Method for refining and detinning tin-containing crude copper

Abstract

The invention discloses a method for refining and detinning tin-containing crude copper, which comprises the following steps: S1, preparing tin-containing crude copper into powder, adding excessive cuprous sulfide powder, and uniformly mixing to obtain a prefabricated mixture; s2, the prefabricated mixture is put into a vacuum distillation furnace for vacuum distillation, the vacuum distillation vacuum degree is set to be 1-100 Pa, the initial temperature is 627-927 DEG C, the heat preservation time is 3-5 h during the period, the temperature is gradually increased to 1000-1083 DEG C, and heat preservation is conducted for 1-2 h; s3, after heat preservation is completed, heating is conducted till the mixture in the vacuum distillation furnace is completely melted, and heat preservation and standing are conducted. The method adopts a three-section temperature control mode to realize deep removal of tin element in tin-containing crude copper and effective recovery of copper.

Description

Technical Field

[0001] The present invention relates to the technical field of crude copper refining, and in particular to a method for refining and removing tin from tin-containing crude copper. Background Art

[0002] Scrap copper refers to copper that is discarded after use or waste generated in copper industrial production. The process of converting discarded copper products or copper-containing waste into reusable copper resources through recycling, processing and treatment has multiple important meanings, covering multiple aspects such as the environment, economy, and resource sustainability.

[0003] Regarding tin-containing scrap copper, CN 118703781 A discloses a green and efficient method for recovering copper and stannous sulfide from waste tinned copper wire. This method utilizes a closed, atmospheric-pressure sulfur vapor sulfurization followed by high-temperature vacuum vaporization process. The waste tinned copper wire and sulfur are placed in a graphite crucible in a high-temperature vacuum distillation furnace for closed, atmospheric-pressure sulfur vapor sulfurization and vacuum vaporization. This results in a 99.95% copper residue in the graphite crucible, and stannous sulfide as a volatile product in a condensation tray. This method involves first sulfurizing the copper to form cuprous sulfide (Cu2S), which is then placed in a high-temperature vacuum distillation furnace for vacuum distillation. During vacuum distillation, the Cu2S reacts with the tin to form stannous sulfide, which is ultimately collected in a condensation tray. This method requires a sulfurization reaction followed by vacuum treatment, resulting in relatively low efficiency. Furthermore, the copper product is a mixture of elemental copper and cuprous sulfide. Summary of the Invention

[0004] To address the above problems, the inventors have provided a method for refining and detinning tin-containing crude copper, which achieves deep detinning and material separation through multi-end temperature control.

[0005] The present invention provides a method for refining and removing tin from tin-containing crude copper, comprising:

[0006] Step S1: Powdering tin-containing crude copper, adding excess cuprous sulfide powder and mixing to obtain a prefabricated mixture;

[0007] Step S2: placing the prefabricated mixture into a vacuum distillation furnace for vacuum distillation, setting the vacuum degree of the vacuum distillation to 1-100 Pa, the starting temperature to 627-927° C., and holding the temperature for 3-5 hours. The temperature is then gradually raised to 1000-1083° C. and held for 1-2 hours. The specific heating time is determined according to the quality of the material. The reaction process is optimal to ensure that the Cu-Sn alloy exists in liquid form. As Sn is removed, the temperature is gradually raised to 1000-1083° C. and held for 1-2 hours to ensure the depth of the reaction.

[0008] Step S3: After the insulation is completed, the temperature is raised until the mixture in the vacuum distillation furnace is completely melted, and the mixture is kept at this temperature and allowed to stand.

[0009] Furthermore, the step S1 further includes: the particle size of the tin-containing crude copper powder and the particle size of the cuprous sulfide powder are both less than 50 mesh.

[0010] Furthermore, the prefabricated mixture is made into mixture tablets.

[0011] Furthermore, in step S1, the molar ratio of S in cuprous sulfide to Sn in tin-containing blister copper is in the range of 1.2-1.5 times.

[0012] Furthermore, in step S3, the temperature is raised to 1130-1300° C. and kept at this temperature for 30-120 minutes.

