Method for recovering valuable metals from copper bismuth slag

Abstract

The invention relates to a method for recovering valuable metals from copper bismuth slag, and belongs to the technical field of metallurgical engineering. The method comprises the following steps: (1) adding the copper-bismuth slag into coke powder, and carrying out reduction smelting in a resistance furnace to obtain a copper-bismuth alloy and reducing slag; and (2) the copper-bismuth alloy is placed in a vacuum furnace for vacuum distillation in the vacuum furnace, and furnace wall and furnace cover attachments arsenic-antimony alloy, volatile matter lead-bismuth-antimony alloy and residual copper-silver alloy are obtained. According to the method for recycling the valuable metal from the copper-bismuth slag, lead, arsenic and copper silver in the copper-bismuth slag are distilled into different products respectively, then efficient recycling can be achieved through a conventional treatment process, and therefore the problem of copper-bismuth slag treatment is solved. In the whole separation process, the process is simple and short, wet operation is not involved, and target elements can be efficiently separated and gathered by means of a pyrogenic process and vacuum distillation.

Description

Technical Field

[0001] The present application relates to the field of metallurgical engineering technology, and in particular to a method for recovering valuable metals from copper-bismuth slag. Background Art

[0002] Copper-bismuth slag is one of the valuable slags produced during precious metal metallurgy. Rich in copper, bismuth, silver, and lead, it holds high value, prompting manufacturers to conduct research on its recovery. The presence of arsenic in copper-bismuth slag treatment, whether by pyrometallurgical or hydrometallurgical methods, can significantly pollute the environment during the anode slime treatment process, complicating the process and impacting the quality of other products. Coupled with increasing environmental protection requirements, arsenic removal is gaining increasing attention. Pyrometallurgical treatment of lead anode slime is simple, but produces large amounts of arsenic and antimony dust, which poses significant environmental risks and is difficult to recycle.

[0003] The traditional copper-bismuth slag treatment process involves coarse crushing of bismuth oxide slag, fine grinding, hydrochloric acid leaching, step-by-step hydrolysis, strong alkaline conversion, converter reduction smelting, and refining to produce No. 1 bismuth ingots. While this process achieves comprehensive recovery of bismuth metal, it has significant drawbacks: a lengthy process, particularly the wet process, which is complex, requires stringent operating conditions, and produces large volumes of wastewater that is difficult to treat. Summary of the Invention

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a method for recovering valuable metals from copper-bismuth slag. The process flow is simple. The copper-bismuth slag is first added with coke powder and then reduced and smelted to reduce the oxides in the copper-bismuth slag to single substances, mainly elements in single substance form. After vacuum distillation, they are finally distilled out according to the differences in the boiling points of the elements, thereby realizing the recovery of specific elements.

[0005] A method for recovering valuable metals from copper-bismuth slag in the present application comprises the following steps:

[0006] (1) After adding coke powder to copper-bismuth slag, reduction smelting is carried out in a resistance furnace to obtain copper-bismuth alloy and reduction slag;

[0007] (2) placing the copper-bismuth alloy in a vacuum furnace for vacuum distillation to obtain the arsenic-antimony alloy attached to the furnace wall and the furnace cover, the volatile lead-bismuth-antimony alloy, and the residual copper-silver alloy.

[0008] Furthermore, the amount of the coke powder added is 1.5-2.5 times the amount required to reduce the oxides of copper, bismuth, lead, antimony and arsenic in the copper-bismuth slag as simple substances.

[0009] Furthermore, the process conditions of the vacuum distillation in the vacuum furnace are: distillation temperature of 690-720° C., distillation time of 4-5 hours, and vacuum degree of 10-15 Pa.

[0010] Furthermore, the process conditions of the reduction smelting are: reduction temperature 600-700° C., time 2-2.5 h.

[0011] The beneficial effects of this application are:

[0012] The method for recovering valuable metals from copper-bismuth slag disclosed in this application distills lead, arsenic, and copper and silver from the slag into separate products, which are then efficiently recovered using conventional treatment processes, thereby resolving the challenges of copper-bismuth slag disposal. The entire separation process is simple and does not involve wet processing. Target elements can be efficiently separated and concentrated through pyrolysis and vacuum distillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0014] Figure 1 It is a schematic diagram of the process flow in this application. DETAILED DESCRIPTION

[0015] The embodiments of the present application will be described in more detail below with reference to the examples. Although the embodiments of the present application are shown in the examples, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0016] Example 1

[0017] The main chemical composition analysis table of the copper-bismuth slag in this embodiment is shown in Table 1

[0018] Table 1

[0019]

[0020] Copper-bismuth slag reduction equipment: high-temperature resistance furnace (GR-45), rated power 45kW, rated voltage 380V, rated temperature 950℃, furnace size 600×680, number of phases 3;

[0021] Distillation equipment: vacuum distillation furnace, power supply voltage 380V, phase number 1, working voltage 0-35V maximum current 1500A, heating power 50kW, crucible capacity 30Kg, limit temperature: 1200℃, limit vacuum 1Pa.

