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CN-121992205-A - Copper-tungsten alloy waste recycling method based on in-situ hydrogen production principle

CN121992205ACN 121992205 ACN121992205 ACN 121992205ACN-121992205-A

Abstract

The invention relates to a clean recovery method of copper-tungsten alloy waste based on hydrogen reduction, belongs to the technical field of clean metallurgy and resource recycling of nonferrous metal waste, and aims to solve the problems of high energy consumption, complex flow, heavy secondary pollution, difficult compromise of metal recovery rate and purity, high safety risk of high-temperature operation and the like of the traditional recovery method. According to the method, the procedures of primary crushing, oxidation, primary reduction, separation, secondary reduction, screening, tertiary reduction, secondary crushing, airflow pulverizing, acid washing impurity removal and the like are sequentially carried out on tungsten copper alloy waste, special equipment such as an oxidation reaction tank, a reduction reaction kettle and the like are matched for cooperative operation, and meanwhile, a mixture separation and hydrogen internal circulation system is integrated, so that tungsten copper is efficiently, cleanly, separately and extracted, and the energy utilization and resource circulation level are improved. The method has the advantages of thorough tungsten-copper separation, high product purity, low energy consumption, high metal recovery rate, no three wastes discharge in the whole process, and excellent granularity uniformity, and the recovery rate of the obtained tungsten powder and copper powder is more than or equal to 99%, the oxygen content is less than 0.05% by weight, and the method is in line with the green low-carbon circular economy concept.

Inventors

  • HE ZHIMIN
  • SHI LEI
  • YUE JIANRONG
  • WEN SHUANG
  • ZHANG ZHENG
  • GUO YUQI
  • SUN ZHIQIANG

Assignees

  • 中南大学
  • 湖南安全技术职业学院

Dates

Publication Date
20260508
Application Date
20260324

Claims (10)

  1. 1. The copper-tungsten alloy waste recycling method based on the principle of in-situ hydrogen production is characterized by comprising the following steps of: s1, crushing for the first time, namely preparing tungsten-copper alloy scraps, and crushing the scraps to obtain tungsten-copper alloy powder; S2, oxidizing the tungsten-copper alloy powder to obtain copper oxide-tungsten trioxide mixed powder; s3, carrying out primary reduction, namely carrying out reduction treatment on the copper oxide-tungsten trioxide mixed powder to obtain copper-tungsten trioxide mixed powder; s4, separating the copper-tungsten trioxide mixed powder to obtain tungsten trioxide powder and copper powder; S5, secondary reduction, namely carrying out reduction treatment on tungsten trioxide powder to obtain tungsten powder; s6, screening by using a 100-500-mesh standard screen to obtain tungsten powder and copper powder which can pass through the 100-500-mesh standard screen; S7, reducing the tungsten powder and the copper powder which are not sieved again for three times; s8, crushing the tungsten powder and the copper powder obtained in the step S7 for the second time to obtain tungsten powder and copper powder; S9, carrying out air flow pulverization, namely loading the tungsten powder and the copper powder obtained in the steps S6 and S8 into an air flow mill for high-pressure air flow pulverization to obtain fine tungsten powder and copper powder with uniform granularity; and S10, acid washing and impurity removal, namely acid washing and drying the fine tungsten powder and copper powder to obtain tungsten powder and copper powder which can pass through a 200-500 mesh standard sieve.
  2. 2. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S2, tungsten-copper alloy powder is placed in an oxidation reaction tank, oxygen of 0.5MPa is introduced into the oxidation reaction tank, the oxidation speed of the tungsten-copper alloy powder is increased through pressurization, the temperature is kept for 1.8h at 750 ℃, the air pressure of the oxygen is reduced to 0.25MPa, the temperature is kept for 0.5h at 750 ℃, and the copper oxide-tungsten trioxide mixed powder is obtained after cooling.
  3. 3. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S3, the copper oxide-tungsten trioxide mixed powder is placed in a reduction reaction kettle, nitrogen with the pressure of 0.25MPa is introduced into the reduction reaction kettle, hydrogen with the pressure of 0.25MPa is introduced into the reduction reaction kettle, the temperature is kept for 1-1.5 h at 450 ℃, and the copper-tungsten trioxide mixed powder is obtained after cooling.
  4. 4. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S4, copper-tungsten trioxide mixed powder is placed in a reduction reaction kettle, nitrogen with the pressure of 0.25MPa is introduced into the reduction reaction kettle, the temperature is kept for 0.5-1 h under the temperature of 1000 ℃, the tungsten trioxide is fully volatilized, copper powder remains in the reaction kettle, a multistage cooling system is adopted in the condensation method, high-temperature flue gas containing tungsten trioxide is led to a condensation chamber with the temperature gradually reduced, the first stage condensation area is maintained at 650 ℃, part of vapor is primarily crystallized and separated out, then the gas enters a second stage condenser and a third stage condenser, the temperature is further reduced to 400 ℃ or below, the residual vapor is continuously sublimated into solid particles, and finally, fine and uniform tungsten trioxide powder is obtained in a low-temperature section.
  5. 5. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production, which is disclosed in claim 1, comprises the following steps of placing the tungsten trioxide powder which is collected through cooling in a reduction reaction kettle, introducing 0.25MPa nitrogen into the reduction reaction kettle, introducing 0.25MPa hydrogen into the reduction reaction kettle, preserving heat for 1.5-2 hours at 720 ℃, and cooling to obtain tungsten powder.
  6. 6. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S7, unscreened tungsten powder and copper powder are placed in a reduction reaction kettle in sequence, nitrogen with the pressure of 0.25MPa is introduced into the reduction reaction kettle, hydrogen with the pressure of 0.25MPa is introduced into the reduction reaction kettle, and the temperature is kept for 2 hours at 720 ℃ and 450 ℃ respectively, and the copper-tungsten alloy waste is cooled.
  7. 7. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production as claimed in claim 1, wherein in the steps S1 and S8, the crushing is carried out by adopting a ball mill.
  8. 8. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S9, inert gas is adopted as high-pressure air flow, and the air pressure is controlled to be 5-7 KPa, so that the granularity of copper powder and tungsten powder is finer, and the purity of the tungsten powder and copper powder is improved.
  9. 9. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein in the step S10, fine tungsten powder and copper powder are soaked in 10-18% hydrochloric acid solution for 8-10 hours, and then cleaned by clean water and dried.
  10. 10. The method for recycling copper-tungsten alloy waste based on the principle of in-situ hydrogen production according to claim 1, wherein the recovery rate of the tungsten powder and the copper powder is more than or equal to 99%, the oxygen content of the tungsten powder and the copper powder is less than 0.05wt% and the particle size uniformity of the tungsten powder and the copper powder is excellent.

