JP6409683B2 - Arsenic recovery method - Google Patents

Description

  The present invention relates to a method for collecting arsenic, and more particularly to a method for collecting arsenic from an electrolytic solution of copper containing arsenic using an ion exchange resin.

  As one of the methods for smelting copper from copper sulfide ore, the following smelting process is most commonly used. That is, first, the copper sulfide ore is subjected to a beneficiation treatment such as crushing or flotation to obtain a copper concentrate having a copper grade concentrated to about 20 to 30%, and then the copper concentrate together with oxygen in a flash smelting furnace, etc. And then melted at high temperature and separated into slag and mat. Next, the obtained mat is refined in a converter and a refining furnace to separate impurities to obtain a refined anode having a copper quality exceeding 99%. Furthermore, by inserting the anode into a battery tank filled with a sulfuric acid acidic solution together with the cathode and conducting electrolytic purification by energizing between the anode and the cathode, electrolytic copper having a purity of 99.99% is obtained.

  Copper sulfide ore contains impurities such as arsenic in addition to copper. However, when the above-described smelting method is used, a large amount of arsenic is distributed to mats and slag, and a part of arsenic is added. Volatilizes and is distributed to the exhaust gas.

  Of these, most of the arsenic distributed to the mat is transferred to the anode, and almost all of the arsenic is eluted in the electrolytic solution in the above-described electrolytic purification process.

  Thus, the electrolytic solution for copper electrolysis always contains arsenic together with main copper. As the arsenic concentration in the ore increases, the arsenic concentration in the electrolytic solution also increases. However, if the arsenic concentration in the electrolytic solution exceeds the allowable limit, it will be eutectoid or entrained in the product copper. This may deteriorate the quality of electrolytic copper. Therefore, it is necessary to manage the arsenic concentration in the electrolytic solution below a certain concentration.

  Although reducing the amount of arsenic input is a fundamental solution to reduce the arsenic concentration in the electrolyte, it is not easy because it is difficult to obtain ores with low arsenic quality in recent years. .

As a method for separating and removing arsenic contained in the electrolyte solution from the electrolyte solution, the electrolyte solution is heated and concentrated and then cooled, and after collecting the precipitated copper as copper sulfate by utilizing the solubility difference, Further, a method of removing arsenic by electrowinning, so-called copper removal electrolysis is generally performed. However, the copper removal electrolysis method has an extremely large amount of power consumption, and a toxic gas such as arsine (AsH ₃ ) may be generated, and it is not easy to manage stable operation.

  In order to solve this problem, for example, Patent Document 1 proposes a method in which hydrogen sulfide is blown into an electrolytic solution to generate and separate arsenic sulfide. However, in this method, a large amount of hydrogen sulfide is handled, which is not preferable in the work environment, and it takes time and effort such as a detoxification facility.

  Moreover, in patent document 2, although the method of producing | generating a sulfide using a water flow soda is proposed, it takes time similarly. Specifically, the method of Patent Document 2 divides the electrolytic solution into two parts, and after removing impurities such as arsenic as metal sulfide through the water flow soda, it further remains by adding excess water soda. It reacts with sulfuric acid to produce hydrogen sulfide, and this hydrogen sulfide is passed through the other electrolyte solution to remove impurities such as arsenic as metal sulfide.

  However, the electrolytic solution through the hydrosolation soda cannot be returned to the system and must be subjected to wastewater treatment, and further, hydrogen sulfide must be handled as in the technique described in Patent Document 1. There is an environmental problem.

  On the other hand, there is a method of adsorbing arsenic in an aqueous solution through an electrolyte solution through a chelate resin. For example, Patent Document 3 proposes a method for recovering arsenic using a chelate resin having an aminopolyalcohol group. In order to remove boron or arsenic in wastewater, resins with glucamine groups, which are one of the aminopolyalcohol groups, are sold by various manufacturers, but these resins are generally developed for wastewater treatment applications. Therefore, the effective pH is in a weakly alkaline to weakly alkaline region of about 6 to 10. Therefore, it is not suitable for use in a strongly acidic sulfuric acid aqueous solution in which the pH value is in a minus region, such as a copper electrolyte.

  However, since arsenic can be adsorbed even from such a strongly acidic solution, for example, as shown in Patent Document 4, a chelate having an aminopolyalcohol group is used to reduce arsenic in a copper electrolyte. A method of applying a resin has also been proposed.

