CN117144155A - A method for separating and extracting arsenic-containing phases from copper slag and its application - Google Patents

Abstract

The invention belongs to the field of environmental engineering, and in particular relates to a method for separating and extracting arsenic-containing phases from copper slag. The method includes: 1) adding copper slag to water, heating and dissolving the material, filtering and separating to obtain filter residue A and filtrate A; 2) placing filter residue A in organic acid, dissolving part of the material, filtering and separating to obtain filter residue B and filtrate B. ; 3) Add filter residue B to the non-oxidizing inorganic acid, dissolve part of the material and then filter and separate to obtain filter residue C and filtrate C; 4) Add filter residue C to the alkali solution, heat to dissolve the material and then filter and separate to obtain filter residue D and filtrate. D; 5) Add the filter residue D to the oxidizing acid solution, perform oxidative extraction, and filter to obtain the filter residue E and the filtrate E; 6) Add the filter residue E to the strong oxidizing solution and dissolve it to obtain the extract solution F. The present invention adopts a selective step-by-step extraction method, and each step of extraction is targeted at a specific form of arsenic-containing phase, thereby solving the problem of difficulty in researching the detection of trace arsenic form content in slag.

Description

A method for separating and extracting arsenic-containing phases from copper slag and its application

Technical field

The invention belongs to the field of metallurgy, and in particular relates to a method for separating and extracting arsenic-containing phases from copper slag.

Background technique

Flash smelting slag contains mixed copper and arsenic. Generally, the ore dressing method is used to select the copper-rich slag concentrate back, and the rest is removed from the system as slag tailings. When the ore dressing method is used to recover copper from slag, part of the arsenic enters the selected copper concentrate and part enters the slag tailings. As a heavy metal impurity, arsenic in different forms has very different solubility and chemical stability in water. For example, arsenic oxide/easily soluble arsenate and slightly soluble arsenate have great leaching toxicity. If the proportion of arsenic in this part is high, there is a certain risk that the slag tailings will enter the environment; and silicate glass The arsenic in the phase is stable and safely solidified, and it is relatively safe to enter the slag tailings.

Therefore, a detailed understanding of the occurrence status of arsenic in copper slag is of great significance to guide the safe treatment of slag and tailings, and the recovery of copper from smelting slag.

The occurrence states of arsenic in copper slag are diverse and complex, and the arsenic content in the slag is low (<0.5wt%). Conventional spectroscopic techniques, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS) can only roughly measure the total arsenic content at low concentrations, and cannot accurately identify the occurrence state of arsenic, and cannot analyze the chemical stability of arsenic.

The patent titled "A method for separating and detecting complex mixed arsenic in coal" (CN 103335991 A) discloses a method for separating and detecting complex mixed arsenic in coal, using the selective stepwise extraction (SSE) method. , the arsenic phase in coal is divided into eight occurrence states: water-soluble state, ion exchange state, alkali-soluble organic combined state, insoluble organic combined state, hydrochloric acid extracted state, hydrofluoric acid extracted state, nitric acid extracted state, and strongly bound state. , using the combination of density classification, step-by-step extraction and column chromatography to separate and measure the mixed inorganic and organically bound arsenic in different macroscopic coal and rock components in coal. This program only has reference value for research on soil and sediments. The extracted target products include adsorbed As-Fe co-sediments, organic arsenic, etc. The arsenic in copper smelting slag is a variety of arsenic-containing phases produced by high-temperature slag-making reactions. It basically does not contain phases such as "adsorbed state" and "organic arsenic". Therefore, the traditional step-by-step extraction method is not suitable for high-temperature smelting. Step-by-step extraction and identification of arsenic-containing phases in slag.

Therefore, it is imperative to find a method suitable for separation and extraction of arsenic phases in copper slag.

Contents of the invention

In order to solve the problems that the existing technology cannot separate and extract the arsenic-containing phase in the slag, and it is difficult to conduct in-depth research and determination of the occurrence form of arsenic, the present invention provides a method for separating and extracting the arsenic-containing phase from copper slag. method.

