LV10706B - Moulding sand for manufacturing building blocks - Google Patents

Abstract

This invention is intended for use in the construction of buildings. The offered mixture of raw materials, containing a binding agent, wood chips, sand, and water, is characterized by the use of shale ash and clay as the binding agent in proportions from 0.44 to 2.6% mass. The mass proportions of the components of the mixture are the following:clay - 12.1/37.0;shale ash - 13.8/42.2;wood chips - 6.8/19.5;sand - 1.9/28.4;and water - the rest.Through the use of this recommended mixture, a fast-hardening and non-rigid composition is obtained for production of wall blocks with sufficient -heat isolation; and wood chips of any sort of wood (including wood processing waste) may be used for this purpose as well as a cheap binding agent.

Description

Description

The invention relates to industrial building materials and can be used for making wall blocks.

The use of soft waste (shavings) is known in the cement industry, but materials such as concrete and gypsum have a common drawback - raw materials (cement, gypsum, lime ...) are scarce and expensive. In addition, when using cement, wood chips must be heat treated and sorted, as the chemical composition of the wood contains sugar, which neutralizes the adhesion of the cement to the chips, which has resulted in a rapid decline in material strength. This results in wasted cement consumption, wasted heat treatment, wasted labor and unnecessary use of expensive chemicals. All this adds up to the cost of concrete as a cement binder. For example, a mixture of arbolite raw materials (USSR Circ. 1708793; CO4B28 / 04, 1987) includes Portland cement, wood waste and shale ash, uses simple technology to produce, but contains 50% deficient and expensive material.

The known composition for the production of insulating material, which includes wood waste as a filler (USSR circ. 130692; C04B 28/30, 16/02, 1987), also contains a defective material, a magnesium binder, which requires high energy consumption for the manufacture of articles thereof. .

The reasons that hinder the achievement of the required technical result by the use of lime compositions for the manufacture of wall blocks are characterized by the fact that the wood filler requires appropriate treatment. As a result, production costs increase. For example, an arbolite-making mixture (USSR aut. App. 1204597; C04B18 / 26, 28/02, 1986) containing pine wood chips with a fraction of 2-15 mm is treated with lime paste, but as a binder is used besolite, which there is also a deficit. In the production of arbolite, particle treatment can be carried out with aerated water in a yeast suspension together with a grain slurry (USSR Circ. 1204597; C04B16 / 02, 1989).

Also known is a mixture of raw materials for the production of building materials containing silica, sand, expanded clay, lime, wood chips and sulfate yeast fiber (USSR aut. 1174402, CO4B14 / 02, 1985), which at low density (800-1000 kg / ιτιθ) and strength (9-10 MPa) require high material intensity and high energy consumption.

The closest to the subject matter according to the invention is the known mixture of raw materials for the production of thermal insulation material (USSR aut. App. 1368291, CO4B26 / 26, 38/00, 1986), containing expanded perlite sand, clay slurry (clay diluted with hot water heated to 70 ° -80 ° C; 1: 1.5 ratio), bituminous binders (bituminous waste from roofing materials diluted with water at ⁰ to 16-25 ° C) at the following component ratio, by weight:

exfoliated perlite sand - 60-65, clay - 7-8, sulfate yeast fiber and carboxylmethyl cellulose - 2-3, roofing bituminous waste - 25-30.

The reasons that hinder the necessary technical result by using a mixture of known raw materials are the defective material used and the energy intensity of the production (mainly due to the heat treatment of the components).

OBJECTIVE OF THE INVENTION: To provide efficient wall materials at low cost using inexpensive and affordable raw materials that do not require special processing and low energy consumption to produce them.

The technical-economic result of the invention translates into a binder economy by reducing the thermal conductivity of the material and increasing the amount of waste from woodworking plants and thermal power plants.

SUMMARY OF THE INVENTION: In a mixture of raw materials for making a wall block containing binder, sand and water, wood chips are additionally introduced and ash binder and clay are used as binder in a ratio of 0.44 to 2.6 with the following components by weight ratio:

clays 12.1-37.0;

shale ash - 13.8-42.2;

wood chips - 6.8-19.5;

sand 1.9-28.4;

water - the rest.

