CN117701903A - A method for recovering copper telluride from copper telluride slag - Google Patents

Abstract

The invention provides a method for recovering copper telluride from copper telluride slag, and belongs to the field of high-purity metal preparation. The method provided by the invention includes the following steps: mixing copper telluride slag and sulfuric acid solution and then roasting to obtain a roasted product containing TeO ₂ and CuSO ₄ ; the copper telluride in the copper telluride slag and the H in the sulfuric acid solution The material amount ratio of ₂ SO ₄ is 1:2; the roasted product is mixed with carbon powder and then vacuum carbothermal reduction distillation is performed to obtain crude tellurium vapor and copper-rich products; the crude tellurium vapor is cooled and then Vacuum distillation to obtain refined tellurium. The present invention controls the ratio of the amount of copper in the copper telluride slag to the sulfate radicals in the sulfuric acid solution, so that the sulfuric acid and copper in the sulfuric acid solution generate copper sulfate without generating waste acid; and through vacuum carbothermal reduction distillation and vacuum The vacuum environment of the distillation increases efficiency.

Description

A method for recovering copper telluride from copper telluride slag

Technical field

The invention relates to the field of high-purity metal preparation, and in particular to a method for recovering copper telluride from copper telluride slag.

Background technique

Tellurium is a rare metal that occurs in very low amounts in the Earth's crust, with an average crustal abundance estimated at 6 ppm and an extremely scattered distribution. In terms of utilizing tellurium resources, extracting copper telluride as a tellurium resource in traditional metallurgy is the key. In addition, it is also very important to develop tellurium recycling technology from secondary resources.

Copper telluride slag is a tellurium-rich substance produced when copper smelters extract precious metals from anode mud. It usually exists in the form of Cu ₂ Te, Ag ₂ Te, Au ₂ Te and other compounds together with copper, gold, silver and other elements. The current methods for extracting tellurium from copper telluride slag include normal pressure oxidation alkali leaching, oxidation acid leaching, sulfation roasting, pressurized acid leaching and extraction separation. However, the current method of treating copper telluride slag has problems such as high production cost, long process flow, and waste generation. With the development of high and new technologies, the demand for tellurium and its metal compounds continues to grow. Issues such as how to separate tellurium from copper telluride slag with high efficiency, high purity and high recovery rate and reduce costs have become the focus of research.

In Chinese Patent No. CN104445101A, a new method for recovering tellurium copper from tellurium copper slag is disclosed. This method involves mixing copper telluride slag, sulfuric acid and hydrogen peroxide and performing oxidative leaching to obtain a leachate. Subsequently, an oxalic acid decoppering agent is added to the leachate to produce copper oxalate and oxalic acid decoppered liquid. Next, a reducing agent (sulfous acid and sulfur dioxide gas) is added to the decoppered liquid to react, thereby obtaining tellurium.

In addition, Chinese patent number CN10445101A also proposes a method for comprehensive recovery of silver, selenium, tellurium and copper. The method is to add copper telluride slag to a dilute sulfuric acid solution containing an oxidant for heating and leaching. Subsequently, sodium hydroxide is added to the acid leaching residue for leaching. Refined tellurium can be obtained from alkali leaching solution through processes such as purification, precipitation, calcination, and electrolysis. At the same time, the alkali leaching residue is returned to the Kaldor furnace to recover silver and selenium.

The above two methods of recycling tellurium copper will produce a certain amount of waste acid and waste alkali and have low efficiency.

Contents of the invention

The object of the present invention is to provide a method for recovering copper telluride from copper telluride slag, which does not produce waste acid and is highly efficient.

In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

The invention provides a method for recovering copper telluride from copper telluride slag, which includes the following steps:

Mix copper telluride slag and sulfuric acid solution and then roast them to obtain a roasted product containing TeO ₂ and CuSO ₄ ;

The ratio of the amount of copper telluride in the copper telluride slag to the H ₂ SO ₄ in the sulfuric acid solution is 1:2;

The roasted product is mixed with carbon powder and then subjected to vacuum carbothermal reduction distillation to obtain crude tellurium vapor and copper-rich products;

The crude tellurium vapor is cooled and then vacuum distilled to obtain refined tellurium.

Preferably, the particle size of the copper telluride slag is 80 to 120 mesh.

Preferably, the mass concentration of the sulfuric acid solution is 98%.

Preferably, the roasting temperature is 500-600°C and the roasting time is 1-2 hours.

Preferably, the mass of the roasted product and carbon powder is 1:1-2.

Preferably, the particle size of the carbon powder is 50 to 400 mesh.

Preferably, the temperature of the vacuum carbothermal reduction distillation is 450-650°C, the vacuum degree is 10-30 Pa, and the time is 60-120 minutes.

Preferably, the temperature of the vacuum distillation is 450-650°C, the vacuum degree is 10-30 Pa, and the time is 45-90 minutes.