The purpose of the present invention is to: 1. Realize the selective extraction of arsenic-containing phases in slag;

2. Realize the selective separation and determination of arsenic-containing phases in slag;

3. Improve the purity of the extracted arsenic-containing materials and reduce impurities.

In order to achieve the above objects, the present invention adopts the following technical solutions.

A method for separating, extracting and measuring arsenic-containing phases from copper slag, which is characterized by: sequentially extracting copper slag with water, organic acid, non-oxidizing inorganic acid, alkali solution, oxidizing acid solution and strong oxidizing solution , six kinds of extraction liquids were obtained, and the arsenic contents in the six kinds of extraction liquids were measured respectively.

The method includes the following steps:

1) Take copper slag and add it to water, heat to dissolve the material and then filter and separate to obtain filter residue A and filtrate A;

2) Place filter residue A in organic acid, dissolve part of the material and then filter and separate to obtain filter residue B and filtrate B;

3) Add filter residue B to the non-oxidizing inorganic acid, dissolve part of the material and then filter and separate to obtain filter residue C and filtrate C;

4) Add filter residue C to the alkali solution, heat to dissolve the material, and then filter and separate to obtain filter residue D and filtrate D;

5) Add filter residue D to the oxidizing acid solution, perform oxidative extraction, and filter to obtain filter residue E and filtrate E;

6) Add the filter residue E into the strongly oxidizing solution and dissolve it to obtain the extract solution F.

In the above technical solution, the main extraction steps of arsenic-containing phases in copper slag are divided into the following categories. 1. Water-soluble arsenic compounds, including arsenic oxides and sodium and potassium arsenates; 2. Slightly soluble arsenates and amorphous iron arsenates. Slightly soluble arsenates mainly include aluminum, magnesium, and calcium. and other arsenates; 3. Insoluble arsenates, such as crystalline iron arsenate, etc.; 4. Arsenic sulfides, including orpiment, realgar and amorphous arsenic sulfide; 5. Arsenic compounds and insoluble arsenic minerals , including arsenopyrite, copper arsenide, elemental arsenic and other arsenic-containing substances that exist in the form of metallic bonds or atoms; 6. Arsenic in the silicate glass phase.

Based on the above classification, hierarchical extraction is performed as shown in Figure 1. In step 1), based on the properties of alkali metal arsenate being soluble in water and the properties of arsenic oxide dissolving in hot water to form arsenous acid. The reaction equation for dissolving arsenic oxide in hot water is as follows: As ₂ O ₃ +3H ₂ O→2H ₃ AsO ₃ . In step 1), using hot water to dissolve arsenic oxide to remove arsenic oxide can avoid the subsequent reaction of arsenic oxide with acid or alkali or oxidizing compounds to produce impurities, which will affect the determination of each occurrence form in the slag. In step 2), the slightly soluble arsenate can be extracted with organic acid, and its complexing effect promotes the dissolution of the slightly soluble arsenate. Taking magnesium arsenate as an example, the reaction equation is as follows: 4n H ⁺ +C ₆ H ₆ O ₇ ^2- +n Mg ₃ (AsO ₄ ) ₂ →[Mg _3n (C ₆ H ₆ O ₇ )] ^6n-2 + _2nH2AsO4- ^. _{_} The insoluble arsenate in step 3) is represented by iron arsenate, which has extremely low solubility in water and citric acid, but can be dissolved with hydrochloric acid to generate arsenic acid. The reaction equation is as follows: FeAsO ₄ +3H ⁺ →Fe ³⁺ +H ₃ AsO ₄ ; In step 4), arsenic sulfide is extracted with a strong alkaline solution. This is because arsenic sulfide is insoluble in water and acid, but in alkali Thioarsenate or thioarsenite can be generated in a chemical environment. Taking the reaction between sodium hydroxide solution and As ₂ S ₃ as an example, the reaction equation is as follows: As ₂ S ₃ +6NaOH→Na ₃ AsO ₃ +Na ₃ AsS ₃ +3H ₂ O; step 5) combine organic acid and inorganic acid, and add hydrogen peroxide as an oxidant to extract metal arsenide and sulfur arsenic minerals. Because in such intermetallic compounds or arsenic-containing minerals, arsenic often exists in the form of metal bonds or covalent bonds of metal bonds, and is insoluble in non-oxidizing acid and alkaline solutions. Using hydrogen peroxide as the oxidant and inorganic and organic acids to promote dissolution, such arsenic-containing phases in the slag can be effectively extracted. Taking arsenopyrite and copper arsenide as an example, the reaction equation is as follows: FeAsS+7H ₂ O ₂ +H ⁺ →Fe ³⁺ +H ₃ AsO ₄ +SO ₄ ^2- +6H ₂ O, 2Cu ₃ As+11H ₂ O ₂ +12H ⁺ →6Cu ²⁺ +2H ₃ AsO ₄ +14H ₂ O; in step 6), use nitric acid, hydrofluoric acid, and hydrogen peroxide to completely digest the slag, so that As in the remaining residue is completely released. This part of arsenic mainly exists in the slag. In the amorphous silicate glass phase, the existence form is stable. Hydrofluoric acid can destroy the silicon-oxygen bond and release arsenic in the glass phase. The reaction equation of hydrofluoric acid and silicon dioxide is as follows: SiO ₂ +4HF = SiF ₄ ↑+2H ₂ O.

