SU1449556A1 - Method of producing porous aggregate - Google Patents

Abstract

The invention relates to the production of building materials and, can be used to obtain a porous granular aggregate mainly from waste of thermal power plants and coal preparation. To reduce the bulk density of the aggregate and increase the productivity of the kiln, the drying of the gravel is carried out to an equilibrium moisture content of O - 1.5% at a temperature of 300-350 ° C, and during the firing process the surface of the granules is heated at a speed of 350 - 550 C / min to puff temperatures 1050 - 115 ° C, followed by isothermal exposure for 6-10 minutes. The resulting aggregate is characterized by a bulk density of 250 - 360 kg / m. - The capacity of the rotary kiln C // 2.5x20 m in size with the release of 400 grade gravity brand is 5.7 MV4. 3 tab.

Description

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The invention relates to the production of building materials and to be used to obtain a porous granular aggregate, mainly from waste of thermal power plants and coal enrichment.

The purpose of the invention is to reduce the bulk density and increase the productivity of the furnace.

The method of obtaining the porous filler mainly from waste t | eshloelectric power and coal preparation in | It includes drying the components j, grinding, mixing with additives, drying the moistened mixture, drying the granules and then burning them in a rotary kiln at the temperature of drying, while drying the granules until they are balanced to about 1.5%. at 300–350 C5 a, in the baking process, the heating of the grain of 350 5150 ° C / min is carried out at a temperature of up to 1050 1150 s and a subsequent

Thermal shutter speed 6-10 min.

Example. To obtain a porous aggregate, a mixture of heat and power plant waste — a spur of Varshtynskaya GRES in the amount of 8Q and 20 May L of coal preparation wastes with a binder additive from bentonite clay is used. The amount of injected high elastic additive of bentonite clay is selected from the conditions for obtaining raw granules of required sizes from ZjS to 10 mm.

High "1 the composition of the used raw materials are presented in table. 1, and the grain composition of the slag - in table. 2

The slag of the Burshtynskaya TPP, a liquid-like removal, is a transparent acidic ferrial aluminosilicate glass of a specific composition, characterized by the total content of glass-forming silica, iron aluminum from 85 to 95 masD. The raw material mixture is granulated on a pinned granulator which is fed in an amount of 13 - 17 the masses of water of 3 granules of the torus raw granules are fed to belt dryers, where they are dried to an equilibrium moisture content of O - 1, 5% with flue gases with a temperature of 300-350 ° C. Dry granules are sorted into two fractions of 2.5–5 and 5–10 mm and subjected to intensive heating to reflux temperature.

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1050-1150 ° C, which is provided by the furnace burner. In the firing process, the surface temperature of the granules with an equilibrium moisture content of O - 155% raise from 20 to. 1050 - 1150 ° С with speed. 350 - 550 ° C / min. In this case, a gas-impermeable shell is formed on the surface, a reducing medium is created in the volume of the granules, which leads to gas formation and swelling. Then, the raw granules with a gas-tight shell are subjected to isothermal aging at 1050 - 1150 ° C for 6-10 minutes before the entire material of the granules goes into the pyroplastic state and the completion of the expansion process is complete.

The properties of the resulting filler are presented in Table "3.

The method ensures a decrease in the aggregate density to the level of 250–360 kg / m and an increase in the furnace productivity to 5.7 with the release of 400 grade bulk density.

Heating the surface of raw granules with an equilibrium moisture content of 0-1.5% up to it050-1t50 C at a speed of 350- 550 C / min ensures the formation of a melted gas-tight casing at the very beginning of the heat treatment process. The gas-tight shell seals the pellet from external diffusion of gases and holds the gas phase in the bulk of the pellet. The isothermal holding of the granules for 6–10 min ensures the gradual accumulation of the gas phase and the transfer of the solid part of the granule to the hydrosplastic state from the surface to its center. This allows you to fully use the potential of the raw material mixture to swell with the formation of a uniform-pore structure of the granules and, accordingly, to provide a decrease in bulk density with obtaining a grade of 250,400 at the maximum furnace productivity.

Claims (1)

Formula of Absorption The method of obtaining the porous aggregate is mainly from waste thermal power plant, coal and coal preparation, including raw materials of raw materials 1414495564    --- ™ sH ™ -ZG - :. ™. r-t .,,Table 1 Raw materials, -Content content, wt.% - --- “-. May / About ---..-: -: Ii i4 L 3Ll ° n F ° T oT Slag Burshtyns- -  - 55.7422.2813,820.8 3.33 1.73 0.32 0.7 1.5 Waste coal coal .ga „e„ „,“ PF s ,, 38 36.05,8.036.820.5.2.5, .6, .250. “,. 44, Glina Dashukovskiy locozhene„ e „„ ,, 7.56 ,, 6.4,8,0,0., 6,2.3 0., 4, .6, 0.46   table 2 Content,%. fractions, mm .: -. JlEE .l five Shpak Burshtynskaya GRES1, „   2 22 24 41 five Table 3 Properties Indicators for the method proposed famous Mode of drying raw granules with waste gases from drying the final furnace: the granules are gently dried temperature, ° С300-3Sn  JUU-JDO impact at 1000 ° C residual moisture,% duration, 180-250 Intubation temperature Р У С1050-11501180 The duration of the isothermal peak at the temperature of the bubbling vani, .min The rate of heating the surface of the granules to the temperature of expansion, C / min. The bulk density of the resulting filler, kg / m Productivity of a rotary kiln with a size of 2.5x20 m at the outflow of gravity brand 400 by bulk density, m / h Continuation of table 2 Not normalized, set at random 400-500 LL