KR950007786B1 - Method of slime treatment with copper & arsenic - Google Patents

Abstract

The method for separating and recovering copper and arsenic from As slime sludge, comprises: leaching the As slime sludge in H2SO4, and separating the leached residues and the reached solution; extracting the leached solution with mixing solvent of 2-hydroxy-5-nonylacetophenone oxime and kerosene, and separating Cu-contg. organic substance and As-contg. extracted residues; and stripping the Cu-contg. organic substance to copper sulfate solution to obtain pure copper sulfate solution, and obtaing As2O3 by reducing the As-contg. residues with sulfide gas, acidifying by addition of sulfuric acid and evaporating in turn.

Description

Treatment method of all materials containing copper (Cu) and arsenic (As)

Attached drawing is process chart of non-sintered material.

The present invention relates to a method for separating and recovering Cu (copper) and As (arsenic) from an arsenic material, and more particularly, to separate and process an electrodeposited material containing Cu and As generated during electrowinning. The present invention relates to a method for treating raw materials containing copper and arsenic, wherein copper-containing solutions are reused and arsenic solutions are recovered in the form of arsenic acid.

In general, copper ore makes an intermediate product in molten furnaces such as smelters, reflectors, etc., and makes crude copper in converters, electric furnaces, etc. and removes sulfur (S) and oxygen from refineries. However, this refined crude copper still contains impurities and valuable metals, which are by-products to be recovered, and thus, refined refining is easy to remove impurities and recover by-products, thereby obtaining pure copper called electrophoresis.

In electrolytic refining, a copper sulfate solution containing a large amount of free sulfuric acid is used as an electrolyte, and the anode is cast as a positive electrode by casting a copper containing impurity.The cathode is a pure copper end plate, and when a current is passed, Cu is dissolved in the anode. Pure copper (more than 99.99%) precipitates at the cathode.

At this time, any of impurities contained in the positive electrode do not dissolve but remain under the electrolytic cell to precipitate as an anode slime, and electrochemically more chemical elements are dissolved and enter the electrolyte.

One element that dissolves is arsenic, and as time passes, arsenic eluted from the anode gradually increases, and copper eluted from the anode is larger than precipitated copper from the cathode, so copper content in the electrolyte increases while sulfuric acid decreases. Therefore, part of the electrolyte is removed from the circulation system and the new electrolyte is replenished. The withdrawn electrolyte is desorbed and degreased by electrowinning.

At this time, when electrolytic extraction is performed with anode as insoluble material and cathode as pure plate as end plate, copper in electrolyte is extracted from cathode, but many arsenic including copper is electrodeposited on the bottom of the tank. Referred to below)

This non-sintered body is a slime phase containing Cu ₃ As as a main component, and also contains Cu ₂ As, Bi, Sb, Pb, and the like. When the arsenic material is returned to the smelting process, a large amount of arsenic is accumulated in the smelting system.

In the situation where copper ore with a large amount of arsenic needs to be used as described above, the amount of arsenic circulating increases, which adversely affects the quality of electrical and electronic products that maintain high purity.

Therefore, the off-system treatment of arsenic becomes an important problem in order to circulate and use the whole thing containing such arsenic in a smelting process.

The out-of-system treatment of non-sintered materials includes dry buck and wet methods, but in the dry method, inevitably, flue gas dust treatment containing As ₂ O ₃ is inevitable, and equipment costs such as pollution prevention facilities are high, especially in response to environmental regulations. The treatment by wet method should be considered.

Japanese Patent Application Laid-Open No. 54-6959 is known as a wet treatment method. In this process, non-sintered materials are oxidized and slurried, and sodium hydroxide is added to leach, and lime is added to the leach liquor. Calcium arsenate produced by addition is dissolved with sulfuric acid and separated into gypsum and arsenic acid. In addition, fugitive is reduced to sulfurous acid gas.

