A method for processing precious lead in a short process

Abstract

The application provides a method for processing precious lead in a short process, and belongs to the technical field of resource comprehensive utilization. The method first melts the precious metal to obtain a melting residue, a melting alloy and antimony-containing soot; the obtained melting residue is sent to a crude bismuth smelting process, the obtained antimony-containing soot is sent to a crude antimony smelting process together with antimony-containing soot obtained in an oxidation blowing process, and the obtained melting alloy is subjected to an oxidation blowing-melting separation copper removal-additive tellurium removal process to obtain a silver bismuth lead alloy; the silver bismuth lead alloy is subjected to vacuum furnace distillation to obtain crude silver. Compared with the prior art, the process realizes efficient separation of valuable elements, reduces the production process of various materials, reduces the dispersed rare and precious metals due to the long process, promotes efficient extraction and utilization of valuable rare and precious metals in the precious lead smelting process, the recovery rate of Bi is increased from 83.34% to more than 91%, the recovery rate of Sb is increased from 82.54% to more than 85%, and the recovery rate of Ag is increased from 98.63% to more than 99%.

Description

Technical Field

[0001] This invention relates to a short-process method for processing precious lead, belonging to the field of comprehensive resource utilization technology. Background Technology

[0002] Precious lead is an alloy of lead and precious metals (such as silver and gold), and is the main product obtained from the pyrometallurgical reduction smelting of lead and copper anode mud. In addition to lead, its main chemical composition is rich in rare and precious metals such as gold, silver, copper, antimony, and bismuth. These elements mainly exist in metallic or alloying states, thus precious lead has high economic value and is a major raw material for the comprehensive recovery of rare and precious metals associated with lead and copper smelting.

[0003] Currently, lead anode mud treatment processes mainly include "traditional pyrometallurgical," "all-hydrometallurgical," "pyrometallurgical-hydrometallurgical combined," and "beneficiation-metallurgical combined." The traditional hydrometallurgical process employs a "pretreatment and impurity removal - precious metal leaching - metal recovery" flow. In the pretreatment stage, copper is selectively leached with acid, followed by the removal of selenium / tellurium through an alkaline oxidation system. In the precious metal leaching stage, gold is efficiently extracted using a chlorination system, and silver is recovered using thiourea or cyanide. The metals are finally separated through chemical reduction and electrolytic refining. This process suffers from problems such as strong dependence on toxic reagents, high wastewater treatment costs, and limited adaptability to high-arsenic and antimony raw materials. The pyrometallurgical-hydrometallurgical combined process enriches precious metals and removes As / Sb through reduction smelting, followed by silver separation with nitric acid, gold extraction with chlorination, and electrolytic refining for efficient recovery. This process suffers from problems such as complex procedures, the need for supporting environmental protection facilities, and high investment costs. The combined beneficiation and smelting process adopts an integrated flow of "mineral beneficiation pretreatment - pyrometallurgical smelting - hydrometallurgical refining". In the pretreatment stage, the separation of precious and base metals is achieved through pH control and selective flotation, and the precious metals are further enriched by gravity separation. In the pyrometallurgical stage, reduction smelting and oxygen top blowing processes are used to effectively remove impurities such as lead, arsenic and antimony. The hydrometallurgical refining process includes electrolysis of silver nitrate system and solvent extraction to extract gold. However, this process has challenges such as complex process control and high requirements for environmental protection facilities.

