Treatment method for high antimony, arsenic, precious and lead

Abstract

The invention relates to a high-antimony-arsenic-precious-lead treatment method, and belongs to the technical field of non-ferrous metal pyrometallurgy. The method comprises the following steps: carrying out vacuum fractionation on high-antimony-arsenic precious lead, and condensing from bottom to top through a graphite condensing disc for two-stage fractional condensation and a stainless steel condensing disc for fractional condensation at the topmost end in sequence from bottom to top to obtain a lead-antimony alloy, crude antimony and crude arsenic as well as a residual high-antimony-copper-silver-gold alloy; the high-antimony copper-silver-gold alloy is subjected to oxidation blowing, and the copper-silver-gold alloy, oxidizing slag and smoke dust are obtained; and carrying out vacuum distillation on the copper-silver-gold alloy to obtain crude copper and crude silver. The method can be used for treating high-antimony and high-arsenic coexisting noble lead materials, realizes open-circuit (recovery in the form of simple substances) of arsenic and antimony, shortens the smelting period of the noble lead, reduces oxidation blowing, reduces the recovery cost of noble metals, greatly reduces the environmental protection pressure, and has the characteristics of low energy consumption, simplicity in operation, high direct recovery rate of metals, high total recovery rate of metals and the like.

Description

Technical Field

[0001] The invention relates to a method for treating high-antimony arsenic noble lead, belonging to the technical field of non-ferrous metal pyrometallurgy. Background Art

[0002] Precious lead is a byproduct produced during the smelting process of crude lead. It is rich in precious metals such as gold, silver, lead, antimony, arsenic, bismuth, copper, tellurium and other valuable metals, and has extremely high economic value. my country is a major producer of refined lead. The annual production capacity of electrolytic lead in the country is 3.5 million tons, and the annual output of precious lead is about 60,000 tons. Therefore, the comprehensive recovery of valuable metals from precious lead is a growth point for the economic benefits of lead smelting enterprises.

[0003] The traditional processing process of precious lead is "blowing-oxidation refining-electrolysis", which uses blowing to remove arsenic and antimony, oxidation refining to remove lead, antimony, bismuth and copper, and electrolysis to extract precious metals. In particular, as the grade of lead ore decreases year by year, the content of arsenic and antimony in precious lead generally increases. During blowing, arsenic and antimony mainly enter the smoke in the form of oxides, which seriously pollutes the environment. The current process does not completely separate and recycle high-arsenic antimony smoke, and arsenic antimony oxides are toxic and harmful substances that are strictly controlled by the environmental protection department. At the same time, the oxidation refining cycle is long, and the slag rate is high during the refining process, resulting in a low yield of precious metals gold and silver during the impurity removal process.

[0004] The Chinese patent with publication number CN110172578A discloses a comprehensive treatment method for precious lead, which uses the difference in saturated vapor pressure of each metal to obtain elemental arsenic, lead-bismuth-antimony alloy, silver and copper alloy by two vacuum distillations, and then uses oxidation refining, electrolytic refining and chlorination refining to treat the lead-bismuth-antimony alloy, silver alloy and copper alloy respectively to obtain refined lead, refined bismuth, antimony trioxide, electrolytic silver and electrolytic copper. The first distillation of this method is divided into two stages of condensation, one stage is for arsenic removal, and the other stage is for enriching the volatile components of lead, antimony and bismuth, and then other valuable metals in the precious lead are recovered one by one through oxidation refining, electrolytic refining and chlorination refining. In this method, antimony is recovered in the form of antimony trioxide by converter oxidation blowing. In addition, the purity of arsenic is low (up to 96.27%), and the separation effect of lead, antimony, bismuth and arsenic in the condensate is not good. The suitable material composition of this method is Pb20-40%, Sb10-20%, As15-40%, Bi5-10%, Cu5-10%, Ag10-15% and Au5-1500g / t, and the antimony content should not be too high. That is, this invention can only process precious lead materials with low antimony content. Antimony is recovered in the form of antimony trioxide, and there are still problems such as high environmental pressure and long comprehensive recovery process.

