A method for recovering valuable metals from waste tungsten slag

Abstract

The present invention relates to the technical field of industrial waste resource recycling and utilization, and in particular to a method for recovering valuable metals from waste tungsten slag, comprising: A) uniformly mixing a first portion of waste tungsten slag powder, a slag-forming agent, and a metal additive, followed by cold isostatic pressing to obtain a first blank; the slag-forming agent comprises CaCO3 and SiO2; and the metal additive comprises at least one of Fe, Co, and Ni; B) heating the first blank to 1300-1600°C under an inert atmosphere to melt it into a melt, maintaining the temperature, and then removing the slag to obtain a stable melt; C) cooling the stable melt to obtain an alloy ingot enriched with valuable metals. The metal additive, combined with the slag-forming agent of a specific composition, can interact effectively with other raw material components and steps, effectively reducing the amount of valuable metals remaining in the slag phase and improving the recovery rate of valuable metals.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial waste resource recycling, and in particular to a method for recovering valuable metals in waste tungsten slag. Background Art

[0002] Currently, there are two types of processes for recovering valuable metals such as tungsten, tantalum, niobium, cobalt, and nickel from metallurgical solid waste: pyrometallurgical and hydrometallurgical. The pyrometallurgical process generally uses reduction smelting, which involves adding a carbonaceous reducing agent at high temperature to reduce the metal oxides in the slag and generate an alloy phase for recovery. However, this process has the disadvantages of high smelting temperatures, high energy consumption, and difficulty in crushing and separating the resulting alloy phase, leading to large alloy inclusion losses in the slag. The hydrometallurgical process primarily uses a high-concentration acid solution to leach the metals from the slag, followed by purification and separation for recovery. However, this process has the disadvantages of high acid consumption, low metal leaching rates, a complex process route, and significant environmental pollution.

[0003] Patent CN110241311A discloses a recovery method that uses a sulfidation-reduction process to recover cobalt, nickel, and iron from tungsten-extracted slag. The added sulfiding agent forms a matte phase primarily composed of FeS at smelting temperatures, effectively dissolving the reduced cobalt, nickel, and iron from the slag. This separates the alloy phase from the slag phase, reduces alloy inclusions in the slag, and thus improves metal recovery. However, this method is less effective at recovering tantalum and niobium metals, with most of the metal remaining in the slag phase. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a method for recovering valuable metals in waste tungsten slag, wherein the recovery rate of the valuable metals is high.

[0005] The present invention provides a method for recovering valuable metals from waste tungsten slag, comprising the following steps:

[0006] A) mixing a first portion of waste tungsten slag powder, a slag-forming agent, and a metal additive, and performing cold isostatic pressing to obtain a first green body;

[0007] The slag-forming agent includes CaCO3 and SiO2; the metal additive includes at least one of Fe, Co and Ni;

[0008] B) heating the first green body to 1300-1600° C. in an inert atmosphere to melt the green body into a melt, holding the temperature, and removing the slag to obtain a stable melt;

[0009] C) cooling the stable melt to obtain an alloy ingot enriched with valuable metals.

[0010] Preferably, the metal additive includes Fe, Co and Ni, and the mass ratio of Fe, Co and Ni is 1:0.03-0.5:0.1-1;

[0011] Or the metal additive includes Fe and Ni in a mass ratio of 0.8 to 1.5:1;

[0012] Or the metal additive includes Fe and Co in a mass ratio of 1.5 to 2.5:1;

[0013] Or the metal additive includes Fe or Ni.

[0014] Preferably, the mass ratio of the first part of waste tungsten slag powder, slag-forming agent and metal additive is 1:0.2-0.6:0.02-0.08.

[0015] Preferably, in step A), the mass content of W in the waste tungsten slag powder is 4% to 10%, the mass content of SiO2 is 30% to 40%, the mass content of Co is 1% to 5%, the mass content of Nb is 0.5% to 2%, the mass content of Ta is 1% to 5%, the mass content of S is 10% to 15%, and the mass content of organic matter is 20% to 40%; the sum of the mass contents of the components is 100%;

[0016] Preferably, the particle size of the waste tungsten slag powder is 1 to 10 μm.

[0017] Preferably, in step A), the mass ratio of CaCO3 to SiO2 is 1:0.4-0.8;

[0018] Preferably, the slag-forming agent further comprises CaF2, and the mass ratio of the CaCO3, SiO2 and CaF2 is 1:0.4-0.8:0.02-0.05.

[0019] Preferably, step A) further comprises:

[0020] pressing the second portion of waste tungsten slag powder to obtain a second green body; wherein the mass ratio of the first portion of waste tungsten slag powder to the second portion of waste tungsten slag powder is 1:0.6-1.0;

[0021] Preferably, the tap density of the second body is 0.6-1.0 g / cm 3 ;

[0022] In step B), after the melt is formed into a molten body, the method further comprises: adding the second green body into the molten body.

[0023] Preferably, in step B), the first green body is heated to 1300-1600° C. and melted in a graphite crucible;

[0024] The first green body occupies 25% to 80% of the volume of the graphite crucible.

[0025] Preferably, in step B), the heating rate of the first green body to 1300-1600° C. is 5-15° C. / min.

[0026] Preferably, in step C), cooling the stable melt comprises:

[0027] First cool down to 800-1200°C at 2-5°C / min, and then cool down to room temperature at 5-10°C / min.

[0028] Preferably, in step C), in the alloy ingot enriched with valuable metals, the mass content of W is 20% to 50%, the mass content of Co is 10% to 30%, the mass content of Ta is 5% to 20%, and the mass content of Nb is 2% to 10%.

