RU2203245C2 - Formulation for manufacturing composite and a composite manufacture method - Google Patents

Abstract

FIELD: composite materials. SUBSTANCE: invention relates to preparing composite formulations from crushed filler and mineral binders to be applied for compression-mediated manufacture of building composites. More particularly, crushed inert filler in amount of 35-40%, crushed carnallite chlorinator slime in amount of 40-45% are mixed with thickened pulp from hydrochlorination of crude serpentinite processing waste in amount of 15-25%. The latter contains 0.2-0.5 wt. parts solid phase per 1 wt.part aqueous phase comprising 150-350 g/cu. dm magnesium chloride at pH 4- 10. Carnallite chlorinator slime with particle size 0.05-1 mm is composed, wt.%: MgCl₂, 26-32; MgO, 30-62; CaO, 1.5-2.0; KCl, 12.5-18.0; NaCl, 2.5-3.0; and undissolved precipitate, the balance. Crushed inert filler may be vegetable- origin one or heat-and-power plant waste, or yet polymetallic slimes. EFFECT: enabled disposal of waste and improved physicochemical characteristics of composites. 6 cl, 1 tbl

Description

 The invention relates to the production of composite mixtures, prepared mainly from crushed plant materials and mineral binders, and can be used for the manufacture of wood-composite materials by pressing raw mixtures obtained from waste products from the chemical and metallurgical industries.

A known method of obtaining composite building materials, which consists in mixing caustic magnesite with a solution of magnesium chloride, which is used as MgCl ₂ • 6H ₂ O, obtained from brine, condensed by evaporation of lake water, or as a waste product of KCl from carnallite (MgCl ₂ • KCl • 6H ₂ O). The dosage of these two components - caustic magnesite and magnesium chloride - is 62-67% MgO and 33-38% MgCl ₂ • 6H ₂ O. (Chemical technology of binders / Edited by V.V. Timishev. M .: Higher school, 1980, p. 54-59). Magnesia binders obtained in this way can be used for the manufacture of xylene, fiberboard, heat-insulating materials, plaster mortars, artificial marble, substrates for "clean floors", artificial millstones, grinding and lithographic stones, for the production of building parts and a number of other products.

The implementation of the known method on a wide industrial scale is limited by the scarcity of the starting components (MgO, MgCl ₂ ), their high cost and limited raw material base.

 Known raw mix for the manufacture of building products - xylolithic blocks and a method for their manufacture. The raw material mixture includes, parts by weight: caustic magnesite - 1.0-1.5; magnesium chloride brine - 1.4-1.9; aggregate, which is used as wood sawdust - 2.8-3.2; polyorganosiloxane - 0.01-0.03; kaolin - 0.04-0.08 and ultramarine - 0.03-0.07. (Patent RU 2062763, C 04 B 28/30, 1996). A method of manufacturing a raw material mixture involves preparing the mixture by mixing caustic magnesite, ground wood aggregate, which is pre-mixed with kaolin, followed by the introduction of polyorganosiloxane, an aqueous solution of magnesium chloride of carnallite production and ultramarine, pressing the resulting raw mixture is carried out at room temperature, the molded product is dried until the binder sets , alternate soaking and drying to reduce the mass of the product by 22-23% of the original o and salt yield up to 70-72% of their initial state.

 The known method of obtaining building products can significantly reduce energy consumption by eliminating hot pressing, however, the process of forming the finished product requires multi-stage drying and soaking to certain moisture and salt content parameters, while the resulting products are characterized by high porosity at high specific gravity, high water absorption.

 There is also a known method of manufacturing sets of building parts for low-rise buildings, including grinding the filler, preparing the press mass, mixing the filler with a binder, forming portions of the press mass, feeding them to the pressing unit, pressing into a continuous billet and dividing it into parts, while the binder is in front of they are heated by mixing, the gas-vapor mixture is removed by mixing, before forming a portion of the press mass, they are heated, and the pressing unit is heated, after separation of the continuous workpiece into parts, and x moisture protection. (Patent RU 2038204, IPC В 27 N 3/02, 1995). Magnesite caustic powder, calcined magnesium ores, a mixture of magnesium and calcium ores are used as a mineral binder, vegetable raw materials — calibrated wood chips, sawdust, annual plants, extracts from tannic extracts, are used as a filler — moisture-proof mixture is carried out with a mixture of calcined clay and drying oil.

