A method for comprehensive recovery of copper anode slime smelting slag

Abstract

The present invention relates to the technical field of non-ferrous metal smelting, and more specifically, to a method for comprehensive recovery of copper anode slime smelting slag. The method comprises the following steps: reducing the copper anode slime smelting slag to obtain crude lead; pyro-refining the crude lead, casting it into anode plates, and electrolyzing it to obtain precipitated lead and lead anode slime; and leaching the lead anode slime to obtain a leachate and a leachate slag. The leachate is purified and impurities removed, and the purified liquid is used to recover antimony and bismuth using an electrodeposition method. The leachate slag is then smelted to recover gold and silver. The method can effectively recover metal elements such as lead, bismuth, antimony, gold, and silver from the copper anode slime smelting slag, while producing minimal wastewater and achieving high treatment efficiency. The method is worthy of widespread application.

Description

Technical Field

[0001] The present invention relates to the technical field of nonferrous metal smelting, and in particular to a method for comprehensive recovery of copper anode mud smelting slag. Background Art

[0002] At present, the advanced Kaldo furnace smelting process for extracting gold and silver from copper anode mud is widely used at home and abroad. This process produces a smelting slag. The main components of the smelting slag are lead, antimony, bismuth, gold and silver, with contents of 20-40%, 3-6%, 1-2%, 50-200g / t and 3000-5000g / t respectively, and the recovery value is relatively high.

[0003] There are generally two methods for treating copper anode slime smelting slag: one is to return it directly to the copper smelting system for treatment. However, lead in the copper smelting process can only be discharged through the smoke, which increases the blowing load of the copper matte, increases the smoke yield, and affects the direct recovery rate of copper and precious metals. Furthermore, the smelting slag contains high levels of antimony and bismuth, and returning it to the copper smelting system for treatment also has a significant impact on the quality of the electrolytic copper. The other is to process it separately to recover the lead-bismuth alloy. This involves mixing the anode slime smelting slag with flux and adding it to a Kaldo furnace for reduction smelting. The lead-bismuth alloy is obtained after reduction smelting and slagging, and then further recovering lead, bismuth, gold, and silver. This method is complex to operate and the resulting lead-bismuth recovery rate is low. Summary of the Invention

[0004] In view of the deficiencies in the above-mentioned prior art, the present invention provides a method for comprehensive recovery of copper anode slime smelting slag.

[0005] The present invention is achieved through the following technical solutions.

[0006] A method for comprehensive recovery of copper anode slime smelting slag, comprising the following steps:

[0007] (1) adding the copper anode slime smelting slag to a reduction smelting furnace used to process copper fume leaching slag to obtain crude lead; in this step, the copper anode slime smelting slag and the copper fume leaching slag are mixed and placed in a reduction smelting furnace for reduction smelting, and the valuable metals in the copper anode slime smelting slag are reduced into the crude lead by utilizing the strong reducing atmosphere of the reduction smelting furnace, with a high recovery rate of metals such as lead, bismuth, antimony, gold, and silver, and the crude lead, slag, and lead matte are discharged through an electric heating fore bed connected to the reduction smelting furnace;

[0008] (2) The crude lead is pyro-refined and then cast into lead anode plates for electrolysis to obtain precipitated lead and lead anode mud; gold, silver, antimony, and bismuth enter the lead anode mud;

[0009] (3) Leaching the lead anode mud and filtering to obtain a leachate and a leach residue; wherein bismuth and antimony metals enter the leachate; lead, gold, silver and other metals are enriched in the leach residue;

[0010] (4) purifying and removing impurities from the leachate obtained in step (3), recovering antimony and bismuth from the purified solution by electrodeposition, and further recovering lead and copper from the purified slag;

[0011] (5) The leached residue obtained in step (3) is returned to the Kaldo furnace and put into the furnace together with the copper anode mud pressure leached residue for smelting to produce a gold-silver alloy, which is cast into silver anode plates to further recover gold and silver.

