阅读说明：本技术 一种含铅渣氯化隔膜电解回收铅方法 (Method for electrolyzing and recovering lead from lead-containing slag by using chlorination diaphragm ) 是由 郑朝振 周起帆 秦树辰 薛宇飞 *** 邓超群 于 2019-10-24 设计创作，主要内容包括：本发明公开的处理对象含铅渣原料可以为来自于铜冶炼中产生的白烟灰浸出渣或阳极泥处理含铅中间渣,或者锌冶炼、铅冶炼、废旧铅酸电池处理中产生的各种含铅物料,其具体包括铅渣的浸出、浸出液的净化、隔膜电解铅以及铅的收集与废液的处理,本工艺本工艺相比传统工艺,节约了传统复杂的铅回收工艺,具体的采用浸出工艺对杂质进行前级处理,保证了含铅废渣其他有效成分的回收；减少废弃物排放,降低了生产能耗,提高了能源的利用率,所述的阳极采用阳离子半透膜包裹,有效解决了氯离子在阳极形成氯气的难题,提高电解效率,降低了设备耐腐蚀性要求并改善了作业环境,该工艺具有良好的环境效益,同样它也具有良好的经济效益。(The raw material of the lead-containing slag of the processing object disclosed by the invention can be white ash leaching slag generated in copper smelting or various lead-containing materials generated in anode slime processing, or zinc smelting, lead smelting and waste lead-acid battery processing, and specifically comprises the steps of leaching the lead slag, purifying a leaching solution, electrolyzing lead through a diaphragm, collecting lead and processing waste liquid; the process has the advantages of reducing waste discharge, reducing production energy consumption, improving energy utilization rate, effectively solving the problem that chlorine is formed at the anode by chloride ions by wrapping the anode by a cation semipermeable membrane, improving electrolysis efficiency, reducing the corrosion resistance requirement of equipment and improving the operation environment, along with good environmental benefit and good economic benefit.)

1. A method for electrolyzing and recovering lead from lead-containing slag by a chlorination diaphragm is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: leaching the lead slag: removing impurities from lead slag powder, crushing, wetting and thinning the lead slag powder, mixing the lead slag powder with a leaching aid and an additive, adjusting the liquid-solid ratio, stirring and leaching to obtain slurry A, and filtering the slurry A to obtain a leaching solution;

step two: purifying the leachate: filtering the slurry A to obtain a high-lead leaching solution, and removing impurities to obtain a cathode electrolyte B;

step three: diaphragm lead electrolysis: carrying out diaphragm electrolysis on the cathode electrolyte B to obtain spongy lead at the cathode;

step four: collecting lead and treating waste liquid: and (4) carrying out filter pressing washing on the spongy lead, conveying the spongy lead to a casting furnace, returning the waste catholyte to the second step for leaching, and opening a circuit to purify and remove impurities or recover other valuable components.

2. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: the raw material of the lead-containing slag in the first step can be white ash leaching slag generated in copper smelting, intermediate slag generated in anode mud treatment, or various lead-containing materials generated in zinc smelting, lead smelting and waste lead-acid battery treatment.

3. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: in the first step, the crushing and ball milling are carried out, dry milling or wet milling can be selected as the ball milling, and the wet milling can be one or more of conventional wet milling, wet milling with leaching aids, activated ball milling and the like.

4. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: in the first step, the leaching is one or more of one-stage leaching or multi-stage countercurrent leaching.

5. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 3, which is characterized by comprising the following steps: in the first step, the wet grinding is performed by firstly performing coarse crushing by an overflow type rod mill and then performing grinding by an overflow type ball mill to a proper particle size, the leaching aid is one or more of industrial salts such as sodium chloride, calcium chloride, potassium chloride, magnesium chloride and the like, and the additive is one or more of hydrochloric acid, chlorine and chlorate.

6. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: in the second step, the filtration is carried out in a rapid filtration mode, the filtration mode comprises one or more of a plate-and-frame filter press, a belt filter press and a leaf filter, the purification is carried out aiming at the solution state, the medium-sized method or one or more of a goethite method and a hematite method is adopted aiming at iron removal, and lead powder/zinc powder is adopted for replacing the solution containing the noble metals to remove the gold and silver elements in the solution and recover the gold and silver noble metals.

7. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: in the third step, the anode is wrapped with a cation semipermeable membrane to prevent chloride ions from being oxidized into chlorine gas at the anode, the anolyte adopts sulfate solution or nitrate solution of solution with high conductivity, the anode adopts graphite or lead plate or plated titanium plate, the cathode adopts stainless steel or nickel plate or titanium plate, and the spongy lead is obtained by electrolysis under the condition of current density of 50-5000A/m 2.

The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: the cation semipermeable membrane adopts a perfluorosulfonic acid membrane.

8. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: and in the fourth step, the spongy lead is directly recycled for sale or cast ingot after being collected, washed and dried.

9. The method for electrolytically recovering lead from the lead-containing slag chlorination membrane according to claim 1, which is characterized by comprising the following steps: and in the fourth step, the waste catholyte is returned to leaching after components are adjusted, and resources can be fully recovered by the open-circuit purification part in various modes, including one or more of step-by-step neutralization recovery of elements such as zinc, manganese and the like, direct extraction recovery of zinc elements, and diaphragm electrodeposition of zinc after concentration.

Technical Field

The invention relates to the technical field of wet lead smelting and the field of lead-containing waste recovery, and relates to a method for electrolytically recovering lead from lead-containing slag by using a chlorinated diaphragm

Background

Lead is an important metal material that cannot be lacked in the national economic development process, and is widely used in industrial production and human production. In the production of the prior nonferrous metals, lead is second to aluminum, copper and zinc, and occupies the fourth place, and the lead-acid storage battery manufacturing industry is the main field of application in modern industry, and is mainly applied to the aspects of automobiles, airplanes, electric vehicles and the like. With the development of the automobile industry, the demand of lead for lead-acid battery manufacturing industry is increasing, China is the biggest lead producing country and consuming country in the world, and the demand of lead is increased from 257.3 ten thousand tons in 2007 to 463.9 ten thousand tons in 2016. Compared with the prior art, the self-sufficiency rate of the lead concentrate in China is seriously insufficient and depends on import, and the import quantity of the lead concentrate in China is up to 140.9 ten thousand tons in 2016, which accounts for 58.7 percent of the yield of the lead concentrate in China in the current year. Due to the shortage of lead concentrate resources, the recycling of lead will be one of the key points of future research.

The lead slag mainly refers to waste slag discharged in the lead pyrometallurgical process, and also comprises waste slag with high lead content discharged in other metal smelting processes. Lead slag can be classified into blast furnace slag, rotary kiln slag, reverberatory slag, fuming slag, etc. according to the lead smelting method. In recent decades, the lead smelting industry in China has been developed rapidly, the total lead yield in China in 2018 reaches 511.3 ten thousand tons, the cumulative increase is 9.8%, and the problem of treatment of a large amount of waste slag generated in the production process is solved while the lead smelting and regeneration industry is rapidly developed. And (3) 0.71 ton of lead slag is discharged when each lead smelting system produces 1 ton of lead, and the discharge amount of the lead slag in 2018 is more than 350 ten thousand tons according to the calculation.

Lead slag generally contains a plurality of metals such as Pb, Zn, Fe, Ag, In, Sn, Cu and the like with recovery value, if the lead slag is directly piled up, the resources are greatly wasted, Pb and Zn In the slag can be seeped into soil and underground water under the action of rainwater and are not easy to decompose, the pollution caused by the lead slag has the characteristics of concealment, long-term property and irreversibility, and the potential harm to the ecological environment is great. Half of the 15 kinds of large mineral products in China have resource shortage, and 40 percent of non-ferrous metal mines in the existing national mines face the dilemma of resource exhaustion. The nonferrous metal is used as a rare resource, the supply and demand of China are seriously unbalanced, the supply gap is large, and a large amount of imports are needed every year to meet the domestic requirements, so that the development of the recovery technology of valuable metals in the lead slag is the necessary requirement of the current resource situation of China. The lead slag is recycled, valuable metals in the lead slag are recovered, the energy consumption and the cost in the production process are far lower than those in the conventional smelting process of the metals, and the resource pressure in China and the environmental pressure caused by waste discharge can be relieved. Therefore, the method has important economic value and environmental protection significance for the research on the separation and recovery technology of valuable metals in the lead slag.

