A method for harmlessly recovering copper and germanium from high-iron and high-copper solution

Abstract

The present invention discloses a method for harmlessly recovering copper and germanium from a high-iron, high-copper solution. The method comprises: subjecting the residue of a primary neutral leaching of a zinc roasted ore obtained by wet smelting to secondary low-acid leaching; subjecting the residue obtained from the liquid-solid separation of the secondary low-acid leaching to a third high-temperature high-acid leaching to recover the valuable metals zinc, copper, and germanium; and producing a lead-silver concentrate containing lead and silver for sale. The liquid after the third high-temperature high-acid leaching contains sulfuric acid, iron, copper, zinc, and germanium, with the iron being primarily trivalent iron. This solution is a high-iron, high-copper solution. The present invention utilizes neutralizing acid and reducing trivalent iron in a single step, and achieves selective reduction, substitution, and separation of copper and germanium, resulting in a high recovery rate of valuable metals and low cost. No new wastewater, waste gas, or waste residue is generated during the process, enabling green production.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metallurgy, and in particular relates to a method for harmlessly recovering copper and germanium from a high-iron and high-copper solution. Background Art

[0002] With the continuous depletion of zinc mineral resources, the continuous rise in the price of zinc smelting raw and auxiliary materials, and the continuous improvement of people's environmental awareness, the waste slag from hydrometallurgical zinc smelting is required to be reduced in amount and emission, and the comprehensive recovery rate of valuable metals in the slag is required to be continuously improved.

[0003] In hydrometallurgical zinc production, zinc roasting ore undergoes a primary leaching process with sulfuric acid. The leached residue then undergoes a secondary low-level leaching followed by neutralization and filtration. This secondary slag, produced in large quantities, is typically sent to a volatilization kiln for recovery of valuable metals. Furthermore, due to the continuous rise in coal prices in recent years, sending the secondary slag to a volatilization kiln for volatilization has resulted in high production costs, high energy consumption, and significant environmental pressure. Therefore, the secondary slag requires further high-temperature, high-acid leaching to reduce the slag volume and produce lead-silver concentrate and a high-iron, high-copper solution. The lead-silver concentrate primarily contains lead and silver for sale, while the high-iron, high-copper solution primarily contains high iron, high copper, germanium, and zinc, with the iron primarily being trivalent iron. If this high-iron, high-copper solution is returned to the primary intermediate leaching process as a slurry, valuable metals will be lost and liquid-solid separation will be difficult after the primary intermediate leaching, resulting in blockages in the production process. Therefore, this is a key constraint on the innovative development of the hydrometallurgical zinc smelting industry.

[0004] Taking the wet zinc smelting of a company in Yunnan as an example, the high-iron and high-copper solution mainly contains 20-26 g / L of total iron, 19-25 g / L of trivalent iron, 0.3-1.5 g / L of copper, 0.020-0.04 g / L of germanium, 40-60 g / L of zinc, 20-40 g / L of sulfuric acid, and 0.01-0.5 g / L of arsenic.

[0005] Current problems include:

[0006] (1) Returning the high-iron and high-copper solution to the primary leaching process as slurry will cause the loss of valuable metals and the difficulty of liquid-solid separation after the primary leaching process, resulting in obstruction of the production process;

[0007] (2) The high iron and high copper solution is neutralized to remove iron and then copper, germanium, and zinc are recovered. The amount of neutralization slag is large, the cost is high, and the recovery rate of valuable metals is low;

[0008] (3) The high-iron and high-copper solution mainly contains high trivalent iron. The conventional oxidation-reduction method for recovering copper and germanium requires a large amount of reducing agent and is costly. The copper-germanium slag produced has low grades of valuable metals copper and germanium. The next step of recovering valuable metals copper and germanium is difficult and costly.

[0009] There are currently the following methods for treating this high-iron and high-copper solution:

[0010] 1. Conventional treatment of high iron and high copper solution is to return it to the first leaching to make slurry;

[0011] 2. Chinese patent CN102031371A discloses a method for enriching germanium from a wet zinc smelting system. The technical solution adopted by the method is: (1) The neutralizing agent is zinc oxide roasted sand, zinc oxide smoke, iron powder, zinc suboxide and iron filings. (2) The ferric ion reducing agent is zinc powder, zinc suboxide, sodium sulfite, iron powder, SO2 or iron filings. The specific amount depends on the amount of ferric ions in the solution. A slight excess is sufficient. (3) The germanium replacement agent is zinc powder, zinc flakes, iron powder or iron filings. (4) The replacement output is germanium precipitate slag;

[0012] 3. Chinese patent CN106834693A discloses a wet comprehensive recovery and utilization method for zinc smelting replacement slag, which uses extraction separation to recover copper;

[0013] 4. Chinese patent CN110093506A discloses a method for efficiently extracting and reducing valuable metals from germanium-zinc leaching residue, the technical scheme adopted by the method is as follows: (1) the reducing agent for trivalent iron ions is germanium-zinc concentrate; (2) the reducing agent for replacing the valuable metals copper and germanium is iron powder, and the amount of iron powder added is 0.5 to 5 times the mass of trivalent iron metal in the pre-neutralized liquid, 0.9 to 1.3 times the mass of copper metal in the pre-neutralized liquid, and 10 to 30 times the mass of germanium metal in the pre-neutralized liquid; (3) the replacement output is germanium-precipitated copper slag.

