Method for preparing white carbon black, coal powder and aluminum hydroxide from fly ash

A technology of fly ash and white carbon black is applied in the field of utilization of fly ash, which can solve the problems of high cost, high energy consumption, and low utilization value of silica, achieve high added value, and solve the effect of accumulation and occupation.

Inactive Publication Date: 2011-03-30
薛彦辉
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the industrial utilization of fly ash is mainly used to prepare aluminum salts, and its technological methods mainly include: 1) extract alumina from fly ash with lime sintering and sodium carbonate dissolution process, the problem that this method exists is: reaction condition It is high temperature and consumes a lot of energy. Only the alumina in the fly ash is extracted, and the utilization value of the silica in the fly ash is low; 2) The soda lime sintering method is used to sinter the fly ash, lime and sodium carbonate at high temperature into soluble sodium aluminate and insoluble calcium silicate, the two are separated to prepare alumina
Every ton of alumina produced will produce 10 tons of calcium-silicon slag. my country's building materials market cannot digest so much calcium-silicon slag, and it will cause accumulation; , directly dissolved by acid leaching, the extraction rate is low (70%), and the amount of residue 30% is large; the acid consumption is large, and neutralization is required, and the cost is high

Method used

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  • Method for preparing white carbon black, coal powder and aluminum hydroxide from fly ash
  • Method for preparing white carbon black, coal powder and aluminum hydroxide from fly ash

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 8 cubic meters of 20% fluosilicic acid and 0.5 cubic meters of 30% sulfuric acid into the reaction kettle, add 1000 kg of fly ash after heating to 80°C, heat and stir to react, and control the reaction temperature at 120°C until the reaction After completion, evaporate to dryness to obtain a solid reaction product. At the same time of the reaction, the gas generated by the reaction is drawn into the absorption tower, and the solid precipitation produced in the sedimentation tank at the bottom of the absorption tower is separated by a centrifuge, and the solid precipitation is washed to a pH value of 3, and the slurry concentration is 10%. Dry the flash dryer to obtain white carbon black; dissolve the solid reaction product in the reactor with 10 times the water of the solid reaction product, centrifuge and separate the solid and liquid, dry the solid part to obtain coal powder, and drip the liquid under stirring Add 20% ammonia water to adjust the pH value to 6 to o...

Embodiment 2

[0022] Add 6 cubic meters of 30% fluosilicic acid and 0.3 cubic meters of 60% sulfuric acid into the reaction kettle, heat to 100°C, add 1,000 kg of fly ash under constant stirring, and slowly raise the temperature to 150°C until the reaction is complete , and evaporated to dryness to obtain a solid reaction product. At the same time of the reaction, the gas generated by the reaction is drawn into the absorption tower, and the solid precipitation produced in the sedimentation tank at the bottom of the absorption tower is separated by a centrifuge, and the solid precipitation is washed to a pH value of 5, and the slurry concentration is 30%. Dry with a flash dryer to obtain white carbon black; dissolve the solid reaction product in the reactor with 7 times the water of the reactant, centrifuge to separate the solid and liquid, dry the solid part to obtain coal powder, and add the liquid dropwise for 25 % ammonia water to adjust the pH value to 8 to obtain aluminum hydroxide pre...

Embodiment 3

[0024] Add 3 cubic meters of fluosilicic acid with a concentration of 45%, 0.2 cubic meters of 98% sulfuric acid, and 1,000 kilograms of fly ash into the reaction kettle, heat and stir the reaction, control the reaction temperature at 180°C until the reaction is completed, and evaporate to dryness to obtain a solid reaction. product. At the same time of the reaction, the gas generated by the reaction is drawn into the absorption tower, and the solid precipitation produced in the sedimentation tank at the bottom of the absorption tower is separated by a centrifuge, and the solid precipitation is washed to a pH value of 6, and the slurry concentration is 40%. Dry the flash dryer to obtain white carbon black; dissolve the solid reaction product in the reaction kettle with 3 times the water of the solid reaction product, centrifuge and separate the solid and liquid, dry the solid part to obtain coal powder, and drip the liquid under stirring Add 30% ammonia water to adjust the pH ...

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Abstract

The invention discloses a process for preparing white carbon blacks with coal ashes, simultaneously provides a process for preparing pulverized coal and aluminium hydroxide with coal ashes, which belongs to the technical field of chemical engineering. Hydrofluosilicic acid and sulphuric acid are used to serve as catalyst and react with coal ashes in an autoclave, by controlling temperature, time and acid-alkali ratio, white carbon blacks, coal ashes and aluminum hydroxide are prepared.

Description

technical field [0001] The invention relates to utilization of fly ash. Background technique [0002] Fly ash is a kind of solid waste discharged from various coal-fired boilers. It is the solid waste left over from coal combustion. It is the main by-product of modern coal-fired power plants and the largest industrial waste. Not only is it a problem of land occupation, its open-air stacking also indirectly affects water resources and the atmospheric environment. The main component of fly ash is rich in SiO 2 and Al 2 o 3 The vitreous body, and contains a small amount of CaO, MgO, Na 2 O, K 2 O and SO 2 etc.; in addition, it also contains Cu, Cr, Ni, Sr, Nb, Ga, Ge and other rare and trace elements. For a long time, my country's use of fly ash is mainly to backfill low-lying land, mines, coal mine subsidence areas and pits in brick factories. At present, the industrial utilization of fly ash is mainly used to prepare aluminum salts, and its technological methods mainl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/12C01F7/02C10L5/48
Inventor 薛彦辉
Owner 薛彦辉
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