to work by die casting, in which case the liquid metal melt is injected into the die casting mold under high pressure at a high mold filling rate. The casting method described above is also preferred in the context of the present invention. (In the sand casting method using a lost mold) The mold base material used for the casting mold and the core is mainly a refractory particulate material, for example, washed fractionated silica sand. For the production of casting molds, the mold base material is combined with an inorganic binder or an organic binder. The binder creates a fixed coherence between the particles of the mold base material, whereby the casting mold or core obtains the necessary mechanical stability. The refractory mold base material premixed with the binder is preferably in a free-flowing form, so that it can be introduced into a suitable cavity and compressed therein. The molding material is compressed to increase strength.

Casting molds and cores must meet various requirements. During actual casting operations, they must first have sufficient strength and thermal stability to accommodate liquid metal in cavities formed from one or more (partial) casting molds. After the solidification operation has started, the mechanical stability of the cast part is ensured by a solidified metal layer formed along the walls of the casting mold.

The material of the casting mold must then change under the influence of heat emitted by the metal to lose its mechanical strength, ie, coherence between the individual particles of the refractory material. In an ideal case, the casting mold and core are broken again to form a filament that can be easily removed from the cast part and thus can have advantageous breaking properties.

Inorganic binders, in particular those based on water glass, have long been known. In particular for the curing of water glass, three different methods are available and may be combined: (i) passing a gas, eg CO ₂ , air or a combination of the two; (ii) addition of liquid or solid curing agents, for example, in particular esters, and (iii) thermal curing, for example in the so-called hot box method, or by microwave treatment.

However, the use of inorganic binder systems is often associated with other common disadvantages:

For example, it is relatively common for foundry moldings produced from inorganic binders to have low strength, unless suitable special measures are taken. This becomes particularly evident immediately after removal of the molding, or the core or the casting mold, from the mold. Here, the strength (“hot strength” or “instant strength”) is particularly important for the safe handling of the core or formwork upon removal from the mold. In addition, high “cold strength” (ie, strength after complete hardening of the core or casting mold) is important so that the desired cast part can be produced with a minimum level of casting defects.

Document EP 1 802 409 B1 describes a molding material mixture for producing casting molds for metalworking, comprising at least a refractory mold base material, a waterglass-based binder, wherein the molding material mixture contains a certain proportion of particulate synthetic amorphous silicon dioxide A molding material mixture characterized in that it is added is disclosed.

Document DE 10 2013 111 626 A1 discloses a molding material mixture for the production of molds or cores, comprising at least a refractory mold base material, water glass as binder, particulate amorphous silicon dioxide and at least one powdered boron oxide compound. This document further discloses that the addition of boron compounds to the molding material mixture improves the moisture stability of the core and molds produced therewith.

Document WO2014/202042A1 discloses a molding material mixture for the production of casting molds and cores for metalworking, comprising at least one refractory mold base material, particulate amorphous SiO ₂ , water glass and a lithium compound. This document further discloses that the addition of a lithium compound to the molding material mixture improves the moisture stability of the molding produced therewith.

Document DE 10 2012 104 934 A1 discloses a molding material mixture for the production of casting molds for metalworking, comprising at least a refractory mold base material, a waterglass-based binder and barium sulfate.

Document DE 10 2012 113 073 A1 describes a molding material mixture for the production of cores and formwork for metalworking, comprising at least a) a refractory mold base material, b) an inorganic binder and c) at least one particulate metal oxide, A molding material mixture is disclosed wherein the particulate metal oxide comprises or consists of at least one aluminum oxide in alpha phase and/or at least one mixed aluminum/silicon oxide, except for mixed aluminum/silicon oxide having a sheet silicate structure.

Document DE 10 2012 113 074 A1 discloses a molding material mixture for the production of cores and formworks for metalworking, comprising at least one refractory mold base material, an organic binder and at least one particulate mixed metal oxide. Oxides of aluminum and zirconium are used in a specific way.

Document DE 10 2017 107 531 A1 discloses a process for producing a casting mold, a core and a mold base material regenerated therefrom. Particulate sheet silicates are used in a specific way.

Document EP 2 104 580 B1 describes at least a refractory mold base material; waterglass-based binders; A molding material mixture for the production of casting molds for metalworking is disclosed, comprising a proportion of particulate metal oxide selected from the group of silicon dioxide, aluminum oxide, titanium oxide and zinc oxide. Carbohydrates were added to the molding material mixture.

Document EP 2 097 192 B1 describes at least a refractory mold base material; waterglass-based binders; A molding material mixture for the production of casting molds for metalworking is disclosed, comprising a proportion of particulate metal oxide selected from the group of silicon dioxide, aluminum oxide, titanium oxide and zinc oxide. A proportion of the phosphorus compound was added to the molding material mixture.

Document DE 10 2012 020 509 A1 describes a casting for metalworking, comprising at least a refractory mold base material, an inorganic binder and particulate amorphous SiO ₂ producible by thermal destruction of ZrSiO ₄ to give ZrO ₂ and SiO ₂ Molding material mixtures for the production of molds and cores are disclosed.

Document DE 10 2012 020 510 A1 discloses the production of casting molds and cores for metalworking, comprising at least a refractory mold base material, an inorganic binder and particulate amorphous SiO ₂ producible by oxidation of metallic silicon by means of an oxygen-containing gas. A molding material mixture for

Document DE 10 2012 020 511 A1 discloses a casting mold and a core for metalworking, comprising at least a refractory mold base material, an inorganic binder and particulate amorphous SiO ₂ , producible by melting crystalline quartz and by rapid re-cooling. A molding material mixture for production is disclosed.

Document DE 10 2012 020 073 A1 discloses the production of casting molds and cores for metalworking, comprising at least a refractory mold base material, an inorganic binder and particulate amorphous SiO ₂ , producible by oxidizing metallic silicon by means of an oxygen-containing gas. A molding material mixture for

Document WO 2009/056320 discloses at least a refractory mold base material; waterglass-based binders; A molding material mixture for the production of casting molds for metalworking is disclosed, comprising a proportion of particulate metal oxide selected from the group of silicon dioxide, aluminum oxide, titanium oxide and zinc oxide. A predetermined proportion of at least one surface-active material was added to the molding material mixture.

The previously recognized patent documents disclose a molding material mixture comprising particulate amorphous SiO ₂ . It is also known from these documents that the addition of selected additives, proceeding from a particular base formulation, affects the properties of the molding material mixture and the moldings produced therefrom.

In the foundry industry, the use of binder and molding material mixtures comprising particulate amorphous silicon dioxide and optionally further solid additives, while at the same time individual doses that are actually additionally associated to date with health risks due to contamination of respirable air And there is a need to minimize the inconvenience associated with mixing. At the same time, it must be ensured that the repeatedly produced binder and molding material mixture always has the same composition and always has the same product properties.

It is also necessary to use substances that do not have long-term stability in waterglass, even in gel or liquid form, as constituents of the corresponding binder and molding material mixtures, without requiring an additional metering step.

Additionally, each very different as an additive for a molding material mixture, without the need for an additional metering step and without any consequential differences in the composition of the formed molding material mixture, for example depending on the level of filling in the reservoir vessel for the particulate material. There is a need to use a variety of particulate materials having a particle size distribution.

Additionally, it is necessary to add the solid and liquid additives for the molding material mixture to the molding material mixture in fixedly defined relative proportions to one another and by means of a single common metering step.

Very specifically, the need to be able to combine the known positive properties of additives for molding material mixtures without having to deal with the additional problems associated with the storage of the additives without requiring additional metering steps for every component added. there is

The invention is defined in the claims and described in detail below.

The present invention relates, in its category, to a process for producing articles for use in the foundry industry, to a granular material, to an apparatus for carrying out the process, to the use of particulate amorphous silicon dioxide, and to the use of the granular material. Embodiments, aspects or characteristics that are described in connection with one of these categories or that are described as preferred are each applicable correspondingly or analogously to the respective other categories, and vice versa.

Unless otherwise stated, a preferred aspect or embodiment of the present invention and its various categories may be combined with other aspects or embodiments of the present invention and its various categories, in particular other preferred aspects or embodiments. Combining the individual preferred aspects or embodiments with one another again yields a preferred aspect or embodiment of the present invention.

In a first aspect of the present invention, the object specified above is achieved, the problem being that

- granular materials for the production of injectable additives for use as constituents of inorganic binders in the foundry industry;

- solid injectable additives for use as constituents of inorganic binders in the foundry industry;

- inorganic binders for use in the foundry industry;

- molding material mixtures comprising inorganic binders for use in the foundry industry, and

- Moldings (particularly cores, casting molds and feeders) for use in the casting of metallic cast parts in the foundry industry

A process for producing an article for use in the foundry industry, selected from the group consisting of:

for the production of goods;

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide;

- Particulate amorphous silicon dioxide each comprising particles combined and each in a proportion of at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains comprising greater than 0.2 mm when measured by

It is solved in whole or in part by the process, including.

The granular material, the solid injectable additive, the inorganic binder and the molding material mixture are, respectively, intermediates produced continuously (in the order specified) in the production of the casting molds or cores. Each of these intermediates may be individually stored or otherwise transported.

Accordingly, the term “granular material” is understood in the context of the above definition to mean the whole of a plurality of grains as defined above.

Here, the grains are the product of an enlargement step carried out as planned and contain particulate amorphous silicon dioxide (and optionally additional material). The grains are thus in each case a composite, for example an agglomerate or an aggregate.

Preferably, the term “particulate” refers to particles of a solid powder (including dust) which are preferably injectable and thus sieveable.

The particulate amorphous silicon dioxide used may be of a synthetically produced type (eg, as defined in the first recognized prior art) or a naturally occurring type. The latter are known, for example, from DE 10 2007 045 649, but are undesirable because they often contain a not small amount of crystalline components and are therefore classified as carcinogenic.

"Particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide" is preferably particulate synthetic amorphous silicon dioxide. Depending on the origin or manufacturing process, natural and/or synthetic amorphous silicon dioxide contains up to 50% by weight of secondary constituents, ie crystalline silicon dioxide and/or non-silicon dioxide material. Accordingly, in addition to silicon dioxide, commercially available (synthetic or natural) "particulate amorphous silicon dioxide" usually contains a certain proportion of one or more additional inorganic oxides and unavoidable impurities. In the context of the present invention, synthetic amorphous silicon dioxide containing in each case less than 30% by weight secondary constituents and/or at least 80% by weight of silicon dioxide, based on the total mass of particulate amorphous silicon dioxide, is Particular preference is given to synthetic amorphous silicon dioxide containing less than 20% by weight of secondary constituents and/or at least 90% by weight of silicon dioxide.

