EP1663899A1

EP1663899A1 - Method for the production of a hydraulic binding agent, a structural component, use thereof and device therefor

Info

Publication number: EP1663899A1
Application number: EP04764896A
Authority: EP
Inventors: Christoph Muther; Eduard Buzetzki; Eckehard Maruhn
Original assignee: Individual
Current assignee: Silver Cay Worldwide Corp
Priority date: 2003-09-08
Filing date: 2004-09-07
Publication date: 2006-06-07
Also published as: AU2004281885A1; KR20070012310A; CA2538056A1; WO2005037727A1; DE102004043614A9; DE102004043614A1; JP2007505023A

Abstract

Latent hydraulic materials are activated as residue from thermal processes by mechanochemical and/or tribomechanical reactions in a method for the production of an organic based binding agent. The lattice structures of the material mixture are altered by means of kinetic impingement, and the interaction of pulse and pulse interruption associated therewith, resulting in plasmoid particle states; the particle structure is altered by shock waves and/or by pent-up energy induced by the pulse and/or the pulse interruption. The particles are altered to form amorphous structures by the occurring pulses and pulse interruptions or reflections. Said alterations occur by means of a device comprising an activator (20) provided with a stator (30) and a rotor (24) arranged on a machine platform (22). The stator (30) and the rotor (24) define an annular chamber or annular gap as a transportation path for the material. Tools are associated with the annular gap of the stator (30) and/or the rotor (24) and are at least partially covered by a layer of the mixture. A dosing device (42) and at least one air flow applied to other ring opening are arranged in front of the annular gap.

Description

DESCRIPTION

Method for producing a hydraulic binder, a component, their use and device therefor

The invention relates to a method for producing a hydraulic binder on an inorganic basis according to the preamble of claim 1 and a component and a gas concrete block. The invention also includes a device for carrying out the method and the use of the binder on the one hand and of polyelectrolytes on the other.

Concrete is one of the most important building materials and usually consists of a mixture of mineral components - such as sand, gravel or quarry stones - and cement as a binder; the latter sets with the addition of water and creates a kind of conglomerate rock.

The most important hydraulic binder for concrete is Portland cement (PZ), which consists of a finely ground mixture of PZ clinker and calcium sulfates - such as gypsum or anhydrite. After mixing with water, it hardens both in air and under water and maintains its strength even under water. Raw materials containing lime and clay - such as limestone, clay, lime marl and clay marl - are mixed with one another in such a way that the raw material mixture in addition to silica (S ^), alumina (Al ₂ 0 ₃ ) and iron oxide (Fe ₂ 0 ₃ ) contains between 75 and 79% by weight of lime (CaC0 ₃ ) from the clay content. There is preferably at least 1.7 parts by weight of lime per part by weight of soluble silica, alumina and iron oxide. The Geraisch is finely ground and then usually heated in rotary kilns with upstream preheating systems of various types until sintering. The Portland cement clinker resulting from this process is then subjected to fine grinding subjected and by admixing additives such as gypsum or the like. processed into Portland cement.

Other types of cements include, for example, the metallurgical cements - Eisenportlandzement and Hocbiofenzement -, the trass cement and the oil shale cement, which contain various other aggregates for the Portland cement clinker (DIN 1164). Special cements not standardized as cement may include a. Alumina cement, deep drilling cement and swelling cement.

Cements are offered in three grades. The high-quality cements CEM * 42.5 and CEM 52.5 differ from normal cement CEM 32.5 in that they have a different composition and a higher fineness of grinding, which results in faster hardening - not setting - and on standardized test specimens after 28 Days gives the compressive strengths indicated by the numbers. The higher initial strengths of the high-quality cements enable the formwork to be stripped earlier and therefore to be built more quickly.

In order to reduce the costs for the production of binders, alternatives to the raw materials used are increasingly being sought. For example, fly ash is used as an additive in the manufacture of concrete; Fly ash is a product that is extracted from the exhaust gas from industrial furnaces or waste incineration plants by means of filter systems, which is carried as combustion residue in the combustion gases, mechanically entrained or condensed from the vapor state when it cools down.

In addition, calcined ashes and fly ash - for example from industrial furnaces in the paper industry - or slag sands are used. The latter distort when the glowing red-hot blast furnace slag flowing from the slag tapping of the blast furnace is moved into moving water.

CEM = international term for cement These above-mentioned aggregates used in cement cause the binder to harden more slowly. For example, the strength achieved with conventional concrete after 28 days is only achieved after about 90 days. These binders, which are considered to be latent hydraulic, can therefore only be used to a very limited extent.

In view of these circumstances, the aim of the invention is to improve the usability of latent hydraulic binders - in particular those based on fly ash, calcined ash or blastfurnace slag and burnt oil shale - for practical use in the construction sector and, in particular, to enable faster hardening.

The teaching of the independent claim leads to the solution of this task; the subclaims indicate favorable further training. In addition, all combinations of at least two of the features disclosed in the description, the drawing and / or the claims fall within the scope of the invention. For the specified design ranges, values within the stated limits should also be disclosed as limit values and can be used as desired.

Appropriate components with which the different fly ash compositions can be balanced, on the one hand, and treatment of the mixture in an activator, on the other hand, will change the substances in the lattice-hydraulic state in the lattice structure and the geometry of the individual particles to the extent that there are active hydraulic effects, which subsequently correspond to high-quality Portland cement clinker.

