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Method for leaching selenium in acid mud by using sodium sulfite

A technology of sodium sulfite and acid sludge, applied in the direction of element selenium/tellurium, can solve the problems of long process flow, high cost, difficult recovery of waste acid and waste liquid, etc., and achieve the effect of short process flow, low cost and good selectivity.

Active Publication Date: 2012-07-18
KUNMING METALLURGY INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Not only the process is long, the cost is high, and the waste acid and liquid are difficult to recycle

Method used

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  • Method for leaching selenium in acid mud by using sodium sulfite
  • Method for leaching selenium in acid mud by using sodium sulfite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Example 1. The selenium content in the acid mud is 13.50%, the iron content is 5.40%, the zinc content is 28.45%, the lead content is 18.42%, and the silver content is 2.50%. This acid mud is used as a raw material for high temperature and pressure leaching.

[0013] Mix the acid mud with industrial water and put it into the mixing tank for water washing. Control the liquid-solid ratio to 5:1, the temperature is 50-55°C, the reaction time is 0.5h and then filtered, repeat this process 3 times until the acid mud reaches neutrality. The filtrate is discharged after neutralization and purification, and the neutral acid mud enters the high temperature and pressure leaching process. Mix the obtained neutral acid mud with sodium sulfite and industrial water, put it into an autoclave, and blow nitrogen into it. The liquid-solid ratio is controlled at 3:1, the concentration of sodium sulfite is 180g / L, the temperature is 120-125°C, the reaction time is 1.5h, and the pressure i...

Embodiment 2

[0014] Example 2. The selenium content in the acid mud is 14.70%, 4.40% iron, 30.45% zinc, 19.40% lead, and 3.20% silver. This acid mud is used as raw material for high temperature and pressure leaching.

[0015] Mix the acid mud with industrial water and put it into the mixing tank for water washing. Control the liquid-solid ratio to 5:1, the temperature is 55-60°C, the reaction time is 1.0h, and then filter, repeat this process 3 times until the acid mud reaches neutrality. The filtrate is discharged after neutralization and purification, and the neutral acid mud enters the high temperature and pressure leaching process. Mix the obtained neutral acid mud with sodium sulfite and industrial water, put it into an autoclave, and blow nitrogen into it. The liquid-solid ratio is controlled at 4:1, the concentration of sodium sulfite is 190g / L, the temperature is 130-135°C, the reaction time is 2.0h, and the pressure is 0.6MPa. After the reaction is finished, the pressure is lowe...

Embodiment 3

[0016] Embodiment 3, the content of selenium in acid mud is 15.20%, iron 4.60%, zinc 31.40%, lead 19.48%, silver 3.60%. This acid mud is used as raw material for high temperature and pressure leaching.

[0017] Mix the acid mud with industrial water and put it into the mixing tank for water washing. Control the liquid-solid ratio to 5:1, the temperature is 60-65°C, the reaction time is 1.5h, and then filter. Repeat this process 3 times until the acid mud reaches neutrality. The filtrate is discharged after neutralization and purification, and the neutral acid mud enters the high temperature and pressure leaching process. Mix the obtained neutral acid mud with sodium sulfite and industrial water, put it into an autoclave, and blow nitrogen into it. The liquid-solid ratio is controlled at 5:1, the concentration of sodium sulfite is 210g / L, the temperature is 135-140°C, the reaction time is 2.0h, and the pressure is 0.7MPa. After the reaction is finished, the pressure is lower...

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Abstract

The invention discloses a method for leaching selenium in acid mud by using sodium sulfite. The method comprises the following steps: selenium-containing acid mud and industrial water are mixed into pulp, and the pulp is put into a stirring groove for water washing till the acid mud is neutral; the neutral acid mud is mixed with the sodium sulfite and the industrial water into pulp, the pulp is put into a high-pressure reactor, nitrogen is introduced for reaction, the pressure and the temperature are reduced after the reaction is finished, the material is taken out and filtered, and the filtrate is sodium selenate solution; the sodium selenate solution is put into an acidizing groove, and sulfuric acid is added under the stirring condition; after the acidification is finished, temperature rise is started, the mixture is continuously stirred and then filtered, and the filter residue is selenium powder with the content of more than or equal to 97.0%; the selenium is leached by using the industrial sodium sulfite in the process of extracting the selenium in the acid mud, and the leached selenium is acidized to obtain the selenium powder with the content of more than or equal to 97.0%; and sodium sulfate produced in the technical process is effectively recycled by a distillation and crystallization method. The method has the characteristics of low cost, easiness in industrialization and low-carbon environmental protection.

Description

technical field [0001] The invention relates to a wet smelting method in which selenium is selectively leached with industrial sodium sulfite from acid mud containing impurities such as selenium, zinc, lead and iron, and the leaching solution is further acidified to obtain selenium powder with higher purity. Background technique [0002] After the selenium-containing zinc sulfide concentrate is roasted, during the process of preparing sulfuric acid from its flue gas, most of the selenium enters the acid mud in the elemental state. The main impurities in the obtained acid mud are zinc, lead, iron and silver. At present, the extraction process of selenium in this kind of acid mud mainly adopts the method of sodium roasting, water immersion and hydrazine hydrate reduction, or the method of reduction after chlorination leaching. Not only the process is long, the cost is high, and the waste acid and waste liquid are difficult to recycle. Moreover, the obtained selenium powder h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B19/02
Inventor 和晓才李怀仁谢刚徐庆鑫陈家辉李俊
Owner KUNMING METALLURGY INST
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