  Here, in general, in the chelate resin, there is a pH range suitable for elution as well as a pH range suitable for adsorption. Further, it is known that the adsorption / elution behavior is influenced not only by the pH value but also by the temperature and the type of acid in the eluent. That is, the behavior of adsorption and elution varies depending on the mutual effects of liquidity and temperature.

  When considering application to copper electrolyte, it is not practical to change the liquidity and temperature during adsorption because it becomes difficult to return the liquid after arsenic adsorption to the electrolytic process. For this reason, at the time of adsorption, the liquidity and temperature of the electrolytic solution are not changed, and the electrolytic solution is often passed through the resin as it is to recover arsenic as much as possible.

  On the other hand, in the elution from the chelate resin, it is possible to select conditions suitable for the elution, so the elution conditions are an important factor for improving the arsenic recovery rate.

  In Patent Document 4 described above, although there is a reference to the repetition of the liquid for improving the arsenic recovery rate, the liquidity and temperature at the time of elution are not explicitly mentioned.

JP-A-57-5884 JP-A-9-78284 JP 58-64180 A JP-A-11-90413

  The present invention has been proposed in view of such circumstances, and in a method for recovering arsenic from a copper electrolyte containing arsenic using a chelate resin having an aminopolyalcohol group, efficient and high recovery is achieved. It aims to provide a method for recovering arsenic at a high rate.

  The inventors of the present invention have made extensive studies in order to solve the above-described problems. As a result, it was found that when arsenic is adsorbed on a chelating resin and the arsenic is eluted from the resin, arsenic can be recovered at a high recovery rate by eluting arsenic into the eluent under specific elution conditions. It came to be completed. That is, the present invention provides the following.

  (1) According to the first aspect of the present invention, a copper electrolyte containing arsenic and a chelate resin having an aminopolyalcohol group are brought into contact, and then the sulfuric acid concentration of the chelate resin is 50 g / L or more and 150 g / L. A method for recovering arsenic from a copper electrolyte, comprising contacting an aqueous sulfuric acid solution as described below to elute and recover arsenic adsorbed on the chelate resin in the aqueous sulfuric acid solution.

  (2) According to a second aspect of the present invention, in the first aspect, the temperature of the aqueous sulfuric acid solution when eluting the arsenic is maintained in the range of 40 ° C. to 85 ° C. Recovery method of arsenic from

  (3) According to a third aspect of the present invention, in the first or second aspect, the electrolytic solution to be contacted with the chelate resin is a sulfuric acid copper electrolysis having a free sulfuric acid concentration of 100 g / L or more and 400 g / L or less. A method for recovering arsenic from a copper electrolyte, characterized by being a liquid.

  (4) A third invention of the present invention is a method for recovering arsenic from a copper electrolyte according to any one of the first to third inventions, wherein the aminopolyalcohol group is a glucamine group. .

  According to the present invention, a chelating resin having an aminopolyalcohol group is used to adsorb arsenic contained in a copper electrolytic solution, and then elute using an aqueous sulfuric acid solution under specific conditions as an eluent. Arsenic can be efficiently recovered at a high recovery rate.

  Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, In the range which does not change the summary of this invention, it can adjust suitably.

  The arsenic recovery method according to the present embodiment is a method for recovering arsenic from a copper electrolyte containing arsenic, wherein the copper electrolyte is brought into contact with a chelate resin, and the arsenic adsorbed on the chelate resin is eluted into the eluent. It is a method of eluting and recovering.

  Specifically, this arsenic recovery method includes an adsorption step in which a copper electrolyte containing arsenic and a chelate resin having a glucamine group are brought into contact with each other to adsorb arsenic to the chelate resin, and a sulfuric acid having a predetermined sulfuric acid concentration on the chelate resin. And an elution step of bringing the aqueous solution into contact and eluting and recovering arsenic adsorbed on the chelate resin in the aqueous sulfuric acid solution.

(1) Adsorption process In an adsorption process, a copper electrolyte containing arsenic and a chelate resin are brought into contact, and arsenic is adsorbed on the chelate resin. In this embodiment, a chelate resin having an aminopolyalcohol group is used as the chelate resin.

  The chelate resin having an aminopolyalcohol group is obtained by immobilizing an aminopolyalcohol group on a resin base material (polymer base material). Although it does not specifically limit as a resin base material, The thing of spherical shape, a granular form, and fibrous shape which mainly has high polymers, such as a polystyrene-divinylbenzene copolymer and a cellulose, can be illustrated.