The product is ground by high mechanical loading of the batch in an activator, which among other things results in an increase in the surface area. In addition, the globular structures of a fly ash are changed in such a way that an amorphous structure is created. This structure benefits the setting process by interlocking the individual particles and increases the strength values, especially the compressive and bending tensile strengths. The newly created reactive areas of the mixture subsequently increase the total specific surface area of the particles or grains - also called the Blain value. The surface enlargement through the fine grinding on the one hand and the transfer of the particle structures into reactive areas on the other hand result in an overall increase in the Blain value of 8 to 24 times compared to a Portland cement.

As a result of the particles colliding or colliding with one another and the reflections occurring on the tools, shock waves continue in the particles, which lead to the fragmentation of the particles into amorphous structures and to disturbances of the lattice structure within the particles.

During the impact of the particles - or due to the collision of the particles on the one hand and the tools on the other - there is an expansion of shock waves in the ultrasound range in interaction with occurring congestion energy due to the pulse interruption.

These energies - such as friction, kinetics, shear force acting on the particles - are largely converted into thermal energy, which in turn is dissipated via the newly created surfaces and released into the process air. The temperature increase of up to over 3000 ° C, which occurs briefly within a few milliseconds at the breaking points, causes a thermoplastic change in the interfaces. The charged particles or particles are briefly in a plasmoid state. The mechanochemical and tribomechanical processes described cause the activation of the latent hydraulic mineral components. The batch can now be used as a substitute for Portland cement.

Tests have shown that this innovative hydraulic binder - in addition to the classic applications in civil engineering - can also be used in the field of aerated concrete and refractory applications thanks to its excellent properties.

An activator is used as the device for producing this hydraulic binder. This device enables the parameters necessary for activation to be reached at high speeds of the rotating tools up to 250m / sec. The control of the material feed, the air supply, the process heat and the material discharge are of great importance. The design of the tools for the mechanochemical as well as tribomechanical effects is of particular importance.

The activator essentially consists of a rotor and a stator, which are held on a machine platform. The arrangement of the axis is vertical. It is driven by an electric motor using a V-belt on the rotor shaft to which the rotor is assigned. The speed of the rotor is infinitely variable via a frequency converter. The tools are exchangeable and adjustable.

The products to be activated are fed into the interior of the activator from a silo from above through a metering device by means of a rotary valve. In an annular space or gap released by the rotor and stator, the batch is conveyed downward in a spiral, the air being held in counterflow by the dwell time of the product in this annular space. Also causes this air flow is the removal of excess heat. In this annular space, the individual particles are thrown outwards against the stator by a pulse - caused by the rotor tools.

The tools of both the rotor and the stator are permanently coated with a layer of the mixture, so that the particles collide with one another or primarily with this layer. This mutual exposure and the effects achieved thereby - such as plastic deformation, resilience, fragmentation, friction - cause a fundamental change in the physical characteristics of the particles.

Since the layers of the batch covering the tools are supported by their support and resistance, the mass of the tools contributes significantly to supporting both the momentum and the momentum interruption and the resulting interactions such as reflections between the tools.

The chemical composition of the mixtures that can be activated is of a similar order of magnitude to that of the cements. The product manufactured, however, is mainly based on the basis of siliceous fly ash, blastfurnace slag and waste incineration slag.

This main component is added with additives - such as calcium oxides, calcium oxides, calcium carbonates and aluminum hydroxide - under oxidative conditions in the activator. The supply of oxygen is ensured by air fed into the activator from below.

The required proportion of admixture for a hardening time comparable to conventional concrete is in the range of 0.2 to 30 percent by weight with calcium aluminate. The admixtures for sodium aluminate or potassium aluminate are 0.1 to 20 percent by weight. The stated weight percentages relate to the finished binder mixture.

Mixtures of calcium aluminate, sodium aluminate or potassium aluminate can, of course, also be used, in which the amount of the respective admixtures is determined in such a way that the ranges of the admixtures specified above are not exceeded.

Process-typical recipes are now presented:

TABLE I Fly ash / stone. Hut sand Oil shale ca-alum. % By weight%% by weight% by weight%% by weight

Type A 69 15 15 1

Type B 65 10 20 5 Type C 65 13 15 7

Types A to C are discussed below:

Type A: (a) Characteristics • Slow setting based on strength class 32.5 N (> 32.5 N / mm ² standard strength after 28 days); • compressive strength after 7 days> 16 N / mm ² ; • E-module is given with the strength class; «High bending tensile strength.

(b) Application of finished products of various concrete elements (stones, slabs, angle slabs or the like). Type B: (a) character! Stika • Medium-fast setting based on strength class 32.5 R (> 32.5 N / mm ² standard strength after 28 days); »Compressive strength after 2 Tg> 10 N / mm ² .

(b) Application As type A and in civil engineering (foundation edge edging, foundation lighting post, substructure noise or the like).

Type C: (c) Characteristics • Fast setting based on strength class 42.5 R (> 42.5 N / mm ² standard strength after 28 days); • Compressive strength after 2 Tg> 20 N / mm ² .

(b) Application of civil engineering, structural elements and hydraulic engineering, because it is quickly binding!