When implementing the known method requires special constant heating of the preparation unit of the press mass, the preparation unit of the binder, the pressing unit, while heating is carried out to sufficiently high temperatures, the temperature of the mineral binder reaches 200 800 ^o , the temperature of the preparation unit of the press mass is from 100 to 275 ^o С, hot pressing temperature - 180-200 ^o C. Thus, the known method requires high energy consumption, significant capital investment, complicated operation, it does not provide uniform impregnation of wood comminuted cheese I mineralizer. When changing the composition of the composition, the known method has limited technological capabilities.

 Closest to the proposed is a composition for the production of structural building timber containing wood waste 40-50 wt.%, Sludge carnallite chlorinators 40-50 wt.%, Caustic magnesite no more than 10 wt. %, water - the rest. (RF patent 2151156, C 08 L 97/02, 2000). A method of manufacturing composite materials from a known composition consists in mixing a pre-crushed filler with crushed solid slurry of carnallite chlorinators used as mineral magnesium-containing binder, to obtain a press mass, the resulting press mass is dosed to form workpieces of parts with subsequent hot pressing to obtain finished products.

 The known composition does not provide high-quality bars - high rates of water absorption, swelling, low frost resistance. In addition, the use of caustic magnesite as a binder in the composition of the mixture involves the organization of a special industrial site for the processing of initial magnesite into caustic magnesite.

 The objective of the invention is to simplify and reduce the cost of the process of obtaining building elements on a mineral binder by expanding the raw material base, while increasing the strength characteristics of the finished product.

The problem is solved in that, in contrast to the well-known, in the claimed invention, as a mixture of a mineralizer and a hardener, a mixture of slime of carnallite chlorinators with condensed pulp from hydrochlorination of a suspension of serpentinite waste products of asbestos production is used. An inert filler is used as a filler, for example, crushed filler of plant origin, polymetallic sludge and waste from energy production, for example, ashes of thermal power plants. A method of producing composite materials consists in mixing an inert filler with pre-ground slurries of carnallite chlorinators, followed by the introduction of condensed pulp from hydrochlorination of waste from the processing of serpentenite raw materials, mixing them together to obtain a press mass. The thickened pulp from hydrochlorination of waste from the processing of serpentinite raw materials contains 0.2-0.5 wt.h. solid phase to 1.0 wt.h. the aqueous phase, while the aqueous phase contains 150-300 g / DM ³ magnesium chloride, and the pH is adjusted to 4-10, with the following ratio of components, wt.%:
Ground inert filler - 35-40
Ground carnallite chlorinator sludge - 40-45
Specified Condensed Pulp - 15-25
To implement the above method, a raw mixture is prepared that contains crushed inert filler, crushed slurry of carnallite chlorinators, a grinder and water, while, in contrast to the known method, a thickened pulp from hydrochlorination of waste from the processing of serpentenite raw materials containing 0 is used as a grinder and water 2-0.5 wt. h solid phase at 1.0 m.ch. the aqueous phase, while the aqueous phase contains 150-350 g / DM ³ magnesium chloride, and the pH is adjusted to 4-10, with the following ratio of components of the composition, wt.%:
Ground inert filler - 35-40
Ground carnallite chlorinator sludge - 40-45
Specified Condensed Pulp - 15-25
As a ground inert filler, a filler of plant origin is used, for example, wood sawdust, wood shavings, dried annual plants, neutralized and dried hydrolysis lignin, mineral filler, for example, waste from thermal power plants, in particular ash from thermal power plants, polymetallic sludge and other known wastes from large-scale industries.