[0012] Furthermore, in the reduction process of step (1), the copper anode mud smelting slag is first crushed into blocks with a particle size of 10 to 15 cm, and then added into a reduction smelting furnace for treating copper fume leaching slag, and the amount of reducing agent coke added is 15% to 20% of the total mass of the added copper anode mud smelting slag and copper fume leaching slag bricks, wherein the mass ratio of copper anode mud smelting slag to copper fume leaching slag is 1:4-8; slag-forming agents limestone powder and ferrous oxide are added to the copper fume leaching slag during brick making, and the mass ratio of copper fume leaching slag: limestone powder: ferrous oxide is 1:(0.04-0.1):(0.05-0.12).

[0013] Furthermore, the crude lead fire refining in step (2) mainly includes tin removal by oxidation refining, copper removal by smelting, and copper removal by adding a copper remover. First, the crude lead is placed in a lead melting pot and heated to 550-600°C. The temperature is stopped, and an oxidant is added to the lead liquid after solid-liquid separation and slag removal. The oxidant is lead oxide, and the amount added is 4-6 times the tin content of the lead liquid. After the temperature is raised to 670-720°C, the liquid phase after solid-liquid separation and tin slag removal is cooled to 320-340°C for copper removal by smelting. After copper removal by smelting, the temperature is raised to 380-420°C, and 0.5-3kg / ton of copper remover (i.e., 0.5-3kg of copper remover is added per ton of liquid phase) is added to continue copper removal. The copper remover is sulfur or ferrous sulfide. The lead liquid is cast into lead anode plates.

[0014] Furthermore, in step (2), the electrolysis process is carried out using a lead fluoride silicate solution as the electrolyte, a lead anode plate as the anode, and a lead-made starting plate as the cathode for electrolysis. The electrolysis temperature is room temperature and the current density is 100-150A / m 2 , the circulation volume of each tank is 15-20L / min, and the electrolysis cycle is 5-7 days.

[0015] Furthermore, hydrochloric acid and an oxidant are added during the leaching of the lead anode slime in step (3), wherein sodium chlorate is used as the oxidant. The reaction conditions are: a liquid-to-solid ratio of 3-6:1 (i.e., the mass ratio of the total amount of hydrochloric acid and oxidant to the lead anode slime), a hydrochloric acid concentration of 2-5 mol / L, an oxidant dosage of 0.25-0.5 kg / kg of lead anode slime, a reaction time of 3-5 hours, and a reaction temperature of 60-85°C.

[0016] Furthermore, in step (4), the leachate is purified by sodium sulfide, and the amount of sodium sulfide added is 1.1-1.5 times the theoretical amount for reacting with copper and lead in the leachate.

[0017] The main reactions are as follows:

[0018] Na2S+Cu 2+ =CuS↓+2Na +

[0019] Na2S+Pb 2+ =PbS↓+2Na +

[0020] Furthermore, in step (4), the purified liquid is used to recover antimony and bismuth by electrodeposition, which is a diaphragm electrowinning method. The cathode is made of a titanium plate with a purity of 99.99%, and the anode is a graphite plate. The electrowinning temperature is room temperature and the current density is 100-300A / m 2 The electrowinning process takes 6-8 days. The solution after electrowinning is returned to the lead anode mud for leaching and recycling, reducing the amount of process wastewater. The antimony and bismuth content of the obtained antimony-bismuth alloy is ≥95%.

[0021] Beneficial technical effects of the present invention:

[0022] 1. The present invention utilizes copper fume leaching slag for reduction smelting while simultaneously treating copper anode slime smelting slag, without the need for new equipment or the addition of new treatment agents. Furthermore, the crude lead obtained through the reduction smelting treatment of the present invention can be recovered through pyrorefining and electrolytic refining to produce lead ingots.

[0023] 2. Antimony, bismuth, gold, and silver in the copper anode slime smelting slag of the present invention enter the anode slime after electrolytic treatment. The anode slime is leached, wherein antimony and bismuth enter the liquid phase, and lead, gold, and silver enter the slag phase, so that antimony and bismuth are effectively separated from lead, gold, and silver, and the leaching rates of antimony and bismuth are both above 90%. Gold and silver are enriched in the slag phase, which can be combined with the copper anode slime pressure leaching slag to enter the Kaldo furnace.

