CN101935761A - A method for separating copper and selenium tellurium from lead copper matte - Google Patents

Abstract

A method for separating copper, selenium and tellurium from lead-copper matte. The invention is to mix crushed lead-copper matte powder, sodium hydroxide, sodium carbonate, and water into an autoclave according to a certain ratio, and pass through the autoclave. Introduce oxygen and control the pressure of oxygen in the kettle to carry out oxidation reaction, selenium is oxidized into alkaline leaching solution, copper, lead and tellurium are oxidized into alkaline leaching residue, alkaline leaching residue is then leached copper and tellurium with sulfuric acid solution, and lead is enriched in the acidic leach residue. The copper leaching rate of the invention reaches over 98%, and the tellurium leaching rate reaches over 90%. The invention has low requirements on materials, less corrosion of equipment by alkaline medium, safe operation, good comprehensive recovery benefits of valuable metals, low labor intensity, short processing time and good operating environment.

Description

A method for separating copper and selenium tellurium from lead copper matte

Technical Field The present invention relates to the hydrometallurgical process in the field of metallurgy, especially the hydrometallurgical method for effectively separating copper, selenium and tellurium from the by-product lead-copper matte in the lead smelting process.

Background technology Lead-copper matte (commonly known as lead matte) is a by-product mainly containing copper and lead sulfide produced during blast furnace smelting and oxygen bottom blowing smelting of lead concentrate, which is enriched in lead concentrate Copper, selenium, tellurium, and contains a part of lead and silver, is an important raw material for recycling copper, selenium, tellurium. At present, the treatment of lead-copper matte is to enter the copper smelting system as the raw material for copper smelting, that is, the lead-copper matte with high copper content is directly smelted in the converter of copper, and the lead and sulfur enter the gas phase to volatilize, and the crude copper is produced for electrolytic refining. Lead is recovered in the form of soot; lead copper matte with low copper content is oxidized and roasted for desulfurization, copper is converted into copper oxide or copper sulfate, copper and lead are separated by sulfuric acid leaching, and the copper sulfate solution produced enters the copper smelting system. The leach residue is returned to the lead system. In recent years, the sulfuric acid pressure oxidation leaching method has been studied for the separation of copper and lead. The produced copper sulfate solution is used to recover copper through electrowinning, and the leached slag is returned to the lead smelting system. "Copper Smelting Technology" by Xu Bingshe, Li Mingzhao et al. Chemical Industry Press. 2007.1; Chinese Patent Application 200810058113.1 "Copper Recovery Process from Lead Matte".

There is following shortcoming in the processing method of above-mentioned lead copper matte (lead matte):

(1) The lead-copper matte with high copper content enters the copper converter blowing system to obtain blister copper, and the lead is oxidized and volatilized into the gas phase separation. The process is long, the metal recovery rate is low, the cost is high, and the quality of the produced blister copper is low. The lead copper matte produced by lead smelters can only be sold to copper smelters as copper raw materials. The lead, silver, selenium, tellurium, etc. in the lead copper matte are not priced, and the economic benefits are low.

(2) Lead copper matte with low copper content is treated by oxidation roasting method, and then copper is separated by sulfuric acid leaching method. Since the roasting process is easy to sinter, the oxidation of copper sulfide is not complete, resulting in low copper recovery rate; Valuable metals such as selenium and tellurium are dispersed and difficult to recover; the process produces low-concentration sulfur dioxide flue gas pollution.

(3) Although the sulfuric acid pressurized oxidation leaching method can realize the separation of copper and lead, the dispersion of selenium and tellurium in the lead-copper matte is not conducive to recovery. At the same time, the equipment corrosion problem inevitably exists in the acid leaching system, and the corrosion speed of the equipment is fast. The high frequency prevents acid pressurization equipment from being normally used in industrial production for a long time.

SUMMARY OF THE INVENTION The purpose of the present invention is to provide a method for oxidizing lead-copper matte in an alkaline medium, which can effectively separate copper from lead, enrich and recover selenium and tellurium in lead-copper matte, and the process is basically pollution-free. Hydrometallurgical method.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to mix the crushed lead-copper matte powder, sodium hydroxide, sodium carbonate, and water into the autoclave according to a certain proportion, and feed oxygen into the autoclave at a certain temperature. And control the pressure of oxygen in the kettle to carry out the oxidation reaction, selenium is oxidized into the alkaline leaching solution, copper, lead and tellurium are oxidized into the alkaline leaching slag, the alkaline leaching slag is then leached copper and tellurium with sulfuric acid solution, and the lead is enriched in the acidic leaching solution. leached into the slag.

