Method for preparing arsenic trioxide from arsenic sulfide waste

A technology of arsenic trioxide and arsenic sulfide, applied in chemical instruments and methods, solid waste removal, arsenic compounds, etc., can solve problems such as pollution and endangering people's life and health, and achieve cost reduction, no secondary pollutants, and short process flow Effect

Inactive Publication Date: 2011-07-06
JIANGSU ZHONGKE MACHINERY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] For a long time, most of the arsenic-containing waste residues have been treated by hoarding and storage. With the accumulation of high-concentration arsenic-containing

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] A method for preparing arsenic trioxide from arsenic sulfide waste residue, comprising the following specific steps:

[0021] Step A: Take arsenic sulfide waste residue with arsenic sulfide content of 5%, mix it with water, the water consumption is calculated as 100ml / 100g arsenic sulfide waste residue, after mixing evenly, add sodium hydroxide solution to extract arsenic sulfide, wherein the amount of sodium hydroxide According to 2.0g / g arsenic sulfide, after leaching for 0.5 hours, filter to obtain filtrate 1 and filter residue 1; neutralize the alkali in filtrate 1 with concentrated sulfuric acid to make the pH of the solution 9, and then filter to obtain filtrate 2 and filter residue 1; filter residue 2; filtrate 2 is further neutralized with concentrated sulfuric acid to pH 1, and sodium sulfide is added to make the pH 2, and then filtered to obtain filter residue 3 and filtrate 3; the filter residue is washed and dried to obtain purified arsenic sulfide;

[0022]...

Embodiment 2

[0026] A method for preparing arsenic trioxide from arsenic sulfide waste residue, comprising the following specific steps:

[0027] Step A: Take arsenic sulfide waste residue with arsenic sulfide content of 10%, mix it with water, the water consumption is calculated as 125ml / 100g arsenic sulfide waste residue, after mixing evenly, add sodium hydroxide solution to extract arsenic sulfide, wherein the amount of sodium hydroxide According to 2.5g / g arsenic sulfide, after leaching for 1 hour, filter to obtain filtrate 1 and filter residue 1; neutralize the alkali in filtrate 1 with concentrated sulfuric acid, make the solution pH value 10, and then filter to obtain filtrate 2 and filter residue two; the filtrate two is further neutralized with concentrated sulfuric acid to have a pH value of 2.5, and sodium sulfide is added to make the pH 3, and then filtered to obtain filter residue three and filtrate three; the filter residue is washed and dried to obtain purified arsenic sulfid...

Embodiment 3

[0032] A method for preparing arsenic trioxide from arsenic sulfide waste residue, comprising the following specific steps:

[0033] Step A: Take arsenic sulfide waste residue with arsenic sulfide content of 20%, mix it with water, the water consumption is calculated as 150ml / 100g arsenic sulfide waste residue, after mixing evenly, add sodium hydroxide solution to extract arsenic sulfide, wherein the amount of sodium hydroxide According to 3.5g / g arsenic sulfide, after leaching for 2 hours, filter to obtain filtrate 1 and filter residue 1; neutralize the alkali in filtrate 1 with concentrated sulfuric acid to make the pH of the solution 11, and then filter to obtain filtrate 2 and filter residue 1; Filter residue 2; filtrate 2 is further neutralized with concentrated sulfuric acid to a pH of 3.5, adding sodium sulfide to make the pH 4, and then filtering to obtain filter residue 3 and filtrate 3; the filter residue is washed and dried to obtain purified arsenic sulfide;

[003...

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PUM

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Abstract

The invention provides a method for preparing arsenic trioxide from arsenic sulfide waste. The arsenic sulfide waste is soaked in a sodium hydroxide solution to extract arsenic sulfide, arsenic sulfide mixes with an excessive amount of arsenic acid, and the mixture reacts at a temperature ranging from 40 DEG C to 95 DEG C for 0.5 to 3 hours, to produce a mixture containing arsenous acid and elemental sulfur; the mixture containing arsenous acid and elemental sulfur mixes with 2 to 5 times (by mass) of water and then oxygen gas is introduced so that arsenous acid is oxidized into arsenic acid, and the reaction product is filtered to remove elemental sulfur and thus to produce an arsenic acid solution; and the arsenic acid solution is reduced by sulfur dioxide gas to arsenous acid with a lower solubility, the reaction liquid is distilled under a reduced pressure to produce a saturated solution of arsenous acid, the saturated solution of arsenous acid is cooled so that arsenous acid is crystallized and then filtered to produce a filter cake of arsenous acid, and the filter cake of arsenous acid is dried and pulverized to obtain an arsenic trioxide product. The method has a short process flow, increases the recovery rate of arsenic, avoids the production of secondary pollutants, adopts simple equipment, greatly reduces the cost of arsenic recovery and is worthy to be widely applied.

Description

[0001] technical field [0002] The invention relates to the technical field of comprehensive utilization and treatment of arsenic-containing wastewater, in particular to a method for preparing arsenic trioxide from arsenic sulfide waste residue. Background technique [0003] For a long time, most of the arsenic-containing waste residues have been treated by hoarding and storage. With the accumulation of high-concentration arsenic-containing wastes, the arsenic-containing waste residues have caused soil and river pollution, and the phenomenon of endangering people's life and health has become more and more serious. In order to prevent secondary pollution, it is necessary to treat the arsenic sulfide waste residue. [0004] In particular, after years of mining, arsenic ore resources have been extremely limited. Due to the special use of arsenic in agriculture, electronics, medicine, metallurgy, chemical industry and other fields, it can be used to prepare herbicides, wood pr...

Claims

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Application Information

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IPC IPC(8): C01G28/00B09B3/00
Inventor 马艳荣
Owner JIANGSU ZHONGKE MACHINERY
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