CN102115165A

CN102115165A - A method for preparing arsenic trioxide from arsenic-containing wastewater

Info

Publication number: CN102115165A
Application number: CN 201010615442
Authority: CN
Inventors: 马艳荣
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-31
Filing date: 2010-12-31
Publication date: 2011-07-06

Abstract

A method for preparing arsenic trioxide by using arsenic sulfide waste residue comprises mixing arsenic sulfide waste residue with water, and leaching arsenic sulfide with sodium hydroxide solution; mixing the obtained arsenic sulfide and water with the mass of 2-5 times to form slurry, and reacting the slurry with a copper sulfate solution to obtain a precipitate containing arsenous acid and copper sulfide and a sulfuric acid solution; mixing the precipitate containing arsenous acid and copper sulfide with water, introducing oxygen to oxidize arsenous acid to generate water-soluble arsenic acid, and filtering to obtain arsenic acid solution and copper sulfide precipitate; reducing the obtained arsenic acid into arsenous acid by using sulfur dioxide to obtain arsenous acid; distilling arsenous acid, concentrating, filtering and drying to obtain the arsenic trioxide product. The method has the advantages of short process flow, high arsenic recovery rate, no secondary pollutant generation, simple equipment and capability of greatly reducing the arsenic recovery cost, and is a method worthy of popularization and application.

Description

A kind of method for preparing white arsenic with arsenic-containing waste water

Technical field

The present invention relates to the comprehensive utilization and the processing technology field of arsenic-containing waste water, particularly, relates to a kind of method for preparing white arsenic with arsenic-containing waste water.

Background technology

For a long time, arsenic-containing waste residue adopts the method for hoarding storage to handle mostly, and along with the accumulation of high density arsenic-containing waste is more and more, arsenic-containing waste residue has caused soil, stream pollution, and the phenomenon of harm people life health is more and more serious.For preventing secondary pollution, must handle the red arsenic waste residue.

Especially, experience exploitation for many years, the arsenic minerals resource is extremely limited.Since arsenic in the special purpose in fields such as agricultural, electronics, medicine, metallurgy, chemical industry, can be used for producing weedicide, wood preservative, glass clarifying discoloring agent, non-ferrous metal alloy, pottery etc.; especially photoelectron and microelectronic are to the demand of arsenic; therefore; reclaiming the demand that arsenic is not only environment protection from arsenic-containing waste residue, also is the needs of national sustained economic development.

Summary of the invention

For this reason, the applicant provides a kind of and has prepared the method for white arsenic with the red arsenic waste residue, and this method is simple to operate, and facility investment is few, and arsenic recovery utilization rate height is worthy of popularization.

In the red arsenic waste residue, contained arsenic mainly is arsenic trisulfide, and it is insoluble in water water, also is insoluble to mineral acid, in alkaline soluble metal hydroxides, carbonate and the sulfide.

Technical scheme of the present invention is as follows: a kind ofly prepare the method for white arsenic with the red arsenic waste residue, comprise following concrete steps:

Steps A: getting red arsenic content is the red arsenic waste residue of 5-20%, mix with water, water consumption is by 100-150ml/100g red arsenic waste residue, after mixing, add sodium hydroxide solution lixiviate red arsenic, wherein the consumption of sodium hydroxide is by the 2.0-3.5g/g red arsenic, after lixiviate 0.5-2 hour, filter, get filtrate one and filter residue one; With filtrate one usefulness vitriol oil neutralization alkali wherein, making the pH value of solution value is 9-11, refilters, and obtains filtrate two and filter residue two; Filtrate two is continued neutralization value PH1-3.5 with the vitriol oil again, and it is 2-4 that adding sodium sulphite makes pH, filters then, obtains filter residue three and filtrate three; Filter residue after washing drying, the red arsenic that obtain purifying;

Step B: the red arsenic of the purification of steps A gained and the water of 2-5 times of quality are mixed into slurry, under the stirring at room, mix, and to make the arsenic contained in the mixing solutions and the ratio of the molar weight of copper be 1:2 with copper-bath; Mixed solution is heated to 65-80 ℃ and carries out chemical reaction, reaction times 0.5-2 hour, be cooled to 4 ℃ after filter at low temperature, obtain containing the precipitation of arsenus acid and cupric sulfide and sulphuric acid soln;

Step C: the precipitation that contains arsenus acid and cupric sulfide of step B gained and the water of 2-5 times of quality are mixed into slurry, and aerating oxygen makes arsenus acid generate arsenic acid soluble in water through oxidation, filters, and obtains arsenic acid solution and copper sulfide precipitation;

Step D: feed sulfur dioxide gas in step C gained arsenic acid solution, gas flow is 16L/h, makes arsenic acid be reduced to arsenus acid, obtains arsenic chloride solution, reaction times 1-3 hour;

Step e:, concentrate, filtration, drying through distillation to step D gained arsenic chloride solution, obtain the white arsenic product.