The specific processing method is as follows:

1 Oxidation leaching

The lead-copper matte is first crushed and ground into a powder with a particle size of 0.25-0.074 mm, slurried with a certain concentration of sodium hydroxide and sodium carbonate solution and added to a high-pressure reactor, and then oxygen is introduced to carry out oxidation reaction after heating up. The temperature of the oxidation reaction is 150-250°C, the concentration of sodium hydroxide is 1.0-3.0mol/L, the concentration of sodium carbonate is 0-2mol/L, and the weight-liquid-solid ratio of leaching (the ratio of solution weight to lead-copper matte weight) is 3-10:1, the partial pressure of oxygen is controlled at 0.3-1.5 MPa, the total pressure of the system is maintained at 1.5-3.5 MPa, and the reaction time is 2-6 hours. After the reaction is complete, cool to 20-60°C and filter. The main chemical reactions that occur in the oxidation leaching process are:

Cu ₂ S+2.5O ₂ +2NaOH+H ₂ O=2Cu(OH) ₂ ↓+Na ₂ SO ₄ (1)

Cu ₂ S+2.5O ₂ +2Na ₂ CO ₃ +H ₂ O＝2CuCO ₃ ↓+Na ₂ SO ₄ +2NaOH (2)

PbS+2O ₂ ＝PbSO ₄ ↓ (3)

PbS+2O ₂ +2NaOH＝Pb(OH) ₂ ↓+Na ₂ SO ₄ (4)

PbS+2O ₂ +Na ₂ CO ₃ ＝PbCO ₃ ↓+Na ₂ SO ₄ (5)

Cu ₂ Se+2O ₂ +2NaOH+H ₂ O=2Cu(OH) ₂ +Na ₂ SeO ₃ (6)

Cu ₂ Te+2.5O ₂ +2NaOH+H ₂ O=2Cu(OH) ₂ +Na ₂ TeO ₄ ↓ (7)

2 Sulfuric acid leaching of alkali leaching residue

The leaching residue obtained after the oxidation leaching reaction is leached for 2 to 3 hours with a sulfuric acid solution with a concentration of 0.5 to 2.5 mol/L at a temperature of 70 to 85 ° C and a weight-liquid-solid ratio of 2 to 8:1, and the sulfuric acid leaching reaction After completion, it is filtered, and the obtained sulfuric acid acidic leaching residue is returned to the lead smelting system. The main chemical reactions that occur in sulfuric acid leaching are:

Cu(OH) ₂ +H ₂ SO ₄ =CuSO ₄ +2H ₂ O (8)

CuCO ₃ +H ₂ SO ₄ =CuSO ₄ +CO ₂ +H ₂ O (9)

Pb(OH) ₂ +H ₂ SO ₄ ＝PbSO ₄ +2H ₂ O (10)

PbCO ₃ +H ₂ SO ₄ ＝PbSO ₄ +CO ₂ +H ₂ O (11)

Na ₂ TeO ₄ +H ₂ SO ₄ =Na ₂ SO ₄ +H ₂ TeO ₄ (12)

3 Displacement of tellurium in copper sulfate solution

Add copper powder whose weight is 2.5 to 3.0 times the tellurium content in the leaching solution to the leaching solution obtained by sulfuric acid leaching at a temperature of 70 to 80° C., and reduce for 2 to 5 hours. The main chemical reactions that occur during the reduction process are:

H ₂ TeO ₄ +5Cu+6H ⁺ ＝Cu ₂ Te↓+3Cu ²⁺ +4H ₂ O (13)

Described sodium hydroxide, sodium carbonate, sulfuric acid, copper powder, oxygen are all industrial grade reagents.

The present invention is suitable for processing lead-copper matte (lead matte) produced by smelting copper-containing lead concentrate, and its composition range is (%): Cu 10-50, Pb 7.5-45, S8-29, Ni 0-10, Se 0.2～4, Te 0.1～3, Au 0.07～3.5, Ag 0.02～0.20, As 0.5～5, Fe 0.5～15; also suitable for processing complex copper-lead-containing sulfide ore concentrates.