Typically, and preferably, in some cases, the particulate amorphous silicon dioxide produced or provided comprises particles in dusty form.

The proportion of particulate amorphous silicon dioxide in the grains of the granular material (after suitable sample processing, in particular after sieving according to VDG-Merkblatt P 27 (see below)) is, for example, optionally, by optical and/or spectroscopic methods and can be determined or confirmed by x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001 in combination with a wet-chemical method; A person skilled in the art will preferably select a suitable measurement method using his knowledge of the materials used in the process.

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

In several cases, for the granular material produced, the index of emission of dust by means of a rotary method is in each case preferably DIN 55992-1 (date: June 2006), type I, rotary drum principle (eg lower, preferably, at least 15% lower, more preferably, at least 25% lower, and most preferably lower than the emission index of particulate amorphous silicon dioxide produced or provided according to a Heubach dust meter) , a process that is at least 40% lower is preferred.

What is meant by "synthetically produced" particulate amorphous silicon dioxide in the context of this text is that amorphous silicon dioxide is

- is the target product of a planned chemical reaction process for the industrial synthesis of amorphous silicon dioxide;

- It is a by-product of a planned chemical reaction process for the industrial synthesis of target products other than amorphous silicon dioxide.

An example of a reaction process with amorphous silicon dioxide as its target product is flame hydrolysis of silicon tetrachloride. Amorphous SiO ₂ (“silicon dioxide”) produced by this process can also be used as “pyrogenic SiO ₂ ” (“pyrogenic silicon dioxide”) or as pyrogenic silica or fumed silica (CAS RN 112945-52-5) is referred to as

An example of a reaction process that forms amorphous silicon dioxide as a by-product is, for example, reduction of quartz in an arc furnace to coke for the production of silicon or ferrosilicon as the target product. The amorphous SiO ₂ (“silicon dioxide”) thus produced is also referred to as silica dust, silicon dioxide dust or SiO ₂ fume condensate or “silica fume” or microsilica (CAS RN 69012-64-2).

A further reaction process for synthetically producing amorphous silicon dioxide is the thermal destruction of ZrSiO ₄ in an arc furnace to give ZrO ₂ and SiO ₂ .

The literature often refers to amorphous silicon dioxide formed by flame hydrolysis of silicon tetrachloride, for example, amorphous silicon dioxide formed as a by-product upon reduction of quartz to coke in an arc furnace, and "pyrogenic SiO ₂ "(" exothermic dioxide silicon") or as pyrogenic silica, which refers to amorphous silicon dioxide formed by thermal destruction of ZrSiO ₄ . These terms are also used in the context of the present application.

Pyrogenic particulate amorphous silicon dioxide to be used with particular preference in the context of the present invention comprises particulate amorphous silicon dioxide of those types identified in the context of the present invention by CAS RN 69012-64-2 and CAS RN 112945-52-5 do. Exothermic particulate amorphous silicon dioxide of these types to be particularly preferably used according to the invention is obtained in a manner known per se, in particular by reduction of quartz to carbon (eg coke) in an arc furnace, followed by (preferably ferro) In the production of silicon and silicon) can be produced by oxidation with silicon dioxide. Likewise, SiO ₂ prepared by thermal destruction of ZrSiO ₄ to give ZrO ₂ from ZrSiO ₄ , and SiO ₂ obtained by flame hydrolysis of silicon tetrachloride are particularly preferred.

Particulate amorphous silicon dioxide of the type produced by reduction of quartz with carbon (eg, coke) in an arc (in the production of ferrosilicon and silicon) contains carbon. Particulate amorphous silicon dioxide of the type produced by thermal destruction of ZrSiO ₄ contains zirconium oxide compounds.

Particulate synthetic amorphous silicon dioxide producible by oxidizing metallic silicon with an oxygen-containing gas and particulate synthetic amorphous silicon dioxide producible by quenching a silicon dioxide melt are very pure SiO ₂ with only a few unavoidable impurities.

Most preferably, the pyrogenic particulate amorphous silicon dioxide to be preferably used in accordance with the present invention comprises particulate amorphous silicon dioxide of the type identified by CAS RN 69012-64-2. It is preferably produced by reducing quartz with carbon (eg coke) in the arc (eg in the production of ferrosilicon and silicon) or obtained as a by-product (silica fume) in the production of ferrosilicon and silicon do. Likewise, SiO ₂ prepared by thermal destruction of ZrSiO ₄ to give ZrO ₂ from ZrSiO ₄ is particularly very preferred. These types of particulate amorphous silicon dioxide are also referred to in the art as “microsilica”.

"CAS RN" indicates a CAS registration number (registry number) and CAS registration number (register number) (CAS = Chemical Abstracts Service) here.

There are various methods suitable for combining particles of particulate amorphous silicon dioxide (and optionally additional material) in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains. Examples of suitable methods include pelletization, briquetting, tableting, granulation, agglomeration, extrusion, and the like.

"Handbuch der Agglomerationstechnik" [Handbook of Agglomeration Technology] by the author Gerald Heinze (WILEY-VCH Verlag GmbH, 2000, ISBN: 3-527-29788-X) discloses processes and products from the field of agglomeration technology has been

EP 1 602 425 A1 discloses a granular material obtainable from a silicon dioxide powder having a content of at least 90% amorphous SiO ₂ by granulation, in particular by pelletization with addition of water and subsequent drying.

A “moulding material mixture” in the context of the present invention as defined above comprises as one of a number of constituents the mold base material. The mold base material here is preferably a refractory mold base material. In this text, according to the ordinary understanding of the person skilled in the art, "refractory" masses, materials and minerals refer to those that are capable of withstanding thermal stresses at least briefly during the casting or solidification of iron melt, usually cast iron. Suitable (refractory) mold base materials are natural and synthetic mold base materials, for example silica sand, zircon sand or chromium ore sand, olivine, vermiculite, bauxite, or refractory clay, and mixtures thereof.

The timing of the addition of the additive to the further constituents in the production of the molding material mixture, or the molding material mixture provided with the additive, is arbitrary and can be freely selected. For example, the additive may alternatively be finally added to the final molding material mixture, or one or more additional components may first be premixed with one or more of the mentioned components before being finally mixed into the molding material mixture.

Solid injectable additives are understood to mean additives for mixtures of molding materials in injectable form and in the form of bitty aggregates, the individual pieces of which are less than 0.2 mm as measured by sieving. has the size of

An “inorganic binder” is, in the context of the above definition of the present invention, a multicomponent binder system comprising, typically, a solution or dispersion comprising an additive comprising at least particulate amorphous silicon dioxide, and water glass. The constituents are present here as two or more spatially separated constituents or as a mixture. The "inorganic binder" as well as particulate amorphous silicon dioxide may contain additional particulate matter, and/or additional substances in liquid or gel form, respectively, as part of the mixture and/or as spatially separate components.

In some cases, mixtures of components that would not be acceptable as individual components (eg, respirable crystalline SiO ₂ , classified as carcinogenic) in a foundry process, although undesirable, would result in significant, if undesirable, dust emissions. It is used according to the invention in granular materials, as it can be effectively prevented or reduced.

The term “combining” means to combine particles of particulate amorphous silicon dioxide with each other and optionally also with further constituents (see below).

The process of the invention is suitable for the production of all moldings customary for metal casting, ie for example cores, casting molds and feeders. It is also particularly advantageously possible to produce moldings with sections with very thin walls. Likewise, particularly advantageously, moldings which combine a particularly high one-hour strength with a maximum relative molding weight (weight based on the volume of a given body of predetermined geometry; in the case of a core, this is referred to as the core weight) It is possible to produce

The present invention in its various aspects, particularly and preferably,

- producing a granular material by the process described above, preferably, and identified above as preferred,

- grinding the grains of granular material to produce a solid injectable additive,

- solid injectable additives for use as constituents of inorganic binders in the foundry industry;

- inorganic binders for use in the foundry industry;

- molding material mixtures comprising inorganic binders for use in the foundry industry, and

- Moldings for use in the casting of metallic cast parts in the foundry industry

to a process (as described above, preferably, as identified above as preferred) for use in the foundry industry, selected from the group consisting of

One of ordinary skill in the art can choose from a number of methods of grinding the grains of granular material to produce a solid injectable additive. Grinding preferably includes grinding or crushing. However, the granular material can also be ground in other ways.

In a preferred embodiment, grinding, preferably grinding or shredding, takes place in a closed device so that a significant amount of dust and/or fine dust is released outside the device and does not contaminate the respirable air. In such a case, it is preferable to meter in the resulting solid injectable additive to the further constituents of the inorganic binder or molding material mixture, so that it also does not emit any dust and/or fine dust.

The present invention particularly and preferably,

(i) - (preferably in a configuration identified as being preferred) producing a solid injectable additive by the above-defined process of the invention;

- contacting the produced solid injectable additive with water glass or suspending the produced solid injectable additive in water glass, or

(ii) - producing a granular material by the above defined process of the invention;

- contacting the granular material produced with water glass, in the presence or absence of a refractory mold base material, and simultaneously or thereafter grinding the grains of the granular material;

- inorganic binders for use in the foundry industry;

- molding material mixtures comprising inorganic binders for use in the foundry industry, and

- Moldings for use in the casting of metallic cast parts in the foundry industry

to a process (as described above, preferably, as identified above as preferred) for use in the foundry industry, selected from the group consisting of

Waterglass can be produced, for example, by dissolving glassy sodium and potassium silicates in water in an autoclave at elevated temperature, or from lithium silicate in a hydrothermal process. According to the invention, it is possible to use water glasses containing one, two or more alkali metal ions mentioned. The proportion of water glass in the molding material mixture in the context of the present invention is preferably in the range from 0.6% to 3% by weight.