[0024] 3. The present invention uses diaphragm electrowinning to recover antimony and bismuth, with a current efficiency of over 90%. The liquid after electrowinning can be returned to the lead anode mud for leaching and recycling, thus reducing the amount of process wastewater.

[0025] In summary, the comprehensive recovery method from copper anode mud smelting slag proposed in the present invention can effectively recover metal elements such as lead, bismuth, antimony, gold, and silver from copper anode mud smelting slag, and has the advantages of small amount of wastewater and high treatment efficiency, and is worthy of promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, a method for comprehensive recovery of copper anode slime smelting slag comprises the following steps:

[0029] (1) The copper anode mud smelting slag is first crushed into blocks with a particle size of 10 to 15 cm, and then added to a reduction smelting furnace for treating copper smoke leaching slag to obtain crude lead, wherein the amount of reducing agent coke added is 15% to 20% of the total mass of the added copper anode mud smelting slag and copper smoke leaching slag bricks, wherein the mass ratio of the copper anode mud smelting slag to the copper smoke leaching slag is 1:4-8; slag-making agents limestone powder and ferrous oxide have been added to the copper smoke leaching slag during brick making, and the copper The mass ratio of smoke leaching residue: limestone powder: ferrous oxide is 1:(0.04-0.1):(0.05-0.12). In this step, the copper anode mud smelting residue and the copper smoke leaching residue are mixed and placed in a reduction smelting furnace for reduction smelting. The strong reducing atmosphere of the reduction smelting furnace is used to reduce the valuable metals in the copper anode mud smelting residue into crude lead, and the recovery rate of metals such as lead, bismuth, antimony, gold, and silver is high. The crude lead, slag, and lead matte are discharged through an electric heating forebed connected to the reduction smelting furnace.

[0030] (2) After the crude lead is pyro-refined, it is cast into anode plates for electrolysis to obtain precipitated lead and lead anode mud; wherein, gold, silver, antimony and bismuth enter the lead anode mud; the pyro-refining mainly includes oxidative refining to remove tin, smelting to remove copper and adding a copper remover to remove copper; first, the crude lead is placed in a lead melting pot, heated to 550-600°C, and the temperature is stopped. The lead liquid after solid-liquid separation and slag removal is added with an oxidant, the oxidant is lead oxide, and the amount added is 4-6 times the tin content of the lead liquid. After the temperature is raised to 670-720°C, the liquid phase after solid-liquid separation and tin slag removal is cooled to 320-340°C after heat preservation and solid-liquid separation, and copper is smelted to remove copper. After smelting and removing copper, the temperature is raised to 380-420°C, and 0.5-3kg / ton of a copper remover is added to continue removing copper. The copper remover is sulfur or ferrous sulfide. The lead liquid is cast into lead anode plates. The electrolysis process uses lead fluoride silicate solution as electrolyte, lead anode plate as anode, and lead as cathode for electrolysis. The electrolysis temperature is room temperature and the current density is 100-150A / m 2 , the circulation volume of each tank is 15-20L / min, and the electrolysis cycle is 5-7 days;

[0031] (3) Leaching the lead anode mud with hydrochloric acid, using sodium chlorate as an oxidant, with a liquid-to-solid ratio of 3-6:1, a hydrochloric acid concentration of 2-5 mol / L, an oxidant dosage of 0.25-0.5 kg / kg of lead anode mud, a reaction time of 3-5 hours, and a reaction temperature of 60-85°C. After leaching and filtration, a leachate and a leach residue are obtained; bismuth and antimony metals enter the leachate; lead, gold, silver and other metals are enriched in the leach residue;

[0032] (4) The leachate obtained in step (3) is purified and impurities removed by sodium sulfide, and the purified liquid is recovered by diaphragm electrowinning method to recover antimony and bismuth, the cathode is made of a titanium plate with a purity of 99.99%, and the anode is made of a graphite plate, the electrowinning temperature is room temperature, and the current density is 100-300A / m 2 The electrowinning time is 6-8 days, and the solution after electrowinning is returned to the lead anode mud for leaching and recycling, thereby reducing the amount of process wastewater. The antimony and bismuth content of the obtained antimony-bismuth alloy is ≥95%. The purified slag is further used to recover lead and copper. The amount of sodium sulfide added is 1.1-1.5 times the theoretical amount for reacting with copper and lead in the leachate.