As a preference,

During the heating and dissolving process described in step 1): the heating temperature is 80 to 100°C, and the duration is 2 to 4 hours.

The above parameters can speed up the dissolution process and improve the dissolution efficiency, and can more effectively improve the separation efficiency of alkali metal arsenate.

As a preference,

Step 2) The organic acid is citric acid, and the concentration of the citric acid solution is 0.5-0.8wt%;

The dissolution process is carried out at 25-35°C and lasts for 1-3 hours.

The above concentration of citric acid can more effectively remove the slightly soluble arsenate in the copper slag and promote the dissolution and separation of the slightly soluble arsenate through the complexing effect. Moreover, citric acid itself is not strongly acidic or oxidizing, and can achieve high-purity, targeted extraction and separation.

As a preference,

Step 3) The hydrogen ion concentration in the non-oxidizing inorganic acid is 1 to 3 mol/L;

The dissolution process is carried out at 25-80°C and lasts for 1-3 hours.

The optimal choice for the above-mentioned inorganic acid is hydrochloric acid, which is laboratory hydrochloric acid with a concentration of 36 to 38 wt%.

Under the above conditions, hydrochloric acid can be used to effectively dissolve and separate poorly soluble arsenates such as iron arsenate.

As a preference,

Step 4) The alkali solution is an alkali metal hydroxide solution;

The concentration of the alkali solution is 1 to 3 mol/L, and the dissolution process is carried out at 70 to 90°C and lasts for 1 to 3 hours.

Sodium hydroxide and potassium hydroxide are both readily available alkali metal compounds and are highly alkaline. Through its strong alkalinity, it can effectively extract arsenic sulfide and form thioarsenate or sixth-generation arsenite for effective separation.

As a preference,

Step 5) The oxidizing acid solution contains glacial acetic acid and hydrogen peroxide, and the pH value is adjusted to acidic with non-oxidizing acid;

The dissolution process is carried out at 60-70°C and lasts for 2-4 hours.

Among them, inorganic acids and non-oxidizing acids are used to promote hydrogen peroxide to improve its oxidizing properties. Under the above conditions, it has relatively better extraction and separation efficiency and extraction and separation effect.

As a preference,

In step 5), the glacial acetic acid content in the oxidizing acid solution is 35-45wt%, the hydrogen peroxide content is 4-6wt%, and the non-oxidizing inorganic acid content is 1.6-2.5wt%.

The above-mentioned oxidizing acid itself is a strong acid, which can effectively separate and extract metal arsenic compounds and sulfur arsenic minerals.