With the addition of additional additives, these binders can be used in various areas. With the addition of cationic surfactants, it is achieved that after the curing phase, the component produced is waterproof after about 28 days; water is no longer absorbed by the structure of the component.

The possible uses include to be seen in the areas of hydraulic engineering, landfill construction, soil remediation, disposal of contaminated sites, etc.

By adding refractory parts and increasing the proportion of calcium aluminate to around 40%, this binder can be used in the area of thermally stable building materials such as in the lining of furnaces, converters, etc. Of particular interest is the use of the binder in the manufacture of aerated concrete. It has been shown here that when aluminum powder (less than 70 micrometers) is added, a closed-pore structure is formed, which corresponds to classic products in terms of strength values, densities, etc.

The decisive advantage, however, is the fact that the use of an autoclave, which is necessary in conventional manufacturing processes, is completely eliminated.

Open shaping and the water resistance and tightness which can be achieved with the addition of cationic surfactants are further advantages which are given in combination with the binder according to the invention.

The scope of the invention also includes a method for producing components such as bricks, plates or molded parts for building construction and civil engineering, which should be inexpensive to carry out; the components produced in this way should prove to be resistant to tensile and compressive loads and to weather.

In order to achieve this, according to the invention, a mixture of the same proportions of clay with particle sizes below 100 μm, fine sand with particle sizes from 100 μm to 2 mm and sand with particle sizes over 2 mm is mixed in a mixer with polyelectrolytes - preferably polymers or copolymers based of acrylamide - and a hydraulic binder mixed, introduced into molds and pressed at a pressure of at least 40 N / mm ² . This process is particularly easy to carry out, since on the one hand only low demands are made on the equipment and on the other hand the required proportioning components are easily and cheaply available. Clay is understood to mean that portion of the soil whose grain sizes are below 100 μm, fine sand that portion with particle sizes of 100 μm - 2 mm and as sand that part with grain sizes over 2 mm. These parts of clay, fine sand and sand are abundant in soils, although the proportions of clay, fine sand and sand obtained by removing the soil can of course differ in their proportions from the required composition. European soils have a high clay and gravel content, so that sand must be added in this case. The necessary hydraulic binders, such as cement, highly hydraulic lime, hydrated lime or fine lime, are also available in abundance and cheaply.

The amount of clay, fine sand and sand required to carry out this process is easy to obtain, since most soils contain these three components to a sufficient extent. In practical applications, only the upper soil layers have to be removed to obtain the mixture of clay, fine sand and sand and, after removing gravel, stone and organic components, mixing plants have to be added in which they are mixed with the respective binder and the polyelectrolytes. It is only necessary to check the composition of clay, fine sand and sand and to ensure that they are present in equal proportions. If necessary, a component must be mixed in if it occurs in too small a proportion. If clay, fine sand and sand portions - as defined above - are present in essentially the same proportions, this batch, which is also referred to below as "prepared batch", can be fed to the further process steps.

The choice of the respective binder and its required admixing amount depend in particular on the exact grain size distribution and moisture of the prepared mixture. With regard to the grain size distribution of the processed batch, not only the quantity distribution between clay, fine sand and sand content is of interest, but also the grain size distribution within each of these Groups. Basic properties of the prepared batch, such as its compressibility, can already be derived from this.

As explained in more detail below, fine lime or hydrated lime generally prove to be suitable as hydraulic binders for carrying out the method according to the invention, although in some cases highly hydraulic lime, cement and bituminous binders can also be used.

In the conventional sense, a polyelectrolyte is a water-soluble ionic polymer that is anionic from polyacids - e.g. polycarboxylic acids - cationic from polybases - e.g. Polyvinylammonium chloride - is formed or is neutral (polyampholytes or polysalts). An example of natural polyelectrolytes are polysaccharides with ionic groups such as carrageenan, but also proteins and long-chain polyphosphates. According to the invention, polyacrylamides are preferably used as polyelectrolytes, that is to say compounds made from monomers based on acrylamide. It is also conceivable to use mixtures of mono- and polymeric polyelectrolytes, possibly together with solubilizers, emulsifiers and catalysts, and with admixtures of propylenediamine, dimethylammonium chloride or isopropyl alcohol. Alternatively, mixtures of cationic surfactants can also be introduced. These polyelectrolytes cause an agglomeration of the fine-grained components, which is not based on the chemical conversion of water.

The mixture of clay, fine sand and sand mixture, polyelectrolyte and hydraulic binder is subsequently introduced into molds and pressed at a pressure of at least 40 N / mm ² . The choice of the pressing pressure influences the ultimate strength of the components, but usually a pressure of 40 - 120 N / mm ² is sufficient. According to a further feature of the invention, the polyelectrolyte is admixed with a preferred proportion of 0.001-2% by weight, based on the dry weight of the mixture of clay, fine sand and sand. In addition, a styrene-acrylic copoly should be added to the hydraulic binder before adding the hydraulic binder, which is particularly advantageous in wet and salty batches.

The objectives of the invention are also achieved by the characterizing features of claim 22. This procedure is particularly advantageous for prepared batches that have low moisture and a high proportion of fine sand. Here, provided that the prepared mixture will be a bitumen emulsion as well as polyelectrolytes, ^"preferably polymers or copolymers based on acrylamide added.