As the proposed binder does not contain cement, the chips do not need to be heat treated, as the sugar contained in the wood counteracts the adhesion of the binder to the wood chips and reduces the strength of the material.

Analysis of the state of the art, including the scientific-technical literature and patents on the inventions disclosed above, show that no analogous solution to the foregoing and included in the formula of this invention has been found. Consequently, the present invention satisfies the requirement of novelty under existing law.

In order to evaluate the level of the invention (step), an additional test was performed to evaluate the presence of features other than the prototype in other known technical solutions. The results of the analysis showed that the proposed mixture for the production of wall blocks contains only significantly different characteristics to achieve the technical result.

Any wood species of any species and any freshness (up to 5% of the total amount of chips) obtained by sawing the wood can be used in the proposed mixture.

Chips that comply with GOST 18320 - 78 may be used:

bulk density - 170 - 220 kg / m ³ ;

moisture - 1-4 to 30%;

fine fraction (up to 0.5 mm) - 8 4-11%;

bark - 1-4 - 4%, and shale ash, which corresponds to GOST 25318 - 83, whereby the fineness of grinding should be not less than 2000 cm2 / g. For example, shale ash from the Baltic TEC or the Estonian TEC can be used, the chemical composition of which is: S1O2 25.2%; CaO = 43.0%; FeO - 5.0%; Al2O3 - 5.6%; MgO - 5.0%; ТЮ2 - 1.0%; K 2 O - 0.7%; SO3 - 5.0%, other components - 7.0%. The amount of harmful substances in this ash content is much lower than the allowable limit according to GOST 12.1.005-88.

For the purpose of the invention, crude clay from the quarry 'Lode (other clay with identical properties) and water conforming to GOST 23732-79 may be used.

The mixture is formed by a vibropressing technique at a vibration amplitude of 0.7 - 0.9 mm and a vertical pressure of 1.3 - 3.0 MPa until a homogeneous mixture is formed without air pores. Molding may also be performed by pneumatic mechanisms having the same operating characteristics.

By using a complex binder (shale ash and clay), no cement is used in the mixture with the filler - wood shavings, which reduces the cost of the material already rapidly, eliminating the need to use a scarce and expensive binder and simplifying production.

The requirement of a water / (sand + shale ash 4-clay) ratio of (0.21 4- 0.65)% by weight in the claimed invention ensures the production of articles having the same strength as the wall materials (2.0 4- 3, 5) MPa at low thermal conductivity (0.2 4- 0.4) W / m ° C over a wide range of mixtures.

In industrial conditions, component dosing can be done by volume rather than by volume, as it reduces labor, material and production time, which rapidly reduces the cost of production. It is possible to use traditional additives - curing accelerators, air uptake and hydrophobising additives - which slightly improve the material properties but drastically increase the production cost.

The obtained wall block samples were tested according to GOST 7025 - 78 Wall and finishing materials. Water absorption and frost resistance tests were performed according to GOST 8462 - 85 Wall materials. Methods for determining strength.

Table 1 shows compositions containing components within the ranges indicated in the invention formula (compositions 5 4-12) as well as several compositions containing components outside the stated limits (compositions 1-4 and 13 4-15), in addition to composition (17). ) has been used as a prototype (USSR aut. app. 1368291; C04B26 / 26, 38/00, 1986).

As can be seen from the table, the use of sand of less than 1.9 wt% (composition 2) does not change the material properties in the wrong direction, but the addition of sand more than 28.4 wt% (composition 14) leads to an increase in density of 1400 kg / m ³ 1340 kg / m ³ (12th composition). Using sand reduces the mixing time of the mixture, which reduces the cost of producing the product. Shale ash to clay ratio of 0.44 to 2.60% by weight encourages the production of such compositions (compositions 5-12) or wall materials with strength (2-3.5) MPa at material density (1100-1930) kg / m ³ corresponding to concrete grade M-35.