As a magnesium binder, crushed sludges of carnallite chlorinators are used, which are formed in chlorinators at the second stage of the processing of carnallite by an electrolytic method. The resulting slurry from chlorinators enters the dumps in the form of a monolithic lump of block and contains,%: MgCl ₂ 26-32; MgO 30-62; CaO 1.5-2.0; KCl 12.5-18.0; NaCl 2.5-3.0; insoluble precipitate - the rest (contains FeO up to 13%, Al ₂ O ₃ up to 30%, SiO ₂ up to 57%). The slurry of carnallite chlorinators before being introduced into the composition of the raw material mixture is ground by known methods to a dispersion of less than 200 microns. After grinding, the sludge becomes suitable for use as a binder without additional preparation.

 The inventive composition and method for its preparation are interconnected by a single inventive concept, leading to the achievement of one technical result, which meets the requirement of the unity of the invention.

The inventive composition and method for its preparation provide the possibility of hot pressing even at temperatures not exceeding 150 ^o With no deterioration of the basic physical and mechanical characteristics. The introduction of the specified thickened pulp from hydrochlorination of waste serpentenite raw materials as a hardener allows not only to expand the raw material base, but also to increase the strength characteristics of the target products.

 The proposed composition for the manufacture of composite materials can be obtained from industry-known wastes of large-scale production, the production of metallic magnesium from carnallite by the electrolytic method, and the production of asbestos. The waste used is uniquely identified by specialists in these industries. A method of obtaining the inventive composition can be implemented on standard commercially available equipment using well-known techniques for their configuration in the production line. All of the above allows us to conclude that the proposed solution meets the criterion of "industrial applicability".

 The proposed method is implemented as follows.

The components of the mixture of the press mass are prepared as follows. Magnesium-containing sludge - the sludge of carnallite chlorinators is crushed by known methods, for example, crushing with subsequent grinding to achieve a dispersion of less than 200 microns. The crushed sludge is examined for the content of the active components MgCl ₂ and MgO and is used as a magnesium binder. The pre-ground inert filler is dried to a relative humidity of not more than 45% and is fed into the mixer reactor in a predetermined quantity through a hopper-dispenser. The crushed slurry of carnallite production is introduced therein in a predetermined quantity and mixed with a filler. The thickened pulp from the hydrochlorination of a suspension of serpentenite raw materials in the claimed amount is introduced into the mixer reactor, mixing is carried out for 1-2 minutes. The specified ingredients of the press are present in the composition in the following ratio of components, parts by weight:
Ground inert filler - 35-40
Ground carnallite chlorinator sludge - 40-45
Condensed pulp from hydrochlorination of wastes of the process of processing serpentenite raw materials - 15-25
The part is made from the calculated dose of the press by pressing in an extrusion press, which is a horizontally located press with a movable punch (plunger) and a fixed open-type die (barrel) equipped with lateral clamps and a cutting machine at the end. Using the proposed ratio allows the pressing process at a pressure not exceeding 80-100 atm and a temperature not exceeding 150 ^o C. The process of forming finished products can be divided into the following stages: the start of heating, at which the process proceeds with intensive vaporization and rapid spread heat inside the cross section of the workpiece, the process of formation of magnesia cements begins; stabilization of heating, in which the intensity of heat penetration into the product decreases sharply, there is a recrystallization of the mineral binder depending on the moisture content and temperature at each point of the formation of cement stone; completion of the product formation process at which recrystallization processes end. The billet from the extrusion press forming chamber enters the stabilization chamber, in which the geometrical and strength parameters of the finished product are stabilized. A slight excess of moisture 10-12% gradually evaporates through the remaining pores to a moisture content of 6-8%, internal stresses are released, the workpiece gains strength characteristics to the specified parameters.

 Examples of specific performance.