[0004] Domestic lead smelting enterprises such as Yuguang Gold & Lead Co., Ltd. (a leading enterprise), Jiangxi Jinde Lead Industry Co., Ltd., and Xing'an Silver & Lead mainly use pyrometallurgical processes. Typical pyrometallurgical processes mainly include reduction smelting, oxidation blowing, and electrolytic refining. This process has a wide range of applications, is simple to operate, and has a high enrichment rate of precious metals. However, it still has problems such as long process, low recovery rate of rare and dispersed metals Sb / Bi / Te, high energy consumption, and high recovery cost. Yuguang Gold & Lead processes 40,000 tons of anode mud annually, using bottom blowing reduction and bottom blowing oxidation continuous smelting technology to process lead anode mud. Then, it uses antimony bottom blowing continuous smelting and vacuum separation of bismuth slag to recover antimony and bismuth. It has strict requirements on slag properties, furnace structure, and furnace atmosphere. It has problems such as long process and dispersion of rare and precious metals. The Bi recovery rate is only 83.34%, the Sb recovery rate is less than 85%, and the Ag recovery rate is 98.63%. As lead ore grades continue to decline, the arsenic and antimony content in precious metal concentrates increases significantly. During the smelting process, these two substances easily accumulate in the flue dust as oxides. Current technologies are insufficient for separating and recovering high-arsenic and antimony flue dust, exacerbating environmental risks. Arsenic and antimony oxides, in particular, are highly hazardous pollutants subject to strict environmental regulations. Furthermore, oxidative refining suffers from long cycles and high slag rates, leading to the dispersion and loss of precious metals during impurity removal, making it difficult to improve recovery rates. Therefore, process optimization is urgently needed to resolve the contradiction between environmental pollution and metal recovery rates. Summary of the Invention

[0005] Based on the current situation, this invention develops a short-process technology for recovering various metals from precious lead. It improves the recovery rates of Bi, Sb, and Ag in the precious lead smelting process and develops a combined process flow for precious lead smelting, deep impurity removal, and vacuum separation, achieving efficient recycling of rare and precious metal resources.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A short-process method for treating precious lead includes the following steps:

[0008] (1) Melt precious lead by heating to obtain molten slag, molten alloy and antimony-containing soot.

[0009] (2) The alloy is melted and subjected to an oxidation blowing process to obtain an antimony-free alloy liquid.

[0010] (3) The antimony-removing alloy liquid is subjected to a copper removal process to remove copper slag and obtain antimony-removing copper alloy liquid.

[0011] (4) After adding caustic soda to the antimony-free copper alloy liquid and heating it, a silver-bismuth-lead alloy liquid is obtained.

[0012] (5) The silver-bismuth-lead alloy liquid was vacuum distilled to obtain solid silver residue.

[0013] (6) After adding reducing coal to the molten slag obtained in step (1) and heating it, crude bismuth is obtained.

[0014] (7) Crude antimony is obtained by adding reducing coal and soda ash to the antimony-containing soot produced in the melting process and oxidation blowing process and then heating and reacting.

[0015] Preferably, in step (1), the precious lead comprises the following components by mass percentage: Pb 10%~25%, Bi 10%~20%, Ag 15%~40%, Cu 5%~10%, Sb 25%~45%, Te < 0.6%, and the total mass percentage of the components is 100%.

[0016] Preferably, the melting process parameters in step (1) are: temperature 660~700℃, time 2~4h.

[0017] Preferably, the conditions for the oxidation blowing process in step (2) are: heat preservation at 750~800℃ for 3~8h under the condition of air introduction.

[0018] Preferably, the conditions for the copper removal process in step (3) are: the temperature is reduced to 340~450℃ for copper removal.

[0019] Preferably, in step (4), the amount of caustic soda added is 1% to 2% of the mass of the antimony-free copper alloy liquid; the heating reaction conditions are: 600 to 700°C for 1 to 9 hours.

[0020] Preferably, the conditions for vacuum distillation in step (5) are: vacuum degree 5~20Pa, temperature 800~850℃, and distillation time 10~15h.

[0021] Preferably, in step (6), the amount of reducing coal used is 10% to 15% of the mass of the molten slag; the heating reaction conditions are: 1000 to 1100℃ for 2 to 4 hours.

[0022] Preferably, in step (7), the amount of reducing coal used is 10%~15% of the mass of antimony-containing flue ash, and the amount of soda ash used is 3%~6% of the mass of antimony-containing flue ash; the heating reaction conditions are: 1000~1100℃ for 2~4 hours.