[0014] In summary, current methods for treating high-iron, high-copper solutions from hydrometallurgical zinc smelting suffer from high costs, low recovery rates of valuable metallic copper and germanium, the use of sodium salts as reducing agents, which introduce impurity hazards into the zinc production system, and the generation of toxic and hazardous gases by metallic zinc reducing agents, making them difficult to implement in actual production. Therefore, there is currently no effective, practical method for treating high-iron, high-copper solutions from hydrometallurgical zinc smelting. To address these issues, a method for harmlessly recovering copper and germanium from high-iron, high-copper solutions is needed. Summary of the Invention

[0015] The purpose of the present invention is to overcome the following shortcomings and / or deficiencies of the prior art:

[0016] (1) The high iron and high copper solution is returned to the first intermediate leaching as slurry, resulting in the loss of valuable metals and difficulty in liquid-solid separation after the first intermediate leaching, leading to blockage of the production process;

[0017] (2) The use of sodium salt as a reducing agent will bring impurity hazards to the zinc production system;

[0018] (3) The use of metallic zinc as a reducing agent will produce toxic and harmful gas arsine gas;

[0019] (4) The extraction method will bring in a large amount of organic matter, which will cause great harm to zinc electrolysis;

[0020] (5) The method of using negative divalent sulfur in the germanium-containing zinc concentrate to reduce trivalent iron will cause sulfur loss. Moreover, the greater the mass ratio of divalent sulfur in the germanium-containing zinc concentrate to iron in the material, the greater the amount of germanium-containing zinc concentrate used, the greater the sulfur loss, the larger the lead-silver sulfur slag, and the higher the depletion rate of valuable metals lead and silver. On the contrary, if the mass ratio of divalent sulfur in the germanium-containing zinc concentrate to iron in the material is too small, the reduction of trivalent iron is incomplete, and a large amount of reducing agent will be consumed when reducing copper in the next process, resulting in high production costs, uneconomical, large amount of waste slag, and difficulty in achieving resource utilization, reduction, and harmless treatment of the slag;

[0021] (6) Using iron powder to replace germanium, the amount of iron powder used is 10 to 30 times the total mass of the germanium metal in the pre-neutralized liquid. A large amount of iron powder is consumed, and a large amount of iron slag will be produced when the iron is processed in the next step. The production cost is high and uneconomical, and the purpose of reducing the slag production cannot be achieved.

[0022] In order to overcome these shortcomings and / or deficiencies, the present invention provides a new method for harmlessly recovering copper and germanium from a high-iron and high-copper solution, which is used to solve the problem of harmlessly recovering copper and germanium from a high-iron and high-copper solution with high levels of trivalent iron, copper and zinc in the hydrometallurgical zinc smelting process.

[0023] The method of the present invention is implemented as follows: the slag from the neutral leaching of zinc roasted ore by wet smelting is subjected to a secondary low-acid leaching, the slag from the liquid-solid separation of the secondary low-acid leaching is subjected to a third high-temperature high-acid leaching to recover the valuable metals zinc, copper, and germanium, and the lead-silver concentrate containing lead and silver is produced for sale. The liquid after the third high-temperature high-acid leaching contains sulfuric acid, iron, copper, zinc, and germanium, and the iron is mainly trivalent iron. This solution is a high-iron and high-copper solution. Specifically, it includes:

[0024] (1) The high-iron and high-copper solution is used to neutralize and reduce the high-valent iron. The high-iron and high-copper solution contains 20 to 40 g / L of sulfuric acid and 19 to 25 g / L of trivalent iron. The method of the present invention uses the intermediate product, zinc sulfite slag, produced during the wet zinc smelting production process as both a neutralizing agent and a reducing agent. The zinc sulfite slag is added to the high-iron and high-copper solution to neutralize the acid and reduce the high-valent iron. When the pH value of the neutralized liquid is between 1.5 and 2.0 and the trivalent iron ion content is below 0.2 g / L, liquid-solid separation is performed to produce neutralized slag and neutralized liquid. The neutralized slag is returned to the secondary low-acid leaching slag and then subjected to three high-temperature high-acid leachings to recover valuable metals. The neutralized liquid contains zinc, copper, germanium, and divalent iron.

[0025] (2) Selective reduction and replacement of copper and germanium in the neutralized liquid. Add reducing agent metal iron powder to the neutralized liquid to replace copper, and obtain crude metal copper powder and replaced liquid after liquid-solid separation. The crude metal copper powder also contains metal iron powder. The method of using magnet to adsorb iron powder is used to purify the crude metal copper powder and improve the grade of the crude metal copper powder. The replaced liquid contains zinc and germanium, which is sent to the neutralization adsorption flocculation system to recover germanium;

[0026] (3) The liquid after displacement is neutralized and adsorbed and flocculated to recover germanium. The pH value of the liquid after displacement is between 2.0 and 2.5. The liquid is heated to 60 to 70°C and the pH value is adjusted to 3.0 to 4.0 with a neutralizing agent, sodium hydroxide. Activated carbon is added and stirred for 1.0 to 2.0 hours. After liquid-solid separation, the liquid after precipitation of germanium and germanium concentrate are obtained. The germanium concentrate is sent to the germanium recovery system to produce germanium dioxide. The liquid after precipitation of germanium is oxidized with air to remove iron, thereby achieving the purpose of opening the iron circuit. The liquid after iron removal is sent to the roasted ore leaching system to recover zinc. The application of the method of the present invention can achieve the purpose of harmless recovery of copper and germanium in the whole process of high-iron and high-copper solution in the wet zinc smelting industry. At the same time, it also creatively finds a process direction for such high-iron and high-copper solution in the wet zinc smelting industry. The application of the method of the present invention can provide a subsequent technical support for the resource utilization, reduction and harmless treatment of zinc-containing leaching slag.

