阅读说明：本技术 一种从湿法炼锌的铜镉渣中回收有价金属的方法 (Method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy ) 是由 王普公 王军辉 焦晓斌 席多祥 冶玉花 崔耀 马菲菲 杨斌 段小维 赵贵俊 于 2021-01-14 设计创作，主要内容包括：本发明涉及有价金属的回收技术领域,用于降低重金属对环境的污染,提高资源利用率,尤其涉及一种从湿法炼锌的铜镉渣中回收有价金属的方法,将铜镉渣进行研磨,然后对研磨之后的铜镉渣粉进行筛分除杂,再将铜镉渣粉进行浆化处理；将浆化处理之后的铜镉渣进行蒸馏,收集馏出物；向馏出物中加入锌粉置换出铜,锌粉的质量为铜镉渣质量的1.3-1.6倍,然后过滤得到铜渣和滤液；向铜渣中加入草酸,得到草酸铜沉淀和混合液,滤出草酸铜沉淀,并将草酸铜沉淀进行洗涤后放入高温焙烧炉,进行加热分解,得到铜粉；将滤液进行电解,得到锌镉合金和电解残液；将锌镉合金引入真空塔盘中分离得锌、镉；该方法操作简单,金属回收率高。(The invention relates to the technical field of valuable metal recovery, which is used for reducing the pollution of heavy metals to the environment and improving the resource utilization rate, in particular to a method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy, wherein the copper-cadmium slag is ground, then ground copper-cadmium slag powder is screened to remove impurities, and then the copper-cadmium slag powder is slurried; distilling the copper-cadmium slag subjected to slurrying treatment, and collecting distillate; adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.3-1.6 times of that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate; adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder; electrolyzing the filtrate to obtain zinc-cadmium alloy and electrolytic residual liquid; introducing the zinc-cadmium alloy into a vacuum tray for separation to obtain zinc and cadmium; the method has simple operation and high metal recovery rate.)

1. A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy is characterized by comprising the following steps:

step 1: grinding copper-cadmium slag, screening and removing impurities from the ground copper-cadmium slag powder, and slurrying the copper-cadmium slag powder;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment, and collecting distillate;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.3-1.6 times of that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

2. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 1, wherein the treatment liquid used for slurrying the copper-cadmium slag in the step 1 is sulfuric acid.

3. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 2, wherein the concentration of sulfuric acid is controlled to be 450 g/L.

4. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 1, wherein the distillation in the step 2 is performed by using a vacuum furnace with a condensing chamber.

5. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 1, wherein the distillation temperature in the step 2 is controlled to be 95-105 ℃, and the distillation time is 6 hours.

6. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 1, wherein the electrolytic cell pressure in the electrolytic cell during electrolysis in step 5 is 4-5V, and the current density is 450 mA.

7. The method for recovering valuable metals from copper-cadmium slag generated in zinc hydrometallurgy according to claim 1, wherein electrolysis is performed in step 5 at an electrolysis temperature of 40-50 ℃ for 30 hours.

Technical Field

The invention relates to the technical field of valuable metal recovery, is used for reducing the pollution of heavy metals to the environment and improving the resource utilization rate, and particularly relates to a method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy.

Background

The zinc hydrometallurgy mainly comprises the working procedures of roasting, leaching, leachate purification, electrodeposition and the like, zinc concentrate is subjected to neutral leaching by using electrolytic waste liquid after roasting, most of zinc oxide is dissolved, supernatant and underflow pulp are separated from the obtained pulp, metal zinc is produced by electrodeposition after the supernatant is purified, and the metal zinc is cast into ingots.

In the process of zinc hydrometallurgy, zinc sulfate solution can enter a zinc electrolysis process only after being purified and removed of copper, cadmium, cobalt and the like, zinc powder is usually added in the purification and impurity removal process, impurities such as copper, cadmium and the like in a zinc removal leaching solution are replaced, a large amount of copper-cadmium slag is generated in the process, the copper-cadmium slag mainly contains elemental copper, cadmium sulfate, elemental zinc and the like, 1300 tons of copper-cadmium slag are generated when 1 ten thousand tons of electrolytic zinc are produced, the yield is high, and the comprehensive recovery value is extremely high.

