A method for recycling copper-tungsten waste

Abstract

The invention belongs to the technical field of tungsten resource recycling and utilization, and specifically relates to a method for recycling copper-containing tungsten waste. Liquid nitrogen is used for rapid cooling immediately after calcination to achieve good separation of the copper-containing tungsten waste from a boat. Ball milling is used to pre-treat the copper-containing tungsten waste, which can be crushed into fine particles, thereby increasing the contact area with the solvent, shortening the reaction process, and being beneficial to improving the efficiency of alkali dissolution and acid dissolution. High-pressure alkali dissolution can effectively open tungsten oxide and copper oxide that are sintered and solid-dissolved together, thereby improving the efficiency of alkali dissolution. The alkali-dissolved product sodium tungstate and the acid-dissolved product copper sulfate of the invention can be returned to the production process for use, thereby realizing a closed-loop cycle and having significant environmental benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of tungsten resource recycling, and specifically relates to a method for recycling copper-containing tungsten waste. Background Art

[0002] With the improvement of environmental awareness, more and more companies have begun to pay attention to environmentally friendly production and resource recycling. The recycling of waste tungsten resources not only helps to reduce environmental pollution, but also saves resources and reduces production costs. At the same time, the strong support of national policies for resource recycling also provides a good development environment for the recycling of waste tungsten resources. The total carbon content is an important indicator for measuring the quality of tungsten carbide. It is usually measured by gas volumetric method. After the test is completed, the boat containing the post-reaction sample is directly discarded, which accumulates over time and causes a large amount of tungsten resources to be wasted. Therefore, it is particularly important to develop a method for recovering the waste tungsten resources generated by the gas volumetric method for measuring carbon content. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the main purpose of the present invention is to provide a method for recycling copper-containing tungsten waste, wherein the copper-containing tungsten waste refers to the copper-containing tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method.

[0004] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0005] A method for recycling copper-tungsten waste comprises the following steps:

[0006] S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method, it is immediately cooled by liquid nitrogen to separate the copper-tungsten waste from the boat;

[0007] S2, taking the copper-tungsten waste and ball-milling it, and testing the composition of the copper-tungsten waste after ball milling;

[0008] S3, adding sodium hydroxide solution and ball-milled copper-tungsten waste into a high-pressure reactor and stirring for reaction, filtering after the reaction is completed, the filtrate is a sodium tungstate solution, and the filter residue is copper oxide;

[0009] S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution.

[0010] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S1, the calcination temperature is 500-550° C. and the calcination time is 20-40 min.

[0011] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S1, the time for rapid cooling with liquid nitrogen is 10 to 20 seconds.

[0012] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in the step S2, the ball-to-material ratio during ball milling is (3-6):1, and the ball milling time is 0.5-1.5h.

[0013] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S3, the amount of sodium hydroxide provided by the sodium hydroxide solution is 1.1 to 2.0 times the theoretical weight of tungsten trioxide required to dissolve the copper-tungsten waste.

[0014] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S3, the pressure of the high-pressure reactor is 0.5-3.0 MPa, the reaction temperature is 100-120°C, the reaction time is 30-60 min, and the stirring speed is 100-200 r / min.

[0015] As a preferred embodiment of the method for recycling copper-containing tungsten waste described in the present invention, in step S3, the sodium tungstate solution is directly returned to the tungsten smelting production for recycling.

[0016] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S4, the amount of sulfuric acid provided by the dilute sulfuric acid is 1.1 to 1.5 times the theoretical weight required to dissolve copper oxide.

[0017] As a preferred embodiment of the method for recycling copper-tungsten waste described in the present invention, in step S4, the heating temperature is 60-80°C, the stirring speed is 100-400 r / min, and the stirring time is 20-60 min.

[0018] As a preferred embodiment of the method for recycling copper-containing tungsten waste described in the present invention, in step S4, the copper sulfate solution is returned to the molybdenum removal process in the tungsten smelting production for recycling.