Compared with the existing lead-copper matte treatment process, the present invention has the following advantages: the lead-copper matte is treated with alkaline pressurized oxidation to oxidize the sulfides of copper, lead, tellurium, etc., which facilitates the separation and recovery of subsequent processes, eliminates The pollution problems caused by sulfur dioxide fume and lead-containing fume produced in the process of pyroprocessing lead-copper matte were solved; when the pressurized alkaline oxidation leaching residue was leached with sulfuric acid solution, the separation effect of copper, tellurium and lead was good, and the copper The leaching rate of tellurium can reach more than 98%, and the leaching rate of tellurium can reach more than 90%. In the copper sulfate solution, copper powder is used to replace tellurium, and the removal effect of tellurium is good and the recovery rate is good for the concentrated treatment of tellurium; the alkaline system is used for pressurized oxidation leaching , the material requirements of the equipment are low, the corrosion of the equipment by the alkaline medium is small, the operation is safe, and the comprehensive recovery of valuable metals is good; the labor intensity of the present invention is low, the processing time is short, and the operating environment is good.

Description of drawings

Figure 1: Schematic diagram of the process flow of the present invention.

Detailed ways

Example 1:

The lead concentrate produced by the oxygen bottom blowing process is ground to a particle size of 100% less than 0.149mm, and its main components are (%) by weight: Cu 44.32, Pb 18.21, S 16.50, Se 0.74, Te 0.21, Ag 0.14, As 0.61, Fe 0.75; industrial caustic _soda , in which the content of sodium hydroxide is ≥96%; industrial sulfuric acid, in which the content of _H2SO4 is ≥98%; industrial oxygen, in which the content of _O2 is ≥99%; industrial copper powder, Among them, the copper content is ≥99%.

Make a solution of 85.0g of the above-mentioned industrial caustic soda with 1200ml of water and add 200g of the above-mentioned lead-copper matte. After slurrying, add it into a reaction kettle with a volume of 2000ml, seal the reaction kettle well, and adjust the stirring speed to 700-800r .min ^-1 , inject industrial oxygen for 5 minutes to drive away the remaining air in the reactor. Then, when the temperature of the reactor was gradually raised to 160°C, industrial oxygen was introduced to maintain the oxygen partial pressure at 0.7 MPa. The reaction temperature rose rapidly to 218°C after 20 minutes, then dropped, and the temperature was maintained at 200°C for 1.5 hours. After reaching the reaction time, feed cooling water into the reactor, and when the temperature drops below 50°C, discharge the slurry from the reactor and filter, and the filter residue is washed with 200ml of water. The weight of the leached slag is 176.2g after drying, and its main components are calculated in weight percent (%): Cu 50.98, Pb 19.52, S 0.9, Se 0.015, Te 0.22, Ag 0.16, As 0.49, Fe 0.85, the leaching rate of selenium 98.20%; 1070ml of leach solution, its composition (g/L) is: Na ₂ SO ₄ 116.16, Pb 0.53, As 0.31, Se 1.19, NaOH 2.50.

Slurry 176g of the above-mentioned alkaline leaching residue with 1500ml of 1.5mol/L sulfuric acid solution, leaching for 2 hours at a stirring speed of 400r.min ^-1 and a temperature of 70°C, filter after leaching, wash the leaching residue with 150ml of water, and then dry Dry, acidic leaching slag 62.48g, its main components are in weight percent (%): Cu 0.43, Pb 54.52, S 8.37, Se 0.032, Te 0.053, Ag 0.422, As 0.96, Fe 1.01, leaching rate of copper and tellurium 99.7% and 90.65% respectively; Obtain 1490ml of copper-containing solution leached by sulfuric acid, its composition is (g/L): Cu 59.21, Fe 0.55, As 0.15, Te 0.23.

Add 400ml of the above copper sulfate solution, at a stirring speed of 400r.min ^-1 and a temperature of 85°C, add 6g of copper powder, react for 2h, and filter after reaching the reaction time to obtain 0.93g of copper tellurium slag, and obtain sulfuric acid after tellurium removal Copper solution 390ml, its composition is (g/L): Cu 62.57, Fe 0.53, As 0.14, Te 0.001, the replacement precipitation rate of tellurium is 99.57%.