As can be seen from the table, the properties of the material can vary over a very wide range. The use of less than 12.1% by weight of clay leads to an insufficient overlap of clay in the chip mixture, which makes the composition unprofitable (high consumption of defective products). If the clay is added at more than 37% by weight (composition 16-38.4% by weight), the composition loses its deformation properties (reduction in compaction ratio) due to the fact that the chips do not perform their function. The product remains ductile (it forms, but does not resist pressing), and the thermal conductivity of the material increases. The optimum consumption of the chips is in the range (6.8-19.5% by weight). High consumption of chips (24.0 wt%, composition 15) at the ratio: shale ash / clay = 0.43 wt% leads to a decrease in the strength of the articles.

Thus, using a complex binder (shale ash + clay), mixed with wood chips and sand, it is possible to obtain from a low stiffness (refractive index 0.16 - 0.30) structural wall material with a wide range of material properties. (0.3-0.5 W / m ° C depending on the composition of the mixture. The resulting material is ecologically clean and provides a feeling of increased comfort in the room. According to thermal characteristics, the proposed 40 cm block can replace a brick wall 51 cm thick. reducing the cost of the building 2-3 times.

Exemplary embodiment of the invention. To make blocks of the proposed mixture, take 154 kg of clay (23.8% by weight), mix them in a forced mixer no. 1 with 150 kg of water (23.7% by weight) until a creamy mass is formed (in addition, the clay can be taken directly from the quarry without any special treatment). Then pour only cream-free clay mixture without stones, clay and parcels, total forced mixer no. 2 Pour 100 kg of sawdust from the sawmill (22.3% by weight of any freshness and any species of wood in the uncompressed state), add the mass of creamy clay concentrate and mix well until the chips are overlapped and partially absorbed. The mixing time depends on the mixer and is approximately 3 min. The resulting mixture is filled with 143 kg sand (22.1 wt%) and 100 kg (15.5 wt%) shale ash and stir until a uniform dark brown mass is obtained after staining. The mixture should be bulk, similar to freshly dug earth. The duration of mixing depends on the mixer parameters. It's 3 min.

The resulting mixture is poured into a mold and subjected to vibration for ~ 1 min. Subsequently, while maintaining vibration, the mixture is pressurized to 2 MPa until a homogeneous mixture without air pores is formed. The reversible deformation of the pressurized mixture must be minimal (compaction factor Ky = 2.5).

Effective compaction can also be accomplished by pneumatic mechanisms and other arbolite compaction techniques. The process is important because it affects the strength of the material. After a thorough compaction of the mixture, the stripping is carried out immediately.

The final product can be dried using a natural drying process, drying at a temperature of 15 4-20 ° C and a humidity of 75 4-85% for 28 days. The compressive strength of the products corresponds to the concrete grade M-35. Blocks can also be dried at slightly lower temperatures, but will increase their drying time.

After 14 days the blocks can be transported and used in construction according to the technical regulations.

Thus, the use of the proposed mixture for the production of wall blocks at the indicated component ratios enables the preparation of fast-curing non-rigid mixtures for wall blocks from woodworking wastes from sawing of any kind of wood and shale ash, which is a waste from thermal power plants.

It is advisable to produce wall blocks from the offered raw material mix near wood processing plants or thermal power plants, which allows reducing the cost price of products even further at the expense of transport costs.

The fabricated wall blocks from the offered blend of raw materials can serve as a constructive thermal insulation wall material, which at the same time reduces industrial costs due to:

- to exclude particleboard processing operations;

- simple technology application;

- use of cheap and scarce raw materials;

- minimum energy, thermal and labor consumption;

- no use of chemicals and other additives;

- a simple manufacturing process and the use of simple equipment.

Thus, the invention is industrially applicable.

Claims (1)

Formula of the Invention A mixture of raw materials for making a wall block containing sand, water and binder is characterized in that the binder used is shale ash and clay, based on the weight ratio of components in the mixture, as follows: clay shale ash wood chips sand water 0.44 to 2.6, the mixture contains wood chips with 12.1 4-37.0; 13.8 4-42.2; 6.8 4-19.5; 1.9 4-28.4; the rest of.