[0005] The Chinese patent with publication number CN118895424A discloses a method for extracting arsenic and silver from precious lead. The first step of the method is to obtain 99% pure elemental arsenic, silver-copper-gold alloy and lead-bismuth-antimony alloy through vacuum gasification-graded condensation, and then the residual silver-copper-gold alloy is gasified for the second time to obtain the copper-gold alloy and crude silver for electrolytic extraction. The material characteristics of this method are: the arsenic content is low at 4-6%, the antimony content is high at 45-55%, bismuth is 3-5%, lead is 15-25%, gold is 0.001-0.005%, copper is 10-20%, and silver is 0.01-10%. In the first gasification process, antimony will be completely condensed in the lead-bismuth-antimony alloy. The antimony content in the alloy is too high, and it is difficult to implement lead-bismuth electrolytic separation. In addition, the invention can only process precious lead materials with low arsenic content, and antimony is not recycled.

[0006] The Chinese patent with the publication number CN114807620B discloses a device and method for vacuum vaporization-directional condensation separation of lead-antimony-arsenic ternary alloy, which can process lead-antimony-arsenic alloy with any lead-antimony-arsenic content, and directional condenses the lead-antimony-arsenic alloy in a horizontal vacuum tube furnace to obtain crude lead with a purity of 95-99wt%, crude antimony with a purity of 95-99wt%, and crude arsenic with a purity of 98-99wt%. However, for precious lead materials, not only the separation of lead-antimony and arsenic-antimony needs to be considered, but also the elements copper, silver, and gold contained in them will form intermetallic compounds such as Cu2Sb, Ag3Sb, AuSb2, Cu3As, etc. with antimony and arsenic, which will also increase the difficulty of separating and purifying antimony. Summary of the invention

[0007] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a method for treating high-antimony arsenic noble lead. The present invention can treat noble lead materials with high antimony and high arsenic, realizes the open circuit of arsenic and antimony (both are recovered in the form of single substances), shortens the noble lead smelting cycle, reduces oxidation and blowing, reduces the cost of precious metal recovery, greatly reduces environmental pressure, and has the characteristics of low energy consumption, simple operation, high metal direct recovery rate, and high total metal recovery rate.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A method for treating high-antimony arsenic noble lead, comprising the following steps:

[0010] Step 1, subjecting high-antimony arsenic noble lead to vacuum fractionation, and then condensing from bottom to top to obtain lead-antimony alloy, crude antimony and crude arsenic, and obtaining a residual high-antimony copper-silver-gold alloy by setting a graphite condensation plate for two-stage graded condensation from bottom to top and a stainless steel condensation plate for graded condensation at the top;

[0011] Step 2, oxidizing and blowing the high antimony copper-silver-gold alloy to obtain the copper-silver-gold alloy, oxide slag and smoke;

[0012] Step 3: subjecting the copper-silver-gold alloy to vacuum distillation to obtain crude copper and crude silver.

[0013] The high antimony arsenic noble lead in step 1 includes the following components in mass percentage: Pb 10-45%, Sb 22-45%, As 6.5-20%, Bi <5%, Cu <10%, Ag 0.01-20%, Au 0.003-0.005%.

[0014] This method can not only process the high antimony arsenic noble lead in the composition of step 1, but is also applicable to other materials with Pb+Sb+As≈100%.

[0015] The vacuum fractionation in step 1 is carried out at a vacuum degree of 5 Pa, a temperature of 850-890° C., and a heat preservation time of 3-8 h.

[0016] The temperatures of the three stages of graded condensation in step 1 are, from bottom to top, 600-800° C. for the lead-antimony alloy stage, 300-600° C. for the crude antimony stage, and 50-300° C. for the crude arsenic stage.

[0017] The oxidation blowing in step 2 is carried out in an oxidizing atmosphere of air or oxygen with a concentration of 20 to 28%, with a pressure of 4 to 100 kPa and a temperature of 600 to 800° C., for 2 to 6 hours.

[0018] The amount of oxidizing atmosphere introduced in step 2 is 20-30 Nm 3 / min.

[0019] In the step 3, the vacuum distillation is carried out at a vacuum degree of 10-20 Pa, a temperature of 1200° C.-1400° C., and is kept warm for 2-4 hours.