The contacting of the produced solid injectable additive with the water glass, or suspending the produced solid injectable additive in the water glass, taking place in variant (i), first grinds the previously produced granular material to provide a solid injectable additive. , preferably by grinding or crushing. Accordingly, the solid injectable additive produced from the granular material is in contact with or suspended in the water glass. More preferably, the contacting of the produced solid injectable additive with water glass is at the same time or after the refractory mold base material is initially filled, then the solid injectable additive is added, and finally the water glass is added, It takes place in such a way that all the ingredients used are preferably mixed with one another until they are homogeneously blended. In a less preferred embodiment, for example, the refractory mold base material is initially filled, then water glass is added, and only then the solid injectable additive is added, simultaneously and/or thereafter, all used The order may be changed so that the ingredients are mixed until they are homogeneously blended with each other. In a further embodiment, the solid injectable additive is blended with water glass to give a suspension, which suspension is then added to the initial charge of refractory mold base material, at the same time and thereafter, all components used being homogeneously blended with each other mixed until

In the presence or absence of the refractory mold base material taking place in variant (ii), the contact of the produced granular material with the water glass and, simultaneously or thereafter, grinding of the grains of the granular material, the (not initially ground) grains of the granular material This means that it comes into contact with the water glass. A person skilled in the art will be able to achieve comminution of grains by adjusting the studding conditions according to the needs of the individual case, in the contacting and blending of the water glass with the granular material produced, according to the circumstances of the individual case. A person skilled in the art will likewise be able to blend the granular material with the water glass in such a way that the individual grains of the granular material are essentially not crushed, depending on the circumstances of the individual case and by appropriate adjustment of the stirring conditions. In both cases, the contacting and blending of the produced granular material with the water glass can take place in the presence or absence of the refractory mold base material. If the contact of the produced granular material with the water glass takes place in the presence of the refractory mold base material, the blending takes place upon (or immediately after) the contacting, and such blending preferably grinds the grains of the granular material.

In each of variants (i) and (ii) it is possible to use waterglass in the form of a mixture with one or more additives, for example a mixture comprising waterglass and one or more surfactants.

Deviating from the prior art, in the process of the present invention, the particulate amorphous SiO ₂ is not used directly for the production of the inorganic binder or molding material mixture, but rather the granular material produced or the solid injectable additive produced therefrom is exclusively used. .

The effects and advantages described above in connection with the process of the invention are here achieved to a certain extent.

The present invention particularly and preferably,

- producing an inorganic binder by the above-defined process of the invention (preferably in a configuration identified as preferred), and

(i) at the same time mixing the components used for the production of the inorganic binder with the refractory mold base material, and/or

(ii) thereafter mixing the produced inorganic binder with the refractory mold base material;

The process of the present invention (as described above, preferably as described above, preferably , as identified above as preferred).

The molding material mixture may be produced by mixing the individual components used for the production of the inorganic binder with each other in the presence of a refractory mold base material to provide a molding material mixture. The molding material mixture can likewise be produced by first producing the inorganic binder by mixing the constituents of the inorganic binder, and mixing the previously produced inorganic binder with the refractory mold base material to provide the molding material mixture. Depending on the requirements of the individual case, preference may be given to one variant or both variants or a combination of two variants in each case.

The refractory mold base material preferably comprises more than 80% by weight, preferably more than 90% by weight, more preferably more than 95% by weight of the total mass of the molding material mixture. The refractory mold base material to be used according to the invention is preferably in particulate form. It is preferably free-flowing.

The refractory mold base material preferably has an AFS grain fineness number in the range of 30 to 100. Here the AFS particle size index is determined according to VDG-Merkblatt (information sheet from "Verein deutscher Gießereifachleute" [Society of German Foundry Experts]) (P34 of October 1999, point 5.2). The AFS particle size index is specified herein by the formula:

a plurality of particles each comprising combined particles and each comprising particulate amorphous silicon dioxide in a proportion of at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, based on the mass of the individual grains When the average grain diameter of the (produced) granular material is measured by sieving in the step of providing grains by combining particles of particulate amorphous silicon dioxide in the expanding step to produce a granular material comprising individual grains of Preference is given to the process of the invention (as described above, preferably, as identified above as preferred), which is greater than 0.5 mm, preferably greater than 1 mm.

Accordingly, this preferred process of the present invention is such that the grains have an average grain diameter (as measured by sieving) greater than 0.5 mm, preferably greater than 1 mm, each (as described above) ) resulting in a granular material comprising particulate amorphous silicon dioxide in a proportion of at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight. The granular material produced by this method has a particularly advantageous combination of the following properties: homogeneous composition, high bulk density, good flowability, good transportability, good meterability, low dust level, prevention of segregation phenomena, grindability, its High molding weight of moldings producible by use, increased moisture stability (moisture resistance) of moldings producible by their use.

The process of the invention, wherein the particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of the particulate amorphous silicon dioxide, consists entirely or in part of particulate synthetic amorphous silicon dioxide (as described above, Preferably, as identified above as preferred) is preferred.

According to the requirements of the individual case, if the particulate amorphous silicon dioxide (comprising at least 80% by weight of silicon dioxide, based on the total mass of the particulate amorphous silicon dioxide) consists entirely or only partly of particulate synthetic amorphous silicon dioxide, in particular It is advantageous. By regularly and preferably using synthetic amorphous silicon dioxide, it is possible to achieve, in a uniform and predictable quality, a particularly advantageous combination of the properties of the molding obtainable therefrom.

The proportion of silicon dioxide in the whole granular material, as determined by x-ray fluorescence analysis, and in each case more than 1 mm, preferably, more than 0.5 mm, more preferably, as measured by sieving and subsequent x-ray fluorescence analysis is that the proportion of silicon dioxide in at least 90% of the grains of the granular material having a grain diameter of greater than 0.2 mm differs, based on the proportion of silicon dioxide in the granular material as a whole, by no more than 30%, preferably no more than 20% Preference is given to the process of the present invention (as described above, preferably as identified above as preferred), more preferably different by no more than 10%.

The proportion of silicon dioxide both in the whole of the granular material and in the individual grains of the granular material is determined by x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001. (average) grain diameter according to VDG-Merkblatt (i.e. information sheet from "Vereins deutscher Gießereifachleute") specifying the use of a test sieve according to DIN ISO 3310 (P 27 of October 1999, point 4.3) It is measured by sieving. The proportion of silicon dioxide in the whole granular material (as measured by x-ray fluorescence analysis), and greater than 1 mm (as measured by sieving), preferably greater than 0.5 mm (as measured by sieving) , more preferably, the proportion of silicon dioxide (as measured by x-ray fluorescence analysis) in at least 90% of the individual grains of the granular material having a grain diameter of greater than 0.2 mm (as measured by sieving), What is meant by the fact that they differ by no more than 30%, preferably no more than 20%, more preferably no more than 10% (based on the proportion of silicon dioxide in the whole granular material) is that these (minimum) It is that this granular grain of size is a good representative of the overall composition of the granular material, and thus of the material used as a whole. For each of the sizes mentioned (1 mm, 0.5 mm, 0.2 mm), in the individual case, it is also possible that any specified maximum difference (30%, 20%, 10%) is justified and advantageous. Accordingly, according to the requirements of the individual case, any resulting combination of magnitude and maximum difference is preferred.

In the enlargement step, the particles of particulate amorphous silicon dioxide

- a substance in the form of a gel, preferably a liquid comprising a liquid wetting agent and/or a suspending medium, preferably water,

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- Rheological additives (thickeners, suspending aids),

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

The process of the present invention (as described above, preferably, as identified above as preferred, same) is preferred.

The particulate amorphous silicon dioxide is preferably mixed and/or contacted in the expansion step with one, two or more additional substances (which are not themselves particulate amorphous silicon dioxide). The selection of one, two or more additional materials that are mixed and/or contacted in the expansion step with the particulate amorphous silicon dioxide is made independently of the above list, which means that the selection of the first material is independent of any subsequent material(s). ) does not affect the choice of

The surfactant(s) is preferably oleyl sulfate, stearyl sulfate, palmityl sulfate, myristyl sulfate, lauryl sulfate, decyl sulfate, octyl sulfate, 2-ethylhexyl sulfate, 2-ethyloctyl sulfate, 2- Ethyldecyl sulfate, palmitoleyl sulfate, linolyl sulfate, lauryl sulfonate, 2-ethyldecyl sulfonate, palmityl sulfonate, stearyl sulfonate, 2-ethylstearyl sulfonate, linolyl sulfonate, hexyl phosphate , 2-ethylhexyl phosphate, caprylic phosphate, lauryl phosphate, myristyl phosphate, palmityl phosphate, palmitoleyl phosphate, oleyl phosphate, stearyl phosphate, poly(ethane-1,2-diyl)phenol hydroxyphosphate , poly(ethane-1,2-diyl)stearyl phosphate, poly(ethane-1,2-diyl)oleyl phosphate, polycarboxylate ether in water (eg Melpers 0030 from BASF), modified in water polyacrylate (eg Melpers VP 4547/240 L from BASF), 2-ethylhexyl sulfate in water (eg Texapon EHS from Cognis), polyglucoside in water (eg from Cognis) Glukopon 225 DK from ), sodium octylsulfate in water (eg Texapon 842 from Lakeland), modified carboxylate ethers (eg Castament ES 60 from BASF, solid state) independently selected from

The film forming agent(s) is preferably independently selected from the group consisting of or comprising polyvinyl alcohol and acrylic acid.

The rheological additive(s) (thickeners, suspending aids) preferably comprises:

- swelling clay, preferably sodium bentonite or attapulgite/paligoskite,

- swellable polymers, preferably cellulose derivatives, in particular carboxymethyl, methyl, ethyl, hydroxyethyl and hydroxypropyl cellulose, plant mucilage, polyvinylpyrrolidone, pectin, gelatin, agar-agar, polypeptide and/or alginate

It is independently selected from the group consisting of or comprising the same.

The hydrophobizing agent(s) preferably consists of or comprises an organosilicon compound, silane, silanol, preferably trimethylsilanol, silicone and siloxane, preferably polydimethylsiloxane, wax, paraffin, metallic soap. It is preferably independently selected from the group

The substances listed above are preferred in the context of the present invention. Additional substances can likewise be used according to the requirements of the individual case.

Accordingly, the materials described above can also be used in the process of the present invention without the need for additional quantification steps or additional storage vessels in the foundry. In addition, the introduction of such components into the molding material mixture produced according to the invention without a further quantification step, preferably comprising such liquid components (including liquid components in gel form) which do not have long-term stability in water glass, is , since they are incorporated into the granules formed in the expansion step.