The smelting and regeneration process of the lead in the prior art is complex, and has more links of pollutant generation, such as long process flow, large energy consumption, more dust, large pollution, large labor intensity and low lead recovery rate in the pyrogenic process for treating the lead-containing slag, so that the design of a reasonable lead-containing slag recovery treatment process for solving the process defects becomes all the problems solved by the technical personnel in the field.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method for electrolyzing and recovering lead by a chlorination diaphragm containing lead slag, which has reasonable structural design.

The technical scheme adopted by the invention for solving the problems is as follows: the raw material of the lead-containing slag to be processed can be white ash leaching slag generated in copper smelting or intermediate slag generated in anode mud processing, or various lead-containing materials generated in zinc smelting, lead smelting and waste lead-acid battery processing.

The method mainly comprises the following steps:

the method comprises the following steps: leaching the lead slag: removing impurities from lead slag powder, crushing, wetting and thinning the lead slag powder, mixing the lead slag powder with a leaching aid and an additive, adjusting the liquid-solid ratio, stirring and leaching to obtain slurry A, and filtering the slurry A to obtain a leaching solution;

step two: purifying the leachate: filtering the slurry A to obtain a high-lead leaching solution, and removing impurities to obtain a cathode electrolyte B;

step three: diaphragm lead electrolysis: taking graphite as an anode, a perfluorosulfonic acid film as an anode bag, a sulfate solution as an anolyte and a stainless steel plate as a cathode plate, and carrying out diaphragm electrolysis on the catholyte B to obtain spongy lead at the cathode;

step four: collecting lead and treating waste liquid: and (4) carrying out filter pressing washing on the spongy lead, conveying the spongy lead to a casting furnace, returning the waste catholyte to the second step for leaching, and opening a circuit to purify and remove impurities or recover other valuable components.

Further: the raw material of the lead-containing slag in the first step can be white ash leaching slag generated in copper smelting, intermediate slag generated in anode mud treatment, or various lead-containing materials generated in zinc smelting, lead smelting and waste lead-acid battery treatment.

Further: in the first step, the crushing and ball milling are carried out, dry milling or wet milling can be selected as the ball milling, and the wet milling can be one or more of conventional wet milling, wet milling with leaching aids, activated ball milling and the like.

Further: in the first step, the leaching is one or more of one-stage leaching or multi-stage countercurrent leaching.

Further: in the first step, the wet grinding is performed by firstly performing coarse crushing by an overflow type rod mill and then performing grinding by an overflow type ball mill to a proper particle size, the leaching aid is one or more of industrial salts such as sodium chloride, calcium chloride, potassium chloride, magnesium chloride and the like, and the additive is one or more of hydrochloric acid, chlorine and chlorate.

Further: in the second step, the filtration is carried out in a rapid filtration mode, the filtration mode comprises one or more of a plate-and-frame filter press, a belt filter press and a leaf filter, the purification is carried out aiming at the solution state, the medium-sized method or one or more of a goethite method and a hematite method is adopted aiming at iron removal, and lead powder/zinc powder is adopted for replacing the solution containing the noble metals to remove the gold and silver elements in the solution and recover the gold and silver noble metals.

Further: in the third step, the anode is wrapped with a cation semipermeable membrane to prevent chloride ions from being oxidized into chlorine gas at the anode, the anolyte adopts sulfate solution or nitrate solution of solution with high conductivity, the anode adopts graphite or lead plate or plated titanium plate, the cathode adopts stainless steel or nickel plate or titanium plate, and the spongy lead is obtained by electrolysis under the condition of current density of 50-5000A/m 2.

Further: the cation semipermeable membrane adopts a perfluorosulfonic acid membrane.

Further: and in the fourth step, the spongy lead is directly recycled for sale or cast ingot after being collected, washed and dried.

Further: and in the fourth step, the waste catholyte is returned to leaching after components are adjusted, and resources can be fully recovered by the open-circuit purification part in various modes, including one or more of step-by-step neutralization recovery of elements such as zinc, manganese and the like, direct extraction recovery of zinc elements, and diaphragm electrodeposition of zinc after concentration.