[0019] The beneficial effects of the present invention are as follows:

[0020] The invention provides a method for recycling copper-tungsten waste. Liquid nitrogen is used for rapid cooling immediately after calcination to achieve good separation of the copper-tungsten waste from a boat. Ball milling is used to pretreat the copper-tungsten waste to break it into fine particles, thereby increasing the contact area with a solvent, shortening the reaction process, and being beneficial to improving the efficiency of alkali dissolution and acid dissolution. High-pressure alkali dissolution can effectively open tungsten oxide and copper oxide that are sintered and solid-dissolved together, thereby improving the efficiency of alkali dissolution. The alkali-dissolved product sodium tungstate and the acid-dissolved product copper sulfate of the invention can be returned to the production process for use, thereby realizing a closed-loop cycle and having significant environmental benefits. DETAILED DESCRIPTION

[0021] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention proposes a method for recycling copper-tungsten waste, which has the following advantages:

[0023] (1) After the test is completed, the tungsten oxide and copper oxide sintered and solid-dissolved together in the boat containing the reacted sample adhere to the boat, making it difficult to separate the copper-containing tungsten waste from the boat. The study found that when the boat containing the reacted sample is calcined within the temperature range of the present invention, the tungsten oxide and copper oxide sintered and solid-dissolved together will show a tendency to expand and loosen, while the boat will not have the above-mentioned expansion and loosening phenomenon. Liquid nitrogen rapid cooling is used immediately after calcination to achieve good and rapid separation of the copper-containing tungsten waste from the boat;

[0024] (2) Ball milling can be used to pre-treat copper-tungsten waste to break it into fine particles, increase the contact area with the solvent, shorten the reaction process, and help improve the efficiency of alkaline and acid dissolution;

[0025] (3) High-pressure alkaline dissolution can effectively open up the difficult-to-separate tungsten oxide and copper oxide that are sintered and solid-dissolved together, thereby improving the efficiency of alkaline dissolution;

[0026] (4) The alkali-soluble product sodium tungstate and the acid-soluble product copper sulfate of the present invention can be returned to the production process for use, thus realizing a closed-loop cycle with significant environmental benefits.

[0027] According to one aspect of the present invention, the present invention provides the following technical solution:

[0028] A method for recycling copper-tungsten waste comprises the following steps:

[0029] S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method, it is immediately cooled by liquid nitrogen to separate the copper-tungsten waste from the boat;

[0030] S2, taking the copper-tungsten waste and ball-milling it, and testing the composition of the copper-tungsten waste after ball milling;

[0031] S3, adding sodium hydroxide solution and ball-milled copper-tungsten waste into a high-pressure reactor and stirring for reaction, filtering after the reaction is completed, the filtrate is a sodium tungstate solution, and the filter residue is copper oxide;

[0032] S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution.

[0033] Preferably, in step S1, the calcination temperature is 500-550° C., and the calcination time is 20-40 min.

[0034] Preferably, in step S1, the time for rapid cooling with liquid nitrogen is 10 to 20 seconds.

[0035] Preferably, in step S2, the ball-to-material ratio during ball milling is (3-6):1, and the ball milling time is 0.5-1.5h.

[0036] Preferably, in step S3, the amount of sodium hydroxide that can be provided by the sodium hydroxide solution is 1.1 to 2.0 times the theoretical weight required to dissolve tungsten trioxide in the copper-containing tungsten waste.

[0037] Preferably, in step S3, the pressure of the high-pressure reactor is 0.5-3.0 MPa, the reaction temperature is 100-120° C., the reaction time is 30-60 min, and the stirring speed is 100-200 r / min.

[0038] Preferably, in step S3, the sodium tungstate solution is directly returned to the tungsten smelting production for recovery.

[0039] Preferably, in step S4, the amount of sulfuric acid provided by the dilute sulfuric acid is 1.1 to 1.5 times the theoretical weight required to dissolve the copper oxide.

[0040] Preferably, in step S4, the heating temperature is 60-80° C., the stirring speed is 100-400 r / min, and the stirring time is 20-60 min.

[0041] Preferably, in step S4, the copper sulfate solution is returned to the molybdenum removal process in tungsten smelting production for recycling.

[0042] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0043] Example 1

[0044] A method for recycling copper-tungsten waste comprises the following steps:

[0045] S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method, the boat is immediately cooled by liquid nitrogen. The calcination temperature is 550° C., the calcination time is 20 min, and the liquid nitrogen cooling time is 10 s, so as to separate the copper-tungsten waste from the boat.