The ground inert filler, which is used as wood waste, in particular hydrolytic lignin, or wood sawdust, or CHP ash, is fed to a combined dryer, the material is dried to a predetermined humidity not exceeding W = 45%, relative humidity is determined, and the relative humidity is determined through an unloading device served in the hopper-dispenser filler. When the specified mass of dried material is reached, the filler hopper through the ACS block receives a command to turn off the combined dryer. Shredded inert filler in the amount of 35, 37.5 and 40 wt.% (Examples 1, 2 and 3 of the table) and preliminarily crushed to the size of 0.05-1 mm sludge of carnallite chlorinators in the amount of 40, 42.5 and 45 wt. % (examples 1, 2 and 3 of the table) of the following composition, wt.%: MgCl ₂ - 26, MgO - 31, KCl, NaCl, CaCl ₂ - 24, the rest are chlorides and oxides of other metals. The drive of the stirring mechanism is turned on, after which a thickened suspension of hydrochlorination of a suspension of serpentenite feed in the amount of 15, 20 and 25 wt.% Is served (examples 1-3 of the table). In the mixing reactor, the components of the press are mixed with two paddle mixers and two unloading augers. Upon completion of the mixing process, the unloading and screw augers are reversibly switched to the unloading stroke, the finished press pulp is unloaded to the conveyor and fed to the dispensing unit, where the pulp is distributed into volume doses and fed into the extrusion press forming chambers. Finished building elements, such as wall panels, are cut with a dividing saw into standard sizes, cooled in natural conditions and stored.

 As can be seen from the data presented, the use of the proposed method and composition for the manufacture of building parts with bearing properties can achieve a significant increase in compressive strength (2.5 times) and improve thermal conductivity. The process of forming the properties of the finished product depends on the method of preparation of the press mass. The properties of the finished product are affected not only by the composition and ratio of components, but also by the degree of its homogeneity. The accuracy of the dosage of the aqueous pulp participating in the reaction of the formation of magnesia cement significantly affects the strength characteristics of the finished product. The ratio of active components in the thickened pulp from the hydrochlorination of serpentenite raw materials also affects the formation of the necessary structure, and as a result, the main characteristics of the finished product.

 The inventive composition and method will allow to realize an easily automated continuous controlled environmentally attractive production of building parts with load-bearing properties, for example, for low-rise housing construction, stable in physical and mechanical properties and geometric dimensions.

Claims (4)

1. A method of manufacturing composite materials, including the preparation of crushed filler, mixing it with crushed sludge of carnallite chlorinators to obtain a press mass, dosing the press mass to form workpieces of parts, their hot pressing to obtain finished products, characterized in that they use as a grinder thickened pulp from hydrochlorination of wastes of the process of processing serpentenite raw materials containing 0.2-0.5 wt.h. solid phase to 1.0 wt.h. the aqueous phase, while the aqueous phase contains 150-350 g / DM ³ magnesium chloride, and the pH is adjusted to 4-10, with the following ratio of the components of the press mass, wt.%:
Ground inert filler - 35 - 40
Ground carnallite chlorinator sludge - 40 - 45
Specified Condensed Pulp - 15 - 25
2. The method according to claim 1, characterized in that the slurry of carnallite chlorinators contains, wt.%: MgCl ₂ - 26-32; MgO - 30-62; CaO - 1.5-2.0; KCl - 12.5-18.0; NaCl - 2.5-3.0; insoluble precipitate - the rest, and grinding is carried out to a dispersion of 0.05-1.0 mm  3. The method according to claim 1, characterized in that as a ground inert filler using a filler of vegetable origin, or waste heat power plants, or polymetallic sludge. 4. Composition for the manufacture of composite materials, including crushed filler and crushed slurry of carnallite chlorinators, characterized in that the condenser is used as a hardener from hydrochlorination of waste from the processing of serpentenite raw materials containing 0.2-0.5 wt.h. solid phase to 1.0 wt.h. the aqueous phase, while the aqueous phase contains 150-350 g / DM ³ magnesium chloride, and the pH is adjusted to 4-10, with the following ratio of the components of the press mass, wt.%:
Ground inert filler - 35 - 40
Ground carnallite chlorinator sludge - 40 - 45
Specified Condensed Pulp - 15 - 25
5. The composition according to claim 4, characterized in that the slurry of carnallite chlorinators contains, wt.%: MgCl ₂ - 26-32; MgO - 30-62; CaO - 1.5-2.0; KCl - 12.5-18.0; NaCl - 2.5-3.0; insoluble precipitate - the rest, with a dispersion of 0.05-1 mm  6. The composition according to claim 4, characterized in that as a ground inert filler using a filler of plant origin, or waste heat power plants, or polymetallic sludge.

Images