Compared with the prior art, the invention has the following advantages and effects: compared with the traditional process, the process saves the traditional complex lead recovery process, particularly adopts the leaching process to carry out the preceding stage treatment on the magazines, and ensures the recovery of other effective components of the lead-containing waste gas liquid; reduce the attempt of discarded object, improved the utilization ratio of the energy, the positive pole adopt the parcel of cation pellicle, chlorine ion forms the chlorine enrichment on the anode plate surface at the positive pole gathering in effectively having solved electrolyte, reduce electrolysis efficiency, useless catholyte in this technology returns and leaches the step and open a way purification edulcoration or retrieve other valuable components before the waste cathode liquid returns, the attempt of waste liquid has further been reduced, the environmental protection performance of technology has been improved, it adopts the pyrometallurgical process flow simple to compare traditional processing lead-containing slag, the energy consumption is little, and is pollution-free, the environment-friendly is good, required intensity of labour is less, and has higher lead recovery rate.

Drawings

FIG. 1 is a process flow chart of the method for electrolytically recovering lead from the lead-containing slag chlorination membrane in the embodiment of the invention.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

The method mainly comprises the following steps:

the method comprises the following steps: leaching the lead slag: the method is characterized in that the lead-containing slag is subjected to impurity removal, wherein the impurity removal mainly comprises the steps of removing partial impurities in advance, such as zinc and iron removal and arsenic, antimony and bismuth removal, and is mainly performed in a leaching mode, removing partial non-lead components in the lead slag and comprehensively recovering and removing products.

Step two: purifying the leachate: after impurity removal, crushing and grinding the mixed ore to 400 meshes, taking a chloride solution as a main leaching aid, preferably selecting one or more of industrial salts such as sodium chloride, calcium chloride, potassium chloride, magnesium chloride and the like as the leaching aid, selecting one or more additives from calcium salts such as hydrochloric acid, chlorine and chlorate, calcium carbonate, calcium chloride and the like as the additives, and carrying out chlorination leaching on the lead-containing slag;

the leaching solution is subjected to solid-solid separation to obtain leaching solution and leaching slag, the leaching solution is subjected to purification and impurity removal, impurity removal is performed by means of replacement, sulfide, neutralization, precipitation and impurity removal according to the components of the solution, Cu, Hg, Fe, Mn, Sb, Se, Bi, Ag, Pd, Au and the like harmful to electrolysis are mainly removed to obtain appropriate high-lead chlorinated solution, for example, a medium-iron method or one or more of a goethite method and a hematite method can be adopted for iron removal of the high-iron solution, and elements such as gold and silver in the solution can be removed by lead powder/zinc powder replacement for the solution containing precious metals, and precious metals such as gold and silver can be recovered.

Step three: diaphragm lead electrolysis: carrying out diaphragm electrolysis on the high-lead chlorinated solution, wherein an ionic membrane is a cationic membrane to prevent chloride ions from being oxidized into chlorine at an anode, an anolyte is a solution with high conductivity, such as a sulfate solution, a nitrate solution and the like, a graphite, a lead plate, a plated titanium plate and the like are adopted as an anode, a stainless steel, a nickel plate, a titanium plate and the like are adopted as a cathode, and the electrolysis is carried out under the condition that the current density is 50-5000A/m2 to obtain spongy lead;

and (3) anode reaction: 2H ₂O-4e ^-＝4H ⁺+O ₂；

And (3) cathode reaction: pb ²⁺+4e ^-＝2Pb；

And (3) total reaction: 2PbCl ₂+2H ₂O＝4HCl+O ₂+2Pb；

And (4) washing, briquetting, drying and melting the cast ingot by using the sponge lead obtained by electrolysis.

Step four: collecting lead and treating waste liquid: the electrolytic waste liquid is purified to remove impurities and recover valuable components, the waste liquid treatment adopts open-circuit treatment according to solution components, and the waste liquid from the open circuit is generally leached after accumulated impurities are removed by working procedures of removing sulfate radicals by lime, removing lead by carbonic acid and the like.

The waste electrolyte is purified to remove impurities and recover valuable components, the waste catholyte is returned to chlorination leaching after the components are adjusted, resources can be fully recovered by a open-circuit purification part in various modes, as shown in figure 1, elements such as zinc, manganese and the like are recovered by step neutralization, zinc elements are directly extracted and recovered, and zinc is electrodeposited by a diaphragm after concentration.