RU2162828C1 - Composition of composite mix for manufacture of building wood-composite materials - Google Patents

Abstract

FIELD: manufacture of building members per wall profile components. SUBSTANCE: composition comprises, wt parts; crushed filler of vegetable origin 100; metallic magnesium production waste as crushed dry slurry, 100-120; coal ash from thermal electric station, 10-20; and water, 50-56. Metallic magnesium production slurry is used as magnesium-containing binder after grinding to attain dispersity of 50-150 mcm without additional preparation operation. Absence of water in slurry makes it possible to regulate binding properties of slurry by certain amount of water during preparation of molding material. Coal ash from thermal electric station includes essentially hollow spherical microspheres with diameter from 30 to 350 mcm with wall thickness from 2 to 10 mcm. Particles are essentially regular spheres having solid nonporous walls in internal cavity of which is field mainly with nitrogen and carbon oxide. Crushed filler of vegetable origin includes sawdust, wood chips, dried annual plants such as straw, neutralized and dried hydrolytic lignin and other wood- processing waste. Invention makes it possible to improve ecological situation using industrial metallic magnesium production waste, improve physico-mechanical properties of final products and reduce energy consumption for manufacturing thereof. EFFECT: improved properties of the composition. 1 tbl

Description

 The invention relates to the production of composite mixtures prepared from crushed plant materials, mainly from wood waste, mineral magnesium-containing binders, and can be used for the manufacture of construction and heat and sound insulation materials.

 Known raw mix for the manufacture of building products. 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 N 2062763, C 04 B 28/30, 1996).

 The resulting products are characterized by high porosity at a high specific gravity, high moisture absorption, high thermal conductivity.

 A raw mixture is also known from which mineral binder building parts can be obtained using technogenic waste from burning coal, wt.% (On dry matter): lime-boiling water 20-30; alkali or alkaline earth metal chloride 0.6 - 1.0; gypsum 3 - 5; surfactant additive 0.05 - 0.15; coal ash - the rest (RF patent N 1837053, IPC 5 C 04 B 7/28, 1993).

 Known raw mix has a limited scope and can only be used as a cement binder. Using a known mixture for the manufacture of building elements seems unrealistic, because the resulting elements will have an extremely high density with low thermal insulation properties.

 Closest to the proposed one is the composition of the raw material mixture used in the method of manufacturing sets of building parts, containing crushed filler of plant origin - calibrated wood chips, sawdust, annual plants, extracts from tannic extracts, mineral binder - magnesite caustic powder, calcined magnesium ores, magnesium mixture - and calcium-containing ores, the substitute is a brine of magnesium chloride.

 The known composition does not provide uniform impregnation of crushed wood raw material mineralizer. When changing the composition of the composition, the known method has limited technological capabilities associated with the need to maintain a certain amount of the ratio of the aqueous phase and the mineral binder. The resulting products - building parts have a fairly high thermal conductivity, which, with stringent requirements of energy saving, limits the scope or require additional techniques to improve the thermal conductivity.

 The objective of the invention is the improvement of strength indicators and thermal conductivity of finished building parts while improving the environmental situation through the use of large-capacity industrial waste.

 The problem is solved by the fact that in the inventive composition for the manufacture of building parts use shredded waste of plant origin, as a mineral magnesium-containing binder use pre-shredded dry slurry for the production of metallic magnesium by electrolytic method, water and optionally coal ash of a thermal power plant in the following ratio of components, in terms of absolutely dry filler of plant origin, wt.h: crushed filler of plant origin ozhdeniya 100, waste production of magnesium metal by electrolysis in the form of dry milled slurry 100-120, coal ash CHP 10-20 water 50-56.

 As a shredded filler of plant origin, wood sawdust, wood shavings, dried annual plants, for example in the form of straw, neutralized and dried hydrolysis lignin, and other known wood processing waste products are used.

As a magnesium binder, crushed slurries of magnesium production are used, which are formed in chlorinators at the dehydration stage during the processing of carnallite by an electrolytic method. The resulting sludge from chlorinators enters the dumps in the form of a monolithic piece - blocks and contains,%: MgCl ₂ - 28-32; MgO - 30-35; CaO - 1.5-2.0; KCl - 12.5-18.0, NaCl - 2.5-3.0; the insoluble precipitate - 2.7 - contains FeO up to 13%, Al ₂ O ₃ up to 30%, SiO ₂ up to 57%. The slurry of magnesium production before introducing into the composition of the raw material mixture is crushed by known methods to a dispersion of 50-150 microns. After grinding, the sludge becomes suitable for use as a binder without additional preparation. The practical absence of water in the sludge allows you to adjust its astringent properties by a certain dosage of water during the preparation of the press mass and thereby obtain the final material with predetermined properties. As our studies have shown, magnesium sludge in magnesium sludge production has a high degree of activity, which ensures its high astringent properties that are not lost after grinding.

The coal ash of a thermal power plant is a hollow spherical microsphere particles with a diameter of 30 to 350 microns with a wall thickness of 2 to 10 microns. Particles are regular spheres with continuous non-porous walls, the inner cavity of which is filled mainly with nitrogen and carbon monoxide. The chemical composition of the shell of such particles,%: SiO ₂ - 50-60, Al ₂ O ₃ - 25-35, Fe ₂ O ₃ - 1.8-2.0, Ca0 - 1-5, MgO - 0.5-1 5, Na ₂ O - 0.3-1.5, K ₂ O - 0.2-2.9.