[0027] The method of the present invention is achieved by following steps:

[0028] 1) Neutralization and reduction of high-valent iron: The high-iron and high-copper solution is heated to 60-70°C, and zinc sulfite slag is slowly added. The sulfur dioxide released during the process is sent to the sulfuric acid system for recovery and acid production. The feeding time is controlled at 1.0-1.5 hours. When the end pH is 1.5-2.0 and the trivalent iron ion content is below 0.2 g / L, filtration I is performed. Filtration I obtains No. 1 neutralized slag and No. 1 neutralized liquid. The No. 1 neutralized slag is incorporated into the leaching workshop for secondary low-acid leaching slag and then subjected to three high-temperature high-acid leaching to recover valuable metals;

[0029] 2) Selective reduction and replacement separation of copper and germanium in the neutralized liquid: The neutralized liquid No. 1 is heated to 40-60°C, and iron powder as a reducing agent is slowly added to replace the copper. The amount of iron powder added is 0.9-1.1 times the mass of the copper metal in the neutralized liquid. After a reaction time of 0.5-1.0 hour, filtration II is performed to obtain crude copper powder No. 2 and the replaced liquid No. 2. The replaced liquid No. 2 is sent to the neutralization adsorption flocculation to recover germanium;

[0030] 3) Magnetic separation of crude copper powder: Magnetic separation is used to recover iron powder from the No. 2 crude copper powder to improve its grade. This separation yields No. 3 iron powder and No. 3 refined copper powder. The No. 3 iron powder is returned to the copper replacement process for reuse, while the No. 3 refined copper powder is sold.

[0031] 4) neutralizing the replaced liquid with alkali and adsorbing and flocculating to recover germanium. The pH value of the replaced liquid No. 2 is between 2.0 and 2.5, heating to 60-70° C., adjusting the pH value to 3.0-4.0 with a neutralizing agent, sodium hydroxide, and adding activated carbon. The amount of activated carbon added is 0.1-0.5 g per liter of replaced liquid. Stirring for 1.0-2.0 hours and performing filtration III to obtain No. 3 germanium precipitated liquid and No. 4 germanium concentrate. The No. 4 germanium concentrate is sent to a germanium recovery system to produce germanium dioxide. The No. 3 germanium precipitated liquid is oxidized with air to remove iron and recover iron.

[0032] 5) The germanium-precipitated liquid is subjected to air oxidation to remove iron. The No. 3 germanium-precipitated liquid is heated to 85-90°C. Compressed air is then introduced to oxidize the iron. The oxidation is continued for 1.0-1.5 hours. Lime is then added to neutralize and remove iron. The neutralization endpoint pH is 2.5-3.0. Stirring is continued for 0.5-1.0 hours, followed by filtration IV. The No. 4 air-oxidized liquid and No. 5 iron slag are obtained by filtration IV. The No. 5 iron slag is sold to achieve the purpose of iron circuit opening. The No. 4 air-oxidized liquid is sent to the roasted ore leaching system to recover zinc.

[0033] Preferred:

[0034] The zinc sulfite slag described in step (1) is waste residue produced by hydrometallurgy, which is produced by absorbing sulfur dioxide in the flue gas of a volatilization kiln with zinc-containing materials during the volatilization process to recover valuable metals. The zinc sulfite slag mainly contains 25-40 wt% zinc, 20-35 wt% zinc sulfite, 1.0-4.0 wt% iron, 0.02-0.04 wt% germanium, 2.0-4.0 wt% lead, 0.001-0.006 wt% silver, and 0.2-1.0 wt% copper.

[0035] In step (1), the high-iron and high-copper solution mainly contains 20-26 g / L of total iron, 19-25 g / L of trivalent iron, 1.0-3.0 g / L of copper, 0.020-0.040 g / L of germanium, 40-60 g / L of zinc, 20-40 g / L of sulfuric acid, and 0.01-0.5 g / L of arsenic;

[0036] In step (1), the No. 1 neutralized slag mainly contains 5.0-13 wt% of zinc, 1.0-4.5 wt% of iron, 0.005-0.015 wt% of germanium, 4.0-10.0 wt% of lead, 0.002-0.02 wt% of silver, and 0.1-0.3 wt% of copper;

[0037] The neutralized liquid No. 1 in step (1) mainly contains 20-28 g / L of total iron, 0.01-0.2 g / L of trivalent iron, 1.0-4.0 g / L of copper, 0.060-0.090 g / L of germanium, and 70-120 g / L of zinc;

[0038] In step (2), the No. 2 replacement solution mainly contains 21-32 g / L of total iron, 0.01-0.10 g / L of trivalent iron, 0.05-0.25 g / L of copper, 0.040-0.090 g / L of germanium, and 70-120 g / L of zinc;

[0039] In step (3), the No. 3 refined metal copper powder contains 75-85% copper;

[0040] In step (4), the No. 4 germanium concentrate contains 1.0-3.0% germanium, 5.0-15% zinc, and 50-70% iron;

[0041] In step (5), the No. 5 iron slag contains 60-70% iron, 0.5-5.0% zinc, and 0.1-0.4% arsenic.

[0042] The present invention has been studied and found in experiments:

[0043] (1) Activated carbon not only improves the slag properties to facilitate liquid-solid separation, but also plays a dual role in assisting iron flocculation and adsorbing germanium;

[0044] (2) When the amount of iron powder added as the reducing agent is controlled to be only 0.8 to 1.1 times the mass of copper metal in the neutralized solution and the pH value is between 1.5 and 2.5, selective reduction and displacement separation of copper and germanium can be achieved;

[0045] (3) Using metallic iron powder as a reducing agent will not produce toxic and harmful gas arsine gas.

[0046] The mechanism of the present invention mainly includes:

[0047] (1) Zinc sulfite reacts with sulfuric acid to neutralize the sulfuric acid, utilizing the effect of the reaction between zinc sulfite and sulfuric acid;

[0048] Ionic reaction formula: SO3 2- +2H + →SO2↑+H2O

[0049] (2) The reduction reaction of zinc sulfite and ferric iron, using the reducing effect of zinc sulfite;

[0050] Ionic reaction formula: SO3 2- +2Fe 3+ →SO4 2- +2Fe 2+

[0051] (3) The replacement reaction between metallic iron powder and divalent copper utilizes the reducing property of iron powder and the oxidizing property of divalent copper.

[0052] Ionic reaction formula: Fe+Cu 2+ →Fe 2+ +Cu↓.