At present, the copper-cadmium slag treatment mode is generally that zinc and cadmium in the copper-cadmium slag are firstly leached by acid washing to obtain zinc sulfate solution and acid-washed copper slag; the zinc sulfate solution can return to the zinc hydrometallurgy purification process, and the acid-washing copper slag has low direct selling price and poor economic benefit due to the fact that the acid-washing copper slag contains more impurities, and needs to be further processed to improve the economic value of the acid-washing copper slag.

Disclosure of Invention

Aiming at the problems of complex working procedures, poor economic benefit, low resource utilization rate and serious environmental pollution in the existing copper-cadmium slag treatment mode mentioned in the background technology, the method for recovering valuable metals from the copper-cadmium slag of zinc hydrometallurgy is provided.

The technical scheme provided by the invention is a method for recovering valuable metals from copper and cadmium slag of zinc hydrometallurgy, which comprises the following steps:

step 1: grinding copper-cadmium slag, screening and removing impurities from the ground copper-cadmium slag powder, and slurrying the copper-cadmium slag powder;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment, and collecting distillate;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.3-1.6 times of that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

By adopting the technical scheme, the method for recovering valuable metals from the copper-cadmium slag of the zinc hydrometallurgy separately recovers the copper and the cadmium, reduces the subsequent process of separating each mixture of the copper again, reduces the workload of workers and improves the working efficiency; meanwhile, before the copper-cadmium slag is treated, the copper-cadmium slag is ground and screened, so that the time for subsequently recovering the copper-cadmium slag is shortened, the working efficiency is further improved, and meanwhile, after the copper-cadmium slag is ground, impurities in the copper-cadmium slag can be separated from the copper-cadmium slag, so that the impurities mixed in the copper-cadmium slag can be directly screened in the screening process, the purity of copper and cadmium obtained by separation is improved, and the subsequent treatment work is reduced.

Further, the treatment liquid used for slurrying the copper-cadmium slag in the step 1 is sulfuric acid.

Further, the concentration of the sulfuric acid is controlled to be 450 g/L.

Further, the distillation in step 2 is carried out by using a vacuum furnace with a condensation chamber.

Further, the distillation temperature in step 2 is controlled to be 95-105 ℃, and the distillation time is 6 hours.

Further, the cell pressure in the cell at the time of electrolysis in step 5 was 4 to 5V, and the current density was 450 mA.

Further, the electrolysis temperature in the step 5 is 40-50 ℃ and the electrolysis time is 30 hours.

Based on the explanation, compared with the prior art, the technical scheme of the application has the advantages that:

(1) the method for recovering valuable metals from the copper-cadmium slag of the zinc hydrometallurgy is simple to operate and high in metal recovery rate, improves the recovery utilization rate of metal resources in the copper-cadmium slag, reduces the pollution to the environment, achieves the effect of efficient recovery of the resources, and also achieves the function of environmental protection;

(2) according to the method for recovering valuable metals from the copper-cadmium slag of the zinc hydrometallurgy, disclosed by the invention, the copper and the cadmium are separately recovered, so that the subsequent process of separating each mixture of the copper again is reduced, the workload of workers is reduced, and the working efficiency is improved;

(3) the copper-cadmium slag is ground and screened before being treated, so that the time for subsequently recovering the copper-cadmium slag is shortened, the working efficiency is further improved, and meanwhile, after the copper-cadmium slag is ground, impurities in the copper-cadmium slag can be separated from the copper-cadmium slag, so that the impurities mixed in the copper-cadmium slag can be directly screened in the screening process, the purity of copper and cadmium obtained by separation is improved, and the subsequent treatment work is reduced.

