阅读说明：本技术 铜碲渣的处理方法 (Treatment method of copper-tellurium slag ) 是由 文燕 郑国渠 王海荣 臧轲轲 甘秀江 周斌 王爱荣 李春侠 沈宇坤 李波 丛超杰 于 2021-08-20 设计创作，主要内容包括：本发明属于有色金属冶炼领域,具体涉及一种铜碲渣的处理方法,包括如下步骤：(1)酸浸；(2)碱浸；(3)氧化沉碲；(4)还原。与现有技术相比,本申请以铜碲渣为原料,首先进行氧化酸性浸出,使得绝大部分的铜进入到液相中,而碲进入固相得到富碲渣；然后将富碲渣进行碱性浸出,使得碲全部进入到液相中,随后加入双氧水使碲全部被氧化成高碲酸钠,从而实现与其他杂质完全分离。最后,将上述高碲酸钠加入到硫化剂溶液中,经还原得到碲粉。本申请采用全湿法工艺,实现了铜碲的充分分离,同时以碲粉的形式高效回收金属碲。并且,本申请工艺流程简单,对设备要求低,易于工业化生产。(The invention belongs to the field of non-ferrous metal smelting, and particularly relates to a method for treating copper-tellurium slag, which comprises the following steps: (1) acid leaching; (2) alkaline leaching; (3) oxidizing and depositing tellurium; (4) and (4) reducing. Compared with the prior art, the method takes the copper-tellurium slag as a raw material, firstly, oxidation acid leaching is carried out, so that most of copper enters a liquid phase, and tellurium enters a solid phase to obtain tellurium-rich slag; then alkaline leaching the tellurium-rich slag to ensure that all tellurium enters a liquid phase, and then adding hydrogen peroxide to ensure that all tellurium is oxidized into high sodium tellurate, thereby realizing the complete separation from other impurities. And finally, adding the sodium tellurate into a vulcanizing agent solution, and reducing to obtain tellurium powder. The method adopts a full wet process, realizes the full separation of copper and tellurium, and efficiently recovers the metal tellurium in the form of tellurium powder. Moreover, the method has the advantages of simple process flow, low requirement on equipment and easy industrial production.)

1. A treatment method of copper-tellurium slag comprises the following steps:

(1) acid leaching: adding the copper-tellurium slag into acid liquor, slowly adding sodium chloride in the acid leaching process, and obtaining acid leaching solution and acid leaching slag after acid leaching;

(2) alkaline leaching: adding the acid leaching residue into alkali liquor for leaching to obtain alkali leaching solution and alkali leaching residue;

(3) and (3) tellurium oxidation and precipitation: adding an oxidant into the alkali leaching solution to precipitate tellurium, and filtering to obtain a precipitate containing tellurium and a solution after tellurium precipitation;

(4) reduction: and (3) washing the tellurium-containing precipitate, adding the tellurium-containing precipitate into a vulcanizing agent solution, adding a reducing agent, and reducing to obtain tellurium powder.

2. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (1), the acid solution is a sulfuric acid solution with the concentration of 50-90 g/L, and the liquid-solid ratio of the copper-tellurium slag to the acid solution is 8-12: 1.

3. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (1), the using amount of sodium chloride is 25-45 g/L.

4. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (1), the reaction temperature is 50-90 ℃, the reaction time is 1-2 h, and the mechanical stirring speed is 200-700 r/min.

5. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (2), the alkali liquor is a sodium hydroxide solution with the concentration of 1-5 mol/L.

6. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (2), the reaction temperature of alkaline leaching is 50-90 ℃, the reaction time is 1-2 h, and the mechanical stirring speed is 200-1000 r/min.

7. The method for treating copper-tellurium slag according to claim 1, characterized in that: in the step (3), the oxidant is 25-30% hydrogen peroxide or sodium chloride solution, and the volume of the oxidant is 5-15% of that of the alkali immersion liquid.

8. The method for treating copper-tellurium slag according to claim 1, characterized in that: and (3) performing the step (3) at normal temperature, and returning the obtained tellurium precipitation solution to the step (2) for recycling after impurity removal and deoxidation.