[0033] (5) The leached residue obtained in step (3) is returned to the Kaldo furnace and put into the furnace together with the copper anode mud pressure leached residue for smelting to produce a gold-silver alloy, which is cast into silver anode plates to further recover gold and silver.

[0034] Example 1

[0035] (1) The reduction smelting furnace operates continuously, with each batch of input materials consisting of: 200 kg of anode mud smelting slag crushed into 10-15 cm blocks, 1600 kg of copper fume leaching slag bricks, and 270 kg of coke. The copper fume leaching slag is mixed with limestone powder and ferrous oxide as slag-forming agents during brick making. The mass ratio of copper fume leaching slag: limestone powder: ferrous oxide is 1:0.04:0.1. The valuable metals in the copper anode mud smelting slag are converted into crude lead, and the crude lead, slag, and lead matte are discharged through an electric heating fore bed connected to the reduction smelting furnace.

[0036] (2) Putting crude lead into a lead melting pot for fire refining to remove copper and tin, and then casting it into lead anode plates on a linear casting machine;

[0037] Fire refining mainly involves oxidative refining to remove tin, smelting to remove copper, and adding a copper remover to remove copper. First, crude lead is placed in a lead melting pot and heated to 550°C. The temperature is then stopped, and lead oxide is added to the lead liquid after solid-liquid separation and slag removal. The amount added is four times the tin content of the lead liquid. The temperature is then raised to 670°C, held, and the liquid phase, after solid-liquid separation and removal of tin slag, is cooled to 340°C and smelted to remove copper. After smelting and removing copper, the temperature is raised to 390°C, and 0.6kg / ton of sulfur is added to continue removing copper. The lead liquid is then cast into lead anode plates.

[0038] (3) The lead anode plate is electrolyzed to produce electrolytic lead and lead anode mud, which is cast into lead ingots. Antimony, bismuth, gold, silver, etc. enter the lead anode mud. The lead anode mud has a grade of Pb: 13-18%, Cu: 0.5-1.5%, Sb: 10-15%, Bi: 20-40%, As: 0.2-0.5%, Au: 150-300g / t, and Ag: 20,000-40,000g / t;

[0039] The electrolysis process uses lead fluoride silicate solution as electrolyte, lead anode plate as anode, and lead as cathode for electrolysis. The electrolysis temperature is room temperature and the current density is 100A / m 2 , the circulation volume of each tank is 15L / min, and the electrolysis cycle is 7 days;

[0040] (4) The lead anode mud is leached with HCl+oxidant, with a liquid-to-solid ratio of 6:1, a hydrochloric acid concentration of 2 mol / L, an oxidant addition amount of 0.25 kg / kg lead anode mud, the oxidant is sodium chlorate, the reaction time is 5 h, the reaction temperature is 60 ° C, and the leachate contains bismuth: 70-90 g / L, antimony: 10-15 g / L, Cu: 0.5-2 g / L, lead: 0.5-1.5 g / L; bismuth and antimony metals> 95% enter the liquid phase; most of the lead, gold, silver and other metals are enriched in the slag phase.

[0041] (5) purifying and removing impurities from the leachate, wherein the amount of sodium sulfide added as an impurity remover is 1.1 times the theoretical amount required to react with copper and lead in the leachate. After purification, the leachate contains 70-90 g / L of bismuth, 10-15 g / L of antimony, 0.02-0.05 g / L of Cu, and 0.01-0.03 g / L of lead. The purified slag is further recovered;

[0042] (6) The antimony and bismuth in the purified solution were recovered by diaphragm electrowinning. The electrowinning cell was made of PPH (size 80*80*150cm), separated by an anion exchange membrane. The distance between the diaphragm and the cathode and the anode was 30mm and 20mm respectively. The electrolyte was composed of the purified and impurity-removed leachate. The current density was 100A / m 2 The electrowinning time is 8 days, the current efficiency is over 90%, and the bismuth-antimony alloy contains 80-85% bismuth and 10-15% antimony.