As a preference,

Step 6) The strong oxidizing solution contains nitric acid, hydrogen fluoride and hydrogen peroxide;

The dissolution process lasts for 0.5 to 2 hours.

Under the above conditions, the residual As in the amorphous silicate glass phase in copper slag can be effectively separated. Hydrogen fluoride plays a key role in destroying the silicon-oxygen bond, making it the key to effective extraction.

As a preference,

The nitric acid concentration is 20-25wt%;

The hydrogen fluoride concentration is 8-10wt%;

The hydrogen peroxide concentration is 10-15wt%.

Under the above concentration ratio, the extraction and separation effect of As in the amorphous silicate glass phase is optimal.

Application of a method for separating and extracting arsenic-containing phases from copper slag,

The method can also be used for purifying copper slag and/or refining arsenic.

The solution of the present invention can realize effective arsenic removal and purification treatment of copper slag, and can also separate arsenic in various phases at the same time, and the separated arsenic can be used for refining or reprocessing.

The beneficial effects of the present invention are:

1) Using a selective step-by-step extraction method, the arsenic-containing phases present in the slag are carefully divided. Each extraction step targets a specific form of arsenic-containing phase, solving the problem of detecting trace forms of arsenic in the slag and its various forms. Difficult issues in studying morphological content;

2) The specific occurrence form of arsenic in the slag is identified, which is of great significance for in-depth understanding of the behavior of arsenic in the copper smelting process and has practical application;

3) The precise determination of arsenic-containing species is an important reference for evaluating the arsenic stability and leaching toxicity of slag;

4) The required extraction solutions are all commonly used reagents, which are low-cost and easy to operate.

Description of the drawings

Figure 1 is a process flow diagram of selective extraction in Embodiment 1 of the present invention;

Figure 2 is an XRD pattern of the slag used in Example 1 of the present invention;

Figure 3 is a mass distribution diagram of arsenic phases extracted in each step of Examples 1 to 3 of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. A person of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention mentioned in the following description are generally only some embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of the present invention.

Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or those available to those skilled in the art. Unless otherwise specified, the methods used in the examples of the present invention are all methods mastered by those skilled in the art.

Example 1

A method for separating and extracting arsenic-containing phases from copper slag,

The method includes the following steps:

1) Extract water-soluble arsenic in copper slag: Add an appropriate amount of deionized water to an Erlenmeyer flask, heat to 80°C, grind the slag sample until it can pass through a 30-mesh screen, and add the slag to deionized water at a ratio of 10g/L. In the above-mentioned Erlenmeyer flask, oscillate in a constant-temperature water bath for 4 hours in a horizontal oscillator, filter with suction, and separate the filtrate and residue A. Use ICP-MS to detect the As concentration in the filtrate;

2) Extract slightly soluble arsenate and amorphous iron arsenate: add an appropriate amount of 0.5wt% citric acid solution into an Erlenmeyer flask and keep it warm at 25°C. Add residue A to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 3 hours, filter with suction, and separate the filtrate and residue B. Use ICP-MS to detect the As concentration in the filtrate;

3) Extract poorly soluble arsenate: Add an appropriate amount of 1mol/L hydrochloric acid solution into an Erlenmeyer flask and keep it warm at 25°C. Add residue B into the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 3 hours, filter with suction, and separate the filtrate and residue C. Use ICP-MS to detect the As concentration in the filtrate;

4) Extract arsenic sulfide: Add an appropriate amount of 1mol/L NaOH solution into an Erlenmeyer flask and keep it warm at 70°C. Add residue C to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 3 hours, filter with suction, and separate the filtrate and residue D. Use ICP-MS to detect the As concentration in the filtrate;