However, in such a method, since arsenic-containing gypsum is produced, there is a problem in the gypsum treatment and a double leaching operation is required for arsenic including loss of sodium hydroxide.

Accordingly, the present invention is to provide a wet treatment method for recovering copper and arsenic contained in non-sintered materials in the form of valuables without circulating the non-sintered materials in a smelting process as in the prior art. By separating copper and arsenic, the solution containing copper is returned to the electrolytic process and the arsenic solution is recovered in the form of arsenic acid.

Hereinafter, the present invention will be described.

The present invention is a process of leaching arsenic containing copper and arsenic with sulfuric acid to obtain a leaching media and leaching solution, and extracting the leaching solution with a mixed solvent to separate the organic phase containing copper and the extraction residue containing arsenic and an organic solvent. The extraction step, the organic phase containing the copper is removed with a copper sulfate solution to obtain a high-purity copper sulfate solution, and the extraction residue containing arsenic is reduced with sulfurous acid gas, acidified and concentrated to evaporate arsenic acid In this process, copper and arsenic are separated and recovered.

The mixed solvent used in the present invention refers to a mixture of a LIX solvent (trade name of Henkel, USA) and a diluent.

LI-based solvent here means LIX84, 2-hydroxy-5-nonylacetophenone Oxime, and the diluent is Kerosine.

The accompanying drawings will be described in detail according to the manufacturing process diagram of the present invention.

It can be carried out in two stages of leaching. In the first stage leaching, the solution is leached with a weak acid in order to obtain a pH = 1.7 solution suitable for the solvent extraction process, and the filtrate is separated into a leaching medium and a leaching solution. The leaching solution thus obtained is sent to a solvent extraction process, the leaching medium is leached with a strong acid in two stages, and the leachate is filtered and separated into a leaching medium and a leaching solution.

This second stage leaching is to recycle the remaining copper and arsenic in the leaching media from the first stage.

The leaching solution obtained in the step 1 leaching process is extracted and separated into an extraction residue containing an organic phase containing ions and arsenic using a mixed solvent of a LIX solvent and a diluent in a solvent extraction step. At this time, the contact ratio (O / A = Organic Phase / Agueous Phase) of the solvent mixture and the leachate may be performed in 3-7. “O” is a mixed solvent of LIX and Kerosene in a volume ratio of 2: 8, and “A” is a one-step leach solution.

Here, the mixing composition of the non-sintered material is not constant, and the contents of copper and arsenic in the non-sintered material may change according to respective working conditions (electrolytic extraction). That is, when the copper content is changed from 25wt% to 45wt%, the O / A ratio may be changed from 3 to 7. The O / A ratio may also vary depending on the nature of the solvent.

As described above, the mixed solvent used in the present invention may be converted according to the quality of the non-sintered material, and thus the O / A ratio of 327 is merely an example. Therefore, the present invention is not limited to the above numerical range.

The organic phase containing copper ions separated in the extraction process is removed with a sulfur phase copper solution to obtain a high purity copper sulfate solution, and the solvent is washed with water and reused in the extraction process.

On the other hand, the extraction residue (arsenic-containing solution) from which the copper is removed is reduced to arsenic (V) using arsenic acid gas, followed by acidification with sulfuric acid, and then concentrated by evaporation to extract arsenic acid to solid-liquid separation.

The crystallization medium obtained at this time is moved to the two-step leaching process.

The following is described according to the embodiment.

A leaching of 75 g of arsenic material containing 27.82 wt% copper and 26.47 wt% arsenic was carried out in two steps under the following conditions.

Stage 1 Leaching Conditions

Sulfuric acid concentration: 30g / l

Leaching time: 4Hr

-Phlp density: 150g / l

Leaching temperature: 90 ℃

Air pressure: 1Kg / cm ² , air supply to 10mmΦ glass cupboard

In the first stage leaching, 500mml of leachate was obtained and the composition of leachate was as follows.