[0020] The antimony content in the crude antimony obtained in the above step 1 is greater than 99wt%, and the arsenic content in the crude arsenic is greater than 99wt%.

[0021] The above-mentioned high antimony arsenic noble lead treatment device includes a furnace body 9, a fractionation system, a vacuum system and a temperature control system; the fractionation system includes a condensation plate 4, a graphite crucible 6 and a quartz tube 10, the vacuum system includes a vacuum tube 1, a vacuum gauge 2 and a built-in vacuum pump 8, the temperature control system includes a temperature control display screen 3, a resistance wire 5, a heat insulation cotton 7, a radiator 11, a thermocouple and a temperature controller, and a built-in vacuum pump 8 is arranged inside the furnace body 9, and the built-in vacuum pump 8 is connected to the top of the quartz tube 10 inside the furnace body 9 through the vacuum tube 1, and the vacuum pump 8 is electrically connected to the top of the quartz tube 10 inside the furnace body 9. A vacuum gauge 2 is connected, a resistance wire 5 with segmented temperature controllable outside of the quartz tube 10 is provided, and the resistance wire 5 outside the quartz tube 10 is provided with heat preservation cotton 7 and a radiator 11 in sequence from the inside to the outside, a graphite crucible 6 is placed at the bottom of the inside of the quartz tube 10, and then condensation plates 4 of various levels are provided in sequence on the upper part, the two-level condensation plates 4 from bottom to top are graphite condensation plates, and the topmost condensation plate 4 is a stainless steel condensation plate; thermocouples are provided to control the temperature in segments, and the temperature control display screen 3, the resistance wire 5, the radiator 11, and the thermocouples are connected to the temperature controller.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention can obtain elemental arsenic and antimony with a purity greater than 99% by one-step fractionation, realizing the open circuit of arsenic and antimony in elemental form, and solving the problem of arsenic and antimony oxide pollution and recovery and separation;

[0024] (2) The high antimony arsenic noble lead separation process of the present invention does not introduce any impurities;

[0025] (3) The raw material of the present invention has high universality. In addition to being suitable for high antimony and arsenic noble lead with mass percentage components of Pb10-45%, Sb22-45%, As6.5-20%, Bi<5%, Cu<10%, Ag0.01-20%, Au0.003-0.005%, it can also process other materials with Pb+Sb+As≈100%. If the arsenic and antimony content in the raw material is high, the advantages of the present invention can be more reflected;

[0026] (4) Compared with the traditional process, the present invention reduces the amount of oxidation blowing, reduces environmental pressure, improves the direct recovery rate of precious metals, and effectively shortens the precious lead smelting cycle.

[0027] (5) In the present invention, in the graded condensation stage, the traditional graphite condensation plate is replaced with a stainless steel condensation plate in the arsenic condensation section, which not only improves the arsenic recovery rate but also makes it easy to peel the arsenic from the condensation plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the process of the present invention;

[0029] Figure 2 It is a diagram of the vacuum fractionation equipment of the present invention.

[0030] In the figure: 1-vacuum tube, 2-vacuum gauge, 3-temperature control display screen, 4-condensation plate, 5-resistance wire, 6-graphite crucible, 7-insulation cotton, 8-built-in vacuum pump, 9-furnace body, 10-quartz tube, 11-radiator. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0032] Example 1

[0033] like Figure 1 and 2 As shown, the method for treating noble lead with high antimony and arsenic content comprises the following steps:

[0034] Step 1, subjecting the high antimony arsenic noble lead to vacuum fractionation, specifically: placing 100g of high antimony arsenic noble lead into a graphite crucible 6, and placing a condensation plate 4 above the graphite crucible 6, setting two-stage graded condensation graphite condensation plates from bottom to top and a stainless steel condensation plate at the top graded condensation, and placing them together in a quartz tube 10 and encapsulating them with a vacuum tube 1, evacuating to a pressure of 5Pa, and after the vacuum degree is stable, adjusting the temperature control display screen 3 to set the condensation section temperature to 50-300℃, 300-600℃, and 600-800℃ respectively, and opening the gasification section to heat up to 890℃ after a stable temperature gradient is formed between the condensation plates in the quartz tube 10. After the temperature gradient is formed, start timing and keep warm for 7h to obtain condensate crude arsenic, crude antimony and lead-antimony alloy and residual high antimony copper-silver-gold alloy;