5) Extract arsenic compounds and insoluble arsenic minerals: Mix deionized water, glacial acetic acid, 30wt% hydrogen peroxide, and 36wt% concentrated hydrochloric acid in a volume ratio of 8:8:3:1 and add them to an Erlenmeyer flask, and heat to 60°C. , add residue D into the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator, add 2 ml of hydrogen peroxide dropwise every 10 minutes, filter after 4 hours, and separate the filtrate and residue E. Use ICP-MS detects the As concentration in the filtrate;

6) Extract arsenic in the silicate glass phase: Mix 68wt% concentrated nitric acid, 48wt% hydrofluoric acid, and 30wt% hydrogen peroxide in a volume ratio of 3:2:5 and add them to a conical flask. Add the residue E to the above conical flask. In the bottle, control the solid-liquid ratio to 10g/L. After it is completely dissolved, use ICP-MS to detect the As concentration in the filtrate.

After testing, the chemical element composition of the copper slag used in this example is shown in the table below.

element Fe Si As Cu S Al Ca Mg Na Zn Pb Content(wt%) 42.40 13.82 0.30 2.18 0.17 2.28 1.77 0.6 5.36 0.41 0.10

Perform statistical calculations on the phase distribution of arsenic extracted in each step of this example and characterize the purity. The results are shown in the table below.

Example 2

A method for separating and extracting arsenic-containing phases from copper slag,

The method includes the following steps:

1) Extract water-soluble arsenic from the slag sample: add an appropriate amount of deionized water to an Erlenmeyer flask, heat to 90°C, grind the slag sample until it can pass through a 60-mesh screen, and add the slag to deionized water at a ratio of 10g/L. In the above-mentioned Erlenmeyer flask, oscillate in a constant-temperature water bath for 3 hours in a horizontal oscillator, filter with suction, and separate the filtrate and residue A. Use ICP-MS to detect the As concentration in the filtrate;

2) Extract slightly soluble arsenate and amorphous iron arsenate: add an appropriate amount of 0.5wt% citric acid solution into an Erlenmeyer flask and keep it warm at 35°C. Add residue A to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 1 hour, filter with suction, and separate the filtrate and residue B. Use ICP-MS to detect the As concentration in the filtrate;

3) Extract poorly soluble arsenate: Add an appropriate amount of 1mol/L hydrochloric acid solution into an Erlenmeyer flask and keep it warm at 80°C. Add residue B to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 2 hours, filter with suction, and separate the filtrate and residue C. Use ICP-MS to detect the As concentration in the filtrate;

4) Extract arsenic sulfide: Add an appropriate amount of 1mol/L NaOH solution into an Erlenmeyer flask and keep it warm at 90°C. Add residue C to the above Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 1 hour, filter with suction, and separate the filtrate and residue D. Use ICP-MS to detect the As concentration in the filtrate;

5) Extract arsenic compounds and insoluble arsenic minerals: Mix deionized water, glacial acetic acid, 30% hydrogen peroxide, and 36wt% concentrated hydrochloric acid in a volume ratio of 8:8:3:1 and add them to an Erlenmeyer flask, and heat to 70°C. , add residue D into the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator, add 2 ml of hydrogen peroxide dropwise every 10 minutes, filter after 2 hours, separate the filtrate and residue E, and use ICP-MS detects the As concentration in the filtrate;

6) Extract arsenic in the silicate glass phase: Mix 68wt% concentrated nitric acid, 48wt% hydrofluoric acid, and 30wt% hydrogen peroxide in a volume ratio of 3:2:5 and add them to a conical flask. Add the residue E to the above conical flask. In the bottle, control the solid-liquid ratio to 10g/L. After it is completely dissolved, use ICP-MS to detect the As concentration in the filtrate.

After testing, the chemical element composition of the copper slag used in this example is shown in the table below.

element Fe Si As Cu S Al Ca Mg Na Zn Pb Content(wt%) 42.40 13.82 0.30 2.18 0.17 2.28 1.77 0.6 5.36 0.41 0.10

Statistical calculation was performed on the arsenic phase distribution extracted in each step of this example, and the results are shown in the table below.