Of the present inventionly prepare the method for white arsenic with the red arsenic waste residue, its chemical principle is:

As ₂S ₃+3CuSO ₄+4H ₂O = 2HAsO ₂+3CuS+3H ₂SO ₄

2HAsO ₂+ O ₂+2H ₂O =2H ₃AsO ₄

H ₃AsO ₄+S O ₂ = HAsO ₂+H ₂SO ₄

4HAsO ₂=2 As ₂O ₃+2H ₂O

Of the present inventionly prepare the method for white arsenic with the red arsenic waste residue, technical process is short, arsenic rate of recovery height, non-secondary pollution deposits yields, and equipment is simple, greatly reduce the cost that arsenic reclaims, and is a method that is worthy of popularization.

Embodiment

Embodiment 1:

A kind ofly prepare the method for white arsenic, comprise following concrete steps with the red arsenic waste residue:

Steps A: get red arsenic content and be 10% red arsenic waste residue, mix with water, water consumption is by 120ml/100g red arsenic waste residue, after mixing, add sodium hydroxide solution lixiviate red arsenic, wherein the consumption of sodium hydroxide is by 3,0g/g red arsenic meter, after the lixiviate 1 hour, filter, get filtrate one and filter residue one; With filtrate one usefulness vitriol oil neutralization alkali wherein, making the pH value of solution value is 10, refilters, and obtains filtrate two and filter residue two; Filtrate two is continued neutralization value pH2.5 with the vitriol oil again, and it is 3 that adding sodium sulphite makes pH, filters then, obtains filter residue three and filtrate three; Filter residue after washing drying, the red arsenic that obtain purifying;

Step B: the red arsenic of the purification of steps A gained and the water of 4 times of quality are mixed into slurry, under the stirring at room, mix, and to make the arsenic contained in the mixing solutions and the ratio of the molar weight of copper be 1:2 with copper-bath; Mixed solution is heated to 70 ℃ and carries out chemical reaction, 1 hour reaction times, be cooled to 4 ℃ after filter at low temperature, obtain containing the precipitation of arsenus acid and cupric sulfide and sulphuric acid soln;

Step C: the precipitation that contains arsenus acid and cupric sulfide of step B gained and the water of 4 times of quality are mixed into slurry, and aerating oxygen makes arsenus acid generate arsenic acid soluble in water through oxidation, filters, and obtains arsenic acid solution and copper sulfide precipitation;

Step D: feed sulfur dioxide gas in step C gained arsenic acid solution, gas flow is 16L/h, makes arsenic acid be reduced to arsenus acid, obtains arsenic chloride solution, 2 hours reaction times;

Embodiment 2:

Steps A: get red arsenic content and be 20% red arsenic waste residue, mix with water, water consumption is by 150ml/100g red arsenic waste residue, after mixing, add sodium hydroxide solution lixiviate red arsenic, wherein the consumption of sodium hydroxide is by the 3.5g/g red arsenic, and lixiviate is after 2 hours, filter, get filtrate one and filter residue one; With filtrate one usefulness vitriol oil neutralization alkali wherein, making the pH value of solution value is 11, refilters, and obtains filtrate two and filter residue two; Filtrate two is continued neutralization value pH3.5 with the vitriol oil again, and it is 4 that adding sodium sulphite makes pH, filters then, obtains filter residue three and filtrate three; Filter residue after washing drying, the red arsenic that obtain purifying;

Step B: the red arsenic of the purification of steps A gained and the water of 5 times of quality are mixed into slurry, under the stirring at room, mix, and to make the arsenic contained in the mixing solutions and the ratio of the molar weight of copper be 1:2 with copper-bath; Mixed solution is heated to 80 ℃ and carries out chemical reaction, 2 hours reaction times, be cooled to 4 ℃ after filter at low temperature, obtain containing the precipitation of arsenus acid and cupric sulfide and sulphuric acid soln;

Step C: the precipitation that contains arsenus acid and cupric sulfide of step B gained and the water of 5 times of quality are mixed into slurry, and aerating oxygen makes arsenus acid generate arsenic acid soluble in water through oxidation, filters, and obtains arsenic acid solution and copper sulfide precipitation;