[0043] (7) The leached residue grade can meet the requirements of the Kaldo furnace. Pb: 20-30%, Cu: 0.5-1%, Sb: 2-5%, Bi: 2-4%, As: 0.5-1%, Au: 400-1000g / t, Ag: 60000-130000g / t.

[0044] Example 2

[0045] (1) The reduction smelting furnace operates continuously, with each batch of input materials consisting of: 400 kg of anode mud smelting slag crushed into 10-15 cm blocks, 1600 kg of copper fume leaching slag bricks, and 400 kg of coke. The copper fume leaching slag is mixed with limestone powder and ferrous oxide as slag-forming agents during brick making, with the mass ratio of copper fume leaching slag: limestone powder: ferrous oxide being 1:0.09:0.06. The valuable metals in the copper anode mud smelting slag are converted into crude lead, and the crude lead, slag, and lead matte are discharged through an electric heating fore bed connected to the reduction smelting furnace;

[0046] (2) Putting crude lead into a lead melting pot for fire refining to remove copper and tin, and then casting it into lead anode plates on a linear casting machine;

[0047] Fire refining mainly involves oxidative refining to remove tin, smelting to remove copper, and adding a copper remover to remove copper. First, crude lead is placed in a lead melting pot and heated to 590°C. The temperature is then stopped, and lead oxide is added to the lead liquid after solid-liquid separation and slag removal. The amount added is six times the tin content of the lead liquid. The temperature is then raised to 710°C, held, and the liquid phase, after solid-liquid separation and removal of tin slag, is cooled to 320°C for smelting to remove copper. After smelting and removing copper, the temperature is raised to 420°C, and 2.9kg / ton of ferrous sulfide is added to continue removing copper. The lead liquid is then cast into lead anode plates.

[0048] (3) The lead anode plate is electrolyzed to produce electrolytic lead and lead anode mud. The electrolytic lead is cast into lead ingots, and antimony, bismuth, gold, silver, etc. enter the lead anode mud. The grade of the lead anode mud is: Pb: 13-18%, Cu: 0.5-1.5%, Sb: 10-15%, Bi: 20-40%, As: 0.2-0.5%, Au: 150-300g / t, Ag: 20000-40000g / t.

[0049] The electrolysis process uses lead fluoride silicate solution as electrolyte, lead anode plate as anode, and lead as cathode for electrolysis. The electrolysis temperature is room temperature and the current density is 140A / m 2 , the circulation volume of each tank is 20L / min, and the electrolysis cycle is 5 days;

[0050] (4) The lead anode mud is leached with HCl+oxidant, with a liquid-solid ratio of 3:1, a hydrochloric acid concentration of 5 mol / L, an oxidant addition amount of 0.5 kg / kg lead anode mud, a reaction time of 3 h, a reaction temperature of 80°C, and an oxidant of sodium chlorate. The leachate contains bismuth: 120-150 g / L, antimony: 15-25 g / L, Cu: 1.5-3 g / L, and lead: 1.5-2.5 g / L; bismuth and antimony metals >95% enter the liquid phase; most of the lead, gold, silver and other metals are enriched in the slag phase.

[0051] (5) purifying and removing impurities from the leachate, wherein the amount of sodium sulfide added as an impurity remover is 1.2 times the theoretical amount required to react with copper and lead in the leachate. After purification, the leachate contains 120-150 g / L of bismuth, 15-25 g / L of antimony, 0.02-0.05 g / L of Cu, and 0.01-0.03 g / L of lead. The purified slag is further recovered;

[0052] (6) Antimony and bismuth were recovered by diaphragm electrowinning. The electrowinning cell was made of PPH (size 80*80*150cm), separated by an anion exchange membrane. The distance between the diaphragm and the cathode and the anode was 30mm and 20mm respectively. The electrolyte was composed of the purified and impurity-removed leachate. The current density was 200A / m 2The electrowinning time is 6 days, the current efficiency is over 90%, and the bismuth-antimony alloy contains 93-95% bismuth and 2-5% antimony.