9. The method for treating copper-tellurium slag according to claim 1, characterized in that: the reaction temperature in the step (4) is 30-70 ℃, the vulcanizing agent is sodium sulfide, and the reducing agent is sodium sulfite or sulfur dioxide gas.

10. The method for treating copper-tellurium slag according to claim 1 or 9, characterized in that: in the step (4), the molar ratio of the sulfide ions to the tellurium elements in the alkaline leaching residue is 3.2-4.8 by using the vulcanizing agent, and the molar ratio of the reducing agent to the tellurium elements is 3-6 by using the reducing agent.

Technical Field

The invention belongs to the field of non-ferrous metal smelting, and particularly relates to a method for treating copper-tellurium slag.

Background

Tellurium is a rare dispersion element and is widely applied to industries such as metallurgy, energy, petrochemical industry, military aerospace and the like.

In nature, most of tellurium forms telluride, tellurium selenium (sulfide), oxide of tellurium, and oxysalt with lead, bismuth, copper, iron, zinc, nickel, gold, silver, and elements such as platinum group, etc., except for a small amount of tellurium existing as a simple substance. Due to the dispersibility and scarcity of tellurium minerals, 80% of tellurium is recovered from anode sludge. In the copper anode mud pretreatment process, part of tellurium can be leached together with copper, and cuprous telluride residues are obtained by adopting a copper powder replacement method and can be used as important raw materials for extracting tellurium. However, due to the technical reasons, the copper and tellurium can not be treated in time, the environment is polluted, and the resource is greatly wasted, so that how to separate the copper and tellurium from the copper telluride slag and recover the metal tellurium becomes a research focus.

At present, methods for recovering metal tellurium from copper telluride slag include oxidation pressure leaching, oxidation roasting high-temperature leaching, sulfating roasting, low-temperature oxidation roasting and the like. Chinese patent CN104928483A discloses a method for comprehensively recovering silver, selenium, tellurium and copper from copper telluride residues, which comprises the steps of adding dilute sulfuric acid solution containing an oxidant into the copper telluride residues, heating, stirring, leaching, recovering copper from a leaching solution, adding alkali into the acid leaching residues, leaching again, purifying the alkali leaching solution, precipitating tellurium, calcining and electrolyzing to obtain refined tellurium. Chinese patent CN109052339A discloses recovery of tellurium by vacuum distillation, which comprises carrying out a sulfurization reaction on copper telluride residues and sulfides, and then carrying out vacuum distillation on the sulfurization products to separate tellurium from the mixture. The treatment methods all need a high-temperature calcination process, have high energy consumption, large equipment investment and high requirements, are limited in application, and have low final copper-tellurium separation degree and low tellurium recovery rate.

Disclosure of Invention

The invention aims to provide a treatment method of copper-tellurium slag, which can efficiently separate copper and tellurium from the copper-tellurium slag and recover metal tellurium, and solves the problems that the separation of copper and tellurium from copper telluride slag is incomplete and the recovery efficiency of metal tellurium is low in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that: a treatment method of copper-tellurium slag comprises the following steps:

(1) acid leaching: adding the copper-tellurium slag into acid liquor, slowly adding a reagent I in the acid leaching process, and obtaining acid leaching solution and acid leaching slag after acid leaching;

(2) alkaline leaching: adding the acid leaching residue into alkali liquor for leaching to obtain alkali leaching solution and alkali leaching residue;

(3) and (3) tellurium oxidation and precipitation: adding a reagent II into the alkali leaching solution for tellurium precipitation, and filtering to obtain a precipitate containing tellurium and a solution after tellurium precipitation;

(4) reduction: and (3) washing the tellurium-containing precipitate, adding the tellurium-containing precipitate into a vulcanizing agent solution, adding a reducing agent, and reducing to obtain tellurium powder.