[0022] During the operation, 109.25 kg of copper-bismuth slag was added to 31.605 kg of coke powder, and then the copper-bismuth slag was subjected to high-temperature reduction at 600 ° C for 2.5 hours. After high-temperature reduction, 70.21 kg of alloy and 54.67 kg of slag were obtained. The direct metal recovery rate of the copper-bismuth slag was: 70.21 ÷ 109.25 × 100% = 64.27%.

[0023] The results of the copper-bismuth slag reduction test are shown in Tables 2 and 3:

[0024] Table 2

[0025]

[0026] Table 3 Main components of copper-bismuth alloy after copper-bismuth slag reduction

[0027]

[0028] The obtained 25.70 kg copper-bismuth alloy was placed in a vacuum furnace, the vacuum furnace shell was covered, and vacuum was evacuated. After the vacuum degree reached 10 Pa, the test raw material was heated by power for distillation. The distillation heating power was 30 kW and 690°C. After distillation for 4 hours, it was naturally cooled to room temperature. The furnace was dismantled and samples were taken to collect the residues in the vacuum furnace (copper-silver alloy), volatiles (lead-antimony-bismuth alloy), attachments deposited on the furnace wall (arsenic-antimony alloy), and attachments on the inside of the furnace cover (arsenic-antimony alloy).

[0029] The obtained components were collected and analyzed, and the results are shown in Table 4:

[0030] Table 4

[0031]

[0032] Example 2

[0033] The obtained 25.70 kg copper-bismuth alloy was placed in a vacuum furnace, the vacuum furnace shell was covered, and vacuum was evacuated. After the vacuum degree reached 10 Pa, the test raw materials were heated by power for distillation. The distillation heating power was 33 kW and 720°C. After distillation for 4 hours, it was naturally cooled to room temperature. The furnace was dismantled and samples were taken to collect the residues in the vacuum furnace (copper-silver alloy), volatiles (lead-antimony-bismuth alloy), attachments deposited on the furnace wall (arsenic-antimony alloy), and attachments on the inside of the furnace cover (arsenic-antimony alloy).

[0034] The obtained components were collected and analyzed, and the results are shown in Table 5:

[0035] Table 5

[0036]

[0037]

[0038] Example 3

[0039] A copper-bismuth alloy was prepared according to the method in Example 1. 25.50 kg of the resulting copper-bismuth alloy was placed in a vacuum furnace, the vacuum furnace shell was covered, and the furnace was evacuated. After the vacuum reached 15 Pa, the test raw material was heated for distillation at a power of 30 kW and a temperature of 690° C. After distillation for 5 hours, the material was naturally cooled to room temperature. The furnace was dismantled and samples were collected to collect the residue (copper-silver alloy), volatiles (lead-antimony-bismuth alloy), deposits on the furnace wall (arsenic-antimony alloy), and deposits on the inside of the furnace cover (arsenic-antimony alloy).

[0040] The obtained components were collected and analyzed, and the results are shown in Table 6:

[0041] Table 6

[0042]

[0043] Example 4

[0044] A copper-bismuth alloy was prepared according to the method in Example 1. 25.50 kg of the resulting copper-bismuth alloy was placed in a vacuum furnace, the furnace shell was covered, and the furnace was evacuated. After the vacuum reached 15 Pa, power was applied to heat the test raw material for distillation. The distillation heating power was 33 kW and the temperature was 720°C. After distillation for 5 hours, the material was naturally cooled to room temperature. The furnace was dismantled and samples were collected to collect the residue (copper-silver alloy), volatiles (lead-antimony-bismuth alloy), deposits on the furnace wall (arsenic-antimony alloy), and deposits on the inside of the furnace cover (arsenic-antimony alloy).

[0045] The obtained components were collected and analyzed, and the results are shown in Table 7:

[0046] Table 7

[0047]

[0048] It can be seen from Tables 4, 5, 6 and 7 that the distribution ratio of metallic lead, antimony, bismuth and arsenic in the residue is less than 4%, indicating that vacuum distillation is effective in separating lead, antimony, bismuth and arsenic, and most of Pb, Bi, Sb and As enter the volatile phase.

[0049] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not 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 selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for recovering valuable metals from copper-bismuth slag, characterized in that: The following steps are involved: (1) After adding coke powder to copper-bismuth slag, reduction smelting is carried out in a resistance furnace to obtain copper-bismuth alloy and reduction slag; (2) placing the copper-bismuth alloy in a vacuum furnace for vacuum distillation to obtain the arsenic-antimony alloy attached to the furnace wall and the furnace cover, the volatile lead-bismuth-antimony alloy, and the residual copper-silver alloy.

2. The method for recovering valuable metals from copper-bismuth slag according to claim 1, wherein: The amount of coke powder added is 1.5-2.5 times the amount required to reduce the oxides of copper, bismuth, lead, antimony and arsenic in the copper-bismuth slag as simple substances.

3. The method for recovering valuable metals from copper-bismuth slag according to claim 1, wherein: The process conditions of the reduction smelting are: reduction temperature 600-700° C., time 2-2.5 h.

4. The method for recovering valuable metals from copper-bismuth slag according to claim 1, wherein: The process conditions of the vacuum distillation in the vacuum furnace are: distillation temperature 690-720° C., distillation time 4-5 h, and vacuum degree 10-15 Pa.

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