JPS6230826A - Method for recovering valuable matter from scrap alloy - Google Patents

Abstract

PURPOSE:To inhibit the corrosion of an device and the worsening of work environment to the minimum extent by dissolving a crushed scrap alloy in an alkali metallic hydroxide soln., oxidizing the resulting soln. and recovering a part of the constituent metallic elements of the alloy as metal. CONSTITUTION:A crushed scrap Se-As alloy consisting of <=40wt% As and the balance essentially Se is dissolved in a sodium hydroxide soln. A gaseous mixture of an inert gas with a preferably one of air, oxygen or ozone is used as an oxidizing agent and blown into the resulting soln. Metallic Se is precipitated by an oxidation reaction at 5-70 deg.C, preferably 20-40 deg.C, separated from As by filtration and recovered.

Description

[Detailed Description of the Invention] [Technical Field Applied] This invention is directed to the production of defective products, vapor deposition residues, or used dry copying machines that have characteristics that deviate from the intended product during the molding of photoreceptors used in dry copying machines. The present invention relates to a method for separating and recovering valuable materials such as selenium and arsenic from scrap alloy mainly containing selenium and arsenic peeled off from photoreceptor drums.

[Prior art and problems]

The conventionally known technology is JP-A-59-350.
No. 06 is known, and in this method, concentrated nitric acid is added to the scrap alloy, heated and melted, and then evaporated to dryness to obtain a metal oxide.
The equipment is severely corroded, and the vaporized gas may leak into and out of the workplace, leaving the problem that it is difficult to maintain a good working environment.

Furthermore, in Japanese Patent Publication No. 53-37294, a scrap selenium-arsenic alloy is dissolved in a 20 to 25% alkali metal hydroxide solution, and then an acid is added to make the pI-I of the solution 2 or less, and a selenium-arsenic containing material is dissolved. It is known to produce precipitates of highly pure selenium-containing substances by precipitation, but this method recovers selenium-arsenic alloys, and there is a risk that other impurities may be mixed in during the recovery operation.

Also, only alloys with a certain composition can be obtained.

[Problem to be solved]

The purpose of this invention is to minimize corrosion of equipment and deterioration of the working environment as in the prior art described above, and to separate and recover two or more types of valuables.

[Means for solving problems]

The first invention of this application is to dissolve a crushed material of a scrap alloy in an alkali metal hydroxide solution and oxidize the solution. This is a method for recovering valuables from scrap alloy, which is characterized by collecting and recovering the scrap alloy as a metal and separating it from the remaining metal elements.

In another invention, a crushed material of a scrap alloy containing selenium and arsenic with a jif ratio of 10% or less is dissolved in an alkali metal oxide solution, and this solution is oxidized to recover metallic selenium from K and separate it from arsenic. F generated during this collection
This is a method for recovering valuable materials from scrap alloy, which is characterized by making the liquid strongly acidic and reducing it to recover metallic selenium from the filtrate.

In another invention, a crushed material of a scrap alloy containing selenium and arsenic is dissolved in an alkali metal oxide solution, and this solution is oxidized to collect selenium scraps and separate them from arsenic. By making the filtrate strongly acidified and reducing it, metallic selenium is recovered from this t1 liquid, and the residual FffK sulfide from which this metallic selenium has been recovered is added to sulfide the arsenic present in this filtrate. This is a method for recovering valuable materials from scrap alloy, which is characterized by recovering as arsenic.

Another invention involves dissolving a crushed material of a scrap alloy in an alkali metal hydroxide solution and oxidizing the solution. The filtrate generated during this recovery is neutralized with acid, the same type of metal element as the separated metal element is precipitated as a crystal, and this crystalline scrap gold element is recovered. This is a method for recovering valuables from scrap alloy.

By dissolving the crushed material of scrap alloy contained in an alkali metal hydroxide solution and oxidizing this solution, metallic selenium is recovered from K and separated from arsenic, and the r generated during this recovery is
After neutralizing the liquid and precipitating red selenium in the filtrate and recovering it, the remaining F liquid after the red selenium was precipitated and recovered is strongly acidified, and by adding a sulfiding agent to this, it is possible to make the red selenium remain in the F liquid. This is a method for recovering valuable materials from scrap alloy, which is characterized by recovering arsenic in the form of arsenic sulfide.

This invention will now be explained in more detail.

First, the first specified invention (Claim 1) is included in the other four inventions in its entirety, and includes an alkali metal hydroxide and sodium hydroxide. Use a solution. The scrap alloy used is selenium-arsenic alloy scrap, in which the arsenic content in the alloy is 40% by weight or less, and most of the remainder is selenium.