Detailed Description

Example 1

A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy comprises the following steps:

step 1: grinding the copper-cadmium slag, then screening and removing impurities from the ground copper-cadmium slag powder,

then pulping the copper-cadmium slag powder by using 450g/L sulfuric acid;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment by using a vacuum furnace with a condensation chamber, and collecting distillate; wherein the distillation temperature is controlled at 95 ℃, and the distillation time is 6 hours;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.3 times that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid; the pressure of the electrolytic cell in the electrolytic cell during electrolysis is 4V, and the current density is 450 mA; the electrolysis temperature is 40 ℃, and the electrolysis time is 30 hours;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

Example 2

A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy comprises the following steps:

step 1: grinding the copper-cadmium slag, then screening and removing impurities from the ground copper-cadmium slag powder,

then pulping the copper-cadmium slag powder by using 450g/L sulfuric acid;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment by using a vacuum furnace with a condensation chamber, and collecting distillate; wherein the distillation temperature is controlled at 100 ℃, and the distillation time is 6 hours;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.4 times that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid; the pressure of the electrolytic cell in the electrolytic cell during electrolysis is 4.5V, and the current density is 450 mA; the electrolysis temperature is 45 ℃ and the electrolysis time is 30 hours;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

Example 3

A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy comprises the following steps:

step 1: grinding the copper-cadmium slag, then screening and removing impurities from the ground copper-cadmium slag powder,

then pulping the copper-cadmium slag powder by using 450g/L sulfuric acid;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment by using a vacuum furnace with a condensation chamber, and collecting distillate; wherein the distillation temperature is controlled at 105 ℃, and the distillation time is 6 hours;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.5 times that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid; the pressure of the electrolytic cell in the electrolytic cell during electrolysis is 5V, and the current density is 450 mA; the electrolysis temperature is 50 ℃, and the electrolysis time is 30 hours;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

Example 4

A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy comprises the following steps:

step 1: grinding the copper-cadmium slag, then screening and removing impurities from the ground copper-cadmium slag powder,

then pulping the copper-cadmium slag powder by using 450g/L sulfuric acid;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment by using a vacuum furnace with a condensation chamber, and collecting distillate; wherein the distillation temperature is controlled at 95 ℃, and the distillation time is 6 hours;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.6 times that of the copper-cadmium slag, and then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid; the pressure of the electrolytic cell in the electrolytic cell during electrolysis is 5V, and the current density is 450 mA; the electrolysis temperature is 50 ℃, and the electrolysis time is 30 hours;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

Example 5

A method for recovering valuable metals from copper-cadmium slag of zinc hydrometallurgy comprises the following steps:

step 1: grinding the copper-cadmium slag, then screening and removing impurities from the ground copper-cadmium slag powder,

then pulping the copper-cadmium slag powder by using 450g/L sulfuric acid;

step 2: distilling the copper-cadmium slag subjected to slurrying treatment by using a vacuum furnace with a condensation chamber, and collecting distillate; wherein the distillation temperature is controlled at 105 ℃, and the distillation time is 6 hours;

and step 3: adding zinc powder into the distillate to replace copper, wherein the mass of the zinc powder is 1.3 times of that of the copper-cadmium slag,

then filtering to obtain copper slag and filtrate;

and 4, step 4: adding oxalic acid into the copper slag to obtain copper oxalate precipitate and mixed liquor, filtering out the copper oxalate precipitate, washing the copper oxalate precipitate, putting the washed copper oxalate precipitate into a high-temperature roasting furnace, and heating and decomposing the copper oxalate precipitate to obtain copper powder;

and 5: electrolyzing the filtrate obtained in the step 3 to obtain zinc-cadmium alloy and electrolytic residual liquid; the pressure of the electrolytic cell in the electrolytic cell during electrolysis is 4V, and the current density is 450 mA; the electrolysis temperature is 40 ℃, and the electrolysis time is 30 hours;

step 6: introducing the zinc-cadmium alloy into a vacuum tray for separating zinc and cadmium.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiment should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and these modifications and adaptations should be considered within the scope of the invention.