[0035] Step 2: The high antimony copper-silver-gold alloy is subjected to oxidation blowing. The oxidation blowing is carried out in an air oxidation atmosphere with an oxidation atmosphere flow rate of 20 Nm 3 / min, the pressure was controlled at 20 kPa, the temperature was 600 °C, and the oxidizing refining was carried out for 6 hours to obtain copper-silver-gold alloy, oxide slag and smoke;

[0036] Step 3: Vacuum distill the copper-silver-gold alloy at 1400°C, 10Pa, and 2h to obtain crude copper and volatile crude silver, which are then electrolyzed to prepare refined copper, refined silver, and refined gold. The experimental results of this embodiment are shown in Table 1.

[0037] Table 1

[0038]

[0039] Note: — is beyond the detection limit of ICP-AES.

[0040] As can be seen from Table 1, the crude arsenic prepared by vacuum fractionation of high antimony arsenic noble lead of the present invention contains As>99%, and the crude antimony contains Sb>99%. The direct recovery rate of crude arsenic of the present invention reaches more than 92%, and the direct recovery rate of crude antimony reaches more than 76.90%. Compared with the patent application with publication number CN110172578A and the patent application with publication number CN118895424A, they both recover arsenic in the form of a single substance, and do not mention the problem of the direct recovery rate of arsenic. In the common vacuum distillation process, the direct recovery rate of arsenic is low (generally 30-40%) due to the volatility of arsenic, while the recovery effect of crude arsenic in the present invention is significantly improved. In addition, antimony is recovered in the form of a single substance, which greatly shortens the precious lead smelting cycle and reduces environmental pressure. At the same time, the present invention eliminates the generation of arsenic antimony oxides at the source during the recovery of antimony and arsenic, and is more suitable for processing precious lead materials containing high antimony and arsenic and industrial promotion.

[0041] Moreover, the high antimony copper-silver-gold alloy of the present invention is only 4g, that is, the amount of oxidation blowing is significantly reduced compared with the traditional process.

[0042] Comparative Example 1

[0043] The three processing steps of this comparative example are the same as those of Example 1, except that the third stage condensation pan of the present invention, that is, the stainless steel condensation pan for graded condensation at the top, is replaced with a traditional graphite condensation pan, and other parameters are completely consistent with those of Example 1, and the condensate crude arsenic, crude antimony and lead-antimony alloy and the residue high antimony copper-silver-gold alloy are obtained. The results are shown in Table 2.

[0044] Table 2

[0045]

[0046] Note: — means exceeding the detection limit of ICP-AES, / means none.

[0047] Comparing Table 1 and Table 2, it can be seen that the graphite condensation plate has better thermal conductivity than the stainless steel condensation plate, and the temperature of the arsenic condensation area is higher due to the radiation heat transfer of the antimony condensation area, and the arsenic content in the crude arsenic is only 89.13%. At this time, the impurity element carbon introduced by scraping the graphite condensation plate to collect the crude arsenic is also detected in the crude arsenic, and the direct recovery rate of arsenic is only 59.65%. At the same time, due to the poor separation effect of crude arsenic, the antimony content in the crude antimony is only 97.09%, and the direct recovery rate is 72.64%. Compared with Example 1, the arsenic content in the crude arsenic is significantly reduced, and the direct recovery rate of arsenic is also significantly reduced.

[0048] Comparative Example 2

[0049] In the process of step 1 of this comparative example, the vacuum is evacuated to 30 Pa, the temperature is kept at 1200° C., and the temperature of the condensation section from bottom to top is controlled to be 500-800° C., 300-500° C., and 150-300° C., and copper-silver-gold alloy, lead-antimony-bismuth alloy, and crude arsenic products are obtained, but the lead-antimony alloy, crude antimony, and residual high-antimony copper-silver-gold alloy of the present invention cannot be obtained. There is no way to carry out the subsequent processing steps.