  The aminopolyalcohol group is preferably a group containing an amino group and a polyhydric alcohol group. In particular, from the viewpoint of arsenic adsorptivity, a glucamine group such as an N-methylglucamine group or a D-glucamine group may be used. Preferably there is.

  Here, as an electrolytic solution of copper in an industrial copper electrolysis process, it is usually heated and maintained at around 60 ° C., and the concentration of free sulfuric acid in the electrolytic solution is, for example, a strongly acidic solution around 190 g / L. is there. In this copper electrolyte, if the liquidity or temperature is changed due to adsorption of arsenic to the chelate resin, it is difficult to return to the subsequent electrolysis process. From this, in this embodiment, without changing the liquid property and temperature of the copper electrolyte, that is, without performing any treatment such as deoxidation treatment as a pretreatment of the ion exchange treatment using the chelate resin, In the state of the copper electrolyte as it is, it is brought into contact with the chelate resin, and arsenic in the electrolyte is adsorbed on the resin.

  Specifically, in the present embodiment, as the copper electrolytic solution to be contacted with the chelate resin, a sulfuric acid electrolysis having a free sulfuric acid concentration of 100 g / L or more and 400 g / L or less, more preferably 150 g / L or more and 200 g / L or less. Use liquid. By subjecting such a sulfuric acid copper electrolyte to contact with a chelate resin as it is and performing an ion exchange treatment, after eluting arsenic in the electrolyte in an elution step described later, it can be easily performed in the electrolysis step. It can be returned and efficient operation becomes possible.

  As a method for bringing the copper electrolyte solution into contact with the chelate resin, a column system is generally used, but it may be brought into contact by batch mixing.

  Specifically, in the column system, for example, a cylindrical column is filled with a chelate resin having an aminopolyalcohol group, and a copper electrolyte containing arsenic is passed through the column. The conditions for passing the liquid are not particularly limited. For example, the flow speed SV (Space Velocity), the flow volume BV (Bed Volume), and the like are appropriately determined from the viewpoint of operation efficiency and adsorption efficiency. It is preferable to adjust.

  After adsorption treatment of arsenic on the chelate resin, collect the effluent after passing through in the case of the column method, and collect the liquid after solid-liquid separation in the case of batch mixing, and remove the arsenic by adsorption. Return to the electrolysis process using the copper electrolyte. In addition, the method of solid-liquid separation in the case of batch mixing is not particularly limited, and any method may be used, but a method that does not destroy the chelate resin substrate such as filtration or sedimentation may be used. preferable.

(2) Elution Step Next, in the elution step, the eluent is brought into contact with the chelate resin after the adsorption step, and arsenic adsorbed on the chelate resin is eluted into the eluent and collected.

  The chelate resin that has adsorbed arsenic in the adsorption step is usually eluted from the resin by contacting with an eluent such as an acid. At this time, a mineral acid such as hydrochloric acid or sulfuric acid is used as the eluent. In particular, since a sulfuric acid aqueous solution is usually used as the copper electrolyte, the present embodiment also has a predetermined concentration as the eluent. An aqueous sulfuric acid solution is used. For example, in the treatment of copper electrolyte produced in a copper smelting factory, sulfuric acid is produced as a by-product when smelting sulfide ore, so there is an economic merit that it can be obtained at a lower price than other acids. is there.

  In addition, when using other types of acids, it causes deterioration of the quality of electrolytic copper and deterioration of production efficiency due to mixing with the electrolyte, and when hydrochloric acid is used, equipment corrosion due to the chlorine occurs. Problems also arise.

  Here, in the present embodiment, the concentration of the sulfuric acid aqueous solution used as the eluent is important. Specifically, an aqueous sulfuric acid solution having a sulfuric acid concentration in the range of 50 g / L to 150 g / L is used as the eluent. More preferably, an aqueous sulfuric acid solution having a sulfuric acid concentration in the range of 60 g / L to 90 g / L is used. By performing the elution process using an aqueous sulfuric acid solution having such a concentration as an eluent, the elution rate of arsenic adsorbed on the chelate resin can be increased.