[0046] S2, taking the copper-tungsten waste and ball milling it, the ball-to-material ratio during ball milling is 3:1, the ball milling time is 1.5h, and the composition of the copper-tungsten waste after ball milling is detected;

[0047] S3. Add sodium hydroxide solution and ball-milled copper-containing tungsten waste into a high-pressure reactor and stir to react. After the reaction is completed, filter. The filtrate is sodium tungstate solution, and the filter residue is copper oxide. The amount of sodium hydroxide provided by the sodium hydroxide solution is 1.1 times the theoretical weight of tungsten trioxide required to dissolve the copper-containing tungsten waste. The pressure of the high-pressure reactor is 3.0 MPa, the reaction temperature is 120°C, the reaction time is 60 min, and the stirring speed is 100 r / min. The sodium tungstate solution is directly returned to the tungsten smelting production for recovery.

[0048] S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution without residual filter residue; the amount of sulfuric acid that can be provided by the dilute sulfuric acid is 1.1 times the theoretical weight required to dissolve copper oxide, the heating temperature is 60°C, the stirring speed is 100r / min, and the stirring time is 60min. The copper sulfate solution is returned to the molybdenum removal process in tungsten smelting production for recycling.

[0049] Example 2

[0050] A method for recycling copper-tungsten waste comprises the following steps:

[0051] S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method, the boat is immediately cooled by liquid nitrogen. The calcination temperature is 500° C., the calcination time is 40 min, and the liquid nitrogen cooling time is 20 s, so as to separate the copper-tungsten waste from the boat.

[0052] S2, taking the copper-tungsten waste and ball milling it, the ball-to-material ratio during ball milling is 6:1, the ball milling time is 0.5h, and the composition of the copper-tungsten waste after ball milling is detected;

[0053] S3. Add sodium hydroxide solution and ball-milled copper-containing tungsten waste into a high-pressure reactor and stir to react. After the reaction is completed, filter. The filtrate is a sodium tungstate solution, and the filter residue is copper oxide. The amount of sodium hydroxide that can be provided by the sodium hydroxide solution is 2.0 times the theoretical weight of tungsten trioxide required to dissolve the copper-containing tungsten waste. The pressure of the high-pressure reactor is 0.5MPa, the reaction temperature is 100°C, the reaction time is 30min, and the stirring speed is 200r / min. The sodium tungstate solution is directly returned to the tungsten smelting production for recovery.

[0054] S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution without residual filter residue; the amount of sulfuric acid that can be provided by the dilute sulfuric acid is 1.5 times the theoretical weight required to dissolve copper oxide, the heating temperature is 80°C, the stirring speed is 400r / min, and the stirring time is 20min. The copper sulfate solution is returned to the molybdenum removal process in tungsten smelting production for recycling.

[0055] Example 3

[0056] A method for recycling copper-tungsten waste comprises the following steps:

[0057] S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by the gas volumetric method, it is immediately cooled by liquid nitrogen. The calcination temperature is 520° C., the calcination time is 30 minutes, and the liquid nitrogen rapid cooling time is 15 seconds, so as to separate the copper-tungsten waste from the boat.

[0058] S2, taking the copper-tungsten waste and ball milling it, the ball-to-material ratio during ball milling is 5:1, the ball milling time is 1.0h, and the composition of the copper-tungsten waste after ball milling is detected;

[0059] S3. Add sodium hydroxide solution and ball-milled copper-containing tungsten waste into a high-pressure reactor and stir to react. After the reaction is completed, filter. The filtrate is sodium tungstate solution, and the filter residue is copper oxide. The amount of sodium hydroxide provided by the sodium hydroxide solution is 1.5 times the theoretical weight of tungsten trioxide required to dissolve the copper-containing tungsten waste. The pressure of the high-pressure reactor is 1.5MPa, the reaction temperature is 110°C, the reaction time is 40min, and the stirring speed is 150r / min. The sodium tungstate solution is directly returned to the tungsten smelting production for recovery.

[0060] S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution without residual filter residue; the amount of sulfuric acid that can be provided by the dilute sulfuric acid is 1.3 times the theoretical weight required to dissolve copper oxide, the heating temperature is 70°C, the stirring speed is 300r / min, and the stirring time is 30min. The copper sulfate solution is returned to the molybdenum removal process in tungsten smelting production for recycling.

[0061] Comparative Example 1

[0062] The difference from Embodiment 3 is that step S2 is not performed.

[0063] After step S4, there is still undissolved filter residue. After testing, the filter residue contains 31wt% copper oxide and 69wt% tungsten trioxide.

[0064] Comparative Example 2

[0065] The difference from Example 3 is that step S3 is carried out by stirring the reaction in a normal pressure reactor.