It has also proven to be advantageous to add the polyelectrolyte in a preferred proportion of 0.001-2% by weight, based on the dry weight of the mixture of clay, fine sand and sand. Finally, claim 35 outlines the use of polyelectrolytes, preferably polymers or copolymers based on acrylamide, for the production of structural elements such as bricks, plates or molded parts for building construction and civil engineering.

Claim 36 discloses bricks and molded parts for civil engineering, which contain polyelectrolytes, preferably polymers or copolymers based on acrylamide.

This method according to the invention is described in more detail below:

First of all, to obtain the mixture of clay, fine sand and sand, the upper layers of the soil have to be removed and, after removing gravel, stone and organic matter, added to mixing plants. The composition of this floor Layers are not particularly demanding, since the clay, fine sand and sand components required to carry out the process are mostly abundant. It is only necessary to check the relative composition of clay, fine sand and sand and to ensure that they are present in equal proportions for further processing. If necessary, a component must be mixed in if it occurs in too small a proportion. If clay, fine sand and sand portions - as defined above - are present in essentially the same proportions, this prepared mixture is mixed with polyelectrolyte in a mixer in a subsequent process step. As already mentioned, water-soluble ionic polymers are referred to here as polyelectrolytes, which are formed anionically from polyacids - for example polycarboxylic acids - cationically from polybases - for example polyvinylammonium chloride - or are neutral (polyampholytes or polysalts). It is also conceivable to use mixtures of mono- and polymeric polyelectrolytes, possibly together with solubilizers, emulsifiers and catalysts, and with admixtures of propylenediamine, dimethylammonium chloride or isopropyl alcohol. These polymers have ionic dissociable groups that can be part of the polymer chain and the number of which is so large that the polymers are water-soluble in dissociated form. Polyacrylamide is preferably used in suspension form. In aqueous solution, polyelectrolytes have reactive groups that show a strong affinity for the surfaces of the colloids and fine particles of the fine-grain portion of the soil. Depending on the ionogenicity of the polyelectrolyte, the interactions with the solid particles are based on the formation of hydrogen bridges, as is the case with nonionic polymers, or on electrostatic interactions and on charge exchange and the resulting destabilization of the particle surface: This is how it works the anionic (= negatively charged) and the cationic (= positively charged) polyelectrolytes. By destabilizing and linking a large number of individual particles there is an irreversible agglomeration of the fine particles in the clay, fine sand and sand mixture, which results in a higher density and thus a higher strength of the component ultimately produced. The polyelectrolytes used in the invention can thus also be referred to as cross ^¬ surface-active substances.

The potentials that are effective on the particle surface are decisive for the optimal effect of the polyelectrolyte. They are dependent on the particles themselves as well as on the environmental conditions, i.e. on the ionic strength of the mixture and the resulting properties, such as pH, electrical conductivity or hardness. By means of relatively simple preliminary tests, the person skilled in the art will determine the polyelectrolyte with the corresponding ionogenicity which is suitable for the respective application. However, it has been shown that polyacrylamide, for example, is suitable in most cases and has good strengthening properties. The polyelectrolyte is used here in a preferred proportion of 0.001-2% by weight, based on the dry weight of the mixture. The proportion will be based in particular on the ionogenicity of the polyelectrolyte used and on the fine-grain fraction of the batch. When polyacrylamide is used, 0.01% by weight has mostly proven to be sufficient. In the case of clay, fine sand and sand mixtures with a low moisture content, any necessary addition of water can be dosed by dilution with water.

In a further process step, in the case of a wet and / or salty batch and / or batch with a high proportion of fine grains, a styrene-acrylic copolymer, for example an acrylic acid dispersion, is added. In the case of a prepared mixture with a low moisture content and a high proportion of fine sand, a bitumen emulsion is preferably added. But it is not out of the question that there will be one Mixture of a styrene-acrylic copolymer and a bitumen emulsion can prove to be advantageous.

Then the hydraulic binder is added. As a rule, fine lime or hydrated lime have proven to be suitable binders for carrying out the process according to the invention, and in cases where there is a large proportion of larger grain sizes, highly hydraulic lime, cement and bituminous binders can also be advantageous. The admixing amount of the respective binder is also based in particular on the moisture of the prepared batch, whereby efforts are made to achieve the so-called Proctor optimum, which is the degree of saturation of the batch at which the batch's optimum compressibility given is. Soils and the clay, fine sand and sand components obtained from them often have too high a moisture content, whereby water is extracted from the mixture when using fine lime, hydrated lime or highly hydraulic lime. This is due on the one hand to the chemical conversion of calcium oxide (CaO) into calcium hydroxide (Ca (OH) ₂ ) with the incorporation of water, and on the other hand to the thermal energy released during this reaction, which leads to the physical evaporation of water. The water content of the batch should be at the Proctor optimum or slightly above for this process according to the invention.

The mixture consisting of clay, fine sand and sand mixture, polyelectrolyte and hydraulic binding agent or any necessary additives such as styrene-acrylic copolymers is then introduced into molds and pressed at a pressure of at least 40 N / mm ² . The choice of the pressing pressure influences the ultimate strength of the components, but usually a pressure of 40-120 N / mm ² is sufficient. After pressing, the components can be loaded after 50% drying. These methods according to the invention thus initially have an irreversible structural influence on the starting components, namely clay, fine sand and sand. This is achieved by agglomeration of the small-grained components and a change in the capillary water flow by breaking up the adhesive water film on the colloidal components. This results in better compressibility of the batch and a high strength of the components produced using the method according to the invention.