[0013] Furthermore, the method further comprises:

[0014] Step S4: After heat preservation and standing, the cuprous sulfide on the upper layer is separated from the copper on the lower layer.

[0015] Working mechanism of the present invention:

[0016] 1. The tin in tin-containing crude copper can react with cuprous sulfide in the following ways under vacuum conditions:

[0017] Sn(l)+Cu2S(l)⇌SnS(g)+2Cu

[0018] When the vacuum degree is 1-100 Pa, the temperature at which the above reaction occurs is 627-927°C, within which the copper-tin alloy is in a solid or liquid state. When the vacuum degree is 1-100 Pa, the volatilization temperature range of the stannous sulfide generated is 672-1164°C. Therefore, selecting a starting temperature that is higher than the reaction temperature and the volatilization temperature can effectively promote the removal of tin from the crude copper. However, the starting temperature should not exceed 1000°C to avoid volatilization of cuprous sulfide.

[0019] 2. Melting to remove Cu2S: This step is mainly achieved by taking advantage of the large difference in density between crude copper and cuprous sulfide. The density of copper is 8.96 g / cm3, and the density of cuprous sulfide is 5.6 g / cm3. After the two are completely melted by heating, cuprous sulfide will float on the upper layer of copper in the form of slag. The cuprous sulfide slag can be picked up to separate the product and the impurity remover.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention uses a first-stage temperature control method to make tin react with cuprous sulfide under vacuum conditions (solid-liquid reaction), a second-stage temperature control method to evaporate the tin sulfide generated by the reaction, and a third-stage temperature control method to melt the remaining cuprous sulfide and copper and then allow them to stand and separate. Deep detinning and material separation are achieved through multi-end temperature control.

[0022] (2) Cuprous sulfide can be returned to the detinning process after reaction and can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a process flow chart of the method for refining and detinning tin-containing crude copper in Example 1. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment discloses a method for refining and removing tin from tin-containing crude copper, comprising:

[0027] Step S1: After tin-containing crude copper is pulverized, an excess of cuprous sulfide powder is added and mixed to obtain a preformed mixture. The preformed mixture is pressed into tablets to facilitate the solid-phase reaction. The particle size of the tin-containing crude copper powder and the particle size of the cuprous sulfide powder are both less than 50 mesh; and the molar ratio of S in the cuprous sulfide to Sn in the tin-containing crude copper is within a range of 1.2-1.5 times.

[0028] Step S2: The prefabricated mixture is compressed into tablets and placed in a vacuum distillation furnace for vacuum distillation. The vacuum distillation is set to a pressure of 1-100 Pa, a starting temperature of 627-927°C, and a holding time of 3-5 hours. During this process, the tin in the tin-containing crude copper reacts with cuprous sulfide under vacuum conditions to produce stannous sulfide and copper. The materials in the vacuum distillation furnace include the stannous sulfide and copper produced by the reaction, as well as the remaining cuprous sulfide. The temperature is gradually raised to 1000-1083°C and held for 1-2 hours. During this process, the stannous sulfide volatilizes and is then condensed and collected, leaving a mixture of cuprous sulfide and copper.

[0029] Step S3: After the insulation is completed, the temperature is raised to 1130-1300° C. to melt all the mixture in the vacuum distillation furnace. The mixture is kept at this temperature and allowed to stand for 30-120 minutes to separate cuprous sulfide from copper by virtue of the density difference between the two.

[0030] Example 2

[0031] Tin-containing crude copper 1 (Sn10%), the melting point of copper-tin alloy is 1000℃;

[0032] 100 g of tin-containing crude copper was powdered, 16.1 g of cuprous sulfide powder was added and mixed to obtain a prefabricated mixture.

[0033] The prefabricated mixture was pressed into a tablet and then placed in a vacuum distillation furnace for vacuum distillation. The vacuum degree of the vacuum distillation was set to 1 Pa and the starting temperature was 923°C. The temperature was kept at this temperature for 5 hours, and then the temperature was gradually increased to within 1000-1083°C and kept at this temperature for 2 hours.