Description

Copper-tungsten alloy waste recycling method based on in-situ hydrogen production principle Technical Field The invention relates to the technical field of nonferrous metal waste clean metallurgy and resource recycling, in particular to a clean low-carbon tungsten-copper alloy waste recycling treatment method based on an in-situ hydrogen production principle. Background The tungsten-copper alloy is a pseudo alloy composite material composed of tungsten with high melting point and high hardness (the melting point is 3422 ℃) and copper with high electric conduction and thermal conduction (the melting point is 1085 ℃), and has the arc erosion resistance and fusion welding resistance of the tungsten and the excellent electric conduction and thermal conduction of the copper. The material is often applied to the fields of high-voltage electrical contacts, electric spark machining electrodes, electronic packaging, heat sink components and the like. In the production and use process, a large amount of scraps such as turning scraps, fragments and the like can be generated, and the efficient recovery of the scraps has important significance in saving strategic resources and reducing production cost. In the prior art, the recovery method for tungsten-copper alloy scraps mainly comprises mechanical separation, a vacuum distillation method, hydrometallurgy and the like. The mechanical separation method has low efficiency, is difficult to realize thorough dissociation of tungsten and copper, and the vacuum distillation method can directly separate metal simple substances, but needs to operate at high temperature of 800-1000 ℃ and high vacuum of 1-10 Pa for a long time, has complex equipment and extremely high energy consumption, has strict requirements on raw material purity, generally relates to leaching with strong acid (such as nitric acid), has long process, generates a large amount of acid wastewater containing heavy metals and toxic waste gas (such as nitrogen oxides), has outstanding environmental pollution risk, and has high subsequent wastewater treatment cost. The traditional methods have the problems of high energy consumption, complex flow, serious secondary pollution, difficult metal recovery rate and purity and the like, and are contrary to the current environment-friendly and low-carbon cyclic economy development concept. The clean metallurgical technology represented by hydrogen metallurgy is characterized in that hydrogen (H 2) is used as a reducing agent, and the hydrogen reacts with metal oxide under heating to generate metal simple substance and water (H 2 O). The process is theoretically free from generating carbon dioxide (CO 2) and other sulfur-containing and nitrogen-containing pollutant gases, and is one of key paths for realizing low carbonization and zero pollution in the metal smelting and recycling process. Compared with the traditional recovery mode relying on carbothermal reduction or high-pollution wet process, the hydrogen reduction technology provides a new solution for efficiently, cleanly separating and extracting nonferrous metals such as tungsten, copper and the like from complex waste materials. Although the metallurgical technology equipment on the market is continuously advanced, the metallurgical technology equipment still has some common defects, and some obvious problems cannot be properly treated all the time, and mainly comprise the following aspects: 1. the energy consumption is high, the energy utilization rate is low, the processes of oxidation, reduction, volatilization separation and the like are all required to be carried out at high temperature (400-1100 ℃), the traditional heat integration design between devices is insufficient, a large amount of reaction waste heat is not effectively recycled, and the comprehensive heat efficiency of the system is low. 2. The resource recovery efficiency is low, the product quality is difficult to ensure, the process control window is narrow, the volatilization loss or incomplete dissociation of valuable metals (such as tungsten) is easy to cause, and the overall recovery rate is low. Meanwhile, intermediate products or impurities are difficult to remove, so that the purity of the finally recovered metal powder is insufficient, and the high-value utilization is affected. 3. The process coupling is poor, the flow is discontinuous, most researches focus on the optimization of single reaction (such as oxidation or reduction), and the design of continuous and automatic systems for efficiently integrating multiple steps of oxidation, selective reduction, volatilization separation and the like is lacking, so that the material transfer is frequent, the heat energy loss is large, and the production efficiency is low. 4. The environmental pollution and the safety risk are high, harmful volatile substances can be generated in the high-temperature process, a large amount of acid and alkali are used in the wet process, and waste water and waste