CN107574305A - A kind of high concn. arsenic and lead matte Recovering Copper and sulphur technique - Google Patents

Abstract

The invention discloses a process for comprehensively recovering copper and sulfur from high-arsenic lead matte. The process is to crush and grind high-arsenic lead matte raw materials and pyrite; the obtained mineral powder is mixed with sulfuric acid and dispersing additives After pulping, carry out pressurized oxidative acid leaching, liquid-solid separation to obtain copper-containing leaching solution and arsenic-containing leaching slag; the copper-containing leaching solution is passed through cyclone electrowinning to obtain copper products; the arsenic-containing leaching slag is recovered by vacuum distillation Elemental sulfur products; this method can eliminate the problem of arsenic pollution in the whole process, realize the efficient separation and recovery of copper, and the copper-containing leaching solution uses cyclone electrowinning technology to extract copper, which reduces DC power consumption and improves production efficiency; during the recovery process of this method , Sulfur exists in the form of elemental sulfur, and the process only involves changes in physical form to achieve efficient separation and recovery of sulfur. The whole process is clean and environmentally friendly, which is conducive to industrial production.

Description

A process for comprehensive recovery of copper and sulfur from high-arsenic lead matte

technical field

The invention discloses a process for treating high-arsenic lead matte, and in particular relates to a process for comprehensively recovering copper and sulfur in high-arsenic lead matte and pyrite through wet treatment. It belongs to the field of non-ferrous metal metallurgy.

Background technique

Lead matte is a by-product produced in the lead pyro-smelting system. Its main components are copper, lead, and iron sulfides. It is often accompanied by valuable metals such as gold and silver as the composition of the upstream lead concentrate changes. , still contains a small amount of scattered metal indium, germanium, tin, bismuth, etc., and contains toxic and harmful metal impurities such as arsenic and iron.

At present, enterprises mainly sell lead matte directly to copper smelters or process it by themselves. Most domestic smelters use pyrotechnics to process lead matte. When the copper content is high, it is directly put into the copper converter for oxidative blowing to obtain blister copper, and the lead is oxidized and volatilized to separate; this process has high energy consumption, SO ₂ and Lead pollution is serious, and the lead, antimony, bismuth, and arsenic in the matte are volatilized as impurities and removed into soot, which cannot be effectively resourced because the arsenic content in the soot is too high. When the lead matte is high-arsenic lead matte, the arsenic will be dispersed in the smelting system during the blowing process, and the arsenic pollution will be more serious.

The traditional wet process requires leaching with sulfuric acid to obtain copper sulfate solution after oxidation roasting. The roasting process also has low-concentration SO ₂ pollution, and the sulfide is difficult to roast completely, and the copper recovery rate is not high. At the same time, the impurity removal pressure of this leaching solution is high, and the electrowinning product is difficult to meet the standard; if iron filings are used to replace copper in the leaching solution, the cost is high and the wastewater treatment pressure is high. When high-arsenic lead matte is treated by wet process, arsenic will partly volatilize in the roasting process and partly enter the solution in the leaching process, resulting in serious arsenic pollution in the whole process.

In the prior art, the problem of arsenic pollution cannot be solved whether the fire process or the wet process is used to treat high-arsenic-lead matte, and the subsequent recovery of sulfur products is also a big problem. Therefore, the high-arsenic-lead matte treatment technology still needs Open up new avenues.

Contents of the invention

Aiming at the existing problems in the process of processing high-arsenic lead matte in the prior art, the purpose of the present invention is to provide a high-efficiency high-efficiency matte that can effectively prevent arsenic leaching, simplify the steps of arsenic removal, realize selective leaching and recovery of copper, and efficiently recover sulfur. The comprehensive recovery process of arsenic, lead and matte has low cost, simple steps, no arsenic damage, clean and high efficiency, and is conducive to popularization and application.