The invention provides a method for recovering copper telluride from copper telluride slag, which includes the following steps: mixing copper telluride slag with a sulfuric acid solution and then roasting to obtain a roasted product containing _TeO2 and _CuSO4 ; the telluride The ratio of the amount of copper telluride in the copper slag to the H ₂ SO ₄ in the sulfuric acid solution is 1:2; the roasted product is mixed with carbon powder and then vacuum carbothermal reduction distillation is performed to obtain crude tellurium vapor and Copper-rich product; the crude tellurium vapor is cooled and then vacuum distilled to obtain refined tellurium. The present invention controls the ratio of the amounts of copper telluride in the copper telluride slag and H ₂ SO ₄ in the sulfuric acid solution, so that the sulfuric acid in the sulfuric acid solution reacts with the copper telluride to exactly generate copper sulfate and tellurium oxide, No waste acid is produced; and the efficiency is improved through the vacuum environment of vacuum carbothermal reduction distillation and vacuum distillation.

Description of the drawings

Figure 1 is a process flow diagram of an embodiment of the present invention;

Figure 2 is the XRD pattern of the copper-rich product in Example 1;

Figure 3 is the XRD pattern of crude tellurium and copper-rich products in Example 1;

Figure 4 is an XRD pattern of crude tellurium in Example 1;

Figure 5 is an XRD pattern of purified tellurium in Example 1.

Detailed ways

The invention provides a method for copper telluride slag, which includes the following steps:

The copper telluride slag is mixed with the sulfuric acid solution and then roasted to obtain a roasted product containing TeO ₂ and CuSO ₄ ;

The ratio of the amount of copper telluride in the copper telluride slag to the H ₂ SO ₄ in the sulfuric acid solution is 1:2;

The roasted product is mixed with carbon powder and then subjected to vacuum carbothermal reduction distillation to obtain crude tellurium vapor and copper-rich products;

The crude tellurium vapor is cooled and then vacuum distilled to obtain refined tellurium.

In the present invention, copper telluride slag and sulfuric acid solution are mixed and then roasted to obtain a roasted product containing TeO ₂ and CuSO ₄ .

In the present invention, the particle size of the copper telluride slag is preferably 80 to 120 mesh, more preferably 90 to 100 mesh; the tellurium content in the copper telluride slag is preferably 35.39wt%, and the copper content is preferably 34.28wt. %.

In the present invention, the ratio of the amounts of copper telluride in the copper telluride slag to H ₂ SO ₄ in the sulfuric acid solution is 1:2, and the mass concentration of the sulfuric acid solution is preferably 98%.

In the present invention, the calcining temperature is preferably 500 to 600°C, more preferably 550 to 580°C; the roasting time is preferably 1 to 2 hours. The reaction equation that occurs during the roasting process is:

Cu ₂ Te+2H ₂ SO ₄ +2O ₂ =2CuSO ₄ +TeO ₂ +2H ₂ O

After obtaining the roasted product, the present invention mixes the roasted product with carbon powder and then sequentially performs vacuum carbothermal reduction distillation to obtain crude tellurium vapor and copper-rich products.

In the present invention, the mass ratio of the roasted product to the carbon powder is preferably 1:1-2; the particle size of the carbon powder is preferably 50-400 mesh, more preferably 100-200 mesh.

In the present invention, the temperature of the vacuum carbothermal reduction distillation is preferably 450~650°C, more preferably 500~550°C; the vacuum degree is preferably 10~30Pa, more preferably 15~20Pa; and the time is preferably 60~ 120min, more preferably 70-80min.

After obtaining the crude tellurium vapor, the present invention cools the crude tellurium vapor and then performs vacuum distillation to obtain refined tellurium.

In the present invention, the temperature of the vacuum distillation is preferably 450-650°C, more preferably 500-550°C, the vacuum degree is preferably 10-30Pa, more preferably 15-20Pa; the time is preferably 45-90min, more preferably It is 60~80min.

The process flow chart of the method of the embodiment of the present invention is shown in Figure 1: copper telluride slag is mixed with sulfuric acid and then roasted to obtain a roasted product; the roasted product is mixed with carbon powder and subjected to vacuum reduction distillation to obtain crude tellurium and rich Copper product; the crude tellurium is subjected to secondary vacuum distillation to obtain refined tellurium (product) and crude tellurium and copper-rich products; the crude tellurium and copper-rich products can be reused in the vacuum reduction finishing step.

The method for recovering copper telluride from copper telluride slag provided by the present invention will be described in detail below with reference to the examples, but they should not be understood as limiting the scope of the present invention.

Example 1

Step 1: First, crush 1500g of copper telluride slag material (tellurium content 35.39wt%, copper content 34.28wt%) into powder to obtain copper telluride slag material powder; copper telluride powder is 100 mesh; copper telluride slag material crushing time is 10min, the rotation speed is 1200r/min;

Step 2: Control the mass ratio of the copper telluride slag powder and sulfuric acid solution (mass concentration: 98%) in step 1 to 1:0.53 to form a uniform mixture.