[0053] The beneficial effects of the present invention include:

[0054] (1) Using activated carbon as a slag modifier not only improves the performance of the slag to facilitate liquid-solid separation, but also has the dual effect of helping iron flocculation and adsorption of germanium;

[0055] (2) Achieve selective reduction and replacement separation of copper and germanium, with high recovery rate of valuable metals and low cost;

[0056] (3) A method for recovering metal iron powder by magnet adsorption to improve the grade of crude metal copper powder, which has high iron powder utilization rate, low cost, and the product refined metal copper powder has high grade and contains 75-85% copper;

[0057] (4) The alkaline neutralization adsorption flocculation method is used to recover germanium, which does not carry organic matter, has a simple process and is easy to operate;

[0058] (5) This method has creatively realized a process direction for this high-iron and high-copper solution in the hydrometallurgical zinc smelting industry;

[0059] (6) This method solves the long-standing problem that the secondary slag in the hydrometallurgical zinc production process cannot be leached at high temperature and high acid, and can only be sent to a volatilization kiln for volatilization and recovery of valuable metals. The application of the method of the present invention can achieve the goal of reducing waste slag;

[0060] (7) This method uses neutralization acid and reduction of ferric iron in one step, which can shorten the process and reduce costs;

[0061] (8) The reducing agent of this method is zinc sulfite. Zinc in zinc sulfite is the main element of hydrometallurgical zinc smelting. The addition of the reducing agent will not introduce impurities into the system.

[0062] (9) The zinc sulfite slag of this method is an intermediate product of hydrometallurgical zinc smelting. The zinc sulfite in the zinc sulfite slag is used as a reducing agent, which does not increase the cost and is economical and efficient.

[0063] (10) This method realizes the harmless recovery of copper and germanium in a hydrometallurgical zinc smelting system in a high-iron and high-copper solution with high trivalent iron;

[0064] (11) This method does not require additional equipment, is easy to operate, and has low investment and production costs. It is a method with good industrial prospects for harmlessly recovering copper and germanium from high-iron and high-copper solutions.

[0065] (12) This method no longer generates new wastewater, waste gas, or waste residue, and has a beautiful operating environment. It can achieve green production and is in line with national environmental protection, comprehensive recycling of limited resources, and sustainable development requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1The present invention is a process flow chart of a method for harmlessly recovering copper and germanium from a high-iron and high-copper solution. DETAILED DESCRIPTION

[0067] Take the wet zinc smelting of a company in Yunnan as an example: the high-iron and high-copper solution mainly contains 20-26 g / L of total iron, 19-25 g / L of trivalent iron, 1-3 g / L of copper, 0.020-0.04 g / L of germanium, 40-60 g / L of zinc, 20-40 g / L of sulfuric acid, and 0.01-0.5 g / L of arsenic; the main components of zinc sulfite slag are: 25-40wt% zinc, 20-35wt% zinc sulfite, 1.0-4.0wt% iron, 0.02-0.04wt% germanium, 2.0-4.0wt% lead, 0.001-0.006wt% silver, and 0.2-1.0wt% copper.

[0068] The method of the present invention can be achieved by the following steps:

[0069] (1) The high-iron and high-copper solution produced in the wet zinc roasting ore leaching workshop is added to zinc sulfite slag to neutralize sulfuric acid and reduce trivalent iron. The sulfur dioxide released during the reaction is sent to the sulfuric acid system for recovery and acid production. The filtered neutralized slag is incorporated into the secondary low-acid leaching slag in the leaching workshop and then subjected to three high-temperature high-acid leaching to recover valuable metals. The neutralized liquid is selectively reduced and replaced to separate copper and germanium;

[0070] (2) Selective reduction and replacement of copper and germanium in the neutralized liquid: Slowly add reducing agent metal iron powder to the neutralized liquid to replace copper, and filter to obtain crude metal copper powder and the replaced liquid;

[0071] (3) Magnetic separation of crude copper powder: The crude copper powder is separated by magnetic adsorption to recover the metallic iron powder, thereby improving the grade of the crude copper powder. The metallic iron powder is then returned to the copper replacement process for reuse, while the refined copper powder is sold.

[0072] (4) Neutralization of the liquid after displacement with alkali and adsorption flocculation to recover germanium: The liquid after displacement is heated and the pH value is adjusted to 3.0-4.0 with the neutralizing agent sodium hydroxide. Activated carbon is added and stirred for 1.0-2.0 hours before filtering to obtain the liquid after precipitation of germanium and germanium concentrate. The germanium concentrate is sent to the germanium recovery system to produce germanium dioxide. The liquid after precipitation of germanium is oxidized with air to remove iron and recover iron.

[0073] (5) Air oxidation of the germanium-precipitated liquid to remove iron: The germanium-precipitated liquid is heated and compressed air is introduced to oxidize the iron. The oxidation time is 1.0 to 1.5 hours, and then lime is added to neutralize and remove iron. The neutralization end point pH is 2.5 to 3.0. After stirring for 0.5 to 1.0 hours, the liquid is filtered to obtain the air-oxidized liquid and iron slag. The iron slag is sold, and the air-oxidized liquid is sent to the roasted ore leaching system to recover zinc.

[0074] Example 1

[0075] Take (1) 10,000 grams of zinc sulfite slag produced by a Yunnan company and dry it for use. The zinc sulfite slag contains 7.5% moisture, 24.5% zinc, 20.1% zinc sulfite, 1.8% iron, 0.029% germanium, 2.6% lead, 0.0035% silver, and 0.8% copper; (2) 30 liters of high-iron and high-copper solution, which mainly contains 22 grams per liter of total iron, 20 grams per liter of trivalent iron, 1.5 grams per liter of copper, 0.03 grams per liter of germanium, 45 grams per liter of zinc, 25 grams per liter of sulfuric acid, and 0.05 grams per liter of arsenic; and (3) 10 liters of electrolytic waste liquid, which contains 42 grams per liter of zinc and 143 grams per liter of sulfuric acid.