  The temperature conditions for elution are not particularly limited, but the arsenic elution rate can be increased as the temperature increases. Specifically, the temperature condition is preferably 40 ° C. or higher, and more preferably 50 ° C. or higher. On the other hand, when the temperature is set high, it is necessary to use an expensive corrosion-resistant material or heat-resistant material, and even when such a material is used, the service life decreases as the temperature increases and the replacement frequency decreases. This increases the processing cost. Accordingly, the temperature condition is preferably 85 ° C. or less, and more preferably 80 ° C. or less. Such an upper limit of the temperature condition is also preferable from the viewpoint of the heat resistant temperature of the chelate resin with which the eluent is brought into contact.

  As a method for bringing the eluent into contact with the chelate resin, a column method can be used as in the method for contacting the copper electrolyte with the chelate resin in the adsorption step, or batch mixing may be used. Specifically, in the case of the column system, arsenic is adsorbed on a column filled with a chelate resin (adsorption step), and then contacted by passing an eluent having a predetermined concentration and temperature through the column. In addition, it does not specifically limit as liquid flow conditions, It is preferable to adjust SV, BV, etc. suitably from viewpoints, such as operation efficiency and elution efficiency.

  In the case of the column system, an aqueous solution of sulfuric acid as an eluent is passed through the chelate resin and brought into contact therewith, and then the effluent is recovered. In the case of batch mixing, after mixing the chelate resin and the sulfuric acid aqueous solution as the eluent, the liquid is recovered by solid-liquid separation of the mixed liquid. In addition, the method of solid-liquid separation in the case of batch mixing is not particularly limited, and any method may be used, but a method that does not destroy the chelate resin substrate such as filtration or sedimentation may be used. preferable.

  In this manner, when arsenic adsorbed on the chelate resin is eluted using an aqueous sulfuric acid solution having a concentration of 50 g / L or more and 150 g / L or less, arsenic is eluted and distributed in the aqueous sulfuric acid solution. In particular, in the arsenic recovery method according to the present embodiment, since an aqueous sulfuric acid solution having a concentration of 50 g / L or more and 150 g / L or less is used as an eluent, the elution rate of arsenic can be improved. Arsenic can be recovered from the copper electrolyte at a high recovery rate.

  The chelate resin after elution of arsenic can be used repeatedly by returning to the adsorption step again. Thus, arsenic can be effectively and efficiently removed from the copper electrolyte by repeating the adsorption process and the elution process.

  Specific examples to which the present invention is applied will be described below, but the present invention is not limited to the following examples.

≪About concentration of sulfuric acid in eluent≫
[Example 1]
1.5 L of sulfuric acid acidic copper electrolyte having an arsenic concentration of 14 g / L, a free sulfuric acid concentration of 190 g / L, and a copper concentration of 45 g / L, and a chelate resin having a glucamine group (DIAION CRB05 manufactured by Mitsubishi Chemical Corporation) 70 ml was placed in a beaker, maintained at a temperature of 50 ° C., and stirred and mixed for 30 minutes to adsorb the arsenic in the copper electrolyte to the chelate resin. Next, the chelate resin and the electrolytic solution were subjected to solid-liquid separation using 5C filter paper, and then the resin remaining on the filter paper was washed with water using pure water to remove the adhered liquid.

  Next, 1 ml of the washed resin is collected, and the resin is put into a beaker, and 20 mL of sulfuric acid aqueous solution having a sulfuric acid concentration of 75 g / L maintained at a liquid temperature of 80 ° C. is added and mixed. The arsenic adsorbed on was eluted in an aqueous sulfuric acid solution.

  Next, the arsenic concentration contained in the sulfuric acid aqueous solution after elution was analyzed using ICP emission spectrometry. As a result, the arsenic concentration was 0.63 g / L.

[Example 2]
In the elution of arsenic, the same operation as in Example 1 was performed except that 20 mL of sulfuric acid aqueous solution having a sulfuric acid concentration of 50 g / L was used.

  When the arsenic concentration in the sulfuric acid aqueous solution after elution was analyzed, it was 0.56 g / L.

[Example 3]
In the elution of arsenic, the same operation as in Example 1 was performed except that 20 mL of sulfuric acid aqueous solution having a sulfuric acid concentration of 150 g / L was used.

  When the arsenic concentration in the sulfuric acid aqueous solution after elution was analyzed, it was 0.55 g / L.

[Comparative Example 1]
In the elution of arsenic, the same operation as in Example 1 was performed except that 20 mL of sulfuric acid aqueous solution having a sulfuric acid concentration of 25 g / L was used.

  When the arsenic concentration in the sulfuric acid aqueous solution after elution was analyzed, it was 0.43 g / L.