Specifically, in the step (1), the acid solution is a sulfuric acid solution with the concentration of 50-90 g/L, the liquid-solid ratio of the copper-tellurium slag to the acid solution is 8-12: 1, and the amount of sodium chloride is 25-45 g/L. The reaction temperature is 50-90 ℃, the reaction time is 1-2 h, and the mechanical stirring speed is 200-700 r/min.

In the step (2), the alkali liquor is a sodium hydroxide solution with the concentration of 1-5 mol/L, the reaction temperature of alkaline leaching is 50-90 ℃, the reaction time is 1-2 h, and the mechanical stirring speed is 200-1000 r/min.

In the step (3), the oxidant is 25-30% hydrogen peroxide or sodium chloride solution, and the volume of the oxidant is 5-15% of that of the alkali immersion liquid. And (3) carrying out the step of oxidizing and precipitating tellurium at normal temperature, and returning the obtained solution after precipitating tellurium to the step (2) for recycling after removing impurities and deoxidizing.

The reaction temperature in the step (4) is 30-70 ℃, the vulcanizing agent is sodium sulfide, and the reducing agent is sodium sulfite or sulfur dioxide gas. The molar ratio of sulfide ions to tellurium elements in the alkaline leaching residues is 3.2-4.8, and the molar ratio of the reducing agent to tellurium elements is 3-6.

Compared with the prior art, the method takes the copper-tellurium slag as a raw material, firstly adopts sodium chlorate to carry out oxidation acid leaching, so that most of copper enters a liquid phase, and tellurium enters a solid phase to obtain tellurium-rich slag; and then, carrying out alkaline leaching on the tellurium-rich slag to ensure that all tellurium enters a liquid phase, and then adding hydrogen peroxide to ensure that all tellurium is oxidized into high sodium tellurate, thereby realizing the complete separation from other impurities. And finally, adding the sodium tellurate into a vulcanizing agent solution, and reducing by sodium sulfite or sulfur dioxide gas to obtain tellurium powder. The method adopts a full wet process, realizes the full separation of copper and tellurium, and efficiently recovers the metal tellurium in the form of tellurium powder. Moreover, the method has the advantages of simple process flow, low requirement on equipment and easy industrial production.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

Example 1

Step 1, 135g of copper-tellurium slag with the water content of 26% (about 37% of Te content is detected) is added into 1L of sulfuric acid solution with the concentration of 70g/L, 35g of sodium chlorate is slowly added when the temperature reaches 80 ℃, the reaction temperature is 2 hours, and copper is dissolved out, so that 1L of acid leaching solution and 120g of acid leaching slag are obtained.

And 2, adding the acid leaching residue into 1.2L of 3M sodium hydroxide solution, reacting at the temperature of 80 ℃ for 2 hours to obtain 1.2L of alkali leaching solution and 12.4g of alkali leaching residue.

And 3, adding 100mL of 30% hydrogen peroxide into the alkali leaching solution, reacting for 2h at normal temperature to obtain 1.2L of solution after tellurium precipitation and 70.5g of sodium tellurate.

And 4, washing and drying the sodium high tellurate, adding the sodium high tellurate into a sodium sulfide solution, slowly adding a low-valent sodium sulfite solution into the sodium sulfide solution, wherein the molar ratio of sulfur ions in the sodium sulfide solution to tellurium elements in the sodium high tellurate is 4.0, reacting to obtain reducing slag, and washing and drying the reducing slag.

The detection shows that the obtained reducing slag is simple substance tellurium, and the purity of the reducing slag is 99.6%. And the primary recovery rate is 95.8%.

Example 2

Step 1, adding 134g of copper-tellurium slag (containing Te-39% in detection) with the water content of 25% into 1L of sulfuric acid solution with the concentration of 80g/L, slowly adding 40g of sodium chlorate when the temperature reaches 70 ℃, reacting for 2h, and dissolving out copper, thereby obtaining 1L of acid leaching solution and 118g of acid leaching slag.

And 2, adding the acid leaching residue into 1.2L of 3M sodium hydroxide solution, reacting at the temperature of 80 ℃ for 2 hours to obtain 1.2L of alkali leaching solution and 11.9g of alkali leaching residue.