The term "carbohydrate" in the context of this text is understood to mean aldose (polyhydroxyaldehyde) and ketose (polyhydroxyketone), and also high molecular weight compounds which can be converted to these compounds by hydrolysis . Carbohydrates used in the context of the present invention are oligomers and polymers having a chain length of n > 2. The present invention also relates to a process of the present invention (as described above, preferably, as identified above as preferred), wherein the grains of granular material resulting from the expanding step, preferably, At least 90% of the grains of the granular material having a particle diameter in each case greater than 1 mm, preferably greater than 0.5 mm, more preferably greater than 0.2 mm as measured by sieving

(i) one, two, more than two or all of the particulate amorphous silicon dioxide and the additional solid material present in the enlargement step; and/or

(ii) particulate amorphous silicon dioxide, and

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- Rheological additives (thickeners, suspending aids),

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

1, 2 or more additional substances independently selected from the group consisting of

The proportion/presence of silicon dioxide in the individual grains of the granular material is confirmed by x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001. The grain diameter is determined by sieving according to VDG-Merkblatt (ie information sheet from "Vereins deutscher Gießereifachleute") (P 27 of October 1999, point 4.3), specifying the use of test sieves according to DIN ISO 3310 . The presence of one, two, more than two or all further solid substances present in the expansion step in the grains of granular material (in particular after sieving according to VDG-Merkblatt P 27 (see above)) likewise, for example, For example, it can be determined or confirmed by x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001, optionally in combination with optical and/or spectroscopic methods and/or wet-chemical methods. A person skilled in the art will preferably select a suitable measurement method using his knowledge of the materials used in the process.

Grains of granular material, preferably grains of granular material with a grain diameter (measured in each case by sieving) of greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm The fact that at least 90% of the particulate amorphous silicon dioxide and one, two or more than two or all of the other solid materials present in the enlargement step is One or more than two or all of a part of the resulting granular material, preferably (having a grain diameter greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm) of granular material It means at least 90% of the grain. Accordingly, one, two or more than two or all of the other solid materials present in the expansion step are preferably part of a granular material; More preferably, it contains at least 90 of the grains of the granular material having a grain diameter (measured in each case by sieving) of greater than 1 mm, preferably greater than 0.5 mm, more preferably greater than 0.2 mm. % is sufficiently uniformly distributed within the granular material present in

In addition to particulate amorphous silicon dioxide, one, two, more than two or all of the other substances present in the expansion step are selected independently of one another. Each of the possible resulting combinations, depending on the requirements of the individual case, results in particularly advantageous properties or combinations of properties of the molded articles producible therefrom.

The production of particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, is

- mixing at least two different types of particulate amorphous silicon dioxide, the at least two types preferably having their particle size distribution as measured by laser scattering, for example their particles as measured by laser scattering the median value of the size distribution, and/or differing in its chemical composition,

Preference is given to the process of the present invention (as described above, preferably, as identified above as preferred), comprising:

Here, it is possible that both types of particulate amorphous silicon dioxide are chemically different and additionally selected to have different particle size distributions. Alternatively, both types may be selected to have only a different particle size distribution with the same chemical composition. Additionally, it is possible that both types of particulate amorphous silicon dioxide are chemically different but selected to have the same particle size distribution.

A median numerical value of a particle size distribution is understood to mean a numerical value in which half of the population of particles examined has a size smaller than that value, while the other half of the population of particles examined has a size greater than that value. These values are preferably ascertained as further described in Example 1 for commercially available materials.

By "measured by light scattering" (herein and below) it is meant that a sample of particulate material to be inspected, if necessary, has been pretreated analogously to the method of Example 1 (see below), and thus that the particle size distribution of the material is then determined by laser scattering as in Example 1 (see below).

The present invention also relates to a process of the present invention (as just described, preferably, as identified above as preferred), wherein:

(i) - particulate amorphous silicon dioxide of the first type has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering,

- a further type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering,

(ii) - one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

or independently selected from the group (of chemically different substances) consisting of

At least 90% of the grains of the granular material having a particle diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are preferably (suitable After sample processing, in particular by sieving according to VDG-Merkblatt P 27 (see below)), for example optionally in combination with optical and/or spectroscopic methods and/or wet-chemical methods, DIN EN ISO 12677, the process of the invention comprising both or at least two of different types of particulate amorphous silicon dioxide, as described above, preferably as determined or confirmed by x-ray fluorescence analysis according to DIN 51001 , as identified above as preferred) is preferred; A person skilled in the art will preferably select a suitable measurement method using his knowledge of the materials used in the process.

enlargement step

- granulation,

- extrusion, and

- agglomeration, preferably press agglomeration

Preference is given to the process of the present invention (as described above, preferably, as identified above as preferred) comprising one or more measures independently selected from the group consisting of

Further suitable processes for carrying out the expansion step are known from the prior art and likewise can be used alternatively or additionally according to the invention (ie, for example pelleting, briquetting, tableting, etc.). Reference is made to the above.

The present invention also relates to the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising (preferably synthetic) particulate amorphous silicon dioxide greater than 0.2 mm as measured by sieving. A granular material having an average grain diameter of

(a) the granular material comprises:

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

Further comprising 1, 2 or more additional substances independently selected from the group consisting of,

wherein at least 90% of the grains of the granular material having a grain diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are particulate amorphous silicon dioxide , and one, two or more of said additional substances, and/or

(b) particulate amorphous silicon dioxide comprises silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, and preferably consists entirely or in part of particulate synthetic amorphous silicon dioxide;

(c) the proportion of silicon dioxide in the granular material as a whole, as determined by x-ray fluorescence analysis, and in each case the grains of the granular material having a grain diameter of greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis The proportion of silicon dioxide in at least 90% of the differs by no more than 30%, preferably no more than 20%, more preferably no more than 10%, based on the proportion of silicon dioxide in the whole granular material. and/or;

(d) in the granular material, particulate amorphous silicon dioxide comprises at least two different types of particulate amorphous silicon dioxide, wherein the at least two types are preferably (in particular after sieving according to VDG-Merkblatt P 27) (see above)) x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001 (optionally in combination with optical and/or spectroscopic methods and/or wet-chemical methods; its chemical composition is different,

Here, preferably, one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from, and/or

(e) granular material relates to a granular material as described above, preferably producible by a process as identified above as preferred.

The granular material thus defined (i.e. the specific grain whole (see above)) has a particularly advantageous combination of the following properties: homogeneous composition, high bulk density, low dust level, good flowability, good transportability, good meterability, Low dust level, prevention of segregation phenomena, grindability, high molding weight of moldings producible by its use, increased moisture stability (moisture resistance) of moldings producible by its use.

Configurations (a) and (e) are particularly economically feasible and are therefore preferred in many cases.

The present invention also relates to a kit comprising granular material (as described above, preferably, as identified above as preferred) as spatially separated components.

The present invention also provides at least:

- granular material (as described above, preferably, as identified above as preferred), and

- solutions or dispersions containing water glass;

an inorganic binder (as described above, preferably, as identified above as preferred), more preferably an inorganic multicomponent binder system, comprising as components arranged spatially separated from one another; / or to a kit for the production of a binder consisting thereof.

The kit of the invention is particularly suitable for carrying out the process of the invention, in which subsequent products of granular material are produced (binder; molding material mixture; molding).

The effects and advantages described above in connection with the process of the invention and the granular material of the invention are achieved when the kit of the invention is used.

The present invention also provides an apparatus (as described above, preferably, as identified as preferred) for carrying out the process of the present invention, comprising:

- a reservoir vessel containing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide;

- a mixing or contacting device for mixing or contacting particulate amorphous silicon dioxide with one, two or more additional substances;

- a device for granulating, extruding and/or agglomerating particulate amorphous silicon dioxide mixed with or in contact with one, two or more additional substances

It relates to a device comprising a.

The apparatus of the invention is particularly suitable for carrying out the process of the invention and for producing the granular material of the invention.

The effects and advantages described above in connection with the process of the invention and the granular material of the invention can be achieved when the apparatus of the invention is used and established according to the requirements of the individual case.

- a device for moving particulate amorphous silicon dioxide from the storage vessel into a mixing or contacting apparatus;

- at least one reservoir container containing a liquid, preferably a liquid wetting agent and/or a suspending medium, preferably water,

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof one or more reservoir containers containing particulate material selected from;

- one or more reservoir containers containing water-soluble substances;

- one or more reservoir containers containing one or more surfactants;

- at least one reservoir container containing at least one hydrophobizing agent;

- one or more storage containers containing one or more carbohydrates

Preferred are devices of the invention (as described above, preferably, as identified above as preferred), further comprising one or more device elements selected from the group consisting of

According to the requirements of the individual case, the preferred apparatus (plant) is particularly advantageously suitable for carrying out the process of the invention and for producing the granular material of the invention.

Preference is given to an apparatus of the invention (as described above, preferably as identified above as preferred) further comprising a device for dispensing or transporting the granular material produced.

The invention also relates to the corresponding use of (preferably synthetic) particulate amorphous silicon dioxide for the production of granular material or as a constituent of granular material (as described above, preferably, identified above as preferred) as has been done).

Depending on the particle size distribution of the particulate amorphous silicon dioxide together with the molding material mixture produced therefrom, the inventive use of particulate amorphous silicon dioxide for the production of a constituent of a granular material or as a constituent of a granular material is specific, preferably produces moldings with particularly high relative molding weights (in the case of cores, core weights). Depending on the particle size distribution of the particulate amorphous silicon dioxide together with the molding material mixture produced therefrom, the inventive use of particulate amorphous silicon dioxide for the production of a constituent of a granular material or as a constituent of a granular material is specific, preferably produces moldings with particularly high moisture stability.

The present invention also relates to a granular material (as described above, preferably according to the invention or as identified above as preferred).

Preferred embodiments of the present invention are specified below.

1. A process for producing granular material for the production of injectable additives for use as a constituent of inorganic binders in the foundry industry, the process comprising:

For the production of granular material,

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide;

- each comprising combined particles and each comprising at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of particulate amorphous silicon dioxide, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving phosphorus step

includes,

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

The product of this process is the granular material.

2. A process for producing a solid injectable additive for use as a component of an inorganic binder in the foundry industry, comprising:

For the production of solid injectable additives,

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide (and further steps);

- each comprising combined particles and each comprising at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of particulate amorphous silicon dioxide, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving Phosphorus, Step (and Additional Steps)

including,

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

3. A process for producing an inorganic binder for use in the foundry industry, comprising:

For the production of inorganic binders,

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide (and further steps);

- each comprising combined particles and each comprising at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of particulate amorphous silicon dioxide, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving Phosphorus, Step (and Additional Steps)

including,

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

4. A process for producing a molding material mixture comprising an inorganic binder for use in the foundry industry, the process comprising:

For the production of molding material mixtures,

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide (and further steps);

- each comprising combined particles and each comprising at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of particulate amorphous silicon dioxide, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving Phosphorus, Step (and Additional Steps)

including,

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

5. A process for producing moldings for use in the casting of metallic cast parts in the foundry industry, comprising:

For the production of moldings,

- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, preferably at least 90% by weight, based on the total mass of the particulate amorphous silicon dioxide (and further steps);

- each comprising combined particles and each comprising at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of particulate amorphous silicon dioxide, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains to produce a granular material comprising a plurality of individual grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving Phosphorus, Step (and Additional Steps)

including,

The particulate amorphous silicon dioxide produced or provided preferably has particles having a size of less than 20 μm as measured by scanning electron microscopy (SEM) or laser diffraction, more preferably having a size between 0.1 μm and 5 μm. particles, most preferably particles having a size between 0.1 μm and 1.5 μm.