In order to realize the above-mentioned technical purpose, the present invention provides a kind of high-arsenic lead matte comprehensive recovery copper and sulfur technology, this technology is high arsenic lead matte raw material and pyrite batching, carry out crushing, grinding; Gained ore powder and After sulfuric acid and dispersing additives are mixed and slurried, pressurized oxidative acid leaching is carried out, and the liquid and solid are separated to obtain a copper-containing leaching solution and an arsenic-containing leaching slag; the copper-containing leaching solution is passed through cyclone electrowinning to obtain a copper product; Slag is recovered elemental sulfur product by vacuum distillation.

In the prior art, due to the high arsenic content of high-arsenic lead matte, no matter whether the high-arsenic lead matte is smelted by hydrometallurgy or pyrometallurgy, it is difficult to get rid of the poison of arsenic. In the process of lead matte, arsenic will be dispersed in the smelting system, causing serious arsenic pollution; in the process of treating high-arsenic lead matte by traditional wet process, arsenic will partly volatilize in the roasting process and partly enter the solution in the leaching process. Arsenic pollution is serious. However, the technical solution of the present invention successfully leaches copper efficiently and selectively from high-arsenic lead matte by wet method, and obtains a copper-containing leaching solution that can be directly used for swirling electrodeposited copper. The key to the technical solution of the present invention is to realize arsenic fixation from the source during the wet treatment process of high-arsenic lead matte, use pyrite raw material and high-arsenic lead matte for processing, and make full use of pyrite to realize arsenic fixation, thereby effectively avoiding The leaching of arsenic in the leaching process is prevented, and iron is effectively fixed at the same time, so that copper selectively enters the solution system. The content of copper ions in the leaching solution is above 20g/L, and the content of impurities such as iron ions is below 3g/L. Cyclone electrodeposition requirements, so that high-purity electrodeposited copper can be obtained directly. This method effectively avoids the process of removing arsenic and iron from the leaching solution required by traditional hydrometallurgy, and also avoids the process of arsenic pollution in the process of pyrometallurgy, and simplifies the process steps.

The technical scheme of the present invention contains a large amount of elemental sulfur in the arsenic-containing leaching slag, mainly pyrite and pyrite in high-arsenic lead white matte and pyrite are mainly oxidized into elemental sulfur during the oxidation leaching process, The arsenic is fixed by iron and will not volatilize together with the sulfur. Therefore, the vacuum distillation method adopted in the technical proposal of the present invention can well realize the recovery of elemental sulfur and obtain high-purity sublimated sulfur. And after the sulfur is recovered, the generation of sulfur oxides in the subsequent metal recovery process is avoided.

The technical scheme of the present invention adopts the swirl electrowinning technology under the premise of obtaining a copper-containing leaching solution with a copper ion content of more than 20 g/L and an impurity content of iron ions below 3 g/L, and the swirl electrowinning process can eliminate The adverse effect of concentration polarization on electrowinning, the whole process can be carried out under the conditions of lower cell voltage and higher current density, which reduces DC power consumption and improves production efficiency; after electrowinning, the liquid concentration can be reduced very low, unit The amount of metal extraction in the electrowinning process increases, and the production efficiency is also increased; the electrowinning process is carried out in a fully enclosed tubular swirl electrolytic cell, which completely eliminates the generation of acid mist in the electrowinning process, and is clean and environmentally friendly.

In a preferred solution, the high-arsenic-lead matte raw material and pyrite are batched according to the mass ratio of iron and arsenic at 1-1.2:1.

More preferably, the arsenic content of the high-arsenic lead matte is 5-25%.

In a preferred solution, the high-arsenic-lead matte raw material and pyrite are mixed and ground until the particle size satisfies -0.074mm or less, and the mass percentage content of the particle size is not less than 90%.

In a preferred scheme, the conditions for the slurry preparation are as follows: the liquid-solid ratio of mineral powder to sulfuric acid is 4-6:1mL/g, the concentration of sulfuric acid is 100-120g/L, the temperature is 75-95°C, and the dispersing additive is mineral powder 1% to 2% of the mass. The main function of the pulping process in the technical solution of the present invention is to pretreat the ore pulp to homogenize the slurry. At the same time, the pulping process makes the temperature reach the starting temperature of the pressurized oxidation reaction. The pressurized leaching process only needs to introduce oxygen, It avoids the need to simultaneously heat and feed oxygen into the pressurized reactor, simplifies equipment and reduces hazards.

