SU730655A1 - Method of light filler production - Google Patents

Description

one

FIELD OF THE INVENTION The invention relates to the building materials industry, and that is. but, to the production of lightweight aggregates, mainly from mineral waste from coal industry.

A known method for the production of aggregates from coal wastes is to conduct an organic binder and a battered shell jtj into the mixture, by which the additive is introduced as a binding agent to granulate the milled waste.

The disadvantage of the method is high heterogeneity of the resulting aggregate due to underburning, low mechanical strength and high bulk density, the material surface is torn, which leads to cement overruns.

There is also known a method for producing aggregates from carbon-containing materials by pre-heat treating the granules in a reducing medium, then in an oxidizing medium and burning

In an oxidizing environment, up to a carbon content of 5% 2J.

The disadvantage of this method is the impossibility of using carbonaceous materials with a high content of carbonaceous substances due to the difficulty of controlling the content of residual carbon, which is necessary for the swelling of the charge, since it is a source of gas release.

ten

The closest to the proposed method is the production of a light-duty grinder (agloporite) from mining waste and coal preparation (mineral oil).

15 coal industry wastes) with a high carbon content (5-35%) by grinding, granulating, preliminary heat treatment in an oxidizing medium at 7OO-1000 ° C for 4 minutes, followed by roasting (sintering). Hydraulic heat treatment guarantees the burning of carbon to a product content of 9.8-10.5%

The resulting aggregate has high strength and density fi,

The purpose of the invention is to intensify the process of carbon burning and increase the swelling of tees.

This is achieved by the fact that in sp (x: both of the production of light zapapnitel from mineral wastes of the coal industry with a carbon content of 5-35%, including grinding of wastes, granulation, preliminary heat treatment in an oxidizing medium at 70 ° C and a subsequent calcination, before granulating it into waste, enter t crystalline sulfates, and the preliminary heat treatment is carried out for 30 -30 minutes to a residual carbon content of 0.01-1.5%; in the firing process, the granules are powdered with a dispersed refractory material.

For coal industry waste, it is characteristic that the carbonaceous substance is highly dispersive and evenly distributed throughout the entire mineral part.

With the introduction of crystalline hydrates, for example, MgeO THrtO in an aqueous solution into the ground mineral waste of the coal industry, the crystalline hydrates adsorb onto the surface and carbonaceous matter. When the granules are heated, the splitting off of the water of the hydrated hydrates (as opposed to physically bound water) under the partial pressure conditions inside the granules is shifted to higher temperatures (up to TOO-UOO C), due to which the duration of the contact of the hydrated crystalline water molecules with the carbonaceous substances increases at high temperatures and leads to intensive oxidation of carbon by reaction C + H "O CO + Nd, + 37 kcal

Thus, the water of sulfate crystalline hydrates acts on carbon as an oxidizing agent; as a result, carbon intensively burns out not only from the surface of the granules, but also from the inside, which leads to a reduction in the carbon burning time.

After the carbon has been burned out, the semi-finished product is further calcined at a temperature of up to .1.35 ° C to expand it. In the roasting process, MgSO2 decomposes to produce gases, which are an additional intumescent agent. Therefore, in the described method, the residual carbon content after burning can be reduced to 0.01%, which makes it easier to control the residual carbon content.

Intense carbon carbon contributes to the early appearance of the liquid phase inside the granules, which, after breaking the crust of the granules, obvakakivat its poverknost and contributes to the addition of granules. To prevent the granules from sticking to each other, the granules are powdered with a particulate refractory material.

The proposed method is carried out

in the following way.

Mineral waste from the coal industry is ground in a shaft or ball mill to a fineness less than 1 mm. In the resulting powder known

crystalline hydrate is introduced in the amount of 2-5% by weight of dry matter (VA, 7H2O), previously dissolved in water, the mixture is brought to molding moisture and granulated on

tape press. The formed pellets of the semi-finished product are dried in a tumble dryer to a moisture content / 1O% and served to burn carbon into a fluidized bed furnace, where the semi-finished product

ZO-9O is kept at 7OO1OOO C. Then the granules are fed for firing into the second rotary kiln, where they are powdered with dispersed refractory material, for example, kaolin.

Example. Idta mine rock with a carbon content of 8, 35%, which is not uncoupled during firing by known methods, bats (1-2-1.31 g / cm) and waste treatment of the Chumakovsk coal preparation plant

Donetsk with a carbon content of 34% (apparent density after firing by the known methods of 1.03 g / cm) is ground in a ball mill before passing through a 1 mm sieve, then granules with the addition of 3% MgSO are formed from powder; H O to the waste of the Chumakovsky factory and 1.5% MgvEf 7H2O + l, 5% Na2, SO -7H O into the Inta mine rock. Freshly formed granules are powdered with kaolin.

After drying to constant weight, the granules are subjected to aging in oKwcnvital medium at 700, 900, 1000 and 1O50s for 30, 6O and 90 min.

for carbon burning. Then the granules are baked at the optimum temperature. (12OO for the Inta breed and 132OC for the waste of the Chumakov factory). For the firing pellets, an apparent

carbon density.

Claims (3)

The technological parameters of the method and the characteristics of the lightweight aggregate are presented in the table. The application of the method intensifies the process of carbon burning and makes it possible to obtain, on the basis of coal mining splits and coal preparation with a carbon content from 8 to 35%, clay with an apparent density of 0.44-0.67 g / cm. what corresponds to bulk density of ZOA-450 kg / m. Claims 1. Method of arbitrariness of lightweight aggregate from mineral wastes of coal industry with a carbon content of 5-35% by grinding granulation wastes, preliminary heat treatment in an oxidizing environment at 7OO-1OOO ° C and subsequent calcination, characterized in that, in order to intensify the process of carbon burning and swelling, before granulation crystalline sulfates are introduced into the dust in the amount of 2–5%, and preliminary heat treatment is carried out for 30–0 min for the residual content leroda O, O11, 5%. 2. The method according to p. 1, about tl and h about (O sh and so that in the process of firing the granules are powdered with dispersed refractory material. Sources of information taken into account in the examination 1. USSR Certificate of the USSR № 461917, cl . С О4 В 31 / 1О,. 2. For the application of the Federal Republic of Germany No. 2315844, cl. С О4 В 21/00, published 1969. 7306558 3. USSR author's certificate No. 548586, class, C O4 B 31/02, 1975 (prototype).