[0076] 1) Neutralization and reduction of high-valent iron: 30 liters of high-iron and high-copper solution were taken, heated to 60-70° C., and zinc sulfite slag was slowly added. The sulfur dioxide released during the process was sent to the sulfuric acid system for recovery and acid production. The feeding time was controlled at 1.0-1.5 hours. The acidity of the reaction process could be adjusted with electrolytic wastewater to control the pH value of the process to 1.5-2.0. Filtration I was performed when the trivalent iron ion content was below 0.2 g / L. A total of 5650 g of zinc sulfite slag was used. Filtration I obtained 2805 g of neutralized slag No. 1 and 28.2 liters of neutralized liquid No. 1. The neutralized slag No. 1 contained 17.3 wt% of water, 12.3 wt% of zinc, 1.2 wt% of iron, 0.0110 wt% of germanium, 6.3 wt% of lead, 0.0085 wt% of silver, and 0.19 wt% of copper. The neutralized liquid No. 1 contained 26.0 g / L of total iron, 0.05 g / L of trivalent iron, 3.04 g / L of copper, 0.081 g / L of germanium, 86.8 g / L of zinc, and 0.06 g / L of arsenic. The No. 1 neutralized residue was incorporated into the leaching plant for a secondary low-acid leaching, followed by a third high-temperature, high-acid leaching to recover the valuable metals.

[0077] 2) Selective reduction and displacement separation of copper and germanium from the neutralized liquid: 27 liters of neutralized liquid No. 1 were heated to 40-60°C. 74 g of iron powder, a reducing agent, was slowly added to displace the copper. The amount of iron powder added was 0.9 times the mass of copper in the neutralized liquid. After a reaction time of 0.5-1.0 hour, filtration II was performed to obtain 109 g of crude copper powder No. 2 and 27 liters of the neutralized liquid No. 2. The crude copper powder No. 2 contained 73.4 wt% copper and 6.4 wt% iron. The neutralized liquid No. 2 contained 28.4 g / L of total iron, 0.04 g / L of trivalent iron, 0.08 g / L of copper, 0.080 g / L of germanium, 85.5 g / L of zinc, and 0.06 g / L of arsenic. The neutralized liquid No. 2 was sent for adsorption flocculation to recover germanium.

[0078] 3) Magnetic Separation of Coarse Copper Powder: 100 grams of No. 2 coarse copper powder was subjected to magnetic separation to recover metallic iron powder and improve the quality of the coarse copper powder. This separation yielded 6 grams of No. 3 metallic iron powder and 94 grams of No. 3 refined copper powder. The No. 3 metallic iron powder was returned to the copper replacement process for reuse, and the No. 3 refined copper powder, containing 78.1 wt% copper, was sold.

[0079] 4) Neutralization of the exchanged liquid with alkali by adsorption and flocculation to recover germanium. 26 liters of exchanged liquid No. 2 were heated to 60-70°C, and the pH was adjusted to 3.0-4.0 with sodium hydroxide as a neutralizer. 2.6 g of activated carbon was added at a rate of 0.1 g per liter of exchanged liquid. After stirring for 1.0-2.0 hours, filtration III was performed. Filtration III yielded 25.5 liters of germanium-precipitated liquid No. 3 and 152 g of germanium concentrate No. 4. The germanium concentrate No. 4 primarily contained 15.0 wt% water, 8.3 wt% zinc, 1.5 wt% germanium, and 65.3 wt% iron. The germanium-precipitated liquid No. 3 primarily contained 25.1 g / L of total iron, 0.05 g / L of copper, 0.004 g / L of germanium, 85.1 g / L of zinc, and 0.05 g / L of arsenic. The germanium concentrate No. 4 was sent to a germanium recovery system to produce germanium dioxide. The germanium-precipitated liquid No. 3 was then oxidized with air to remove iron and recover iron.

[0080] 5) Air oxidation of the germanium precipitated liquid to remove iron: Take 25 liters of the germanium precipitated liquid No. 3 and heat it to 85-90°C. Then, introduce compressed air to oxidize the iron. After 1.0-1.5 hours of oxidation, lime is added to neutralize and remove iron. The neutralization end point pH is 2.5-3.0. After continuing to stir for 0.5-1.0 hours, filter IV to obtain 24.6 liters of the air-oxidized liquid No. 4 and 900 grams of iron slag No. 5. The iron slag No. 5 mainly contains 25wt% water, 65wt% iron, 2.3wt% zinc, and 0.17wt% arsenic. The air-oxidized liquid No. 4 mainly contains 7.7g / L of total iron, 0.04g / L of copper, 85.8g / L of zinc, and 0.004g / L of arsenic. The iron slag No. 5 is sold to achieve the purpose of opening the iron and arsenic circuit. The air-oxidized liquid No. 4 is sent to the roasting ore leaching system to recover zinc.

[0081] The technical and economic indicators obtained by calculation in this embodiment are:

[0082] 1. Germanium direct recovery rate: 85.5%;

[0083] 2. Copper direct recovery rate is 90.3%.

[0084] Example 2

[0085] Take (1) 10,000 grams of zinc sulfite slag produced by a Yunnan company and dry it for use. The zinc sulfite slag contains 7.0% moisture, 29.1% zinc, 27.6% zinc sulfite, 2.3% iron, 0.034% germanium, 3.4% lead, 0.0048% silver, and 0.75% copper; (2) 30 liters of high-iron and high-copper solution, which mainly contains 24g / L total iron, 23g / L trivalent iron, 2.2g / L copper, 0.032g / L germanium, 49g / L zinc, 31g / L sulfuric acid, and 0.06g / L arsenic; (3) 10 liters of electrolytic waste liquid, which contains 43g / L zinc and 145g / L sulfuric acid.