Step 3: Roast the mixture obtained in Step 2 at a controlled temperature of 550°C for 120 minutes in a smelting furnace to obtain a roasted product.

Step 4: The ratio of the roasted product obtained in Step 3 to carbon powder (particle size is 100-400 mesh) is 1:2, and vacuum carbothermal reduction distillation is performed to obtain crude tellurium vapor and copper-rich products; the crude tellurium vapor is Cool to obtain crude tellurium; the temperature of vacuum carbothermal reduction distillation is 650°C, the vacuum degree is 20Pa, and the time is 90 minutes.

Step 5: Perform vacuum distillation and purification of the crude tellurium obtained in step 4 to obtain crude tellurium, copper-rich products and refined tellurium; the temperature is 500°C, the vacuum degree is 20Pa, and the time is 90 minutes.

In this example, 479.74g of refined tellurium was finally obtained, and a total of 1134.37g of copper-rich product, crude tellurium and copper-rich product were obtained. Chemical analysis was performed on the finally obtained copper-rich product, crude tellurium and copper-rich product, crude tellurium and refined tellurium. The results were as follows As shown in Table 1, its XRD patterns are shown in Figures 2, 3, 4, and 5.

Table 1 Chemical analysis results of copper-rich products, crude tellurium and copper-rich products, crude tellurium and refined tellurium

Example 2

Step 1: First, crush 1500g of copper telluride slag material (tellurium content 35.39%, copper content 34.28%) into powder to obtain copper telluride slag material powder; the copper telluride powder is 100 mesh; the copper telluride slag material crushing time is 10 minutes , the rotation speed is 1200r/min;

Step 2: Control the mass ratio of the copper telluride slag powder and sulfuric acid solution (mass concentration: 98%) in step 1 to 1:0.53 to form a uniform mixture.

Step 3: Roast the mixture obtained in Step 2 at a controlled temperature of 600°C for 90 minutes in a smelting furnace to obtain a roasted product.

Step 4: The ratio of the roasted product obtained in Step 3 to carbon powder (particle size is 100-400 mesh) is 1:2, and vacuum carbothermal reduction distillation is performed to obtain crude tellurium vapor and copper-rich products; the crude tellurium vapor is Cool to obtain crude tellurium; the temperature of vacuum carbothermal reduction distillation is 650°C, the vacuum degree is 20Pa, and the time is 120 minutes.

Step 5: Carry out vacuum distillation and purification of the crude tellurium obtained in step 4 to obtain crude tellurium, copper-rich products and refined tellurium; the temperature is 550°C, the vacuum degree is 20Pa, and the time is 60 minutes.

In this example, 477.87g of refined tellurium was finally obtained, and a total of 1132.34g of copper-rich products, crude tellurium and copper-rich products were obtained. Chemical analysis was performed on the finally obtained copper-rich products, crude tellurium and copper-rich products, crude tellurium and refined tellurium. The results were as follows Table 2 shows:

Table 2 Chemical analysis results of copper-rich products, crude tellurium and copper-rich products, crude tellurium and refined tellurium

project Te(wt%) Cu(wt%) S(wt%) Copper-rich products 1.94 80.87 15.87 Crude tellurium and copper-rich products 17.48 65.31 16.04 crude tellurium 98.74 0.0054 0.2541 Fine tellurium 99.97 0.0001 0.0001

The above are only the preferred embodiments of the present invention. It should be pointed out that those of ordinary skill in the art can also make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications can also be made. should be regarded as the protection scope of the present invention.

Claims (8)

1. A method for recovering copper telluride from copper telluride slag, characterized in that it includes the following steps: Mix copper telluride slag and sulfuric acid solution and then roast them to obtain a roasted product containing TeO ₂ and CuSO ₄ ; The ratio of the amount of copper telluride in the copper telluride slag to the H ₂ SO ₄ in the sulfuric acid solution is 1:2; The roasted product is mixed with carbon powder and then subjected to vacuum carbothermal reduction distillation to obtain crude tellurium vapor and copper-rich products; The crude tellurium vapor is cooled and then vacuum distilled to obtain refined tellurium. 2. The method according to claim 1, characterized in that the particle size of the copper telluride slag is 80-120 mesh. 3. The method according to claim 1, characterized in that the mass concentration of the sulfuric acid solution is 98%. 4. The method according to claim 1, characterized in that the roasting temperature is 500-600°C and the roasting time is 1-2 hours. 5. The method according to claim 1, characterized in that the mass of the roasted product and carbon powder is 1:1-2. 6. The method according to claim 1, characterized in that the particle size of the carbon powder is 50-400 mesh. 7. The method according to claim 1 or 6, characterized in that the temperature of the vacuum carbothermal reduction distillation is 450-650°C, the vacuum degree is 10-30 Pa, and the time is 60-120 min. 8. The method according to claim 1, characterized in that the temperature of the vacuum distillation is 450-650°C, the vacuum degree is 10-30 Pa, and the time is 45-90 minutes.