[0050] Example 2

[0051] like Figure 1 and 2 As shown, the method for treating noble lead with high antimony and arsenic content comprises the following steps:

[0052] Step 1, subjecting high antimony arsenic noble lead to vacuum fractionation, specifically: placing 100g high antimony arsenic noble lead into a graphite crucible 6, and placing a condensation plate 4 above the graphite crucible 6, setting two-stage graded condensation graphite condensation plates from bottom to top and a stainless steel condensation plate at the top graded condensation, and placing them together in a quartz tube 10 and encapsulating them with a vacuum tube 1, evacuating to a pressure of 5Pa, and after the vacuum degree is stable, adjusting the temperature control display screen 3 to set the condensation section temperature to 50-300℃, 300-600℃, and 600-800℃ respectively, and opening the gasification section to heat up to 850℃ after a stable temperature gradient is formed between the condensation plates in the quartz tube 10. After the temperature gradient is formed, start timing and keep warm for 8h to obtain condensate crude arsenic, crude antimony and lead-antimony alloy and residual high antimony copper-silver-gold alloy;

[0053] Step 2: The high antimony copper-silver-gold alloy is subjected to oxidation blowing. The oxidation blowing is carried out in an air oxidation atmosphere with an oxidation atmosphere flow rate of 30 Nm 3 / min, the pressure was controlled at 80 kPa and the temperature was 800 °C, and the oxidizing refining was carried out for 2 h to obtain copper-silver-gold alloy, oxide slag and smoke;

[0054] Step 3: Vacuum distill the copper-silver-gold alloy at 1200°C, 20Pa, and 4h to obtain crude copper and volatile crude silver, which are then electrolyzed to prepare refined copper, refined silver, and refined gold. The experimental results of this embodiment are shown in Table 3.

[0055] Table 3

[0056]

[0057] Note: — exceeds the detection limit of ICP-AES.

[0058] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for treating noble lead containing high antimony and arsenic, characterized in that the steps include: Step 1, subjecting high-antimony arsenic noble lead to vacuum fractionation, and then condensing from bottom to top to obtain lead-antimony alloy, crude antimony and crude arsenic, and obtaining a residual high-antimony copper-silver-gold alloy by setting a graphite condensation plate for two-stage graded condensation from bottom to top and a stainless steel condensation plate for graded condensation at the top; Step 2, oxidizing and blowing the high antimony copper-silver-gold alloy to obtain the copper-silver-gold alloy, oxide slag and smoke; Step 3: subjecting the copper-silver-gold alloy to vacuum distillation to obtain crude copper and crude silver.

2. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: The high antimony arsenic noble lead in step 1 includes the following components in mass percentage: Pb 10-45%, Sb 22-45%, As 6.5-20%, Bi <5%, Cu <10%, Ag 0.01-20%, Au 0.003-0.005%.

3. The method for treating high antimony and arsenic noble lead according to claim 2, characterized in that: This method can not only process the high antimony arsenic noble lead in the composition of step 1, but is also applicable to other materials with Pb+Sb+As≈100%.

4. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: The vacuum fractionation in step 1 is carried out at a vacuum degree of 5 Pa, a temperature of 850-890° C., and a heat preservation time of 3-8 hours.

5. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: The temperatures of the three stages of graded condensation in step 1 are, from bottom to top, 600-800° C. for the lead-antimony alloy stage, 300-600° C. for the crude antimony stage, and 50-300° C. for the crude arsenic stage.

6. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: The antimony content in the crude antimony obtained in step 1 is greater than 99wt%, and the arsenic content in the crude arsenic is greater than 99wt%.

7. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: The oxidation blowing in step 2 is carried out in an oxidizing atmosphere of air or oxygen with a concentration of 20 to 28%, with a pressure of 4 to 100 kPa and a temperature of 600 to 800° C., for 2 to 6 hours.

8. The method for treating high antimony and arsenic noble lead according to claim 7, characterized in that: The amount of oxidizing atmosphere introduced in step 2 is 20-30 Nm 3 / min.

9. The method for treating high antimony and arsenic noble lead according to claim 1, characterized in that: In the step 3, the vacuum distillation is carried out at a vacuum degree of 10-20 Pa, a temperature of 1200-1400° C., and is kept warm for 2-4 hours.

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