[0086] 1) Neutralization and reduction of high-valent iron: 30 liters of high-iron and high-copper solution were heated to 60-70° C., and zinc sulfite slag was slowly added. The sulfur dioxide released during the process was sent to the sulfuric acid system for recovery and acid production. The feeding time was controlled at 1.0-1.5 hours. The acidity of the reaction process could be adjusted with electrolytic wastewater to control the pH value of the process at 1.5-2.0. Filtration I was performed when the content of trivalent iron ions was below 0.2 g / L. A total of 5600 g of zinc sulfite slag was used. Filtration I obtained 2782 g of neutralized slag No. 1 and 27.6 liters of neutralized liquid No. 1. The neutralized slag No. 1 contained 17.1 wt% of water, 10.5 wt% of zinc, 4.1 wt% of iron, 0.008 wt% of germanium, 7.6 wt% of lead, 0.0108 wt% of silver, and 0.12 wt% of copper. The No. 1 neutralized liquid contained 27.0 g / L of total iron, 0.05 g / L of trivalent iron, 3.7 g / L of copper, 0.092 g / L of germanium, 99.4 g / L of zinc, and 0.05 g / L of arsenic. The No. 1 neutralized residue was incorporated into the leaching plant for a secondary low-acid leaching, followed by a third high-temperature, high-acid leaching to recover the valuable metals.

[0087] 2) Selective reduction and displacement separation of copper and germanium from the neutralized liquid: 27 liters of neutralized liquid No. 1 were heated to 40-60°C. 100 g of iron powder, a reducing agent, was slowly added to displace the copper. The amount of iron powder added was 1.0 times the mass of copper metal in the neutralized liquid. After a reaction time of 0.5-1.0 hour, filtration II was performed to obtain 123 g of crude copper powder No. 2 and 27 liters of the neutralized liquid No. 2. The crude copper powder No. 2 contained 78.8 wt% copper and 8.8 wt% iron. The neutralized liquid No. 2 contained 30.7 g / L of total iron, 0.03 g / L of trivalent iron, 0.11 g / L of copper, 0.091 g / L of germanium, 98.7 g / L of zinc, and 0.05 g / L of arsenic. The neutralized liquid No. 2 was sent for adsorption flocculation to recover germanium.

[0088] 3) Magnetic Separation of Crude Copper Powder: 110 grams of No. 2 crude copper powder was subjected to magnetic separation to recover metallic iron powder and improve its grade. This separation yielded 7 grams of No. 3 metallic iron powder and 103 grams of No. 3 refined copper powder. The No. 3 metallic iron powder was returned to the copper replacement process for reuse, and the No. 3 refined copper powder, containing 84.1 wt% copper, was sold.

[0089] 4) Neutralization of the exchanged liquid with alkali by adsorption and flocculation to recover germanium. 26 liters of exchanged liquid No. 2 were heated to 60-70°C, and the pH was adjusted to 3.0-4.0 with sodium hydroxide as a neutralizer. 5.2 g of activated carbon was added at a rate of 0.2 g per liter of exchanged liquid. After stirring for 1.0-2.0 hours, filtration III was performed. Filtration III yielded 25.2 liters of germanium-precipitated liquid No. 3 and 156 g of germanium concentrate No. 4. The germanium concentrate No. 4 primarily contained 14.7 wt% water, 7.8 wt% zinc, 1.7 wt% germanium, and 64 wt% iron. The germanium-precipitated liquid No. 3 primarily contained 28.3 g / L of total iron, 0.1 g / L of copper, 0.0037 g / L of germanium, 101 g / L of zinc, and 0.05 g / L of arsenic. The germanium concentrate No. 4 was sent to a germanium recovery system to produce germanium dioxide. The germanium-precipitated liquid No. 3 was then oxidized with air to remove iron and recover iron.

[0090] 5) Air oxidation of the germanium precipitated liquid to remove iron: Take 25 liters of the germanium precipitated liquid No. 3 and heat it to 85-90°C. Then, introduce compressed air to oxidize the iron. After 1.0-1.5 hours of oxidation, lime is added to neutralize and remove iron. The neutralization end point is 2.5-3.0. After continuing to stir for 0.5-1.0 hours, filter IV to obtain 24.2 liters of the air-oxidized liquid No. 4 and 930 grams of iron slag No. 5. The iron slag No. 5 mainly contains 20.6wt% water, 68wt% iron, 3.4wt% zinc, and 0.16wt% arsenic. The air-oxidized liquid No. 4 mainly contains 8.9g / L of total iron, 0.07g / L of copper, 103g / L of zinc, and 0.003g / L of arsenic. The iron slag No. 5 is sold to achieve the purpose of opening the iron and arsenic circuit. The air-oxidized liquid No. 4 is sent to the roasting ore leaching system to recover zinc.

[0091] The technical and economic indicators obtained by calculation in this embodiment are:

[0092] 1. Germanium direct recovery rate is 89.7%;

[0093] 2. Copper direct recovery rate is 94.1%.

[0094] Example 3

[0095] Take (1) 10,000 grams of zinc sulfite slag produced by a Yunnan company and dry it for use. The zinc sulfite slag contains 8.3% moisture, 34.8% zinc, 32.7% zinc sulfite, 1.4% iron, 0.038% germanium, 3.8% lead, 0.0053% silver, and 0.92% copper; (2) 30 liters of high-iron and high-copper solution. The high-iron and high-copper solution mainly contains 23 grams per liter of total iron, 21 grams per liter of trivalent iron, 2.7 grams per liter of copper, 0.026 grams per liter of germanium, 53 grams per liter of zinc, 34 grams per liter of sulfuric acid, and 0.08 grams per liter of arsenic; and (3) 10 liters of electrolytic waste liquid. The electrolytic waste liquid contains 47 grams per liter of zinc and 141 grams per liter of sulfuric acid.