The scope of the invention also includes a method for producing a gas concrete block, in which a mixture of a hydraulic binder, a fine-grained component, water and a blowing agent is produced, poured into molds and dried.

Various methods are known for producing gas concrete blocks, each of which is a mixture of one

• fine-grained component, such as quartz sand, • lime, • a hydraulic binder such as cement, • water • and a blowing agent as a pore former

is used. Lime and cement are used in roughly equal parts, and aluminum powder is generally used as the blowing agent. The proportion of the blowing agent is less than 0.05% by weight of the total mixture. The reaction of the calcium hydroxide with the aluminum releases hydrogen, which is responsible for the high proportion of pores. The mixture is poured into molds, and different formats and profiles can be cut in the semi-solid state. The The high strength of the aerated concrete is achieved by steam curing in autoclaves at approx. 160-220 ° C and approx. 12-15 bar pressure after about four to eight hours. The hydrogen escapes and the pores formed fill with air. The action of pressure and hot steam releases silica from the surface of the grains of sand, which, together with the lime (hydrated lime) binder, forms crystalline binder phases - so-called CSH phases. These crystalline binders combine with the grains of sand and. create a firm bond between the individual supplements. The gas concrete blocks manufactured in this way have comparatively low densities of up to around 400 kg / m ³ and, due to the pore structure and their air pockets, have good thermal insulation properties.

However, processes of this type are complex and energy-intensive due to the machines and systems to be used. For example, high pressures must be maintained in the autoclave for several hours, with the high energy consumption being primarily due to the required heat treatment with steam. Another disadvantage is that the tongue and groove, for example, have to be milled into the stones afterwards; complicated shapes are often not possible due to the necessary steam hardening. The quartz sands usually used for the manufacture of gas concrete blocks must also be of high quality and can sometimes only be made available after long transport to the production site. There is also a risk of explosion when aluminum is used in production.

In order to avoid these disadvantages and to provide a comparatively inexpensive method, household waste is comminuted, homogenized and prepared with calcium-containing additives such as dolomite, calcite, lime marl or marl as well as with aluminum oxide-containing additives such as corundum dust, clay marl or to produce the hydraulic binder used for this method according to the invention Clinker mixed and burned; then up to 40% by weight Framework silicates, for example tuff, are added, and the product obtained is ground to a grain size of less than 0.063 mm. In addition, fine slag from waste incineration plants, metallurgical or steel slag is used as a fine-grained component and a surfactant is used as a blowing agent. These components are explained in more detail below.

Typical household waste usually contains 59-69% silicon oxide, 4.9-7.8% iron oxide, 5.1-6.3% aluminum oxide and 8.3-10.3% lime in% by weight and is therefore suitable for production an inorganic binder for concrete-like hardening masses.

The binder can be produced in waste incineration plants that are run on special refuse-derived fuels (BRAM). These are 18% to 26% by weight of silicon oxide, 2% to 5% iron oxide, 4% to 12% aluminum oxide and 58% to 66% lime, and 2% to 5% magnesium oxide.

The combustion bed temperature is at least 950 ° C and the calorific value of the waste is at least 13MJ / kg. The latter circumstance ensures that practically no additional primary energy has to be added for combustion.

As additives, calcium-containing industrial waste or calcium-containing rock, such as dolomite, calcite, lime marl and the like. added that are readily available.

With the additives, industrial waste such as corundum dust, but also clay marl, clinker and the like can also be used. be used.

In general, there is a loss on ignition of about 5%, a sulfate content of 4%, a chloride content of about 3%, a Blaire value of 5000 cm ² / g and a base degree of p> 2, the calculation of the base degree using p (CaO + MgO + Al ₂ 0 ₃ + Fe ₂ 0 ₃ ) Si0 ₃ takes place. Due to the ion exchange and sorption that occur during the process, any pollutants contained in household waste are incorporated into the dressing and are therefore difficult to leach out of the binder and the concrete produced with it, and therefore do not pose any significant risk to the environment. their extraction is associated with considerable effort, can largely be dispensed with. In addition, the problem of storing and treating household waste is largely mitigated. Since the energy is essentially provided by household waste itself, there are also considerable energy savings in the production of the binder.

According to the invention, fine slag from waste incineration plants (MVA), metallurgical slag or steelworks slag is used as the fine-grained component. These are the solid, non-combustible residues that arise in the course of combustion in industrial furnaces or incinerators.

When incinerating waste, slag still accounts for around 35% of the original weight of the waste. In addition to the iron-containing components, waste incineration slag also contains significantly smaller amounts of non-ferrous metals such as copper, nickel, lead, zinc or tin in varying amounts.

Iron and steel slag can be broken down into blast furnace slag and steel works slag, whereby blast furnace slag is produced in the production of pig iron in the blast furnace and steel works slag in steel production in converters, in electric furnaces and Siemens Martin furnaces.

Metallurgical slag is formed during the extraction of non-ferrous (NE) metals. According to the current state of the art, about 250 kg of blast furnace slag is produced per ton of pig iron and about 120 kg of steelworks per ton of crude steel. slag. This results in large amounts of slag that can be recycled.