More preferably, the dispersing additive is sodium lignosulfonate.

In a preferred scheme, the conditions of the pressurized oxidative acid leaching are as follows: leaching temperature is 130-170° C., leaching time is 2-3 hours, pressure is 0.6-1.8 MPa, and oxygen is introduced into the system during the leaching process.

In a preferred scheme, the conditions of the vacuum distillation are: the relative vacuum degree is not less than -0.1MPa, the temperature is 200-300°C, the distillation time is 40-50min, and the steam extraction rate is controlled at 2-3L/S.

In a preferred solution, the conditions for the cyclone electrowinning are: the acidity of the copper-containing leachate is 90-110g/L, the current density of the first stage is 400-600A/m ² , the current density of the second stage is 200-300A/m 2 , and the current density of the second stage is 200-300A/m ² . The accumulation period is 10h.

In a more preferred solution, the electrowinning liquid produced by the cyclone electrowinning is used for slurry adjustment. After electrowinning, the concentration of copper ions in the liquid is below 5g/L, and it can be directly returned to the pulping process for pressurized oxidative acid leaching.

In the preferred solution, the arsenic-containing leaching slag is washed, dried, ground, and sieved in sequence, and the powder with a particle size of less than 0.074mm is added to the vacuum furnace. The vacuum furnace is equipped with an exhaust system, and the sulfur in the arsenic-containing leaching slag Through sublimation, volatilization, and continuous extraction of sulfur vapor out of the vacuum furnace, and cooling under the protection of inert gas, qualified sulfur products are finally obtained.

According to the solution of the present invention, the remaining solid residue in the vacuum furnace is discharged from the vacuum furnace and enters the lead smelting system to comprehensively recover lead, gold, silver, antimony, bismuth and other valuable metals.

In a preferred scheme, the arsenic content of the high-arsenic lead matte is 5-25%, and other main components include Cu: 10-65%; Pb: 5-40%; Ag: 0.1-0.4%; Fe: 2-25% ; S: 1-30%.

The sulfur in the lead matte oxygen pressure leaching slag described in the technical solution of the present invention is mainly elemental sulfur.

In the technical solution of the present invention, the arsenic-containing leaching slag is preferably washed to remove residual sulfuric acid in the oxygen pressure acid leaching slag.

In a preferred solution, after the drying treatment, the moisture in the arsenic-containing leach residue is not higher than 9%.

In a preferred solution, the arsenic-containing leaching slag is ground and sieved until the mass percentage of the particle size below -0.074mm is 70% to 85%.

The main function of the vacuum distillation process in the technical solution of the present invention is to enrich the sulfur in the leach slag in the form of elemental sulfur instead of releasing it in the form of sulfur dioxide, which pollutes the environment.

According to the technical proposal of the invention, the recovery rate of sulfur in the arsenic-containing leaching slag can reach more than 98 percent, and the sulfur purity can reach more than 99 percent, fully meeting the industrial application standards.

In the technical scheme of the present invention, the main reaction principle of the high-arsenic lead matte raw material and pyrite ingredients being matched in sulfuric acid for pressurized oxidative leaching: through the oxygen pressure condition, in the sulfuric acid solution, the copper in the lead matte is The form of copper sulfate is leached into the solution, the sulfur enters the leaching slag in the form of elemental sulfur and iron in the form of hematite, and the arsenic in the matte also enters the leaching slag in the form of iron arsenate. The whole process realizes the selection of copper. Sexual leaching and arsenic fixation. The specific reaction is as follows:

2CuS+2H ₂ SO ₄ +O ₂ ＝2CuSO ₄ +2S↓+2H ₂ O(1-1)

2Cu ₂ S+4H ₂ SO ₄ +O ₂ ＝4CuSO ₄ +2S↓+2H ₂ O(1-2)

2PbS+2H ₂ SO ₄ +O ₂ ＝2PbSO ₄ ↓+2S↓+2H ₂ O(1-3)