[0023] The beneficial effects of this invention are:

[0024] This invention provides a short-process method for processing precious lead, developing a novel process of "precious lead alloy pot smelting - oxidation blowing melting and copper removal - additive removal of tellurium - vacuum distillation enrichment of silver". Through the synergistic effect between each process, it achieves efficient separation of valuable elements, reduces various material production steps, and promotes the efficient extraction and utilization of valuable rare and precious metals in the precious lead smelting process. Compared with Yuguang Gold & Lead, which uses bottom blowing reduction and bottom blowing oxidation continuous smelting technology to process lead anode mud, and then uses antimony bottom blowing continuous smelting and bismuth slag vacuum separation technology to recover antimony and bismuth, this invention, through the synergistic effect between each step, increases the recovery rate of Bi from 83.34% to over 91%; the recovery rate of Sb from 82.54% to over 85%; and the recovery rate of Ag from 98.63% to over 99%. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0026] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention. Example 1

[0027] A short-process method for treating precious lead, comprising the following steps:

[0028] (1) The precious lead (containing 16.17% Pb, 14.62% Bi, 28.06% Ag, 7.86% Cu, 32.71% Sb, and 0.58% Te) was placed in an alloy pot and melted at 700°C for 2 hours to obtain molten alloy, molten slag (containing 35.42% Pb, 38.66% Bi, 0.06% Ag, 0.03% Cu, 17.44% Sb, 0.04% Te, and 10.35% O) and antimony-containing flue dust. The molten slag was collected by scooping, and the antimony-containing flue dust was collected by bag dust collection.

[0029] (2) The obtained molten alloy continues to be carried out in the pot for oxidation blowing process. The oxidation blowing process is heated to 700°C and held for 7 hours under the condition of air introduction to obtain antimony-free alloy liquid. The antimony-free alloy liquid contains 0.77% antimony by mass.

[0030] (3) The antimony-removing alloy liquid is left in the pot for the melting and copper removal process. The melting and copper removal process is as follows: the temperature is lowered to 380℃ for melting and copper removal, and antimony-removing copper alloy liquid and copper removal slag are obtained. After the copper removal slag is removed, the antimony-removing copper alloy liquid is obtained. The mass percentage of copper in the antimony-removing copper alloy liquid is 0.89%.

[0031] (4) The obtained antimony-removed copper alloy liquid is left in the pot for the tellurium removal process. First, caustic soda is added, and the amount of caustic soda is 1.7% of the mass of the antimony-removed alloy liquid. Then, it is kept at 640℃ for 5 hours to obtain silver-bismuth-lead alloy liquid (mass percentage composition: Pb 20.12%, Bi 19.23%, Ag 58.35%, Cu 0.89%, Sb 0.77%, Te 0.64%), which is then sent to the vacuum furnace.

[0032] (5) The silver-bismuth-lead alloy liquid was sent to a vacuum furnace, the vacuum degree was controlled at 10 Pa, the temperature at 800 °C, the distillation time was 12 h, and the mass percentage of silver in the residue was 99.77%.

[0033] (6) The molten slag collected in step (1) is fed into a converter, and reducing coal is added. The amount of reducing coal is 12% of the mass of the molten slag. The temperature is kept at 1000℃ for 2 hours. The mass percentage of bismuth in the crude bismuth is 70%.

[0034] (7) The antimony-containing ash produced in step (1) melting process and oxidation blowing process is fed into the converter at a temperature of 1000℃ for 2 hours. The amount of reducing coal is 10% of the mass of antimony-containing ash, and the amount of soda ash is 4% of the mass of antimony-containing ash. The mass percentage composition of antimony in the crude antimony is 76%. The soda ash and reducing coal used are both from Guangdong Xilong Scientific Co., Ltd.

[0035] The recovery rates of various metals obtained in Example 1 are shown in Table 1.

[0036] Table 1 shows the recovery rates of various metals obtained in Example 1:

[0037] Example 2

[0038] A short-process method for treating precious lead, comprising the following steps:

[0039] (1) The precious lead (containing 20.34% Pb, 19.2% Bi, 26.03% Ag, 6.99% Cu, 26.44% Sb, and 0.99% Te) was placed in an alloy pot and melted at 660℃ for 4 hours to obtain molten alloy, molten slag (containing 34.37% Pb, 35.13% Bi, 0.05% Ag, 0.05% Cu, 19.77% Sb, and 0.07% Te) and antimony-containing flue dust. The molten slag was collected by scooping, and the antimony-containing flue dust was collected by bag dust collection.