Blast furnace and steelworks slag differ in their chemical composition, but because of their main components calcium oxide, silicon dioxide, aluminum oxide and iron oxide they are both also suitable for use with the method according to the invention.

It can now be seen that, owing to the chemical composition of the binder obtained from household waste as well as the fine slag from MVA or industrial firing, the use of aluminum powder can be dispensed with. Instead, a comparatively cheap blowing agent such as a surfactant can also be used. This is understood to mean compounds that accumulate strongly from their solution at interfaces (eg water / oil) and thereby reduce the surface tension - in the case of liquid / gaseous systems, the surface tension. Although polar solvents such as alcohols, ethers, pyridines, alkylformamides, etc. are also surface-active, the compounds used as surface-active substances in the context of the invention are those which have a lipophilic hydrocarbon radical and one, possibly also several, hydrophilic functional groups. - -COONa, -S0 ₃ Na, -0-S0 ₃ Na and the like - have; such substances are also referred to as surfactants or detergents.

These can be water-soluble sodium or potassium salts of saturated and unsaturated higher fatty acids (also known as lye soap) or water-soluble sodium or potassium salts of the rosin rosin acids (also known as rosin soap), or water-soluble sodium or potassium salts of naphthenic acids - for example alkyl naphthalene sulfonic acid enriched on the casein basis. In addition, the surface-active Agents are added in an amount of 0.03 to 0.001% by weight, based on the mixture before drying.

As a non-restrictive embodiment, in absolute quantities about a mixture of 780 kg of the hydraulic binder according to claim 1, 290 kg of fine slag, 250 kg of water and 0.25 kg of the surfactant can be produced, with a gas concrete block after drying with air gives a density of about 600 kg / m ³ .

Drying can also be carried out without steam curing and without the production of high pressures; instead, air drying has proven to be sufficient. The maturing process until the gas concrete blocks can be processed takes about 3 to 7 days, with the final strength increasing as the drying time increases. This not only achieves high energy savings, but also enables the production of more complicated shapes due to the elimination of the steam autoclave. The risk of explosion associated with the use of aluminum powder is eliminated.

It also shows that the expansion process results in a lower expansion pressure compared to conventional manufacturing processes. As a result, cheaper materials can also be used as formwork material for the casting of molded parts. The use of cheap raw materials such as household waste or fine slag from incineration plants or industrial furnaces ensures an additional cost reduction of the method according to the invention.

The practical test of the gas concrete blocks produced with this method according to the invention also shows that less water is drawn through the closed-cell structure of the gas concrete blocks and that no shrinkage occurs, but on the contrary a slight one Sets swelling. This counteracts the risk of crack formation in the joint area.

The density of the gas concrete blocks produced according to the invention is between 650 and 1200 kg / cm ³ . The compressive strengths and the bending tensile strengths are dependent on the density, the ratio between compressive strength and bending tensile strength being significantly greater than in the case of concrete, ie the existing bending tensile strength is comparatively high in relation to the compressive strength. This ensures that thermal insulation panels made from this material have excellent stability. By means of this method according to the invention, however, it is also possible to reinforce the gas concrete block produced in this way with fibers, for example based on coconut or plastic, whereby the bending tensile strength can be increased considerably. It is shown that in particular the use of fine slag instead of the fine sand usually used has extremely favorable effects on the strength of the gas concrete block produced by the method according to the invention.

In order to achieve lower densities of up to 300 kg / m ³ , powdered aluminum can also be used in addition to the surfactant, which is aluminum from recycled materials. In this case too, the energy-intensive and complex steam autoclaving can be dispensed with.

According to a further feature, the powdered aluminum is added in an amount of 0.05 to 0.001% by weight, based on the mixture before drying. The amount of aluminum powder used will depend on the one hand on the amount of the surfactant used and on the other hand depend on which properties, in particular what density, the final gas concrete block should have. In principle, additional quantities of aluminum powder ensure that the pore structure turns out coarser after drying, which reduces the density of the gas concrete block. In particular, the average pore size depends on the average grain size of the aluminum powder used. It is obvious that depending on the mixing ratio and grain sizes of the aluminum powder used and the blowing agent, different properties of the final gas concrete block can be realized.

Particularly when using aluminum powder from recycled materials, a measure has proven to be advantageous according to which the powdered aluminum is mixed with an alcohol solution before it is added to the overall mixture. This is because aluminum tends to coat with an oxide layer that makes the aluminum less reactive. The coating with alcohol prevents oxidation of the surface of the aluminum powder, as a result of which the effect of the aluminum powder is optimized in the course of the process according to the invention.

However, it is also conceivable according to the invention that, instead of the fine slag, fly ash from waste incineration plants, smelter or steelworks slag is also used as the fine-grained component. Of course, it is also possible to replace the proportions of the hydraulic binder described above with conventional cement or the proportions of the fine slag with conventional fine sand if certain properties of the gas concrete block produced in this way can be optimized. The following recipes for gas concrete blocks with a density of 500 to 600 kg / cm ³ and strengths of 25 to 40 kg / cm ² (after drying for 28 days) can thus be mentioned as non-limiting exemplary embodiments: 330 kg of hydraulic binder according to claim 25, 165 kg of fine sand, 230 kg of water and 0.5 kg of a mixture of the surfactant and aluminum powder; 330 kg of hydraulic binder according to claim 25, 165 kg of fly ash, 300 kg of water and 0.5 kg of a mixture of the surfactant and aluminum powder; • 165 kg of hydraulic binder according to claim 25, 165 kg of cement, 165 kg of fly ash, 300 kg of water and 0.5 kg of a mixture of the surfactant and aluminum powder.