Example 3

A method for separating and extracting arsenic-containing phases from copper slag,

The method includes the following steps:

1) Extract water-soluble arsenic in slag samples: Add an appropriate amount of deionized water to an Erlenmeyer flask, heat to 100°C, grind the slag samples until they can pass through a 100-mesh screen, and add the slag to deionized water at a ratio of 10g/L. In the above-mentioned Erlenmeyer flask, oscillate in a constant-temperature water bath for 2 hours in a horizontal oscillator, filter with suction, and separate the filtrate and residue A. Use ICP-MS to detect the As concentration in the filtrate;

2) Extract slightly soluble arsenate and amorphous iron arsenate: add an appropriate amount of 0.8wt% citric acid solution into an Erlenmeyer flask and keep it warm at 25°C. Add residue A to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 2 hours, filter with suction, and separate the filtrate and residue B. Use ICP-MS to detect the As concentration in the filtrate;

3) Extract poorly soluble arsenate: Add an appropriate amount of 3mol/L hydrochloric acid solution into an Erlenmeyer flask and keep it warm at 80°C. Add residue B to the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 2 hours, filter with suction, and separate the filtrate and residue C. Use ICP-MS to detect the As concentration in the filtrate;

4) Extract arsenic sulfide: Add an appropriate amount of 2mol/L NaOH solution into an Erlenmeyer flask and keep it warm at 80°C. Add residue C into the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator for 2 hours, filter with suction, and separate the filtrate and residue D. Use ICP-MS to detect the As concentration in the filtrate;

5) Extract arsenic compounds and insoluble arsenic minerals: Mix deionized water, glacial acetic acid, 30wt% hydrogen peroxide, and 36wt% concentrated hydrochloric acid in a volume ratio of 8:8:3:1 and add them to an Erlenmeyer flask, and heat to 70°C. , add residue D into the above-mentioned Erlenmeyer flask, control the solid-liquid ratio to 10g/L, oscillate in a constant-temperature water bath in a horizontal oscillator, add 2 ml of hydrogen peroxide dropwise every 10 minutes, filter after 4 hours, and separate the filtrate and residue E. Use ICP-MS detects the As concentration in the filtrate;

6) Extract arsenic in the silicate glass phase: Mix 68wt% concentrated nitric acid, 48wt% hydrofluoric acid, and 30wt% hydrogen peroxide in a volume ratio of 3:2:5 and add them to a conical flask. Add the residue E to the above conical flask. In the bottle, control the solid-liquid ratio to 10g/L. After it is completely dissolved, use ICP-MS to detect the As concentration in the filtrate.

After testing, the chemical element composition of the copper slag used in this example is shown in the table below.

element Fe Si As Cu S Al Ca Mg Na Zn Pb Content(wt%) 42.40 13.82 0.30 2.18 0.17 2.28 1.77 0.6 5.36 0.41 0.10

Statistical calculation was performed on the arsenic phase distribution extracted in each step of this example, and the results are shown in the table below.

step S1 S2 S3 S4 S5 S6 Arsenic distribution ratio % 0.55 4.09 9.14 17.87 11.87 56.48 Arsenic phase purity (%) 99.8 99.6 99.5 99.9 99.5 99.5

It can be clearly seen from the above-mentioned Examples 1 to 3 that the method of the present invention can effectively realize the effect of stepwise separation and extraction of arsenic phases. At the same time, the distribution ratios of the arsenic phase extraction results of the above-mentioned Examples 1 to 3 were integrated to obtain a distribution diagram as shown in Figure 3. It can be seen from the figure that the concentration, dosage and processing parameters (temperature, time) of reagents in each step will have a significant impact on the extraction and separation effect in a single step.

Moreover, compared with the smelting and extraction methods of ores in the prior art, the present invention can be more effectively used for the slag produced by smelting, can effectively separate and remove the arsenic phase in the slag, and can be used for the recycling and utilization of valuable metals. The study of the morphology and content of arsenic phases in slag is of great significance.