Next, as an oxidizing agent for the solution, a gas mixture of any one of air, oxygen, and ozone and an inert gas is slowly blown into the solution.

Alternatively, the oxidation reaction is carried out using an oxidizing agent such as hydrogen peroxide or sodium hypochlorite in an atmosphere in which an inert gas is mixed with any one of air, oxygen, and ozone. The oxidation reaction temperature ranges from 5 to 70° C., preferably from 20 to 40° C., or is carried out under pressure in an autoclave. Then, it is separated into metallic selenium and r liquid.

Second invention (Claim 8) A selenium-arsenic alloy scrap that is the same as the scrap alloy of the first invention, and using this as a starting material, the first invention can be processed in one step. Then, the P solution containing some selenium and arsenic remaining after recovering metallic selenium according to the first invention is made into a strong acidic solution (pH 1 to 2) by adding a strong acidifying agent, and then a reducing agent is added. This is a method of recovering metallic selenium from the r-liquid, using one of sulfuric acid and hydrochloric acid as a strong acidifying agent, and reducing agents such as hydrazine, sulfur dioxide, hydroxylamine, and thiourea. In this second selenium-arsenic ratio using one of the selenium-arsenic agents, there is no particular limitation on this ratio, but preferably the arsenic content is 10% or less.

Fang's third invention (Claim 11) In addition to the second method, a sulfiding agent is added to the remaining f liquid after separating metallic selenium twice to convert arsenic into arsenic sulfide. It is a method of recovering from liquid, and the sulfurizing agent is hydrogen sulfide or sulfurizing agent)
This is a method using IJum.

Fang 4th invention (Claim 13) The above 21st invention is a contradictory step, and then a strong acidifying substance is added to the remaining filtrate to neutralize it, and in the P solution, first, This is a method in which the same type of metal as the metal separated in the tl step is separated by precipitation as a crystalline substance, and the same acidifying substance as in the 22nd invention is used as the acidifying substance.

This method is suitable for use as a starting material for a selenium-arsenic scrap alloy containing 10 to 40% by weight of arsenic in the scrap alloy, and the metallic selenium precipitated as a crystalline substance is red selenium.

Fifth Invention (Claim 16) A sulfurizing agent is added to the last filtrate of the fourth method invention in the same manner as in the third invention, and arsenic sulfide is separated from the r liquid. It is suitable for processing selenium-arsenic scrap alloys containing 10-40% arsenic.

[First Effect of the Invention] As stated in the paper, selenium was recovered from scrap alloy made of selenium arsenic alloy by the method of this invention, and the yield of metallic selenium was 72% to 88%. Metallic selenium with a purity of 98 to 99.9% can be obtained.

The relationship between the reaction temperature and the recovery rate when performing an oxidation reaction is as shown in Figure 2, and the relationship between the amount of oxidizing agent used and the reaction temperature when hydrogen peroxide is used as the oxidizing agent is shown in Figure 3. As shown in , the temperature of the oxidation reaction is preferably 5 to 70°C, preferably 20 to 40°C. It can be relatively inexpensive, and the reaction atmosphere can be an inexpensive gas such as air or oxygen (recovery costs can be kept low).

In particular, when air is used as the oxidation method, the only cost involved is the equipment that supplies it, resulting in further cost reduction.

When an oxidizing agent such as hydrogen peroxide or sodium hypochlorite is used as the oxidation method, the oxidation reaction is rapid and the yield is high.

Further, the oxidation reaction is promoted by performing oxidation 5 under pressure using an autoclave.

[Effects of the second invention] In addition to the effects of the second invention, the effects of this invention include:
It is possible to further recover metallic selenium by applying the above-mentioned treatment to the solution separated by the first method, and 'in particular, the Scjig alloy contains less than 10% arsenic and the rest has an excellent odor of selenium alloy. Shows the recovery rate.

Further, the strong acidifying agent and reducing agent used in the method of strongly acidifying are also easily available, commercially available ones can be used, and no particularly complicated equipment is required.

By this method, metallic selenium with a purity of 99.9% can be obtained.

In the reduction reaction of this method, the temperature should be around 80℃.
Therefore, reduction reaction is the most effective.

[Effects of the Third Invention] By adding the solution-pressure sulfide separated door to door by the method of the second invention, 4 to 99% of the content in the solution can be recovered as arsenic sulfide.

[Effect of the Fourth Invention] According to the present invention, the same type of metal as the metal separated by the first method can be precipitated and separated as a crystalline substance by simply neutralizing the solution separated by the method 1-1. Further, the acidifying agent can be simply added by injection, and the operation is extremely easy.