Ag ₂ S+H ₂ SO ₄ +1/2O ₂ =Ag ₂ SO ₄ ↓+S↓+H ₂ O(1-4)

4FeS+6H ₂ SO ₄ +3O ₂ ＝2Fe ₂ (SO ₄ ) ₃ +6H ₂ O+4S↓(1-5)

_CuxAsy + _H2SO4 + _{O2 → xCuSO4 + yH3AsO4 + H2O} (1-6)

Fe ₂ (SO ₄ ) ₃ +2H ₃ AsO ₄ ＝2FeAsO ₄ ↓+3H ₂ SO ₄ (1-7)

Except for sulfur in the lead matte oxygen pressure leaching slag raw material described in the technical solution of the present invention, other elements are all high boiling point elements, and the boiling points of sulfides and sulfates of these elements are much higher than the boiling point of sulfur , and is a non-volatile substance, the difference in vapor pressure between sulfur and other components is also very large. The above differences in these properties provide a fundamental theoretical basis for the recovery of sulfur by vacuum distillation and the remaining of other materials in the residue.

Compared with the prior art, the beneficial technical effect brought by the technical solution of the present invention:

1) The technical solution of the present invention realizes arsenic fixation at the source during the leaching process of high-arsenic lead matte, effectively avoiding the leaching of arsenic at the same time during the copper leaching process, and the leaching solution does not need to be purified and removed after liquid-solid separation, and can be directly spun Qualified cathode copper products are obtained by galvanic deposition; this scheme simplifies the steps of de-arsenic treatment of the leachate in the existing wet process, and eliminates the problem of arsenic pollution.

2) The technical solution of the present invention adopts pyrite as the arsenic-fixing agent, and the arsenic and iron are fixed at the same time, mainly in the form of stable ferric arsenate, the copper leaching rate reaches more than 95%, the arsenic slag rate is more than 99%, and the iron The slag rate is more than 90%; the selective leaching of copper can be achieved, and the leachate with copper ion content of 20-80g/L and iron ion and other impurities below 3g/L can be obtained, which meets the requirements of cyclone electrowinning.

3) The technical scheme of the present invention adopts the swirl electrowinning technology in the copper electrodeposition process, and the swirl electrowinning process can eliminate the adverse effects of the concentration polarization on the electrowinning, and the whole process can be performed at a lower cell voltage and a higher current It is carried out under density conditions, which reduces DC power consumption and improves production efficiency; after electrowinning, the concentration of the liquid can be reduced very low, and the amount of metal extracted per unit electrolytic solution is increased, and the production efficiency is also increased; the electrowinning process is in a fully closed tube It is carried out in a swirl electrolytic cell, which completely eliminates the generation of acid mist in the electrowinning process, and is clean and environmentally friendly.

4) The swirling electrowinning technology of the present invention can control the concentration of liquid copper ions after electrowinning to below 5g/L, effectively increasing the amount of metal extracted per unit electrolyte, improving production efficiency, and reducing power consumption.

5) In the technical scheme of the present invention, the sulfur in the minerals is mainly produced in the form of elemental sulfur, rather than in the form of sulfur dioxide, and the vacuum distillation process is carried out in a sealed vacuum furnace without toxic gas emissions, pollution-free, Environmentally friendly and efficient.

6) The technical solution of the present invention adopts the vacuum distillation process to reclaim the sulfur in the lead matte leaching slag, no matter the recovery rate of sulfur in the leaching slag, or the purity of reclaimed sulfur all meet the requirements of industrial application; and the residue obtained after treatment can be directly Return to the lead smelting system to comprehensively recover other valuable metals.

Description of drawings

[Fig. 1] is a process flow diagram of the present invention.

detailed description

The present invention is further described below in conjunction with the examples, but the present invention is not limited to the scope of the examples.