[0034] After the heat preservation is completed, the temperature is increased to 1300℃, and the mixture in the vacuum distillation furnace is completely melted. After the heat preservation and standing, the upper cuprous sulfide is separated from the lower copper, and the cuprous sulfide is recovered and used for subsequent tin removal.

[0035] Example 3

[0036] The tin-containing crude copper 2 (Sn 20%) has a copper-tin alloy melting point of 970℃;

[0037] The tin-containing crude copper 100g is powdered and mixed with 35g of cuprous sulfide powder to obtain a pre-prepared mixture.

[0038] The pre-prepared mixture is made into a mixture tablet, and then placed in a vacuum distillation furnace for vacuum distillation. The vacuum degree of the vacuum distillation is set to 10Pa, and the initial temperature is 723℃. During the process, the heat preservation time is 4 hours, and the temperature is gradually increased to 1000~1083℃. The heat preservation time is 1.5 hours.

[0039] After the heat preservation is completed, the temperature is increased to 1200℃, and the mixture in the vacuum distillation furnace is completely melted. After the heat preservation and standing, the upper cuprous sulfide is separated from the lower copper, and the cuprous sulfide is recovered and used for subsequent tin removal.

[0040] Example 4

[0041] The tin-containing crude copper 3 (Sn 25%) has a copper-tin alloy melting point of 820℃;

[0042] The tin-containing crude copper 100g is powdered and mixed with 50g of cuprous sulfide powder to obtain a pre-prepared mixture.

[0043] The pre-prepared mixture is made into a mixture tablet, and then placed in a vacuum distillation furnace for vacuum distillation. The vacuum degree of the vacuum distillation is set to 100Pa, and the initial temperature is 672℃. During the process, the heat preservation time is 3 hours, and the temperature is gradually increased to 1000~1083℃. The heat preservation time is 2 hours.

[0044] After the heat preservation is completed, the temperature is increased to 1130℃, and the mixture in the vacuum distillation furnace is completely melted. After the heat preservation and standing, the upper cuprous sulfide is separated from the lower copper, and the cuprous sulfide is recovered and used for subsequent tin removal.

[0045] The above application of specific examples to the present application is only used to help understand the present application and does not limit the present application. For those skilled in the art to which the present application belongs, according to the idea of the present application, a number of simple deductions, deformations or substitutions can be made.

Claims

1. A method for refining and removing tin from tin-containing crude copper, characterized in that: include: Step S1: Powdering tin-containing crude copper, adding excess cuprous sulfide powder and mixing evenly to obtain a prefabricated mixture; Step S2: placing the prefabricated mixture into a vacuum distillation furnace for vacuum distillation, setting the vacuum degree of the vacuum distillation to 1-100 Pa, the starting temperature to 627-927°C, and the holding time for 3-5 hours, gradually raising the temperature to 1000-1083°C, and holding the temperature for 1-2 hours; Step S3: After the insulation is completed, the temperature is raised until the mixture in the vacuum distillation furnace is completely melted, and the mixture is kept at this temperature and allowed to stand.

2. The method for refining and detinning tin-containing crude copper according to claim 1, wherein: The step S1 further includes: the particle size of the tin-containing crude copper powder and the particle size of the cuprous sulfide powder are both less than 50 mesh.

3. The method for refining and detinning tin-containing blister copper according to claim 1 or 2, characterized in that: The preformed mixture is made into a mixture tablet.

4. The method for refining and removing tin from tin-containing crude copper according to claim 1, wherein: In step S1, the molar ratio of S in cuprous sulfide to Sn in tin-containing blister copper is in the range of 1.2-1.5 times.

5. The method for refining and removing tin from tin-containing crude copper according to claim 1, wherein: In step S3, the temperature is raised to 1130-1300° C. and kept at this temperature for 30-120 minutes.

6. The method for refining and removing tin from tin-containing crude copper according to claim 1, wherein: Also includes: Step S4: After heat preservation and standing, the cuprous sulfide on the upper layer is separated from the copper on the lower layer.

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