[0040] (2) The obtained molten alloy continues to be carried out in the pot for oxidation blowing process. The oxidation blowing process is heated to 750°C and held for 8 hours under the condition of air introduction to obtain antimony-free alloy liquid. The antimony-free alloy liquid contains 0.32% antimony by mass.

[0041] (3) The antimony-removing alloy liquid is left in the pot for the melting and copper removal process. The melting and copper removal process is as follows: the temperature is lowered to 450℃ for melting and copper removal, and antimony-removing copper alloy liquid and copper removal slag are obtained. After the copper removal slag is removed, the antimony-removing copper alloy liquid is obtained. The mass percentage of copper in the antimony-removing copper alloy liquid is 0.77%.

[0042] (4) The obtained antimony-removed copper alloy liquid is left in the pot for the tellurium removal process. First, caustic soda is added, and the amount of caustic soda is 1.3% of the mass of the antimony-removed copper alloy liquid. Then, it is kept at 600℃ for 9 hours to obtain silver-bismuth-lead alloy liquid (mass percentage composition: Pb 24.55%, Bi 22.33%, Ag 51.63%, Cu 0.77%, Sb 0.32%, Te 0.4%), which is then sent to a vacuum furnace.

[0043] (5) The silver-bismuth-lead alloy liquid was sent to a vacuum furnace, the vacuum degree was controlled at 5 Pa, the temperature at 850 °C, the distillation time was 15 h, and the mass percentage of silver in the residue was 99.78%.

[0044] (6) The molten slag collected in step (1) is fed into a converter, and reducing coal is added. The amount of reducing coal is 15% of the mass of the molten slag. The temperature is kept at 1100℃ for 4 hours. The mass percentage of bismuth in the crude bismuth is 80%.

[0045] (7) The antimony-containing flue dust generated in step (1) melting process and oxidation blowing process is fed into the converter at a temperature of 1100℃, a time of 4h, a reducing coal amount of 15% of the antimony-containing flue dust mass, and a soda ash amount of 6% of the antimony-containing flue dust mass. The mass percentage composition of antimony in the crude antimony obtained is 85%.

[0046] The recovery rates of various metals obtained in Example 2 are shown in Table 2:

[0047] Table 2 shows the recovery rates of various metals obtained in Example 2.

[0048] Example 3

[0049] A short-process method for treating precious lead, comprising the following steps:

[0050] (1) The precious lead (containing 16.17% Pb, 14.62% Bi, 28.06% Ag, 7.86% Cu, 32.71% Sb, and 0.58% Te) was placed in an alloy pot and melted at 700℃ for 2 hours to obtain molten alloy, molten slag (containing 35.36% Pb, 37.96% Bi, 0.06% Ag, 0.34% Cu, 15.98% Sb, 0.09% Te, and 10.21% O) and antimony-containing flue dust. The molten slag was collected by scooping, and the antimony-containing flue dust was collected by bag dust collection.

[0051] (2) The obtained molten alloy continues to be carried out in the pot for oxidation blowing process. The oxidation blowing process is heated to 800°C and held for 3 hours under the condition of air introduction to obtain antimony-free alloy liquid. The antimony-free alloy liquid contains 0.67% antimony by mass.

[0052] (3) The antimony-removing alloy liquid is left in the pot for the melting and copper removal process. The melting and copper removal process is as follows: the temperature is lowered to 340℃ for melting and copper removal, and antimony-removing copper alloy liquid and copper removal slag are obtained. After the copper removal slag is removed, the antimony-removing copper alloy liquid is obtained. The mass percentage of copper in the antimony-removing copper alloy liquid is 0.84%.

[0053] (4) The obtained antimony-removing copper alloy liquid is left in the pot for the tellurium removal process. First, caustic soda is added. The amount of caustic soda is 1.7% of the mass of the antimony-removing alloy liquid. Then, it is kept at 700℃ for 4.5h to obtain silver-bismuth-lead alloy liquid (mass percentage composition: Pb 21.02%, Bi 20.3%, Ag 56.58%, Cu 0.84%, Sb 0.67%, Te 0.59%), which is then sent to the vacuum furnace.