Through precisely coordinated formulations, different properties of the gas concrete blocks produced with the method according to the invention can thus be achieved. The elimination of steam hardening also makes it much easier to replace, even with complicated shapes.

This invention thus provides an extremely inexpensive method of manufacturing a gas concrete block that is extremely suitable for use as a high-quality, heat-insulating lightweight building material.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing; this shows sketchy in

1: an oblique view of a product to be ground;

2: an oblique view of the ground product;

3: an oblique view of a device for treating the product; 4 shows an enlarged partial cross section through the device;

5: an enlarged section from FIG. 4;

Fig. 6: the side view of a tool part.

In Fig. 1 a pile 10 of spherical components 12 is shown. Due to the high mechanical loading of this mixture in an activator described below, the product is ground, whereby u. a. an increase in the surface is achieved. In addition, the globular structures of a fly ash are changed in such a way that an amorphous structure is created. This structure favors the setting process by interlocking the individual particles 14 which have arisen after a comminution process and increases the strength values, in particular the compressive and bending tensile strengths.

As a result of the particles 12 colliding or colliding with one another and the reflections occurring at the activator, shock waves continue in the particles 12, which break them down into amorphous structures and disrupt the structures Lattice structure within the particles lead, as shown in FIG. 2.

The comminution takes place in a so-called activator 20, which has a rotor 24 and a stator 30 on a machine platform 22, the top plate 32 of which is penetrated by a rotor shaft 26. The latter runs coaxially to the vertical axis A of the rotor 24.

The rotor 24 is driven by an electric motor 36, which can be seen outside the stator wall 34, by means of a V-belt 38 on the rotor shaft 26. The speed of the rotor 24 is infinitely variable via a frequency converter, which cannot be seen.

40 is a cylindrical silo from which the pile 10 is fed to a metering device 42. Beneath this is a floor-level horizontal arm 45 of a conveyor 44 - in longitudinal section here Z-shaped - whose inclined central section 46 merges into a ridge arm 47 above the cover plate 32 of the stator 30. The latter is followed by a cellular wheel sluice 50 through which the material to be conveyed 10 is fed to the interior of the activator 20.

4, 5 illustrate an annular space 52 of radial width a between the outer surface 28 of the rotor 24 and the inner surface 29 of the stator 30. Tools 54 and 54 _r protrude radially from both surfaces 28, 29. 6, near their end faces 56, they have a groove-like indentation 58 on both sides.

The batch 10 is conveyed downward in a spiral in the annular space or annular gap 52, the dwell time of which can be regulated by counter-flowing air. This air flow also removes the excess heat. In this annular space 52, the individual particles 14 are thrown outwards against the stator 30 by a pulse - caused by the rotor tools 54 _r . The tools 54 and 54 _{r of} both the stator 20 and the rotor 24 are continuously coated with a layer of the mixture 10, so that the particles 14 collide with one another or primarily with this layer. This mutual action and the effects achieved thereby - such as plastic deformation, resilience, fragmentation, friction - cause a fundamental change in the physical properties of the particles 14.

Since the layers 54, 54 _r covering layers of the batch are supported by their support and resistance, the mass of the layers 54, 54 _r contributes significantly to both the momentum and the momentum interruption and the resulting interactions such as reflections between the figures 54, 54 _r to support.

Claims

Patent claims

1. A method for producing an organic-based hydraulic binder, characterized in that latent hydraulic substances are activated as residues from thermal processes by mechanochemical and / or tribomechanical processes.

2. The method according to claim 1, characterized in that the lattice structures of the mixture of substances are changed by kinetic loading and the associated interaction between impulse and impulse interruption, which causes plasmoid states of the particles.

3. The method according to claim 2, characterized in that the particle structure is changed by shock waves or by accumulation energies, which are triggered by the pulse or the pulse interruption.

Method according to claim 2 or 3, characterized by a change of the particles into amorphous structures due to occurring pulses and pulse interruptions or reflections.

Method according to claim 4, characterized in that the shock wave or the accumulation energies are generated by the particles colliding against one another and the latter are converted into amorphous structures.

6. Method according to one of claims 3 to 5, characterized in that the shock waves propagate in interaction with the congestion energy in the ultrasonic range.

7. The method according to any one of claims 3 to 5, characterized in that the accumulation energy acting on particles is mostly converted into thermal energy.

8. The method according to claim 7, characterized in that the thermal energy is dissipated via the resulting surfaces and released into process air.

3. Method according to one of claims 1 to 8, characterized in that fly ash, burned oil shale, blast furnace slag are oxidatively processed with the addition of calcium oxides, calcium hydroxides, calcium carbonates and / or aluminum oxides or aluminum hydroxides with the supply of an oxygen-containing fluid.

10. The method according to any one of claims 1 to 9, characterized in that the binder is obtained from residues of the fly ash resulting from the combustion of substances containing silica, alumina, iron oxide and lime, which preferably come from hard coal, lignite and anthracite coal power plants were removed.