Step D: feed sulfur dioxide gas in step C gained arsenic acid solution, gas flow is 16L/h, makes arsenic acid be reduced to arsenus acid, obtains arsenic chloride solution, 3 hours reaction times;

Embodiment 3:

Steps A: get red arsenic content and be 5% red arsenic waste residue, mix with water, water consumption is by 100ml/100g red arsenic waste residue, after mixing, add sodium hydroxide solution lixiviate red arsenic, wherein the consumption of sodium hydroxide is by the 2.0g/g red arsenic, and lixiviate is after 0.5 hour, filter, get filtrate one and filter residue one; With filtrate one usefulness vitriol oil neutralization alkali wherein, making the pH value of solution value is 9, refilters, and obtains filtrate two and filter residue two; Filtrate two is continued neutralization value pH1 with the vitriol oil again, and it is 2 that adding sodium sulphite makes pH, filters then, obtains filter residue three and filtrate three; Filter residue after washing drying, the red arsenic that obtain purifying;

Step B: the red arsenic of the purification of steps A gained and the water of 2 times of quality are mixed into slurry, under the stirring at room, mix, and to make the arsenic contained in the mixing solutions and the ratio of the molar weight of copper be 1:2 with copper-bath; Mixed solution is heated to 65 ℃ and carries out chemical reaction, 0.5 hour reaction times, be cooled to 4 ℃ after filter at low temperature, obtain containing the precipitation of arsenus acid and cupric sulfide and sulphuric acid soln;

Step C: the precipitation that contains arsenus acid and cupric sulfide of step B gained and the water of 2 times of quality are mixed into slurry, and aerating oxygen makes arsenus acid generate arsenic acid soluble in water through oxidation, filters, and obtains arsenic acid solution and copper sulfide precipitation;

Step D: feed sulfur dioxide gas in step C gained arsenic acid solution, gas flow is 16L/h, makes arsenic acid be reduced to arsenus acid, obtains arsenic chloride solution, 1 hour reaction times;

Above content be in conjunction with concrete preferred implementation to further describing that the present invention did, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, its framework form can be flexible and changeable, can the subseries product.Just make some simple deduction or replace, all should be considered as belonging to the scope of patent protection that the present invention is determined by claims of being submitted to.

Claims

1. a method for preparing arsenic trioxide with arsenic sulfide waste residue, is characterized in that, comprises following specific steps:

Step A: Take arsenic sulfide waste residue with arsenic sulfide content of 5-20%, mix it with water, the water consumption is calculated as 100-150ml/100g arsenic sulfide waste residue, after mixing evenly, add sodium hydroxide solution to extract arsenic sulfide, wherein hydrogen The amount of sodium oxide is calculated according to 2.0-3,5g/g arsenic sulfide. After leaching for 0.5-2 hours, filter to obtain filtrate 1 and filter residue 1; neutralize the alkali in filtrate 1 with concentrated sulfuric acid, so that the pH of the solution is 9-11, and then filtered to obtain filtrate two and filter residue two; filtrate two continued to neutralize the value of pH1-3.5 with concentrated sulfuric acid, added sodium sulfide to make the pH 2-4, and then filtered to obtain filter residue three and filtrate three; After washing and drying, purified arsenic sulfide is obtained;

Step B: Mix the purified arsenic sulfide obtained in step A with 2-5 times the mass of water to form a slurry, mix it with copper sulfate solution under stirring at room temperature, and make the molar weight of arsenic and copper contained in the mixed solution equal to The ratio is 1:2; the mixture is heated to 65-80°C for a chemical reaction, the reaction time is 0.5-2 hours, cooled to 4°C and then filtered at low temperature to obtain a precipitate containing arsenous acid and copper sulfide, as well as a sulfuric acid solution;

Step C: Mix the precipitate containing arsenous acid and copper sulfide obtained in step B with 2-5 times the mass of water to form a slurry, feed oxygen to oxidize the arsenous acid to form arsenic acid that is easily soluble in water, and filter , to obtain arsenic acid solution and copper sulfide precipitation;

Step D: Pass sulfur dioxide gas into the arsenic acid solution obtained in step C, the gas flow rate is 16L/h, and reduce the arsenic acid to arsenous acid to obtain the arsenous acid solution, and the reaction time is 1-3 hours;

Step E: distill the arsenous acid solution obtained in step D, concentrate, filter, and dry to obtain the arsenic trioxide product.