And 3, adding 100mL of 30% hydrogen peroxide into the alkali leaching solution, reacting for 2h at normal temperature to obtain 1.2L of solution after tellurium precipitation and 72.1g of high-sodium tellurate.

And 4, washing and drying the sodium high tellurate, adding the sodium high tellurate into a sodium sulfide solution, slowly adding a low-valent sodium sulfite solution into the sodium sulfide solution, wherein the molar ratio of sulfur ions in the sodium sulfide solution to tellurium elements in the sodium high tellurate is 4.5, reacting to obtain reducing slag, and washing and drying the reducing slag.

The detection shows that the obtained reducing slag is simple substance tellurium, and the purity of the reducing slag is 99.7%. And the primary recovery rate was 96.1%.

Example 3

Step 1, 143g of copper telluride slag with the water content of 30% (the detected content of Te is Te-36%) is added into 1L of sulfuric acid solution with the concentration of 70g/L, 35g of sodium chlorate is slowly added when the temperature reaches 90 ℃, the reaction temperature is 2 hours, and copper is dissolved out, so that 1L of acid leaching solution and 128g of acid leaching slag are obtained.

And 2, adding the acid leaching residue into 1.2L of 3M sodium hydroxide solution, reacting at the temperature of 80 ℃ for 2 hours to obtain 1.2L of alkali leaching solution and 10.1g of alkali leaching residue.

And 3, adding 100mL of 30% hydrogen peroxide into the alkali leaching solution, reacting for 2h at normal temperature to obtain 1.2L of post-tellurium precipitation solution and 68.9g of sodium tellurate.

And 4, washing and drying the sodium high tellurate, adding the sodium high tellurate into a sodium sulfide solution, slowly adding a low-valent sodium sulfite solution into the sodium sulfide solution, wherein the molar ratio of sulfur ions in the sodium sulfide solution to tellurium elements in the sodium high tellurate is 3.5, reacting to obtain reducing slag, and washing and drying the reducing slag.

The detection shows that the obtained reducing slag is simple substance tellurium, and the purity of the reducing slag is 99.5%. And the primary recovery rate is 95.9%.

Example 4

Step 1, 138g of copper-tellurium slag (containing Te-45% in detection) with the water content of 28% is added into 1L of sulfuric acid solution with the concentration of 90g/L, 35g of sodium chlorate is slowly added when the temperature reaches 80 ℃, the reaction temperature is 2 hours, and copper is dissolved out, so that 1L of acid leaching solution and 119g of acid leaching slag are obtained.

And 2, adding the acid leaching residue into 1.2L of sodium hydroxide solution with the concentration of 4M, reacting at the temperature of 80 ℃ for 2 hours to obtain 1.2L of alkali leaching solution and 10.5g of alkali leaching residue.

And 3, adding 100mL of 30% hydrogen peroxide into the alkali leaching solution, reacting for 2h at normal temperature to obtain 1.2L of post-tellurium precipitation solution and 71.1g of sodium tellurate.

And 4, washing and drying the sodium high tellurate, adding the sodium high tellurate into a sodium sulfide solution, slowly adding a low-valent sodium sulfite solution into the sodium sulfide solution, wherein the molar ratio of sulfur ions in the sodium sulfide solution to tellurium elements in the sodium high tellurate is 3.8, reacting to obtain reducing slag, and washing and drying the reducing slag.

The detection shows that the obtained reducing slag is simple substance tellurium, and the purity of the reducing slag is 99.7%. And the primary recovery rate was 95.3%.

From the above embodiments, it can be seen that the method for treating copper-tellurium slag of the present invention not only realizes effective separation of copper and tellurium, but also achieves a high purity of the obtained tellurium powder of 99.5% or more, a primary recovery rate of 95% or more, reduces loss of valuable elements, and realizes effective recovery of resources. The whole treatment process has simple conditions, easily obtained equipment and low cost of used reagents, and is suitable for large-scale popularization in smelting enterprises.