Example 1:

The present invention takes high-arsenic lead matte produced by a lead smelting plant in Chenzhou, Hunan as the research object, and 500g of lead matte (Cu41.08%; Pb14.14%; Ag0.35%; Fe1.576%; S3.23 %; As14.25%) is mixed with pyrite according to the mass ratio of iron and arsenic at 1:1, then crushed and ground until more than 90% of the material is below 0.074mm, and then mixed with additives and sulfuric acid. The liquid-solid ratio is 5: 1. The initial sulfuric acid concentration is 120g/L, add 2% sodium lignosulfonate additive for pulping, put the material after pulping into the high-pressure reactor, pressurize the pressure at 1.6MPa, and the oxidation reaction starts at this time, just It can control the reaction temperature at 130-160°C, heat and hold the pressure for 2 hours, then lower the temperature and pressure, and then discharge the material at normal pressure and around 90°C, control the acidity at the end of leaching to 60g/L, and carry out solid-liquid separation. Copper is in the form of divalent copper ions After entering the leaching solution, the leaching rate of copper is 95.7% through laboratory analysis, and the leaching slag is returned to the lead smelting system to comprehensively recover valuable metals such as lead, gold, silver, antimony, and bismuth. Adjust the acidity of the leaching solution to 90g/L and directly carry out cyclone electrowinning, control the current density of the first stage to 500A/m ² , the current density of the second stage to 260A/m ² , and the electrodeposition time for 10h, and finally obtain the cathode copper product with a purity of 99.997%, which meets the requirements of National standard copper cathode product quality requirements.

Then the obtained leaching residue is washed, dried, ground and sieved, and the obtained powder has a particle size of less than 0.074mm, and the mass percentage is 75%. Put the material into the vacuum distillation furnace, seal it, evacuate it to a relative vacuum of -0.1MPa, heat it to 200°C, keep the temperature constant, the sulfur vapor is extracted and undergoes secondary condensation, after distillation for 40min, cool down and recover To normal pressure, open the distillation equipment to obtain sulfur and residue. After calculation, the recovery rate of sulfur reaches 98.2%, and the purity of sulfur is 99.23%, which fully meets the industrial application standard. The residue is returned to the lead smelting system to recover other valuable metals.

Example 2:

The present invention takes high-arsenic lead matte produced by a lead smelting plant in Chenzhou, Hunan as the research object, and 500g of lead matte (Cu31.57%; Pb15.22%; Ag0.41%; Fe10.53%; S1.13 %; As17.31%) is mixed with pyrite according to the mass ratio of iron and arsenic of 1.2:1, and then crushed and ground until more than 90% of the material is below 0.074mm, and then mixed with sodium lignosulfonate additive and sulfuric acid, The liquid-solid ratio is 4:1, the initial sulfuric acid concentration is 100g/L, and 1% additive is added for normal pressure leaching. The material after normal pressure leaching is put into a high-pressure reactor, and the pressurized pressure is 1.4MPa. At this time, the oxidation reaction starts , can just control the reaction temperature at 140-170°C, keep the temperature and pressure for 3 hours, then lower the temperature and pressure, and then discharge the material to normal pressure and about 90°C, control the acidity at the end of leaching to 40g/L, and carry out solid-liquid separation. Copper is separated by divalent copper ions The form enters the leaching solution, and the leaching rate of copper is 95.53% through laboratory analysis, and the leaching slag is returned to the lead smelting system to comprehensively recover valuable metals such as lead, gold, silver, antimony, bismuth, etc. Adjust the acidity of the leaching solution to 110g/L and directly carry out cyclone electrowinning, control the current density of the first stage to 600A/m ² , the current density of the second stage to 300A/m ² , and the electrodeposition time for 10h, and finally obtain the cathode copper product with a purity of 99.998%, which meets the requirements of National standard copper cathode product quality requirements.

Then the obtained leaching residue is washed, dried, ground and sieved, and the mass percentage of the obtained powder with a particle size below 0.074 mm is 85%. Put the material into the vacuum distillation furnace, seal it, evacuate it to a relative vacuum of -0.2MPa, heat it to 300°C, keep the temperature constant, the sulfur vapor is extracted and undergoes secondary condensation, after distillation for 50min, cool down and recover To normal pressure, open the distillation equipment to obtain sulfur and residue. After calculation, the recovery rate of sulfur reaches 98.1%, and the purity of sulfur is 99.01%, which fully meets the industrial application standard. The residue is returned to the lead smelting system to recover other valuable metals.

