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A method for preparing gypsum powder using zinc smelting dirty acid

A zinc smelting and gypsum powder technology, applied in chemical instruments and methods, solid waste removal, calcium/strontium/barium sulfate, etc., can solve the problem of only storage, difficult resource utilization, excessive heavy metal content in gypsum slag, etc. problem, to achieve the effect of improving the effect, improving the economic benefit and benefiting the follow-up utilization

Active Publication Date: 2020-01-07
HENAN YUGUANG ZINC IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, the zinc smelting enterprises mainly use chemical precipitation method, electrocoagulation method, biological preparation method, etc. to deal with dirty acid. Most of the processes need to use limestone (or quicklime, slaked lime) to neutralize the dirty acid to a pH of 7-9. At this time The heavy metal impurities in the sewage acid are hydrolyzed into the neutralization slag, and the resulting neutralization slag, that is, the gypsum slag, is difficult to utilize as a resource because the content of heavy metals exceeds the standard, so it can only be piled up

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  • A method for preparing gypsum powder using zinc smelting dirty acid

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Such as figure 1 Shown, a kind of method utilizing zinc smelting polluted acid to prepare gypsum powder may further comprise the steps:

[0024] Step 1: Increase the concentration of dirty acid: increase the number of cycles of zinc smelting dirty acid to obtain high-concentration dirty acid, the mass fraction of sulfuric acid in the high-concentration dirty acid is 16%, and discharge the high-concentration dirty acid to a thickener for solid-liquid separation , to obtain the supernatant; the zinc smelting dirty acid is the dilute sulfuric acid produced in the purification process in the zinc smelting flue gas acid production process;

[0025] Step 2: Neutralization process: part of the supernatant obtained in step 1 enters the 1# slurry mixing tank to adjust the calcium carbide slag with a solid-to-liquid mass ratio of 1:1.5, and the other part enters the neutralization reaction tank, and the calcium carbide after slurry mixing The slag is continuously added to the ne...

Embodiment 2

[0030] Such as figure 1 Shown, a kind of method utilizing zinc smelting polluted acid to prepare gypsum powder may further comprise the steps:

[0031] Step 1: Increase the concentration of dirty acid: increase the number of cycles of zinc smelting dirty acid to obtain high-concentration dirty acid, the mass fraction of sulfuric acid in the high-concentration dirty acid is 20%, and discharge the high-concentration dirty acid to a thickener for solid-liquid separation , to obtain the supernatant; the zinc smelting dirty acid is the dilute sulfuric acid produced in the purification process in the zinc smelting flue gas acid production process;

[0032] Step 2: Neutralization process: part of the supernatant obtained in step 1 enters the 1# slurry mixing tank to adjust the calcium carbide slag with a solid-to-liquid mass ratio of 1:1.8, and the other part enters the neutralization reaction tank, and the calcium carbide after slurry mixing The slag is continuously added to the ne...

Embodiment 3

[0037] Such as figure 1 Shown, a kind of method utilizing zinc smelting polluted acid to prepare gypsum powder may further comprise the steps:

[0038] Step 1: Increase the concentration of dirty acid: increase the number of cycles of zinc smelting dirty acid to obtain high-concentration dirty acid, the mass fraction of sulfuric acid in the high-concentration dirty acid is 18%, and discharge the high-concentration dirty acid to a thickener for solid-liquid separation , to obtain the supernatant; the zinc smelting dirty acid is the dilute sulfuric acid produced in the purification process in the zinc smelting flue gas acid production process;

[0039] Step 2: Neutralization process: part of the supernatant obtained in step 1 enters the 1# slurry mixing tank to adjust the calcium carbide slag with a solid-to-liquid mass ratio of 1:2, and the other part enters the neutralization reaction tank, and the calcium carbide after slurry mixing The slag is continuously added to the neut...

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Abstract

The invention provides a method for preparing gypsum powder from zinc smelting dirty acid, comprising the following steps: increasing the number of cycles of zinc smelting dirty acid to obtain high-concentration dirty acid, discharging it to a thickener for solid-liquid separation to obtain a supernatant; The slag is slurried, and the supernatant is neutralized until the acidity is 10-20g / L, and the liquid and solid are separated, and the obtained solid is the neutralized slag; the neutralized slag is washed by multi-stage countercurrent, and the liquid and solid are separated, and the obtained solid is dihydrate Gypsum: The obtained dihydrate gypsum is made into α gypsum powder by hydrothermal method or autoclaving method. The invention recycles zinc smelting dirty acid, protects the environment, increases the value of carbide slag, and improves economic benefits; the mass fraction of sulfuric acid in zinc smelting dirty acid is increased to 15% to 20%, which reduces the treatment capacity and equipment investment.

Description

technical field [0001] The invention relates to the technical field of zinc smelting, in particular to a method for preparing gypsum powder by using dirty acid from zinc smelting. Background technique [0002] At present, the production of zinc hydro-smelting has accounted for more than 85% of the world's zinc production, mainly composed of roasting, acid production, leaching, purification, electrolysis, melting and casting and other processes. A large amount of SO will be produced during the roasting of zinc concentrate 2 Flue gas, the flue gas is cooled and dedusted by waste heat boiler, cyclone dust collector and electrostatic precipitator, and then washed by reverse jet high-efficiency scrubber to remove a small amount of soot and SO 2 Gas, and then produce concentrated sulfuric acid through the second-to-two-absorption process. In the purification process, 2% to 4% dilute acid is used to wash and cool the flue gas. The concentration of the dilute acid after washing in...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F11/46B09B3/00
CPCC01F11/466C01P2006/80B09B3/80
Inventor 倪恒发张向阳杨腾蛟孔金换董高峰张富兵
Owner HENAN YUGUANG ZINC IND