6. according to aspect 2,

- producing a granular material by the process according to aspect 1,

- grinding the grains of the granular material to produce a solid injectable additive;

A process for producing a solid injectable additive for use as a component of an inorganic binder in the foundry industry, comprising:

7. according to aspect 3,

- producing a granular material by the process according to aspect 1,

- grinding the grains of the granular material to produce a solid injectable additive;

A process for producing an inorganic binder for use in the foundry industry, comprising:

8. according to aspect 4,

- producing a granular material by the process according to aspect 1,

- grinding the grains of the granular material to produce a solid injectable additive;

A process for producing a molding material mixture comprising an inorganic binder for use in the foundry industry, comprising:

9. according to aspect 5,

- producing a granular material by the process according to aspect 1,

- grinding the grains of the granular material to produce a solid injectable additive;

A process for producing moldings for use in the casting of metallic cast parts in the foundry industry, comprising:

10. according to aspect 3 or aspect 7,

- producing a solid injectable additive by the process according to aspect 2 or aspect 6;

- contacting the produced solid injectable additive with water glass, or suspending the produced solid injectable additive in water glass

A process for producing an inorganic binder for use in the foundry industry, comprising:

11. according to any one of aspect 3, aspect 7 and aspect 10,

- producing a granular material by the process according to any one of aspects 1 to 9;

- contacting the produced granular material with water glass, in the presence or absence of a refractory mold base material, and grinding the grains of the granular material simultaneously or thereafter

A process for producing an inorganic binder for use in the foundry industry, comprising:

12. according to aspect 4 or aspect 8,

- producing a solid injectable additive by the process according to any one of aspects 2, 6 and 10;

- contacting the produced solid injectable additive with water glass, or suspending the produced solid injectable additive in water glass

A process for producing a molding material mixture comprising an inorganic binder for use in the foundry industry, comprising:

13. The method according to any one of embodiments 4, 8 and 12,

- producing a granular material by the process according to any one of aspects 1 to 9 or 11;

- contacting the granular material produced with water glass, in the presence or absence of a refractory mold base material, and grinding the grains of the granular material simultaneously or thereafter

A process for producing a molding material mixture comprising an inorganic binder for use in the foundry industry, comprising:

14. according to aspect 5 or aspect 9,

- producing a solid injectable additive by the process according to any one of aspects 2, 6 and 10;

- contacting the produced solid injectable additive with water glass, or suspending the produced solid injectable additive in water glass

A process for producing moldings for use in the casting of metallic cast parts in the foundry industry, comprising:

15. The method according to any one of embodiments 5, 9 and 14,

- producing a granular material by a process according to any one of aspects 1 to 9, 11 and 13,

- contacting the granular material produced with water glass, in the presence or absence of a refractory mold base material, and grinding the grains of the granular material simultaneously or thereafter

A process for producing moldings for use in the casting of metallic cast parts in the foundry industry, comprising:

16. The method of any one of Aspect 4, Aspect 8, Aspect 12, and Aspect 13,

- producing an inorganic binder according to any one of aspects 3, 7, 10 and 11, and

- at the same time mixing the components used for the production of the inorganic binder with the refractory mold base material;

A process for producing a molding material mixture comprising a refractory mold base material and an inorganic binder comprising water glass and particulate amorphous silicon dioxide for use in the foundry industry, comprising:

17. The method of any one of Aspect 4, Aspect 8, Aspect 12, Aspect 13, and Aspect 16,

- producing an inorganic binder according to any one of aspect 3, aspect 7, aspect 10, aspect 11, aspect 16, and

- at the same time mixing the components used for the production of the inorganic binder with the refractory mold base material, and

- after that, mixing the produced inorganic binder with the refractory mold base material

A process for producing a molding material mixture comprising a refractory mold base material and an inorganic binder comprising water glass and particulate amorphous silicon dioxide for use in the foundry industry, comprising:

18. according to any one of aspect 4, aspect 8, aspect 12, aspect 13, aspect 16 and aspect 17,

- producing an inorganic binder according to any one of aspect 3, aspect 7, aspect 10, aspect 11, aspect 16, aspect 17, and

- after that, mixing the produced inorganic binder with the refractory mold base material

A process for producing a molding material mixture comprising a refractory mold base material and an inorganic binder comprising water glass and particulate amorphous silicon dioxide for use in the foundry industry, comprising:

19. according to any one of aspects 1 to 5,

a plurality of particles each comprising combined particles and each comprising particulate amorphous silicon dioxide in a proportion of at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to produce a granular material comprising individual grains of

wherein the average grain diameter of the granular material is greater than 0.5 mm, preferably greater than 1 mm, as measured by sieving.

20. The process according to any of aspects 1 to 19, wherein the particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of the particulate amorphous silicon dioxide, consists entirely of particulate synthetic amorphous silicon dioxide.

21. The process according to any of aspects 1 to 20, wherein the particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of the particulate amorphous silicon dioxide, consists in part of particulate synthetic amorphous silicon dioxide .

22. The method according to any one of embodiments 1 to 21, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 30%, based on the proportion of silicon dioxide in the whole of the granular material.

23. The method according to any one of embodiments 1 to 22, wherein the proportion of silicon dioxide in the whole granular material as determined by x-ray fluorescence analysis and grains greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 20%, based on the proportion of silicon dioxide in the whole of the granular material.

24. The method according to any one of embodiments 1 to 23, wherein the proportion of silicon dioxide in the total granular material as determined by x-ray fluorescence analysis and grains greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 10%, based on the proportion of silicon dioxide in the whole of the granular material.

25. The method according to any one of embodiments 1 to 24, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.5 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 30%, based on the proportion of silicon dioxide in the whole of the granular material.

26. The method according to any one of embodiments 1 to 25, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.5 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 20%, based on the proportion of silicon dioxide in the whole of the granular material.

27. The method according to any one of embodiments 1 to 26, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.5 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 10%, based on the proportion of silicon dioxide in the whole of the granular material.

28. The method according to any one of embodiments 1 to 27, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.2 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 30%, based on the proportion of silicon dioxide in the whole of the granular material.

29. The aspect of any one of aspects 1 to 28, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.2 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 20%, based on the proportion of silicon dioxide in the whole of the granular material.

30. The aspect of any one of embodiments 1 to 29, wherein the proportion of silicon dioxide throughout the granular material as determined by x-ray fluorescence analysis and grains greater than 0.2 mm as determined by sieving and subsequent x-ray fluorescence analysis. wherein the proportion of silicon dioxide in at least 90% of the grains of the granular material having a diameter differs by no more than 10%, based on the proportion of silicon dioxide in the whole of the granular material.

31. The method according to any one of embodiments 1 to 30, wherein in the step of enlarging, the particles of particulate amorphous silicon dioxide are

- a liquid, preferably a liquid wetting agent and/or a suspending medium, preferably water,

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

A process that is mixed with and/or contacted with one, two or more additional substances independently selected from the group consisting of.

32. The grain of the granular material resulting from the expanding step according to aspect 31, preferably greater than 1 mm, preferably greater than 0.5 mm, more preferably 0.2 mm as measured by sieving in each case At least 90% of the grains of the granular material having a grain diameter greater than

(i) particulate amorphous silicon dioxide and one, two, more than two or all of the additional solid material present in the expansion step;

(ii) particulate amorphous silicon dioxide, and

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

1 , 2 or more additional substances independently selected from the group consisting of

33. The grain of the granular material resulting from the expanding step according to aspect 31, preferably greater than 1 mm, preferably greater than 0.5 mm, more preferably 0.2 mm, as measured in each case by sieving At least 90% of the grains of the granular material having a grain diameter greater than

- a process comprising one, two, more than two or all of the particulate amorphous silicon dioxide and other solid materials present in the expansion step.

34. The grain of the granular material according to aspect 31, preferably in each case greater than 1 mm, preferably greater than 0.5 mm, more preferably 0.2 mm as measured by sieving At least 90% of the grains of the granular material having a grain diameter greater than

- particulate amorphous silicon dioxide, and

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

1 , 2 or more additional substances independently selected from the group consisting of

35. The method according to any one of aspects 1 to 34,

The production of particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, comprises:

- mixing at least two different types of particulate amorphous silicon dioxide, wherein at least two types differ in their particle size distribution and/or in their chemical composition

Including, process.

36. The method of aspect 35,

- a process wherein one type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering.

37. The method of aspect 35,

- a process wherein one type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering.

38. The method of aspect 35,

One, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from the group consisting of.

39. The method of aspect 35,

- particulate amorphous silicon dioxide of the first type has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering,

- a process, wherein the particulate amorphous silicon dioxide of a further type has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering.

40. The method of aspect 35,

- particulate amorphous silicon dioxide of the first type has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering,

- one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from the group consisting of.

41. The method of aspect 35,

- particulate amorphous silicon dioxide of the first type has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering,

- a further type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering,

- one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from the group consisting of.

42. The method of aspect 35,

- a further type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering,

- one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from the group consisting of.

43. The granular material according to any one of aspects 35 to 42, having a particle diameter in each case of greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving. At least 90% of the grains of are preferably (in particular by sieving according to VDG-Merkblatt P 27 (see above)), for example optionally, with optical and/or spectroscopic methods and/or wet-chemical methods both or at least two of different types of particulate amorphous silicon dioxide, as determined or confirmed by x-ray fluorescence analysis according to DIN EN ISO 12677, DIN 51001, in combination; The skilled person will preferably select a suitable measurement method using his knowledge of the materials used in the process.

44. The method according to any one of aspects 1 to 43, wherein the step of enlarging comprises

- granulation,

- extrusion, and

- agglomeration

A process comprising one or more measures independently selected from the group consisting of.

45. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

(a) the granular material is

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

Further comprising 1, 2 or more additional substances independently selected from the group consisting of,

wherein at least 90% of the grains of the granular material having a grain diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are particulate amorphous silicon dioxide , and one, two or more of said additional substances, and/or

(b) particulate amorphous silicon dioxide comprises silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, and preferably consists entirely or in part of particulate synthetic amorphous silicon dioxide;

(c) the proportion of silicon dioxide in the granular material as a whole, as determined by x-ray fluorescence analysis, and in each case the grains of the granular material having a grain diameter of greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis The proportion of silicon dioxide in at least 90% of the differs by no more than 30%, preferably no more than 20%, more preferably no more than 10%, based on the proportion of silicon dioxide in the whole granular material. and/or;

(d) in the granular material, the particulate amorphous silicon dioxide comprises at least two different types of particulate amorphous silicon dioxide, wherein the at least two types differ in their chemical composition;

Here, preferably, one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

selected from the group consisting of or independently selected from, and/or

(e) the granular material is producible by a process according to any one of aspects 1 to 9, or any one of aspects 20 to 44.

46. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

(a) the granular material is

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

Further comprising 1, 2 or more additional substances independently selected from the group consisting of,

wherein at least 90% of the grains of the granular material having a grain diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are particulate amorphous silicon dioxide , and one, two or more of said additional substances;

(b) particulate amorphous silicon dioxide comprises silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, and preferably consists entirely or in part of particulate synthetic amorphous silicon dioxide;

(c) the proportion of silicon dioxide in the granular material as a whole, as determined by x-ray fluorescence analysis, and in each case the grains of the granular material having a grain diameter of greater than 1 mm as determined by sieving and subsequent x-ray fluorescence analysis The proportion of silicon dioxide in at least 90% of the differs by no more than 30%, preferably no more than 20%, more preferably no more than 10%, based on the proportion of silicon dioxide in the whole granular material. and,

(d) in the granular material, the particulate amorphous silicon dioxide comprises at least two different types of particulate amorphous silicon dioxide, wherein the at least two types differ in their chemical composition;

Here, preferably, one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

or independently selected from the group consisting of

(e) the granular material is producible by a process according to any one of aspects 1 to 9, or any one of aspects 20 to 44.

47. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

granular material

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactants,

- film formers,

- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and

- carbohydrate

Further comprising 1, 2 or more additional substances independently selected from the group consisting of,

At least 90% of the grains of the granular material having a grain diameter in each case of greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm as measured by sieving are particulate amorphous silicon dioxide, and A granular material comprising one, two or more of said additional materials.

48. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

The particulate amorphous silicon dioxide comprises silicon dioxide in a proportion of at least 80% by weight, based on the total mass of the particulate amorphous silicon dioxide, and preferably consists entirely or partly of particulate synthetic amorphous silicon dioxide.

49. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

At least 90 of the grains of the granular material having a proportion of silicon dioxide in the whole granular material as determined by x-ray fluorescence analysis, and in each case sieving and a grain diameter greater than 1 mm as measured by subsequent x-ray fluorescence analysis the proportion of silicon dioxide in % differs by no more than 30%, preferably by no more than 20%, more preferably by no more than 10%, based on the proportion of silicon dioxide in the granular material as a whole, granular material .

50. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

In a granular material, particulate amorphous silicon dioxide comprises two or more different types of particulate amorphous silicon dioxide, wherein the two or more types differ in their chemical composition;

Preferably, one, two, more than two or all of the different types of particulate amorphous silicon dioxide

- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;

- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;

- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;

- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt

A granular material selected from or independently selected from the group consisting of.

51. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,

The granular material is producible by a process according to any one of aspects 1 to 9 or any one of aspects 20 to 44.

52. A kit comprising the granular material according to any one of aspects 45 to 51 as spatially separated and arranged components, preferably comprising:

At least,

- a granular material according to any one of aspects 45 to 51, and

- solutions or dispersions containing water glass;

A kit for the production of an inorganic binder, preferably a binder, comprising and/or consisting of an inorganic multi-component binder system, comprising as components arranged spatially separated from one another.

53. An apparatus for carrying out the process according to any one of aspects 1 to 44, comprising:

- a reservoir vessel containing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide;

- a mixing or contacting device for mixing or contacting particulate amorphous silicon dioxide with one, two or more additional substances;

- a device for granulating, extruding and/or agglomerating particulate amorphous silicon dioxide mixed with or in contact with one, two or more additional substances

A device comprising a.

54. according to aspect 53,

- a device for moving particulate amorphous silicon dioxide from the storage vessel into a mixing or contacting apparatus;

- at least one reservoir container containing a liquid, preferably a liquid wetting agent and/or a suspending medium, preferably water,

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof one or more reservoir containers containing particulate material selected from;

- one or more reservoir containers containing water-soluble substances;

- one or more reservoir containers containing one or more surfactants;

- at least one reservoir container containing at least one hydrophobizing agent;

- one or more storage containers containing one or more carbohydrates

A device further comprising one or more device elements selected from the group consisting of

55. The apparatus of any of clauses 53 or 54, further comprising a device for dispensing or transporting the produced granular material.

56. Use of particulate amorphous silicon dioxide for the production of a constituent of a granular material according to aspects 45 to 51 or as a constituent of a granular material according to aspects 45 to 51.

57. Use of a granular material according to any one of aspects 45 to 51 for producing a solid injectable additive having a homogenized grain composition for use as a constituent of an inorganic binder in the foundry industry.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in detail below with reference to the drawings.
1 shows a flow diagram of a first embodiment of a process 100 of the present invention for producing a molding material mixture 107 for use in the foundry industry.
In a first step 101 of process 100 , particulate amorphous silicon dioxide is produced or provided as defined above.
In a second (enlargement) step 102 , the particles of particulate amorphous silicon dioxide are combined to provide grains to produce a granular material 103 as defined above comprising a plurality of individual grains.
The granular material produced was already the product of the process of the invention.
In a further step 104 , the granular material produced is directly contacted with waterglass to produce the inorganic binder 105 . Likewise, the inorganic binder produced is the product of the process of the present invention.
In a further step 106 , the inorganic binder 105 produced is mixed with a refractory mold base material to produce a molding material mixture 107 as a product of the process of the present invention.
In a further step 108 , the resulting molding material mixture 107 is molded and (at least partially) cured to produce a molding 109 as a product of the process of the present invention.
2 shows a flow diagram of a second embodiment of a process 200 of the present invention for producing a molding material mixture 209 for use in the foundry industry.
In a first step 201 of process 200 , particulate amorphous silicon dioxide is produced or provided as defined above.
In a second (enlargement) step 202 , the particles of particulate amorphous silicon dioxide are combined to provide grains to produce a granular material 203 as defined above comprising a plurality of individual grains. The granular material produced was already the product of the process of the invention.
In a next step 204 , the grains of granular material 203 are milled to form a solid injectable additive 205 . Likewise, the additive produced is the product of the process of the present invention.
In a further step 206 , the granular material produced is contacted with water glass to produce the inorganic binder 207 . Likewise, the inorganic binder produced is the product of the process of the present invention.
In a further step 208 , the inorganic binder 207 produced is mixed with a refractory mold base material to produce a molding material mixture 209 as a product of the process of the present invention.
In a further step 210 , the resulting molding material mixture 209 is molded and (at least partially) cured to produce a molding 211 as a product of the process of the present invention.
3 shows a flow diagram of an alternative embodiment of a process 300 of the present invention for producing a molding material mixture 309 for use in the foundry industry.
In a first step 301 of process 300 , particulate amorphous silicon dioxide is produced or provided as defined above.
In a separate step 301a , additional material is produced or provided (as defined in aspect 27 and the description above).
In the next (enlargement) step 302 , the particles of particulate amorphous silicon dioxide are combined into grains, wherein additional material produced or provided in step 301a is added before or during step 302a , and thus particulate amorphous silicon dioxide The particles of silicon dioxide are mixed with and/or contacted with this further material in the expanding step, whereby the expanding step produces a granular material 303 as defined above comprising a plurality of individual grains. These individual grains contain particulate amorphous silicon dioxide and additional materials. The granular material produced was already the product of the process of the invention.
In a subsequent step 304 , the grains of granular material 303 are milled to form a solid injectable additive 305 . Likewise, the additive produced is the product of the process of the present invention.
In a further step 306 , the granular material produced is contacted with water glass to produce the inorganic binder 307 . Likewise, the inorganic binder produced is the product of the process of the present invention.
In a next step 308 , the inorganic binder 307 produced is mixed with a refractory mold base material to produce a molding material mixture 309 as a product of the process of the present invention.
In a further step 310 , the resulting molding material mixture 309 is molded and (at least partially) cured to produce a molding 311 as a product of the process of the present invention.
Steps 102, 202 and 302 shown in Figures 1, 2 and 3 represent steps essential to the respective embodiments of the process of the present invention. There is no model for this step in the prior art.

Example 1 - Measurement method of particle size distribution by laser scattering

The choice of material in this example is exemplary only, and it is also possible to determine the particle size distribution or median of other particulate species to be used in the context of the present invention by means of laser scattering according to the procedure of this example.

1.1 Sample Preparation:

As an example, the particle size distribution of silica fume particles (CAS No: 65012-64-2; particulate amorphous silicon dioxide) in the form of particulate powder from Si production that are commercially available (RW Silicium GmbH) was determined.

In each case, about 1 teaspoon of this particulate amorphous silicon dioxide was mixed with about 100 mL of demineralized water, and the resulting mixture was stirred with a magnetic stirrer (IKAMAG RET) for 30 seconds at a stirrer speed of 500 revolutions per minute. Subsequently, a 100% amplitude pre-tuned ultrasound probe (from Hielscher; model: UP200HT) equipped with an S26d7 sonotrode (from Hielscher) was immersed in the sample and the sample was sonicated with it. Sonication was continuous (not pulsed). For the examined silica fume particles, an optimal sonication time of 300 seconds was selected, which was previously measured as described in Example 1, section 1.3 below.

1.2 Laser Scattering Measurements:

Measurements were performed with a Horiba LA-960 instrument (LA-960 below). For the measurements, the circulation rate is set to 6, the stirrer speed is set to 8, the data record for the sample is set to 30 000, the convergence coefficient is set to 15, the distribution mode is set to volume, the refractive index ( R) was set between 1.50 and 0.01i (1.33 for the demineralized water dispersion medium), and the refractive index (B) was set between 1.50 and 0.01i (1.33 for the demineralized water dispersion medium). Laser scattering measurements were performed at room temperature (20° C. to 25° C.).

The measuring chamber of the LA-960 was filled to about three quarters with demineralized water (maximum fill level). Thereafter, the stirrer was started at the set speed, the circulation was turned on, and the water was degassed. Subsequently, a zero measurement was performed with the specified parameters.

Thereafter, 0.5-3.0 mL samples were taken from the center of the sample prepared according to item 1.1 of Example 1 immediately after sonication using a disposable pipette. Subsequently, all contents of the pipette were introduced into the measuring chamber, so that the transmittance of the red laser was 80% to 90% and the transmittance of the blue laser was 70% to 90%. After that, the measurement was started. Measurements were evaluated in an automated manner, based on the specified parameters.