In addition, in this method, selenium 9 is used as scrap alloy.
It is excellent at treating materials with a relatively high arsenic content, such as 0-60% arsenic and 10-40% arsenic, as a starting material, and the recovery rate of metallic selenium is 97-98.8% and purity is 97-97%.
99% of them are obtained.

Furthermore, the acidifying agent used as a neutralizing agent may be the very common sulfuric acid, hydrochloric acid, etc., and the recovery cost can be kept low.

[Effect of the fifth invention] In this invention, an acidifying agent is added to the remaining solution K filtered by the fourth method to make the solution a strong acidic liquid, and then a sulfurizing agent is added to the solution. In addition, the arsenic contained in the solution is recovered as arsenic sulfide.In addition to the effect of the fourth invention, the arsenic contained in the solution can be recovered as arsenic sulfide in the entire process, and the recovery rate of arsenic is improved. is 95%~98
It has an effect of %.

[Experiment example]

As an example of an experiment, the first and second methods were invented during the third method invention.
The first invention of Fang and the fourth invention of Fang are included in the method invention of No. 5, respectively.
Experimental examples of the third and fifth inventions are shown below.

a) Experimental examples of the first to third inventions Experimental example 1 025g of 25% sodium hydroxide solution was heated to 60°C,
10kg of scrap alloy containing 98% selenium and 2ft% arsenic was melted, and after filtering undissolved materials, 0.0% of air was dissolved.
2 N1'/m was oxidized by bumping into the solution for 3 days,
When P was separated again, metallic selenium was found to be 8.6-1, purity 99.9.
% or more (arsenic contains 10 p, p, m).

Next, 20.5 kg of diluted sulfuric acid was added to the remaining filtrate separated by r to form a solution with a pH of 1.5, and then heated at 80'Cπ, and 1.75 g of sulfur dioxide gas was blown into the liquid as a reducing agent. As a result, 1.0 kg of metallic selenium with a purity of 99.9% (arsenic content: 5 p, p, m) was obtained. Furthermore, 200 y of hydrogen sulfide was blown into the P-separated solution and 360 y of arsenic sulfide was obtained after f-separating. In all of these methods, the selenium yield was 98% and the arsenic yield was 99%.

Experimental Example 2 The same scrap alloy as in Experimental Example 1 was dissolved in the same solution, placed in an autoclave, and heated with air at 5 kg/a11.
When oxidized under
p, p-m) or more was obtained.

Furthermore, add 20.5 kg of dilute sulfuric acid to the KP solution and adjust the pH of the solution to 1.5.
After that, it was heated to 80'C and sulfur dioxide gas was added to 1.70K.
When g was blown into it, the purity was 99.9% (arsenic 7p,
1.08 Kg of metallic selenium having a particle size of p, m) or more was obtained. Furthermore, this filtrate was treated in the same manner as in Experimental Example 1 to obtain 360y of arsenic sulfide. The yield of selenium was 98% and the yield of arsenic was 99%.

Experimental Example 3 Oxygen 0, I was added to the same scrap alloy solution as in Experimental Example 1.
When Ni7m was oxidized by bumping into the solution for 3 days, 8.7 kg of metallic selenium with a purity of 99.9%' (arsenic 9p, p, m) or more was obtained. Furthermore, add 1 part of 35% hydrochloric acid to the f solution.
After adding 8 kg of hydrazine to make it strongly acidic to pH 2, it was heated to 80°C and hydrazine hydrate was added.
．． 7 Kg was obtained. Furthermore, approximately 4% sodium sulfide is added to this f-liquid.
When 60y was added, 370y of arsenic sulfide was obtained. The yield of selenium was 9670, and the yield of arsenic was 99%.

Experimental Example 4 The same scrap alloy as Experimental Example 1 was melted by the same method, and after separating the undissolved materials, 3.75% of 30% hydrogen peroxide solution was added at room temperature for about 1.5 hours. , 8.7 kg of metallic selenium, purity 99.9% (contains arsenic 10
p, p, m) or more were obtained. Furthermore, this F? [After adjusting the pH to 1.5 with 20.5 kg of potassium sulfuric acid, it was heated for 80'CK, and about 2.10 tons of sulfur dioxide gas was blown into the m solution as a reducing agent to obtain 0.9 kg of metallic selenium. Further, the filtrate was treated in the same manner as in Experimental Example 1 to obtain 360y of arsenic sulfide. The yield of selenium was 98.0% and the yield of arsenic was 99%.