A comparative analysis of the proposed composition for the manufacture of building parts with the known ones allows us to conclude that the proposed solution is new, because a new form is proposed in which a magnesium-containing binder is embodied - ground dry sludge from the production of metallic magnesium with a certain ratio of its active components, a departure from burning coal in the form of ash containing hollow spherical particles filled with H ₂ and CO. Using the proposed composition allows you to achieve an unobvious result - a significant improvement in thermal conductivity, a decrease in the density of finished products while maintaining and even increasing their strength. All of the above allows us to conclude that the proposed solutions meet the criteria of "novelty" and "inventive step".

 The proposed composition for the manufacture of building products can be obtained from industry-known waste wood processing plants, hydrolysis plants, the production of magnesium metal from carnallite by the electrolytic method, waste from the burning of coal formed at the thermal power plant. The waste used is uniquely identified by specialists in these industries. The use of the inventive composition to obtain building parts can be implemented on standard commercially available equipment using well-known techniques for their configuration. All of the above allows us to conclude that the proposed solution meets the criterion of "industrial applicability".

 The proposed composition is used as follows.

The components of the mixture of the press mass are prepared as follows. The crushed filler of vegetable origin is dried in a combination dryer to stabilize (averaging) the content of the aqueous phase to a predetermined moisture content and is fed into a screw reactor-mixer to obtain a press mass. The slurry of the production of metallic magnesium in the form of a block is crushed by known methods, for example, crushing with subsequent grinding to achieve a dispersion of 50-150 microns. The crushed sludge is examined for the content of the active components MgCl ₂ and MgO and is used as a magnesium binder. In the mixing reactor, the filler of plant origin is mixed first with the calculated amount of water for 1-2 minutes, and then the claimed amount of mineral binder is introduced 100-120% by weight of the absolutely dry filler of plant origin, the resulting press mass is mixed for 1-2 minutes and enter coal ash CHP in the amount of 10-20% by weight of absolutely dry filler. These ingredients of the press mass are used in the composition in the following ratio of components (in terms of absolutely dry filler), wt. h: crushed filler of vegetable origin 100, the waste product of the production of metallic magnesium by electrolytic method in the form of crushed dry sludge 100-120, coal ash TPP 10-20, water 50-56.

 A building part is made from a calculated dose of the press by pressing in an extrusion press. The process of forming finished products can be divided into the following stages: the start of heating, in which the process proceeds with intensive vaporization and the rapid spread of heat inside the workpiece section, the process of formation of magnesia cements begins; stabilization of heating, in which the rate of heat penetration into the product decreases sharply, the mineral binder is recrystallized depending on the moisture content and temperature at each point in the process of formation of cement stone; completion of the product formation process, at which the 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.

 Shredded wood waste (sawdust or calibrated wood chips or hydrolytic lignin or other known material) is fed to a combination dryer, the material is dried to a predetermined humidity, relative humidity is determined and fed through a discharge device to a filler hopper. Upon reaching the specified mass of dried material, the filler hopper through the ACS block receives a command to turn off the combined dryer, to empty the filler hopper into the loading hatch of the reactor-mixer. In the reactor-mixer serves 100 wt.h. filler in terms of absolutely dry material, include rotary drives of bladed shafts and unloading-auger screws of the reactor-mixer. The calculated amount of water is supplied to the mixer reactor until the water content reaches 56, 54 and 50 parts by weight. (examples 1-3 of the table, respectively) and include the drive of the mixing mechanism, after which a mineral binder in the amount of 100, 110 and 120 parts by weight is fed from the hopper-metering device of crushed sludge at the command of the ACS block by a screw feeder. (examples 1-3 tables, respectively). From a coal ash dosing hopper, 10, 15, 20 wt. h (examples 1-3 table). In the mixing reactor, the components of the press are mixed with two paddle mixers and two unloading augers. At the end of the mixing process, the unloading and screw augers reversibly switch to the unloading stroke, unload the finished press pulp onto the conveyor and feed it to the dispensing unit, where the press pulp is distributed into volumetric doses and fed to the extrusion press forming chambers. Finished building elements, such as building wood-composite materials, are cut with a dividing saw into types - sizes, cooled in natural conditions and stored.

 As can be seen from the data presented in the table, the use of the inventive composition for the manufacture of building parts can achieve a significant increase in compressive strength (2.0-2.5 times) and improve thermal conductivity by at least 2.5 times.

 The ratio of the active components of the slurry of magnesium production affects the formation of the necessary structure and, as a result, the main characteristics of the finished product. When using crushed sludge of magnesium production, the astringent properties of the mineral component increase in comparison with the traditionally used mixture of caustic magnesite and magnesium chloride brine, which, in our opinion, can be explained by an increase in the share of active magnesium oxide. Improving the astringent properties of the mineral component allows to increase the share of the filler of vegetable origin and to provide the possibility of introducing coal ash in the claimed amount and, as a result, reduce the thermal conductivity of the finished product. The absence of water in the crushed sludge of magnesium production allows to widely control astringent properties by a certain dosage of water at a certain stage of mixing the components.

 The inventive composition will allow for the implementation of easily automated continuous controlled production of building parts, for example, for low-rise housing construction, stable in physical and mechanical properties and geometric dimensions.

Claims (1)

Composition for the manufacture of pressed building parts, including crushed filler of vegetable origin, mineral magnesium-containing binder and water, characterized in that as a mineral magnesium-containing binder, waste metal is used for the production of metallic magnesium from carnallite in the form of crushed dry sludge and, in addition, production waste from burning coal in the form of coal ash CHP in the following ratio of components in terms of absolutely dry filler, parts by weight:
Ground vegetable filler - 100
Waste from the production of metallic magnesium by electrolysis in the form of crushed dry sludge - 100 - 120
Coal ash CHP - 10 - 20
Water - 50 - 56

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