For silica fume particles tested from Si production, the particle size distribution was identified as the median rounded to two decimal places.

1.3 Determination of optimal sonication time:

Depending on the type of sample, the optimal duration of sonication is confirmed by performing a series of measurements with different sonication times for each particulate species. This was done by starting the sonication time at 10 s, extending it by 10 s each time for each additional sample, and individually by laser scattering (LA-960) immediately after the end of sonication as described in section 1.2 of Example 1 This is done by measuring the particle size distribution. As the duration of sonication increases, the median values found in the particle size distribution drop at first and then eventually rise again at longer sonication times. For the sonication described in item 1.1 of Example 1, the sonication time selected was the time in this series of measurements at which the lowest median of the particle size distribution was determined for the particle species; These sonication times are "optimal" sonication times.

Example 2 - Method of Production of Granular Material

10 kg of synthetic particulate amorphous silicon dioxide (in powder form, particle size less than 1.5 μm; for example, Microsilica POS BW 90 LD (Possehl Erzkontor GmbH) or silica fume (Doral Fused Materials Pty., Ltd.); in each case Production process: production of ZrO ₂ and SiO ₂ from ZrSiO ₄ ) is introduced into a flowshare mixer (from Gebruder Lodige Maschinenbau GmbH, model L50), the flowshare mixer, for mixing, at a speed of 180 revolutions per minute It operates at the rotational speed of the flowshare shaft and the blade head at 3000 revolutions per minute. During mixing, water is fed to the synthetic particulate amorphous silicon dioxide in several steps: 0.25 kg of water, followed by a mixing time of 60 seconds, then an additional 0.5 kg of water, followed by a mixing time of an additional 240 seconds , followed by feeding an additional 0.5 kg of water, followed by a further mixing time of 120 seconds, followed by an additional 1.0 kg of water, followed by a mixing time after a further mixing time of 180 seconds.

The suspension thus produced is individually dripped by pipette onto a commercial aluminum foil (optionally sprayed with a separating agent) heated to 250° C. on a hotplate and dried, so that the particles of the powder used are combined to form grains and produce the granular material of the present invention. The hotplate is preferably protected from contamination here by an additional layer of aluminum foil (arranged below the layer in contact with the suspension).

In granular materials, the mass fraction of particles having a size of less than 20 μm as measured by laser scattering is lower than in particulate amorphous silicon dioxide.

Example 3 - Bulk Density; Reduced dust emission

The bulk density was measured on a laboratory balance (measurement uncertainty ± 0.1 g), a metal measuring cylinder having a volume of (100 ± 0.5) mL and an inner diameter of (45 ± 5) mm, and a funnel with a closed lower opening (according to DIN EN ISO 60). according to).

The funnel is fixed centrally at a height of 20 to 30 mm above the measuring cylinder and the sample is mixed well. About 120 mL to 130 mL of sample is introduced into the funnel. The stopper of the funnel is quickly opened to drop the sample material into the cylinder. Excess sample material is removed from the cylinder with the aid of a straight-edged article, and then the contents of the cylinder are weighed; The mass of the contents of the cylinder is m _samples .

The evaluation is made by the following equation:

Results are reported as 1 g/L.

According to Example 2, a granular material was produced using synthetic particulate amorphous silicon dioxide having a bulk density of 550 g/L. After drying, the granular material of the invention thus obtained had an average grain diameter of 6 mm and a bulk density of 950 g/L.

When poured, the granular material exhibited a much lower (fine) dust emission than the starting material, and the synthetic particulate amorphous silicon dioxide has a bulk density of 550 g/L.

Example 4 - Examination of One Hour Strength of Different Test Bars

4.1 Production of molding material mixture 4-A

0.80 parts by weight synthetic particulate amorphous silicon dioxide (powdered; non-granulated; for example, Microsilica POS BW 90 LD (Possehl Erzkontor GmbH) or silica fume (Doral Fused Materials Pty., Ltd.); production process in each case: production of ZrO ₂ and SiO ₂ from ZrSiO ₄ ) was mixed by hand with 100 parts by weight of HS 00232 sand (silica sand, AFS particle size index 47, from Quarzwerke GmbH). Thereafter, 2.00 parts by weight of a waterglass-based liquid binder (commercial name Cordis 9032; Huttenes-Albertus Chemische Werke GmbH) are added and all ingredients are mixed in a bull mixer (RN from Morek Multiserw) at 220 revolutions per minute. 10/20 type) for 120 seconds, thereby homogeneously distributing the materials used to produce the molding material mixture.

4.2 Production of molding material mixture 4-B

A granular material was produced according to Example 2 using synthetic particulate amorphous silicon dioxide (same material as used in Example 4.1) and water having a bulk density of 550 g/L. The granular material thus produced was ground in a mixer (Universal Plus MUM 6N11 food processor, from Bosch) for 10 seconds to produce a solid injectable additive.

0.80 parts by weight of this solid injectable additive were mixed by hand with 100 parts by weight of H-S 00232 sand (siliceous sand from Quarzwerke GmbH, AFS particle size index 47). Thereafter, 2.00 parts by weight of a waterglass-based liquid binder (commercial name Cordis 9032; Huttenes-Albertus Chemische Werke GmbH) are added and all ingredients are mixed with a fire mixer (type RN 10/20 from Morek Multiserw at 220 revolutions per minute) ) for 120 s, thereby homogeneously distributing the materials used to produce the molding material mixture.

4.3 Production of molding material mixture 4-C

20.05 kg of synthetic particulate amorphous silicon dioxide with a bulk density of about 550 g/L (same material as used in Example 4.1) was introduced into a flowshare mixer (model L50, from Gebruder Lodige Maschinenbau GmbH). 3 kg of water was fed to the synthetic particulate amorphous silicon dioxide, and the flowshare mixer was operated for 120 seconds at a rotation speed of the flowshare shaft at 180 revolutions per minute and the blade head at 3000 revolutions per minute. After that, the operation of the blade head was stopped and mixing was continued at the rotation speed of the flowshare shaft at 180 revolutions per minute to form a soft granular material.

In order to produce a (dried) granular material, a part of the still moist soft granular material was then dried at 105° C. to a constant weight. The cooled dried material was then sorted by a sieving tower according to VDG-Merkblatt P 27 (October 1999), and parts smaller than 125 μm were discarded. The sieve yield was about 85%.

When poured, the fractionated granular material exhibited a much lower (fine) dust emission than the starting material, and the particulate amorphous silicon dioxide has a bulk density of about 550 g/L.

The classified granular material thus produced was ground in a mixer (Universal Plus MUM 6N11 food processor, from Bosch) for 10 seconds to form a solid injectable additive.

0.80 parts by weight of this solid injectable additive were mixed by hand with 100 parts by weight of H-S 00232 sand (siliceous sand from Quarzwerke GmbH, AFS particle size index 47). Thereafter, 2.00 parts by weight of a waterglass-based liquid binder (commercial name Cordis 9032; Huttenes-Albertus Chemische Werke GmbH) are added and all ingredients are mixed in a bull mixer (RN from Morek Multiserw) at 220 revolutions per minute. 10/20 type) for 120 seconds, thereby homogeneously distributing the materials used to produce the molding material mixture.

4.4 production of test rods

Molding material mixtures 4-A, 4-B and 4-C produced according to items 4.1, 4.2 and 4.3 of Example 4 were formed into test rods having dimensions of 22.4 mm Х 22.4 mm Х 185 mm, respectively. For this purpose, the individual molding material mixtures were introduced into the mold for the test rod with a temperature of 160° C. with compressed air (4 bar) and a shooting time of 3 seconds. Subsequently, the test rod was hot cured at 160° C. without gas supply for 30 seconds. The mold was then opened, the cured test rods removed, and stored for cooling.

4.5 Measurement of 1-Hour Intensity

After a cooling time of 1 hour, test rods produced from molding material mixtures 4-A, 4-B and 4-C according to item 4.4 of Example 4 were subjected to Georg Fischer strength equipped with a three-point bending device (from Morek Multiserw). It was introduced into the tester and the force causing failure of the test rod was measured. Readings (in N/cm ² ) represent 1 hour intensity. The results are shown in Table 1, with individual 1-hour intensity values corresponding to the median values from 6 individual measurements.

The results listed in Table 1 show that test bars produced using either granular material (produced by the process of the invention) or solid injectable additives (produced by the process of the invention) surprisingly exhibited an elevated 1-hour strength. indicates having

Example 5 - Production of a granular material with a homogeneous distribution of a number of additives

Similar to the production method from Example 2, the granular material was prepared in a number of in-house experiments with the addition in each case of one or more of the following materials as additional materials, in addition to the particulate amorphous silicon dioxide used. Produced:

- a liquid, preferably a liquid suspending medium, preferably water,

-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from

- water-soluble substances;

- alkali metal hydroxides,

- Surfactant (preferably,

- oleyl sulfate, stearyl sulfate, palmityl sulfate, myristyl sulfate, lauryl sulfate, decyl sulfate, octyl sulfate, 2-ethylhexyl sulfate, 2-ethyloctyl sulfate, 2-ethyldecyl sulfate, palmitoleyl sulfate, Linolyl sulfate, lauryl sulfonate, 2-ethyldecyl sulfonate, palmityl sulfonate, stearyl sulfonate, 2-ethylstearyl sulfonate, linolyl sulfonate, hexyl phosphate, 2-ethylhexyl phosphate, caprylic Phosphate, lauryl phosphate, myristyl phosphate, palmityl phosphate, palmitoleyl phosphate, oleyl phosphate, stearyl phosphate, poly(ethane-1,2-diyl)phenol hydroxyphosphate, poly(ethane-1,2- Diyl)stearyl phosphate, poly(ethane-1,2-diyl)oleyl phosphate, polycarboxylate ether in water (Melpers 0030 from BASF), polyacrylate modified in water (Melpers VP 4547/240 from BASF) L), 2-ethylhexyl sulfate in water (Texapon EHS from Cognis), polyglucoside in water (Glukopon 225 DK from Cognis), sodium octylsulfate in water (Texapon 842 from Lakeland), modified carboxylate ethers ( Castament ES 60 from BASF, solid state)),

- film-forming agents, preferably polyvinyl alcohol and/or acrylic acid,

- rheological additives (thickeners, suspending aids) (preferably,

- swelling clay, preferably sodium bentonite or attapulgite/paligoskite,

- swellable polymers, preferably cellulose derivatives, in particular carboxymethyl, methyl, ethyl, hydroxyethyl and hydroxypropyl cellulose, plant mucilage, polyvinylpyrrolidone, pectin, gelatin, agar-agar, polypeptides, and/or selected from the group consisting of alginate),

- hydrophobizing agents, preferably organosilicon compounds, silanes, silanols, preferably trimethylsilanol, silicones and siloxanes, preferably polydimethylsiloxane, waxes, paraffins, metal soaps, and

- carbohydrate.