Comparative ratio

Based on the specific implementation of each step in Example 1, only in the case of changing the order of the steps, the arsenic phase in the copper slag was separated and extracted, and the arsenic product distribution ratio and arsenic phase purity at each stage were characterized. .

After testing, the chemical element composition of the copper slag used in this example is shown in the table below.

element Fe Si As Cu S Al Ca Mg Na Zn Pb Content(wt%) 42.40 13.82 0.30 2.18 0.17 2.28 1.77 0.6 5.36 0.41 0.10

The specific results are shown in the table below.

It can be clearly seen from the above sets of comparative examples that the technical solution of the present invention has strict requirements for controlling the sequence of steps. Changes in the order of steps will have a significant impact, especially moving the S1 step later, which will lead to a significant decrease in the purity of the arsenic phase obtained from the preceding steps. Comparative Example 1, Comparative Example 2, Comparative Example 3, etc., and it can be seen that the extraction sequence of the original effective process of the present invention focuses on reducing the interference of by-products on the subsequent extraction process, and it is not a simple extraction from easy to difficult. The timing is based on the extraction range corresponding to the method, and is carried out in a post-package manner to ensure that the pre-steps do not affect the post-steps, and the post-steps basically include the extraction range of the pre-steps to a certain extent. Therefore, for the selection of extraction methods and Sorting is the core of the solution of the present invention.

Claims (10)

1. A method for separating and extracting arsenic-containing phase from copper slag is characterized in that,

the method comprises the following steps:

1) Adding copper slag into water, heating and dissolving materials, and filtering and separating to obtain filter residue A and filtrate A;

2) Placing the filter residue A in organic acid, dissolving part of materials, and filtering and separating to obtain filter residue B and filtrate B;

3) Adding the filter residue B into non-oxidizing inorganic acid, dissolving part of materials, and filtering and separating to obtain filter residue C and filtrate C;

4) Adding the filter residue C into alkali liquor, heating and dissolving materials, and filtering and separating to obtain filter residue D and filtrate D;

5) Adding the filter residue D into an oxidizing acid solution, performing oxidation extraction, and filtering to obtain filter residue E and filtrate E;

6) And adding the filter residue E into the strong oxidizing solution, and dissolving to obtain an extracting solution F.

2. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

in the heating and dissolving process of the step 1): the heating temperature is 80-100 ℃ and the duration time is 2-4 h.

3. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

the organic acid in the step 2) is citric acid, and the concentration of the citric acid solution is 0.5-0.8 wt%;

the dissolution process is carried out at 25-35 ℃ for 1-3 hours.

4. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

step 3), the concentration of hydrogen ions in the non-oxidative inorganic acid is 1-3 mol/L;

the dissolution process is carried out at 25-80 ℃ for 1-3 hours.

5. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

step 4) the alkali liquor is alkali metal hydroxide solution;

the concentration of the alkali liquor is 1-3 mol/L, and the dissolution process is carried out at 70-90 ℃ for 1-3 h.

6. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

step 5), glacial acetic acid and hydrogen peroxide are contained in the oxidizing acid solution, and the pH value is adjusted to be acidic by non-oxidizing acid;

the dissolution process is carried out at 60-70 ℃ for 2-4 hours.

7. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 6,

the content of glacial acetic acid in the oxidizing acid solution in the step 5) is 35-45 wt%, the content of hydrogen peroxide is 4-6 wt% and the content of non-oxidizing inorganic acid is 1.6-2.5 wt%.

8. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 1,

step 6), the strong oxidizing solution contains nitric acid, hydrogen fluoride and hydrogen peroxide;

the dissolution process lasts for 0.5-2 hours.

9. A process for the separation and extraction of an arsenic-containing phase from copper slag according to claim 8,

the concentration of the nitric acid is 20-25 wt%;

the concentration of the hydrogen fluoride is 8-10wt%;

the concentration of the hydrogen peroxide is 10-15 wt%.

10. The use of a method according to any one of claims 1 to 9,

the method is used for purifying copper slag and/or refining arsenic.