[0054] (5) The silver-bismuth-lead alloy liquid was sent to a vacuum furnace, the vacuum degree was controlled at 20 Pa, the temperature at 800 °C, the distillation time was 12 h, and the mass percentage of silver in the residue was 99.81% Ag.

[0055] (6) The molten slag collected in step (1) is fed into a converter, and reducing coal is added. The amount of reducing coal is 10% of the mass of the molten slag. The temperature is kept at 1000℃ for 2 hours. The mass percentage of bismuth in the crude bismuth is 68%.

[0056] (7) The antimony-containing flue dust generated in step (1) during the melting process and the oxidation blowing process is fed into the converter at a temperature of 1000℃ for 2 hours. Under the conditions that the amount of reducing coal is 10% of the mass of the antimony-containing flue dust and the amount of soda ash is 5% of the mass of the antimony-containing flue dust, the mass percentage composition of antimony in the crude antimony obtained is 75%.

[0057] The recovery rates of various metals obtained in Example 3 are shown in Table 3.

[0058] Table 3 shows the recovery rates of various metals obtained in Example 3.

[0059]

[0060] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for short-process processing of precious lead, characterized in that: Includes the following steps: (1) Melt precious lead by heating to obtain molten slag, molten alloy and antimony-containing fume; (2) The molten alloy is subjected to an oxidation blowing process to obtain an antimony-free alloy liquid; (3) The antimony-removing alloy liquid is subjected to a melting and copper removal process to remove copper slag and obtain antimony-removing copper alloy liquid; (4) After adding caustic soda flakes to the antimony-free copper alloy liquid and heating it to react, a silver-bismuth-lead alloy liquid is obtained; (5) The silver-bismuth-lead alloy liquid was vacuum distilled to obtain solid silver residue; (6) After adding reducing coal to the molten slag obtained in step (1) and heating it to react, crude bismuth is obtained; (7) Crude antimony is obtained by adding reducing coal and soda ash to the antimony-containing soot produced during the melting and oxidation blowing processes and then heating it.

2. The method for short-process processing of precious lead according to claim 1, characterized in that: In step (1), the precious lead comprises the following components by mass percentage: Pb 10%~25%, Bi 10%~20%, Ag 15%~40%, Cu 5%~10%, Sb 25%~45%, Te <0.6%, and the total mass percentage of the components is 100%.

3. The method for short-process processing of precious lead according to claim 1, characterized in that: The melting process parameters in step (1) are: temperature 660~700℃, time 2~4h.

4. The method for short-process processing of precious lead according to claim 1, characterized in that: The conditions for the oxidation blowing process in step (2) are: heat preservation at 700~800℃ for 3~8h under the condition of air introduction.

5. The method for short-process processing of precious lead according to claim 1, characterized in that: The conditions for the copper removal process in step (3) are: the temperature is reduced to 340~450℃ for copper removal.

6. The method for short-process processing of precious lead according to claim 1, characterized in that: In step (4), the amount of caustic soda added is 1% to 2% of the mass of the antimony alloy liquid; the heating reaction conditions are: 600 to 700℃ for 1 to 9 hours.

7. The method for short-process processing of precious lead according to claim 1, characterized in that: The conditions for vacuum distillation in step (5) are: vacuum degree 5~20Pa, temperature 800~850℃, and distillation time 10~15h.

8. The method for short-process processing of precious lead according to claim 1, characterized in that: In step (6), the amount of reducing coal used is 10% to 15% of the mass of the molten slag; the heating reaction conditions are: 1000 to 1100℃ for 2 to 4 hours.

9. The method for short-process processing of precious lead according to claim 1, characterized in that: In step (7), the amount of reducing coal used is 10% to 15% of the mass of antimony-containing flue ash, and the amount of soda ash used is 3% to 6% of the mass of antimony-containing flue ash; the heating reaction conditions are: 1000 to 1100℃ for 2 to 4 hours.

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