[0053] (7) The leached residue grade can meet the requirements of the Kaldo furnace: Pb: 20-35%, Cu: 0.3-0.7%, Sb: 1-2%, Bi: 1.5-3%, As: 0.5-1%, Au: 400-1000g / t, Ag: 60000-130000g / t.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the invention. It should be noted that for those skilled in the art, under the technical enlightenment provided by the present invention, other equivalent improvements can be made, all of which can achieve the purpose of the present invention and should be considered as the scope of protection of the present invention.

Claims

1. A method for comprehensive recovery of copper anode slime smelting slag, characterized in that: The following steps are involved: (1) reducing copper anode mud smelting slag to obtain crude lead, wherein the reduction process includes first crushing the copper anode mud smelting slag into blocks with a particle size of 10 to 15 cm, and then adding the blocks into a reduction smelting furnace for treating copper fume leaching slag, wherein the amount of reducing agent coke added is 15% to 20% of the total mass of the copper anode mud smelting slag and the copper fume leaching slag bricks, wherein the mass ratio of the copper anode mud smelting slag to the copper fume leaching slag is 1:(4-8); (2) pyro-refining the crude lead and then casting it into lead anode plates for electrolysis to obtain precipitated lead and lead anode mud; The crude lead fire refining process includes tin removal by oxidation refining, copper removal by smelting, and copper removal by copper remover: first, the crude lead is placed in a lead melting pot and heated to 550-600°C. The temperature is then stopped, and an oxidant is added to the lead liquid after solid-liquid separation and slag removal. The oxidant is lead oxide, and the amount added is 4-6 times the tin content of the lead liquid. The temperature is raised to 670-720°C, and after holding, the liquid phase after solid-liquid separation and tin slag removal is cooled to 320-340°C for copper removal by smelting. After copper removal by smelting, the temperature is raised to 380-420°C, and 0.5-3 kg / ton of copper remover is added to continue copper removal. The copper remover is sulfur or ferrous sulfide. The lead liquid is then cast into lead anode plates. The electrolysis process includes using lead fluoride silicate solution as electrolyte, lead anode plate as anode, and lead-made starting plate as cathode for electrolysis. The electrolysis temperature is room temperature and the current density is 100-150A / m 2 , the circulation volume of each tank is 15-20L / min, and the electrolysis cycle is 5-7 days; (3) leaching the lead anode mud and filtering to obtain a leachate and a leach residue; the lead anode mud leaching process includes adding hydrochloric acid and an oxidant, wherein the oxidant is sodium chlorate; the reaction conditions are a liquid-solid ratio of 3-6:1, wherein the hydrochloric acid concentration is 2-5 mol / L, the oxidant dosage is 0.25-0.5 kg / kg of lead anode mud, the reaction is 3-5 hours, and the reaction temperature is 60-85°C; (4) The leachate obtained in step (3) is purified and impurities removed, and the purified leachate is used to recover antimony and bismuth by electrodeposition; the leachate is purified by sodium sulfide, and the amount of sodium sulfide added is 1.1-1.5 times the theoretical amount of sodium sulfide that reacts with copper and lead in the leachate; the purified leachate is used to recover antimony and bismuth by electrodeposition using a diaphragm electrowinning method, wherein the cathode is made of a titanium plate with a purity of 99.99%, and the anode is a graphite plate, and the liquid after electrowinning is returned to the lead anode mud for leaching and recycling; wherein the electrowinning temperature is room temperature, and the current density is 100-300A / m 2 , electrowinning time 6-8 days; (5) smelting the leached residue obtained in step (3) to recover gold and silver; the leached residue is returned to the Kaldo furnace and smelted with the copper anode mud pressure leached residue.

Images