Experimental Example 5 25J of 25% sodium hydroxide solution is heated to 60'C to dissolve scrap alloy 10KII containing 95% by weight of selenium and 5% by weight of arsenic. Undissolved substances were removed from the f side, and 3.5 ml of 30% hydrogen peroxide solution was added to this solution at room temperature. I about 1
．． When injected over 5 hours, the metal cell V was 78.4 K.
g, purity 99.9% (arsenic content: 6 p, p, m) was obtained. Furthermore, apart from this filtration, add 20.5 kg of diluted sulfuric acid to adjust the pH.
After setting the temperature to 1,,7, it was heated to SO'C and about 2.0 kg of sulfur dioxide gas was blown into the liquid, and 0 of metallic selenium was found.
．． 9-1 purity was 99.9% (arsenic content: 5p, p, m). Furthermore, when about 500 tons of hydrogen sulfide gas was blown into the filtrate, 880 tons of arsenic sulfide was obtained. The selenium yield was 97.9% and the arsenic yield was 99%.

Experimental Examples of the First Fang Invention, the Fourth Invention, and the Fifth Invention Experimental Example 6 Heat 25% sodium hydroxide 101 to 60°C and dissolve scrap alloy 10 containing 70% by weight of selenium and 30jtf% of arsenic. do. After diluting this solution with 20 g of filtered water, 30% hydrogen peroxide 141 was added at room temperature over about 6 hours. I got ~. Further, this filtrate was neutralized by adding dilute sulfuric acid to obtain 1.0 kg of red selenium with a purity of 99.9% (arsenic: 20 p, p, m).

Furthermore, when sulfuric acid was added to the f solution to adjust the pH to 2, arsenic was found to be 5.
5.20 kg of arsenic sulfide containing 5.5% was obtained. The selenium recovery rate was 98.6% and the arsenic recovery rate was 96.2%.

Experimental Example 7 25% sodium hydroxide bath solution 101 was heated to 60°C,
10 kg of scrap alloy containing 70% by weight of selenium and 30% by weight of arsenic is melted. After filtering the non-fermented product, 70℃
14 g of 30% hydrogen peroxide was added over about 5 hours to obtain 5.9 kg of metallic selenium with a purity of 98.3% (containing 1.7% arsenic).

Furthermore, when the P solution was neutralized with dilute sulfuric acid, the purity was 99.9% (
Arsenic 25p, p edition 6゛) or more red selenium crystal 1.
I got 0~. Furthermore, sulfuric acid was added to this filtrate to adjust the pH to 1.5, and when approximately 3 kg of hydrogen sulfide gas was blown into the filtrate, 5.5 kg of arsenic was added.
5.20 Kg of arsenic sulphide containing 5.4% was obtained.

Selenium recovery rate is 97.1%, arsenic yield is 96.0%
Met.

Experimental Example 8 10 tI of 25% sodium hydroxide solution is heated to 60° C. and 10 kg of scrap alloy containing 70% by weight of selenium and 30% by weight of arsenic is dissolved.

After filtering this f-liquid to remove unmelted substances, it was diluted 3 times with water, and the solution was placed in an autoclave at an air pressure of 5 kg/cd.
When the solution was oxidized by applying pressure, 5.4 kg of metallic selenium containing 1.8% arsenic was obtained.

Furthermore, when this filtrate was neutralized with dilute sulfuric acid, the purity was 99.9.
% (containing 20 gp, m arsenic) of metallic selenium 1.6-% was obtained. Furthermore, after adding dilute sulfuric acid to this F solution and adjusting the pH to 2,
About 3 kg of hydrogen sulfide gas was blown into the solution.

Experimental Example 9 After separating undissolved substances from P and diluting them three times with water as in other experimental examples, the solution was placed in an autoclave and heated with oxygen for 10 minutes.
When pressurized at Kg/cIl, the purity was 98.2% (
The filtrate obtained from metallic selenium with arsenic content of 1.7%) was neutralized with dilute sulfuric acid, resulting in a purity of 99.9% (arsenic content of 2.0%).
5 p, p, m) metallic selenium of 1.0~ was obtained. Furthermore, after adding dilute sulfuric acid to the filtrate to adjust the pH to 2, hydrogen sulfide gas was blown into the solution, and arsenic was detected during the above experiment.
In scrap alloys containing 10 to 40% arsenic, such as No. 9, the metallic selenium obtained by melting with sodium hydroxide and post-oxidation contains a relatively large amount of arsenic ((1, 5 to 1.8%], this metal separator

[Brief explanation of the drawing]