Example 2:

The lead concentrate produced by the oxygen bottom blowing process is ground to a particle size of 100% less than 0.149mm, and its main components are (%) by weight: Cu 26.21, Pb 8.04, S 10.50, Se 0.40, Ag 0.07, As 0.82, Fe 15.7; industrial sodium carbonate, _its content ≥96%; industrial sulfuric acid, its _H2SO4 content ≥98%; industrial oxygen, its _O2 content ≥99%.

80.0 g of industrial sodium carbonate of the above-mentioned components was made into a solution with 1200 ml of water, and then 200 g of lead-copper matte of the above-mentioned components were added, and after slurrying, it was added into a pressure reaction kettle with a volume of 2000 ml. Seal the reactor well, turn on the stirring, adjust the stirring speed to 700-800r.min ^-1 , and inject industrial oxygen for 1 minute to drive out the remaining air in the reactor. Then, the reaction kettle was gradually heated up. When the temperature rose to 160°C, industrial oxygen was introduced to maintain the partial pressure of oxygen at 0.7MPa. The reaction temperature rose rapidly to 215°C after 20 minutes, and then dropped, and the temperature was maintained at 200°C for the reaction. 1.5h. After reaching the reaction time, feed cooling water into the reactor, and when the temperature drops below 50°C, discharge the slurry from the reactor and filter, and the filter residue is washed with 200ml of water. The leached slag weighs 164.7g after drying, and its main components are (%) by weight percentage: Cu 32.51, Pb 9.18, S 0.73, Se 0.03, Ag 0.09, As 0.69, Fe 18.91, and the leaching rate of selenium is 93.93%; The leach solution is 1030ml, and its composition (g/L) is: Na ₂ SO ₄ 87.6, Pb 0.42, As 0.423, Se 0.67, pH 8.81.

Slurry 150g of the above-mentioned alkaline leaching residue with 900ml of 1.5mol/L sulfuric acid solution, leaching for 2 hours at a stirring speed of 400r.min ^-1 and a temperature of 70°C, filter after leaching, wash the leaching residue with 100ml of water, and then dry Dry, acid leaching slag 61.2g, its main component is (%) by weight percent: Cu 0.49, Pb 22.37, S 5.08, Se 0.068, Ag 0.207, As 1.41, Fe 23.17, the leaching rate of copper is 99.39%; Obtain 892ml of copper-containing solution leached by sulfuric acid, its composition is (g/L): Cu 52.73, Fe 17.12, As 0.17.

Claims (2)

1. the method for separating copper and selen-tellurjum from a lead copper matte is characterized in that being made up of following steps:

(1) oxidation is leached

Lead copper matte is earlier broken and wear into the powder that particle diameter is 0.25～0.074mm, with sodium hydroxide and sodium carbonate solution pulp and add in the autoclave, the back aerating oxygen that heats up carries out oxidizing reaction, the temperature of oxidizing reaction is 150～250 ℃, naoh concentration is 1.0～3.0mol/L, concentration of sodium carbonate is 0～2mol/L, the weight liquid-solid ratio that leaches is 3～10: 1, the dividing potential drop of oxygen is controlled at 0.3～1.5MPa, the total pressure of system maintains 1.5～3.5MPa, and the reaction times is 2～6h, after reaction finishes, be cooled to 20～60 ℃, filter;

(2) alkali soaks the sulfuric acid leaching of slag

The leached mud that obtains after the reaction is leached in oxidation, is under 70～85 ℃ in temperature, is that the sulphuric acid soln of 0.5～2.5mol/L is 2～8: 1 with the weight liquid-solid ratio with concentration, leach 2～3h, after sulfuric acid leaching reaction finishes, filter, the sulfuric acid leached mud that obtains returns plumbous smelting system;

(3) displacement of tellurium in the copper-bath

Sulfuric acid leaches the leach liquor obtain, is under 70～80 ℃ in temperature, adds weight and be the copper powder of 2.5～3.0 times of tellurium content in the leach liquor, reductase 12～5h.

2. according to claim 1 from lead copper matte the method for separating copper and selen-tellurjum, it is characterized in that: described sodium hydroxide, yellow soda ash, sulfuric acid, copper powder and oxygen are technical grade reagent.