SU1625847A1 - Method for preparing lightweight aggregate - Google Patents

Description

The invention relates to the production of building materials and can be used in the manufacture of lightweight aggregate calcined in a rotary kiln, in particular, expanded clay, ash gravel, shuntizite.

The purpose of the invention is to reduce the filler density and improve working conditions.

The method of producing a lightweight filler involves mixing and granulating the dusting powder with a binder and then feeding the powder granules into the burning zone of the rotary kiln, the opurifying powder from the synthetic rubber divinyl production waste mixing with the alkaline caprolactam production drain in an amount of 30-35% by weight, and the obtained granules of the dusting agent are pre-thermoathed for 20-30 minutes at 150-200 ° C.

Example. As a dusting threshold used waste production of divinyl IM-2201.

The chemical composition of the waste is given in the table. Characteristics of alkaline runoff SCHS11K and used clay - in Table. 2 and 3.

Divine production waste is mixed in a forced-action mixer, for example, a closed screw mixer, with an alkaline caprolactam production drain and fed to the pellet-torus (dish-shaped, drum, auger. Press, drying drum). At okom & Yu SL

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forging in a drum-type grabber or drying drum they are supplied with heat carrier with a temperature of 150–200 ° C. During pelletizing on a plate granulator or press, the resulting lumpy material is subjected to subsequent heat treatment at 150–200 ° C for 20–30 min in a tumble dryer.

After heat treatment, the pelleted powdered material is fed into the rotary kiln directly to the burning zone by known devices or from the cold end of the kiln together with the granules in the quantity required for their dusting. When powdering material is fed into the burning zone, the lumps are quickly destroyed into powder as a result of the high content of organic substances in caprolactam production in alkaline drains. At the same time, due to the content of sodium salts of mono-dicarboxylic acids in alkaline drains of caprolactam production, a reducing medium is created in the layer of baking granules, contributing to the increase in their swelling.

Indicators of the firing process and the properties of the filler obtained from clay are given in table. four.

The method provides a lightweight aggregate with a density in a piece of 0.4 L - 0.47 g / cm, a compressive strength of 0.9-0.97 MPa, with no toxic substances in the exhaust gases of the rotary kiln, which provides improved working conditions staff.

A heat treatment temperature of 150–200 ° C affects the completeness of the reduction of Cr6464 contained in the waste product of divinyl, in Cr due to the strong reducing ability of the sodium salts of mono- and dicarboxylic acids contained in the alkaline drain, and the retention of the strength of the pelletized powder.

Mixing waste production of divinyl for synthetic rubber with

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30 - 35 / J by weight with an alkaline drain of caprolactam production provides the connection of fine particles of waste production of divinyl for synthetic rubber due to the binding capacity of resinous substances contained in the alkaline drain of caprolactam production in the amount of 5-7 wt.%,

jg which reduces conversion during subsequent operations of the technological process and provides ease of transport and storage. Content in alkaline production flow

When caprolactam is consumed, significant amounts of sodium salts of mono- and dicarboxylic acids, when burned out, cause intense destruction of the pelletized divinyl production waste for the synthetic rubber to a powdery state in the firing process in the rotary kiln of the aggregate granules. In addition, these salts decarboxylate with the formation of heat.

The use of soda Na2C03, which with a further increase in temperature, decomposes with the release of carbon dioxide, which creates a reducing environment in the intergranular space of the burning granules of the aggregate, which favorably affects the decrease in the density of the aggregate.

Claims (1)

Invention Formula Method for the production of lightweight aggregate by granulating the dusting powder with a binder and feeding the powder granules into the burning zone rotary kiln, characterized in that, in order to reduce the density of the aggregate and improve working conditions, the opulent powder from the waste production of divinyl for synthetic rubber is granulated with an alkaline caprolactam production effluent, taken in an amount of 30-35 wt.%, and the resulting granules before serving in the oven thermoablative during 50 20-30 minutes at a temperature of 150-200 C. i The content of oxides, Z SiOz T A170, T Feoeu; I FeO Cr40, F CaOMgO I Ti04 G SO, | R20 j n.n.n. 8.073.140.44 -14.02 0.961.25-0.33 1.10. 0.76 Table 1 Characteristics of caprolactam production runoff Appearance Mass dol,% sodium salts of mono- and dincarboxylic acids (in terms of sodium adapate) Cyclohexanol Cyclohexanone Resins solution pH Density at 20 C, g / cm3 A1.0, Tio. Gay Oxide content, X FeO Re, 0 $ Sa 59.13 16.43 0.7 / 6.5 3.4 Indicators for composition J 2J con thirty 32.5 150 175 thirty 25 Table 2 Indicators Liquid from brown to dark brown, opaque, without mechanical impurities 27.8 0.3 0.2 10.0 ten 1.1 Table 3 X Cao MgO SO. I scientifically I substances . 2.8 1.6 1.54 4.17 6.020.98 R, 0 OrganizedTable4 to control famous 35 Without alkaline drain 200 0.97 0.90 0.93 No toxic gases Continuation of table 4 0.93 Dusty particles of IM-2201 with hexavalent chromium oxide