[Comparative Example 2]
In the elution of arsenic, the same operation as in Example 1 was performed except that 20 mL of sulfuric acid aqueous solution having a sulfuric acid concentration of 200 g / L was used.

  When the arsenic concentration in the sulfuric acid aqueous solution after elution was analyzed, it was 0.20 g / L.

  From the results of Examples 1 to 3 and Comparative Examples 1 and 2 described above, it is understood that the recovery rate of arsenic can be increased by using a sulfuric acid aqueous solution having a sulfuric acid concentration of 50 g / L or more and 150 g / L or less as an eluent. It was.

≪Teluting temperature≫
[Example 4]
A cylindrical column made of Pyrex (registered trademark) glass having an inner diameter of 10 mm is filled with 10 ml of chelate resin having a glucamine group (manufactured by Mitsubishi Chemical Co., Ltd., DIAION CRB05), then arsenic concentration is 5.3 g / L, free sulfuric acid A sulfuric acid acidic copper electrolyte having a concentration of 190 g / L and a copper concentration of 45 g / L is passed through the column in an amount of 200 ml (BV = 20) at a flow rate of 120 ml / hr (SV = 12). Arsenic was adsorbed on the resin. During the flow, the solution in the column was heated so as to maintain 50 ° C.

  After passing through the solution, the solution remaining in the column is extracted and removed, and an aqueous sulfuric acid solution having a sulfuric acid concentration of 75 g / L is added in an amount of 70 ml (BV = 7) at a flow rate of 10 ml / hr (SV = 1). The solution was passed through to elute arsenic adsorbed on the resin. During the flow of the sulfuric acid aqueous solution, the sulfuric acid aqueous solution in the column was heated so as to be maintained at 80 ° C.

  After elution, arsenic in the sulfuric acid aqueous solution was analyzed using ICP emission spectrometry. As a result, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.30 g.

[Example 5]
During elution, the same operation as in Example 4 was performed except that the temperature of the aqueous sulfuric acid solution in the column was maintained at 70 ° C.

  When the arsenic in the sulfuric acid aqueous solution after elution was analyzed, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.33 g.

[Example 6]
During elution, the same operation as in Example 4 was performed, except that the temperature of the aqueous sulfuric acid solution in the column was maintained at 60 ° C.

  When arsenic in the sulfuric acid aqueous solution after elution was analyzed, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.32 g.

[Example 7]
During elution, the same operation as in Example 4 was performed, except that the temperature of the aqueous sulfuric acid solution in the column was maintained at 50 ° C.

  When arsenic in the sulfuric acid aqueous solution after elution was analyzed, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.28 g.

[Example 8]
During elution, the same operation as in Example 4 was performed except that the temperature of the aqueous sulfuric acid solution in the column was maintained at 40 ° C.

  When arsenic in the sulfuric acid aqueous solution after elution was analyzed, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.24 g.

[Comparative Example 3]
During elution, the same operation as in Example 4 was performed, except that the temperature of the sulfuric acid aqueous solution in the column was maintained at 30 ° C.

  When arsenic in the sulfuric acid aqueous solution after elution was analyzed, the amount of arsenic recovered in the sulfuric acid aqueous solution was 0.12 g.

  As described above, from the results of Examples 4 to 8 and Comparative Example 3, the amount of arsenic recovered can be increased by setting the temperature of the sulfuric acid aqueous solution in the column to 40 ° C. or higher, preferably 50 ° C. or higher during elution. I found out that

Claims (3)

The Rukoto contacting the chelating resin having an electrolyte and amino polyalcohol group of copper containing arsenic is adsorbed arsenic to the chelate resin, and then, the chelate resin, wherein the arsenic is adsorbed, sulfuric acid concentration of 50 g / L characterized in that 150 g / L Ri der hereinafter, temperature eluted arsenic adsorbed on the chelate resin in sulfuric aqueous acid solution by contacting the aqueous sulfuric acid solution was maintained in the range of 40 ° C. or higher 85 ° C. less recovery than A method for recovering arsenic from a copper electrolyte. 2. The arsenic solution from a copper electrolyte according to claim 1, wherein the electrolyte solution in contact with the chelate resin is a sulfuric acid copper electrolyte solution having a free sulfuric acid concentration of 100 g / L or more and 400 g / L or less. Collection method. The method for recovering arsenic from a copper electrolyte according to claim 1 or 2 , wherein the aminopolyalcohol group is a glucamine group.