[0096] 1) Neutralization and reduction of high-valent iron: 30 liters of high-iron and high-copper solution were heated to 60-70° C., and zinc sulfite slag was slowly added. The sulfur dioxide released during the process was sent to the sulfuric acid system for recovery and acid production. The feeding time was controlled at 1.0-1.5 hours. The acidity of the reaction process could be adjusted with electrolytic wastewater to control the pH value of the process to 1.5-2.0. Filtration I was performed when the content of trivalent iron ions was below 0.2 g / L. A total of 5280 g of zinc sulfite slag was used. Filtration I obtained 2410 g of neutralized slag No. 1 and 28.1 liters of neutralized liquid No. 1. The neutralized slag No. 1 contained 16.2 wt% of water, 13.0 wt% of zinc, 3.4 wt% of iron, 0.006 wt% of germanium, 9.1 wt% of lead, 0.0126 wt% of silver, and 0.24 wt% of copper. The No. 1 neutralized liquid contained 24.5 g / L of total iron, 0.03 g / L of trivalent iron, 4.2 g / L of copper, 0.089 g / L of germanium, 107.2 g / L of zinc, and 0.08 g / L of arsenic. The No. 1 neutralized residue was incorporated into the leaching plant for a secondary low-acid leaching, followed by a third high-temperature, high-acid leaching to recover the valuable metals.

[0097] 2) Selective reduction and displacement separation of copper and germanium from the neutralized liquid: 27 liters of neutralized liquid No. 1 were heated to 40-60°C. 125 g of iron powder, a reducing agent, was slowly added to displace the copper. The amount of iron powder added was 1.1 times the mass of copper metal in the neutralized liquid. After a reaction time of 0.5-1.0 hour, filtration II was performed to obtain 160 g of crude copper powder No. 2 and 27 liters of the neutralized liquid No. 2. The crude copper powder No. 2 contained 69.9 wt% copper and 13.8 wt% iron. The neutralized liquid No. 2 contained 28.3 g / L of total iron, 0.01 g / L of trivalent iron, 0.06 g / L of copper, 0.083 g / L of germanium, 104.6 g / L of zinc, and 0.08 g / L of arsenic. The neutralized liquid No. 2 was sent for adsorption flocculation to recover germanium.

[0098] 3) Magnetic Separation of Coarse Copper Powder: 150 grams of No. 2 coarse copper powder was subjected to magnetic separation to recover metallic iron powder and improve its grade. This separation yielded 12 grams of No. 3 metallic iron powder and 138 grams of No. 3 refined copper powder. The No. 3 metallic iron powder was returned to the copper replacement process for reuse, and the No. 3 refined copper powder, containing 76.0 wt% copper, was sold.

[0099] 4) Neutralization of the exchanged liquid by alkali adsorption and flocculation to recover germanium. 27 liters of exchanged liquid No. 2 were heated to 60-70°C. The pH was adjusted to 3.0-4.0 with sodium hydroxide as a neutralizer. 13.5 g of activated carbon was added at a rate of 0.5 g per liter of exchanged liquid. After stirring for 1.0-2.0 hours, filtration III was performed. Filtration III yielded 26.1 liters of germanium-precipitated liquid No. 3 and 118 g of germanium concentrate No. 4. The germanium concentrate No. 4 primarily contained 12.3 wt% water, 6.3 wt% zinc, 2.12 wt% germanium, and 51 wt% iron. The germanium-precipitated liquid No. 3 primarily contained 27.3 g / L of total iron, 0.06 g / L of copper, 0.0022 g / L of germanium, 107.9 g / L of zinc, and 0.08 g / L of arsenic. The germanium concentrate No. 4 was fed to a germanium recovery system to produce germanium dioxide. The germanium-precipitated liquid No. 3 was then oxidized with air to remove iron and recover iron.

[0100] 5) Air oxidation of the germanium precipitated liquid to remove iron: Take 25 liters of the germanium precipitated liquid No. 3 and heat it to 85-90°C. Then, introduce compressed air to oxidize the iron. After 1.0-1.5 hours of oxidation, lime is added to neutralize and remove iron. The neutralization end point is 2.5-3.0. After continuing to stir for 0.5-1.0 hours, filter IV to obtain 24.4 liters of the air-oxidized liquid No. 4 and 915 grams of iron slag No. 5. The iron slag No. 5 mainly contains 19.0wt% water, 75wt% iron, 2.7wt% zinc, and 0.26wt% arsenic. The air-oxidized liquid No. 4 mainly contains 5.3g / L of total iron, 0.04g / L of copper, 109.7g / L of zinc, and 0.002g / L of arsenic. The iron slag No. 5 is sold to achieve the purpose of opening the iron and arsenic circuit. The air-oxidized liquid No. 4 is sent to the roasting ore leaching system to recover zinc.

[0101] The technical and economic indicators obtained by calculation in this embodiment are:

[0102] 1. Germanium direct recovery rate: 92.9%;

[0103] 2. Copper direct recovery rate is 94.6%.

[0104] Example 4

[0105] Example 4 shows the unexpected effect of adding activated carbon as a modifier in the present invention. The moisture content, germanium grade and germanium recovery rate of the germanium concentrate are compared with those without adding activated carbon. The results are shown in the following table.

[0106] Serial number Activated carbon addition amount (g / L solution) Moisture content of germanium concentrate (%) Germanium grade (%) Germanium recovery rate (%) 1 0 29.8 0.6 76.2 2 0 31.1 0.5 71.4 3 0.1 15.0 1.5 85.5 4 0.2 14.7 1.7 89.7 5 0.5 12.3 2.12 92.9 6 0.6 12.2 2.19 93.0

[0107] It can be seen from the table that the addition of modifier activated carbon not only improves the performance of the slag to facilitate liquid-solid separation, but also plays a dual role in helping iron flocculation and adsorption of germanium.