In each case, granular material was obtained in a similar manner. The granular material obtained can each be processed by grinding to provide a solid injectable additive. Each of the granular material or the solid injectable additive was successfully treated to give a molding material mixture, which was further treated to provide a test bar.

Claims (20)

- granular material for the production of pourable additives for use as a constituent of inorganic binders in the foundry industry;
- solid injectable additives for use as constituents of inorganic binders in the foundry industry;
- inorganic binders for use in the foundry industry;
- molding material mixtures comprising inorganic binders for use in the foundry industry, and
- Moldings for use in the casting of metallic cast parts in the foundry industry
A process for producing an article for use in the foundry industry, selected from the group consisting of:
for the production of goods;
- producing or providing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide;
- enlargement step, to produce a granular material comprising a plurality of individual grains each comprising combined particles and each comprising particulate amorphous silicon dioxide in a proportion of at least 30% by weight, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to provide grains, wherein the average grain diameter of the granular material is greater than 0.2 mm as measured by sieving;
A process comprising According to claim 1,
- producing a granular material by the process as claimed in claim 1,
- grinding the grains of granular material to produce a solid injectable additive,
- solid injectable additives for use as constituents of inorganic binders in the foundry industry;
- inorganic binders for use in the foundry industry;
- molding material mixtures comprising inorganic binders for use in the foundry industry, and
- Moldings for use in the casting of metallic cast parts in the foundry industry
A process for producing an article for use in the foundry industry, selected from the group consisting of 3. The method of claim 1 or 2,
(i) - producing a solid injectable additive by the process as claimed in claim 1 or 2;
- contacting the produced solid injectable additive with a water glass or suspending the produced solid injectable additive in a water glass;
(ii) - producing a granular material by the process as claimed in claim 1 or 2,
- contacting the granular material produced with water glass, in the presence or absence of a refractory mold base material, and simultaneously or thereafter grinding the grains of the granular material;
- inorganic binders for use in the foundry industry;
- molding material mixtures comprising inorganic binders for use in the foundry industry, and
- Moldings for use in the casting of metallic cast parts in the foundry industry
A process for producing an article for use in the foundry industry, selected from the group consisting of 4. The method according to any one of claims 1 to 3,
- producing an inorganic binder according to any one of claims 1 to 3, and
(i) at the same time mixing the components used for the production of the inorganic binder with the refractory mold base material, and/or
(ii) thereafter mixing the produced inorganic binder with the refractory mold base material;
A process for producing a molding material mixture comprising a refractory mold base material and an inorganic binder comprising water glass and particulate amorphous silicon dioxide for use in the foundry industry. According to claim 1,
a plurality of particles each comprising combined particles and each comprising particulate amorphous silicon dioxide in a proportion of at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight, based on the mass of the individual grains combining particles of particulate amorphous silicon dioxide in an enlargement step to produce a granular material comprising individual grains of
wherein the average grain diameter of the granular material is greater than 0.5 mm, preferably greater than 1 mm, as measured by sieving. 6. The method according to any one of claims 1 to 5,
wherein the particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of the particulate amorphous silicon dioxide, consists entirely or in part of particulate synthetic amorphous silicon dioxide. 7. The method according to any one of claims 1 to 6,
The proportion of silicon dioxide in the whole granular material, as determined by x-ray fluorescence analysis, and in each case more than 1 mm, preferably, more than 0.5 mm, more preferably, as measured by sieving and subsequent x-ray fluorescence analysis , the proportion of silicon dioxide in at least 90% of the grains of the granular material having a grain diameter of greater than 0.2 mm differs by no more than 30%, preferably no more than 20%, based on the proportion of silicon dioxide in the whole granular material different, more preferably different by 10% or less. 8. The method according to any one of claims 1 to 7, wherein in the step of enlarging, the particles of particulate amorphous silicon dioxide are
- a liquid, preferably a liquid wetting agent and/or a suspending medium, preferably water,
-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from
- water-soluble substances;
- alkali metal hydroxides,
- Surfactants,
- film formers,
- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and
- carbohydrate
A process that is mixed with and/or contacted with one, two or more additional substances independently selected from the group consisting of. 9 . The grain of the granular material resulting from the enlargement step according to claim 8 , preferably greater than 1 mm, preferably greater than 0.5 mm, more preferably greater than 0.2 mm as measured in each case by sieving. At least 90% of the grains of the granular material having a grain diameter of
(i) one, two, more than two or all of the particulate amorphous silicon dioxide and the additional solid material present in the enlargement step; and/or
(ii) particulate amorphous silicon dioxide, and
-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from
- water-soluble substances;
- alkali metal hydroxides,
- Surfactants,
- film formers,
- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and
- carbohydrate
1 , 2 or more additional substances independently selected from the group consisting of 10. The method according to any one of claims 1 to 9,
The production of particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, comprises:
- mixing at least two different types of particulate amorphous silicon dioxide, wherein at least two types differ in their particle size distribution and/or in their chemical composition
Including, process. 11. The method of claim 10,
(i) - particulate amorphous silicon dioxide of the first type has a particle size distribution with a median value in the range from 0.1 to 0.4 μm as measured by laser scattering,
- a further type of particulate amorphous silicon dioxide has a particle size distribution with a median value in the range from 0.7 to 1.5 μm as measured by laser scattering,
(ii) - one, two, more than two or all of the different types of particulate amorphous silicon dioxide
- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;
- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;
- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;
- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt
selected from the group consisting of or independently selected from the group consisting of. 12. The method of claim 10 or 11,
At least 90% of the grains of the granular material having a grain diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are particulate amorphous dioxide of a different type both or at least two of the silicon. 13. The method according to any one of claims 1 to 12, wherein the step of enlarging
- granulation,
- extrusion, and
- agglomeration
A process comprising one or more measures independently selected from the group consisting of. 1. A granular material having an average grain diameter of greater than 0.2 mm as measured by sieving for the production of injectable additives for use as constituents of inorganic binders in the foundry industry comprising particulate amorphous silicon dioxide,
(a) the granular material is
-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof a particulate material selected from
- water-soluble substances;
- alkali metal hydroxides,
- Surfactants,
- film formers,
- hydrophobizing agents, preferably organosilicon compounds, silanes, silicones and siloxanes, waxes, paraffins, metal soaps, and
- carbohydrate
Further comprising 1, 2 or more additional substances independently selected from the group consisting of,
wherein at least 90% of the grains of the granular material having a grain diameter in each case greater than 0.2 mm, preferably greater than 0.5 mm, more preferably greater than 1 mm, as measured by sieving, are particulate amorphous silicon dioxide , and one, two or more of said additional substances, and/or
(b) particulate amorphous silicon dioxide comprises silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide, and preferably consists entirely or in part of particulate synthetic amorphous silicon dioxide;
(c) the proportion of silicon dioxide in the granular material as a whole, as determined by x-ray fluorescence analysis, and in each case a sieve and grains of the granular material having a grain diameter of greater than 1 mm as determined by subsequent x-ray fluorescence analysis The proportion of silicon dioxide in at least 90% of the differs by no more than 30%, preferably no more than 20%, more preferably no more than 10%, based on the proportion of silicon dioxide in the whole granular material. and/or;
(d) in the granular material, the particulate amorphous silicon dioxide comprises two or more different types of particulate amorphous silicon dioxide, wherein the two or more types differ in their chemical composition;
Here, preferably, one, two, more than two or all of the different types of particulate amorphous silicon dioxide
- particulate synthetic amorphous silicon dioxide containing silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate synthetic amorphous silicon dioxide, and at least as a secondary constituent carbon producible by reducing quartz, preferably in an arc furnace;
- particulate synthetic amorphous silicon dioxide containing zirconium oxide as a secondary component, preferably produced by thermal destruction of ZrSiO ₄ ;
- particulate synthetic amorphous silicon dioxide producible by oxidation of metallic silicon with an oxygen-containing gas;
- Particulate synthetic amorphous silicon dioxide that can be produced by quenching a silicon dioxide melt
selected from the group consisting of or independently selected from, and/or
(e) the granular material is producible by the process as claimed in claim 1 or any one of claims 6 to 13. At least,
- the granular material as claimed in claim 14, and
- solutions or dispersions containing water glass;
A kit for the production of an inorganic binder comprising as components arranged spatially separated from each other. Apparatus for carrying out the process as claimed in any one of claims 1 to 13, comprising:
- a reservoir vessel containing particulate amorphous silicon dioxide comprising silicon dioxide in a proportion of at least 80% by weight, based on the total mass of particulate amorphous silicon dioxide;
- a mixing or contacting device for mixing or contacting particulate amorphous silicon dioxide with one, two or more additional substances;
- a device for granulating, extruding and/or agglomerating particulate amorphous silicon dioxide mixed with or in contact with one, two or more additional substances
A device comprising a. 17. The method of claim 16,
- a device for moving particulate amorphous silicon dioxide from the storage vessel into a mixing or contacting apparatus;
- at least one reservoir container containing a liquid, preferably a liquid wetting agent and/or a suspending medium, preferably water,
-preferably particulate inorganic material, preferably an oxide of aluminum, preferably aluminum oxide in the alpha phase, bauxite, oxide of zirconium, preferably zirconium(IV) oxide, mixed aluminum/silicon oxide, zinc The group consisting of oxides, barium sulfate, phosphorus compounds, sheet silicates, graphite, carbon black, glass beads, oxides of magnesium, borosilicates, ceramic hollow beads, boron oxide compounds, preferably powdered boron oxide compounds, and mixtures thereof one or more reservoir containers containing particulate material selected from;
- one or more reservoir containers containing water-soluble substances;
- one or more reservoir containers containing one or more surfactants;
- at least one reservoir container containing at least one hydrophobizing agent;
- one or more storage containers containing one or more carbohydrates
A device further comprising one or more device elements selected from the group consisting of 18. The method of claim 16 or 17,
An apparatus further comprising a device for dispensing or transporting the produced granular material. Use of particulate amorphous silicon dioxide for the production of a constituent of the granular material as claimed in claim 14 or as a constituent of the granular material as claimed in claim 14 . Use of a granular material as claimed in claim 14 for producing a solid injectable additive having a homogenized grain composition for use as a constituent of an inorganic binder in the foundry industry.

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