11. The method according to any one of claims 1 to 9, characterized in that the binder is obtained from residues of the calcined ash or fly ash resulting from the combustion of substances containing silicic acid, alumina, iron oxide and lime, which were preferably taken from industrial furnaces.

12. The method according to any one of claims 1 to 9, characterized in that the binder is provided with blastfurnace sand or burnt oil shale created by burning substances containing silicic acid, alumina, iron oxide and lime.

13. The method according to any one of claims 9 to 12, characterized by calcium aluminate in the range of approximately 0.2 to 30% by weight as the additive.

14. The method according to any one of claims 9 to 12, characterized by sodium aluminate or potassium aluminate of approximately 0.1 to 20% by weight as an admixture proportion.

15. The method according to any one of claims 1 to 14, characterized in that an aluminum powder is added to the binder to produce aerated concrete.

16. The method according to any one of claims 1 to 15, characterized in that cationic surfactants are added to the binder and it is made waterproof and water-resistant.

17. The method according to any one of claims 1 to 16, characterized in that the hydraulic binder is produced from latent hydraulic components in an activator.

18. The method according to claim 17, characterized in that the substances to be activated are guided into counterflowing air in an annular gap of the activator against gravity.

19. The method according to claim 18, characterized in that the particles of the substances are thrown against a stator which delimits the annular gap to the outside and an impulse is generated.

20. The method according to claim 18 or 19, characterized in that the particles of the substances are thrown against a mixture layer on tools of the activator and an impulse is generated.

21. A method for producing a component such as a brick, plate or molded part for civil engineering, characterized in that a mixture of equal proportions of clay with grain sizes below 100 μm, fine sand with grain sizes of 100 μm to 2 mm and sand Grain sizes over 2 mm are mixed with polyelectrolytes, preferably polymers or copolymers based on acrylamide, and a hydraulic binder, placed in molds and pressed at a pressure of at least 40 N/mm ² .

22. A method for producing a component such as a brick, plate or molded part for civil engineering, characterized in that a mixture of equal proportions of clay with grain sizes below 100 μ, fine sand with grain sizes of 100 μm to 2 mm and sand Grain sizes over 2 mm are mixed with polyelectrolytes, preferably polymers or copolymers based on acrylamide, and a bitumen emulsion, placed in molds and pressed at a pressure of at least 40 N/mm ² .

23. The method according to claim 21 or 22, characterized in that the polyelectrolyte is added in a proportion ^of 0.001 to 2% by weight, based on the dry weight of the mixture of clay, fine sand and sand.

24. The method according to claim 21 or 23, characterized in that a styrene-acrylic copolymer is added to the hydraulic binder before mixing with the hydraulic binder.

25. Process for producing a gas concrete block, in which a mixture of a hydraulic binder, a fine-grained component, water and a blowing agent is produced, poured into molds and dried, characterized in that to produce the hydraulic binder, household waste is shredded and homogenized Calcium-containing additives such as dolomite, calcite, lime marl or marl as well as additives containing aluminum oxide such as corundum grinding dust, clay marl or clinker are mixed and burned, then up to 40% by weight of framework silicates, for example tuff, are added and the product obtained is reduced to an average grain size smaller than 0.07 mm, preferably 0.063 mm, is ground, fine slag from waste incineration plants, metallurgical or steelworks slag is used as the fine-grain component and the blowing agent is a surface-active agent.

26. The method according to claim 25, characterized in that water-soluble sodium or potassium salts of the saturated and unsaturated higher fatty acids or the resin acids of rosin (rosin soap) or the naphtenic acids, preferably casein-based enriched alkylnaphthalenesulfonic acid, are used as the surface-active agent.

27. The method according to claim 25 or 26, characterized in that the surface-active agent is added in an amount of 0.03 to 0.001% by weight, based on the mixture before drying.

28. The method according to any one of claims 25 to 27, characterized in that powdered aluminum from recycled materials is used as an additional blowing agent.

29. The method according to claim 28, characterized in that the powdered aluminum is added in an amount of 0.05 to 0.001% by weight, based on the mixture before drying, the powdered aluminum preferably being mixed with an alcohol solution before being added is mixed.

30. The method according to one of claims 25 to 29, characterized in that fly ash from waste incineration plants, metallurgical or steelworks slag is used as the fine-grained component.

31. Device for carrying out the method according to at least one of claims 1 to 20, characterized by an activator (20) with a stator (30) and rotor (24) on a machine platform (22), the stator and rotor having an annular space or annular gap (52) limit as a transport route for the substances (10, 12).

32. The device according to claim 31, characterized by tools (54, 54 _r ) of the stator (30) and / or the rotor (24) assigned to the annular gap (52), which are at least partially covered by a layer of the mixture.

33. Device according to claim 31 or 32, characterized by a metering device (42) arranged upstream of the annular gap (52) and at least one air supply line attached to the other end of the annular gap.

34. Use of a binder produced by the process of at least one of claims 1 to 20 with an increased proportion of calcium aluminates and the addition of refractory components for the production of refractory brick linings and molded parts.

35. Use of polyelectrolytes, preferably polymers or copolymers based on acrylamide, for producing components such as bricks, panels or molded parts for civil engineering.

36. Molded part or brick for civil engineering, characterized in that it contains polyelectrolytes, preferably polymers or copolymers based on acrylamide.