Comparative Example 1

The steps of the embodiment are as in Example 1, except that the high-arsenic lead matte and pyrite are mixed according to the mass ratio of iron and arsenic of 0.8:1 in the test process, and other steps remain unchanged, then the arsenic concentration of the copper-containing leachate obtained in the test is greater than 600mg/L , the purity of the cathode copper product finally obtained is 99.8%, which does not meet the quality requirements of the national standard cathode copper product.

Comparative Example 2

Embodiment step is as embodiment 2, just reduces the process distillation time to 40min, and other steps remain unchanged, then the sulfur product recovery rate that experiment obtains is 88.31%, and the sulfur product purity is 99.02%, and the product purity obtained in experiment is basically constant, In line with industrial requirements, while the recovery rate of sulfur products has dropped significantly.

Claims (10)

1. A process for comprehensively recovering copper and sulfur from high-arsenic lead matte, characterized in that: the high-arsenic lead matte raw material and pyrite are mixed together for crushing and grinding; the obtained mineral powder is mixed with sulfuric acid and dispersing additives for slurry preparation After that, pressurized oxidative acid leaching and liquid-solid separation are carried out to obtain copper-containing leaching solution and arsenic-containing leaching slag; the copper-containing leaching solution is passed through cyclone electrowinning to obtain copper products; the arsenic-containing leaching slag is recovered by vacuum distillation to recover elemental sulfur product. 2. The high-arsenic-lead matte comprehensive recovery process for copper and sulfur according to claim 1, characterized in that: the high-arsenic-lead matte raw material and pyrite ingredients are formulated according to the mass ratio of iron and arsenic in the range of 1 to 1.2:1 . 3. The process for comprehensive recovery of copper and sulfur from high-arsenic lead matte according to claim 2, characterized in that: the arsenic content of the high-arsenic lead matte is 5-25%. 4. The high-arsenic lead matte comprehensive recovery process for copper and sulfur according to any one of claims 1 to 3, characterized in that: the high-arsenic lead matte raw material and pyrite ingredients are ground until the particle size meets -0.074 The mass percentage content of particle size below mm is not less than 90%. 5. The process for comprehensive recovery of copper and sulfur from high-arsenic lead matte according to any one of claims 1 to 3, characterized in that: the condition of the slurry preparation is: the liquid-solid ratio of mineral powder to sulfuric acid is 4-6 : 1mL/g, the sulfuric acid concentration is 100-120g/L, the temperature is 75-95°C, and the dispersing additive is 1%-2% of the mineral powder mass. 6. The process for comprehensively recovering copper and sulfur from high-arsenic lead matte according to claim 5, characterized in that: the dispersing additive is sodium lignosulfonate. 7. The process for comprehensive recovery of copper and sulfur from high-arsenic lead matte according to claim 1-3 or 6, characterized in that: the conditions of the pressurized oxidative acid leaching are: the leaching temperature is 130-170°C, the leaching time For 2-3 hours, the pressure is 0.6-1.8MPa, and oxygen is introduced into the system during the leaching process. 8. The process for comprehensive recovery of copper and sulfur from high-arsenic lead matte according to claim 1-3 or 6, characterized in that: the conditions of the vacuum distillation are: the relative vacuum degree is not less than -0.1MPa, the temperature is 200-300 ℃, the distillation time is 40~50min, and the steam extraction rate is controlled at 2~3L/S. 9. The process for comprehensive recovery of copper and sulfur from high-arsenic lead matte according to claim 1-3 or 6, characterized in that: the condition of the cyclone electrowinning is: the acidity of the copper-containing leaching solution is 90-110g/L , the current density of the first stage is 400-600A/m ² , the current density of the second stage is 200-300A/m ² , and the electrowinning cycle is 10h. 10. The process for comprehensively recovering copper and sulfur from high-arsenic-lead matte according to claim 9, characterized in that: the post-electrowinning solution produced by said swirl electrowinning is used for slurry mixing.