[0108] Summary of the effects of Examples 1-4

[0109] 1. From Examples 1, 2, and 3, it can be concluded that the average direct recovery rate of germanium is as high as 89.1%, and the average direct recovery rate of copper is as high as 93.0%;

[0110] 2. It can be concluded from Example 4 that the addition of the modifier activated carbon not only improves the performance of the slag and facilitates liquid-solid separation, but also has the dual effect of helping iron flocculation and adsorption of germanium; and the best effect is achieved when the activated carbon is added in an amount of 0.1 to 0.5 grams per liter of the replaced liquid.

Claims

1. A method for harmlessly recovering copper and germanium from a high-iron and high-copper solution, characterized in that: The following steps are involved: Step 1, neutralization and reduction of high-valent iron: The high-iron and high-copper solution is heated and zinc sulfite slag is slowly added. The sulfur dioxide released during the process is sent to the sulfuric acid system for recovery and acid production. When the end point pH is 1.5-2.0 and the trivalent iron ion content is below 0.2 g / L, filtration I is performed. Filtration I obtains No. 1 neutralized slag and No. 1 neutralized liquid. The No. 1 neutralized slag is incorporated into the leaching workshop for secondary low-acid leaching slag and then subjected to three high-temperature high-acid leaching to recover valuable metals; Step 2, selective reduction and replacement separation of copper and germanium in the neutralized liquid: the neutralized liquid No. 1 is heated and slowly added with a reducing agent, metallic iron powder, to replace the copper. The amount of iron powder added is 0.9 to 1.1 times the mass of the copper metal in the neutralized liquid. After sufficient reaction, filtration II is performed to obtain crude metallic copper powder No. 2 and the replaced liquid No. 2; the replaced liquid No. 2 is sent to neutralization for adsorption flocculation to recover germanium; Step 3, magnetic separation of crude copper powder: The No. 2 crude copper powder is subjected to magnetic adsorption to recover metallic iron powder to improve the grade of the crude copper powder, and the No. 3 metallic iron powder and No. 3 refined copper powder are separated; the No. 3 metallic iron powder is returned to the copper replacement process for reuse, and the No. 3 refined copper powder is sold; Step 4, neutralizing the replaced liquid with alkali and adsorbing and flocculating to recover germanium: the pH value of the replaced liquid No. 2 is in the range of 2.0 to 2.5, heating and adjusting the pH value to 3.0 to 4.0 with a neutralizing agent of sodium hydroxide, adding activated carbon, and adding 0.1 to 0.5 grams of activated carbon per liter of replaced liquid. After stirring, filtering III is performed to obtain the No. 3 germanium precipitation liquid and the No. 4 germanium concentrate. The No. 4 germanium concentrate is sent to the germanium recovery system to produce germanium dioxide. The No. 3 germanium precipitation liquid is oxidized with air to remove iron and recover iron; Step 5, air oxidation and iron removal of the germanium precipitation liquid: The No. 3 germanium precipitation liquid is heated and compressed air is introduced to oxidize the iron, and then lime is added after oxidation to neutralize and remove the iron, and the neutralization end point pH is 2.5-3.

0. After continuing to stir, the liquid is filtered IV, and the No. 4 air-oxidized liquid and No. 5 iron slag are obtained by filtration IV; the No. 5 iron slag is sold to achieve the purpose of opening the iron circuit, and the No. 4 air-oxidized liquid is sent to the roasted ore leaching system to recover zinc.

2. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 1: The zinc sulfite slag is waste residue produced by hydrometallurgy, and is produced by absorbing sulfur dioxide in the flue gas of a volatilization kiln with zinc-containing materials during the volatilization process to recover valuable metals. The product comprises 25-40 wt% zinc, 20-35 wt% zinc sulfite, 1.0-4.0 wt% iron, 0.02-0.04 wt% germanium, 2.0-4.0 wt% lead, 0.001-0.006 wt% silver, and 0.2-1.0 wt% copper.

3. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 1: The high-iron and high-copper solution comprises 20-26 g / L of total iron, 19-25 g / L of trivalent iron, 1.0-3.0 g / L of copper, 0.020-0.040 g / L of germanium, 40-60 g / L of zinc, 20-40 g / L of sulfuric acid and 0.01-0.5 g / L of arsenic.

4. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 1: The No. 1 neutralization slag comprises 5.0-13 wt% of zinc, 1.0-4.5 wt% of iron, 0.005-0.015 wt% of germanium, 4.0-10.0 wt% of lead, 0.002-0.02 wt% of silver and 0.1-0.3 wt% of copper.

5. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 1: The No. 1 neutralized liquid comprises 20-28 g / L of total iron, 0.01-0.2 g / L of trivalent iron, 1.0-4.0 g / L of copper, 0.060-0.090 g / L of germanium and 70-120 g / L of zinc.

6. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 2: The No. 2 replacement solution includes 21-32 g / L of total iron, 0.01-0.10 g / L of trivalent iron, 0.05-0.25 g / L of copper, 0.040-0.090 g / L of germanium and 70-120 g / L of zinc.

7. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 3: The No. 3 refined metal copper powder contains 75-85% copper.

8. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 4: The No. 4 germanium concentrate contains 1.0-3.0% germanium, 5.0-15% zinc and 50-70% iron.

9. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to claim 1, characterized in that: In step 5: The No. 5 iron slag contains 60-70% iron, 0.5-5.0% zinc and 0.1-0.4% arsenic.

10. The method for harmlessly recovering copper and germanium from a high-iron and high-copper solution according to any one of claims 1 to 9, characterized in that: In step 1, the high iron and high copper solution is heated to 60-70° C., and the addition time is controlled within 1.0-1.5 hours; In step 2, the neutralized solution No. 1 is heated to 40-60° C. for 0.5-1.0 hour; In step 4, the temperature is raised to 60-70° C. and then the acidity is adjusted using a neutralizing agent, sodium hydroxide; In step 5, the temperature of the No. 3 germanium-precipitated solution is heated to 85-90° C., and the oxidation time is 1.0-1.5 hours; and the stirring time is continued for 0.5-1.0 hour.

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