In the figure, Fig. 1 is a block diagram showing the outline of the invention of this application, Fig. 2 is a graph showing the relationship between temperature and selenium recovery rate during oxidation reaction, and Fig. 3 is a graph showing the relationship between selenium recovery rate and temperature during oxidation reaction. It is a graph showing the relationship between usage amount and reaction temperature. Applicant for the above patents: Shinko Kagaku Kogyo Co., Ltd. Agent: Patent attorney: Yamada Kingdom
- (%) 0 20 40 60 8o (℃) Reaction temperature (tttl) 0 20 40 60 80 ('C) Reaction temperature

Claims (1)

[Scope of Claims] 1) By dissolving the crushed material of the scrap alloy in an alkali metal hydroxide solution and oxidizing the solution, at least one metal element among the elements contained in the scrap alloy is dissolved into metal. A method for recovering valuable materials from scrap alloy, which is characterized by collecting and recovering valuable materials from scrap alloys and separating them from remaining metal elements. 2) The scrap alloy is a scrap alloy containing arsenic and selenium, and the recovered metal is separated from the arsenic by metallic selenium. How to collect things. 3) A method for recovering valuables from a scrap alloy according to claim 2, wherein the arsenic content is 40% by weight or less. 4) The method of oxidizing the solution is carried out while blowing air, oxygen, ozone, or a mixture of one of oxygen and ozone and an inert gas into the solution. A method for recovering valuables from the described scrap alloy. 5) The method of oxidizing the solution is carried out using an oxidizing agent such as hydrogen peroxide or sodium hypochlorite in an atmosphere of air, oxygen, ozone, or oxygen and ozone and an inert gas atmosphere. A method for recovering valuables from scrap alloy. 6) The method for recovering valuables from scrap alloy according to claim 2 or 4, wherein the oxidation of the solution is carried out under pressure in an autoclave. 7) The oxidation reaction temperature is 5 to 70°C, preferably 20 to 4°C.
A method for recovering valuables from scrap alloy according to claim 5, wherein the temperature is 0°C. 8) Dissolving a crushed scrap alloy containing selenium and arsenic at a weight ratio of 10% or less in an alkali metal oxide solution,
The method is characterized by recovering metallic selenium and separating it from arsenic by oxidizing this solution, making the filtrate generated during this recovery strongly acidic, and recovering metallic selenium from this filtrate by reducing it. A method for recovering valuables from scrap alloy. 9) The method for recovering valuables from scrap alloy according to claim 8, wherein the strong acidification is a method of making the filtrate strong acidic with one of sulfuric acid and hydrochloric acid. 10) The method for recovering valuables from scrap alloy according to claim 9, wherein one of hydrazine, sulfur dioxide, hydroxylamine, and thiourea is used as a reducing agent in the reduction. 11) Dissolve the crushed material of scrap alloy containing selenium and arsenic in an alkali metal oxide solution, oxidize this solution to recover metallic selenium and separate it from arsenic, and make the filtrate generated at this time strongly acidic. Metal selenium is recovered from this filtrate by reducing it, and sulfide is added to the remaining filtrate after recovering this metal selenium, and arsenic remaining in this filtrate is recovered as arsenic sulfide. A method for recovering valuables from scrap alloy. 12) The method for recovering valuables from scrap alloy according to claim 11, wherein the sulfide is one of hydrogen sulfide and sodium sulfide. 13) By dissolving the crushed material of the scrap alloy in an alkali metal hydroxide solution and oxidizing the solution, at least one metal element among the elements contained in the scrap alloy is separated as a metal from the remaining metal elements. Scrap characterized by collecting the filtrate generated during the collection with an acid, precipitating a metal element of the same type as the separated metal element as a crystalline substance, and recovering the crystalline metal element. A method of recovering valuables from alloys. 14) The scrap alloy contains 10 to 40% by weight of arsenic;
A method for recovering valuables from a scrap alloy according to claim 13, wherein the scrap alloy contains 90 to 60% by weight of selenium, and the recovered metal is metallic selenium separated from arsenic. . 15) The method for recovering valuables from scrap alloy according to claim 13, wherein the neutralization is performed using one of sulfuric acid and hydrochloric acid. 16) A crushed product of scrap alloy containing 10 to 40% by weight of arsenic and selenium is dissolved in an alkali metal hydroxide solution, and this solution is oxidized to recover metallic selenium and separate it from arsenic. After neutralizing the filtrate to precipitate red selenium in the filtrate and recovering it, the remaining filtrate from which the red selenium has been precipitated and recovered is strongly acidified, and a sulfiding agent is added to the filtrate. A method for recovering valuable materials from scrap alloy, characterized by recovering arsenic remaining in the scrap alloy as arsenic sulfide. 17) The method for recovering valuables from scrap alloy according to claim 16, wherein the sulfide is one of hydrogen sulfide and sodium sulfide.