TABLE 1

Stage 2 Leaching Conditions

Sulfuric acid concentration: 90g / l

Leaching time: 4Hr

-Phlp density: 150g / l

Leaching temperature: 90 ℃

Air pressure: 1Kg / cm ² , air supply to 10mmΦ glass cupboard

In the first stage leaching, the leaching media obtained were leached under the above two stage leaching conditions to obtain 2.6 gr of a two stage leaching media having the following composition.

TABLE 2

As described above, the total leaching rates of the first and second stages were As 97% and Cu 99% or more. The first stage leaching solution was carried out in a multi-stage solvent extraction apparatus under the following conditions.

Solvent Extraction Conditions

1) Extraction

-Feel sol'n: Stage 1 leachate

Solvent: LIX84 (20Vol% in Kerosene)

-pH: (adjusted to 1.7 as ammonia water)

Contact ratio (O / A ratio): 5.5

-Single stage: 4 stage

2) Stripping

Strip sol'n: Cu 25g / l, H ₂ SO ₄ : 200g / l

O / A ratio: 2

-Single stage: 2 stage

* O / A in ˝O˝ will rough the extraction step with a mixed solvent of copper ion loading, A is also a deodorizing liquid (25g Cu / l, H ₂ Composition of SO ₄ 200g / l)

Quantity of solvent extraction (Cu, As)

TABLE 3

By the above solvent extraction, 1325 ml of copper stripping solution (Pregnatn Strip sol'n) and 500 ml of arsenic-containing extract (Raffinate) were obtained, and the composition of each was as described above. Cu was 99% and As 96% or more.

In order to recover arsenic in the form of arsenic from 500 ml of the extract (Raffinate sol'n) obtained by the solvent extraction as described above, arsenic acid was purified under the following conditions.

Absorption conditions

1) Sulfur Dioxide Reduction: 3Hr at 600ml / min at room temperature

2) Acidification and evaporation were performed to determine the arsenic acid using the solubility difference of As (III) according to sulfuric acid concentration.

Acidification treatment: 500 ml of a solution of 735 g / l H ₃ SO ₄ was added to the sulfurous acid gas reduction filtrate.

Evaporative concentration: up to 1/2 of the volume before evaporative concentration.

By the above arsenic acid crystallization process, 5.96 gr of arsenic acid crystals and 500 ml of crystallized liquid were obtained, and the composition of each was as follows.

TABLE 4

Arsenic recovery was more than 83%.

As a result, considering the solvent extraction and extraction process from the first stage leachate, the copper recovery rate is over 99% and the arsenic recovery rate is over 80%, thus separating and recovering copper and arsenic from raw materials containing copper and arsenic. Will be provided.

Claims (2)

Leaching arsenic containing copper (Cu) and arsenic (As) with sulfuric acid (H ₂ SO ₄ ) to separate the leaching media and leaching liquors, and separating the leaching liquor into 2-hydroxy-5-noni Solvent extraction process of extracting with a mixed solvent mixed with 2-hydvoxy-5-nonylacetophenone oxime and kerosene and separating it into an organic phase containing copper and an extract residue containing arsenic, The organic phase containing copper is removed with a copper sulfate solution to obtain a high-purity copper sulfate solution, and the extraction residue containing arsenic is reduced with sulfurous acid gas, acidified by adding sulfuric acid, and then evaporated and concentrated to arsenic acid (AS ₂ O ₃ ). Method of treating the whole thing containing copper and arsenic, characterized in that consisting of a process of crystallization. According to claim 1, leaching in two stages, one leaching as a weak acid to separate the leaching media and leaching liquor, the leaching liquor is sent to the solvent extraction process, the leaching media through the first step is leached two stages using a strong acid A method of treating whole materials containing copper and arsenic, wherein the leachate is separated into a leachate and a leachate, and the leachate is circulated in the above-described one-step leaching process.