[0066] After step S4, there is still a filter residue that has not been dissolved. After testing, the filter residue contains 99.25wt% tungsten trioxide, and the tungsten trioxide is not completely dissolved during the alkaline dissolution process at room temperature.

[0067] Comparative Example 3

[0068] The difference from Example 3 is that the calcination temperature in step S1 is 400°C.

[0069] If the copper-tungsten waste is not separated from the boat, subsequent steps cannot be performed and the copper-tungsten waste cannot be recycled.

[0070] Comparative Example 4

[0071] The difference from Example 3 is that the amount of sodium hydroxide that can be provided by the sodium hydroxide solution in step S3 is 1.0 times the theoretical weight required to dissolve tungsten trioxide in the copper-containing tungsten waste.

[0072] After step S4, there is still undissolved filter residue. After testing, the filter residue contains 99.31wt% tungsten trioxide. The amount of sodium hydroxide solution is not excessively set according to the present invention, and the tungsten trioxide is not completely dissolved.

[0073] Comparative Example 5

[0074] The difference from Example 3 is that the reaction temperature in step S3 is room temperature.

[0075] After step S4, there is still undissolved filter residue. After testing, the filter residue contains 98.85wt% tungsten trioxide, and the tungsten trioxide is not completely dissolved by the reaction at room temperature.

[0076] Comparative Example 6

[0077] The difference from Example 3 is that the amount of sulfuric acid provided by the dilute sulfuric acid in step S4 is 1.0 times the theoretical weight required to dissolve copper oxide.

[0078] After step S4, there is still filter residue that has not been dissolved. After testing, the filter residue contains 99.17wt% copper oxide. The amount of sulfuric acid is not set excessively according to the present invention, and the copper oxide is not completely dissolved.

[0079] The present invention uses liquid nitrogen rapid cooling immediately after calcination to achieve good separation of copper-containing tungsten waste and boats, and uses ball milling to pre-treat the copper-containing tungsten waste to break it into fine particles, increase the contact area with the solvent, shorten the reaction process, and help improve the efficiency of alkali dissolution and acid dissolution; high-pressure alkali dissolution can effectively open tungsten oxide and copper oxide sintered and solid-dissolved together, thereby improving the efficiency of alkali dissolution; the alkali-dissolved product sodium tungstate and the acid-dissolved product copper sulfate can be returned to the production process for use, thereby realizing a closed-loop cycle and having significant environmental benefits.

[0080] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for recycling copper-tungsten waste, characterized in that: The steps include: S1. After calcining the boat containing the copper-tungsten waste produced by measuring the carbon content of tungsten carbide by gas volumetric method, liquid nitrogen is used for rapid cooling to separate the copper-tungsten waste from the boat; the calcination temperature is 500-550°C, the calcination time is 20-40 minutes, and the liquid nitrogen rapid cooling time is 10-20 seconds; S2, taking the copper-tungsten waste and ball-milling it, and testing the composition of the copper-tungsten waste after ball milling; S3, adding sodium hydroxide solution and ball-milled copper-tungsten waste into a high-pressure reactor and stirring for reaction, filtering after the reaction is completed, the filtrate is a sodium tungstate solution, and the filter residue is copper oxide; S4. Add the filter residue into dilute sulfuric acid, heat and stir to obtain a copper sulfate solution.

2. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In the step S2, the ball-to-material ratio during ball milling is (3-6):1, and the ball milling time is 0.5-1.5h.

3. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S3, the amount of sodium hydroxide provided by the sodium hydroxide solution is 1.1 to 2.0 times the theoretical weight required to dissolve tungsten trioxide in the copper-containing tungsten waste.

4. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S3, the pressure of the high-pressure reactor is 0.5-3.0 MPa, the reaction temperature is 100-120° C., the reaction time is 30-60 min, and the stirring speed is 100-200 r / min.

5. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S3, the sodium tungstate solution is directly returned to the tungsten smelting production for recovery.

6. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S4, the amount of sulfuric acid provided by the dilute sulfuric acid is 1.1 to 1.5 times the theoretical weight required to dissolve the copper oxide.

7. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S4, the heating temperature is 60-80° C., the stirring speed is 100-400 r / min, and the stirring time is 20-60 min.

8. The method for recycling copper-tungsten waste according to claim 1, characterized in that: In step S4, the copper sulfate solution is returned to the molybdenum removal process in the tungsten smelting production for recycling.