[0029] The present invention provides a method for recovering valuable metals from waste tungsten slag, comprising the following steps: A) mixing a first portion of waste tungsten slag powder, a slag-forming agent, and a metal additive, and then cold isostatically pressing the mixture to obtain a first blank; the slag-forming agent comprises CaCO3 and SiO2; and the metal additive comprises at least one of Fe, Co, and Ni; B) heating the first blank to 1300-1600°C under an inert atmosphere to melt the blank into a melt, holding the temperature, and then removing the slag to obtain a stable melt; C) cooling the stable melt to obtain an alloy ingot enriched with valuable metals. The recovery method provided by the present invention employs a metal additive of a specific composition, which, on the one hand, acts as a reducing agent to promote the occurrence of carbon reduction reactions, and on the other hand, can significantly increase the density of high-entropy carbides (refractory phases), promote the sedimentation of the alloy liquid, reduce the amount of valuable metal residues in the slag phase, and improve the recovery rate. The metal additive, combined with the slag-forming agent of a specific composition, can interact well with other raw material components and steps, effectively reducing the amount of valuable metal residues in the slag phase and improving the recovery rate of valuable metals. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The present invention provides a method for recovering valuable metals from waste tungsten slag, comprising the following steps:

[0032] A) mixing a first portion of waste tungsten slag powder, a slag-forming agent, and a metal additive, and performing cold isostatic pressing to obtain a first green body;

[0033] The slag-forming agent includes CaCO3 and SiO2; the metal additive includes at least one of Fe, Co and Ni;

[0034] B) heating the first green body to 1300-1600° C. in an inert atmosphere to melt the green body into a melt, holding the temperature, and removing the slag to obtain a stable melt;

[0035] C) cooling the stable melt to obtain an alloy ingot enriched with valuable metals.

[0036] In step A):

[0037] After uniformly mixing the first portion of waste tungsten slag powder, slag-forming agent and metal additive, cold isostatic pressing is performed to obtain a first green body;

[0038] The slag-forming agent includes CaCO3 and SiO2; the metal additive includes at least one of Fe, Co and Ni.

[0039] In certain embodiments of the present invention, the waste tungsten slag powder is dry waste tungsten slag powder.

[0040] In certain embodiments of the present invention, the mass ratio of CaCO3 to SiO2 is 1:0.4 to 0.8; specifically, 1:0.6, 1:0.8, or 1:0.4.

[0041] In certain embodiments of the present invention, the slag-forming agent further comprises CaF2, and the mass ratio of CaCO3, SiO2 and CaF2 is 1:0.4-0.8:0.02-0.05; specifically, 1:0.6:0.04, 1:0.8:0.05, and 1:0.4:0.02.

[0042] In certain embodiments of the present invention, the metal additive includes Fe, Co and Ni, and the mass ratio of Fe, Co and Ni is 1:0.03~0.5:0.1~1, preferably 1:0.03~0.3:0.1~0.6; specifically, 1:0.2:0.5, 1:0.03:0.1, 1:0.1:0.4, 1:0.1:0.5, 1:0.2:0.4, 1:0.3:0.6, 1:0.5:1.

[0043] In certain embodiments of the present invention, the metal additive includes Fe and Ni in a mass ratio of 0.8 to 1.5:1; specifically, 1:1.

[0044] In certain embodiments of the present invention, the metal additive includes Fe and Co in a mass ratio of 1.5 to 2.5:1; specifically, 2:1.

[0045] In certain embodiments of the present invention, the metal adjuvant includes Fe or Ni.

[0046] In certain embodiments of the present invention, the waste tungsten slag powder comprises 4% to 10% by weight of W, 30% to 40% by weight of SiO2, 1% to 5% by weight of Co, 0.5% to 2% by weight of Nb, 1% to 5% by weight of Ta, 10% to 15% by weight of S, and 20% to 40% by weight of organic matter; the sum of the weight contents of these components is 100%. In certain embodiments, the waste tungsten slag powder comprises 6% by weight of W, 36% by weight of SiO2, 4.5% by weight of Co, 1.5% by weight of Nb, 3% by weight of Ta, 15% by weight of S, and 34% by weight of organic matter. In certain embodiments, the waste tungsten slag powder comprises 4% by weight of W, 40% by weight of SiO2, 4% by weight of Co, 1% by weight of Nb, 3% by weight of Ta, 14% by weight of S, and 34% by weight of organic matter.

[0047] In certain embodiments of the present invention, the particle size of the waste tungsten slag powder is 1 to 10 μm.

[0048] In certain embodiments of the present invention, the mass ratio of the first part of waste tungsten slag powder, slag forming agent and metal additive is 1:0.2~0.6:0.02~0.08; specifically, it can be 1:0.35:0.04, 1:0.35:0.02, 1:0.35:0.05, 1:0.35:0.08, 1:0.5:0.08, 1:0.35:0.15.

[0049] In certain embodiments of the present invention, the pressure used in the cold isostatic pressing is 180-200 MPa; specifically, it can be 190 MPa.

[0050] In certain embodiments of the present invention, step A) further comprises:

[0051] The second portion of waste tungsten slag powder is pressed to obtain a second green body.

[0052] In some embodiments of the present invention, the tap density of the second body is 0.6-1.0 g / cm 3 ; Specifically, 1.0g / cm 3 .

[0053] In certain embodiments of the present invention, the mass ratio of the first portion of waste tungsten slag powder to the second portion of waste tungsten slag powder is 1:0.6-1.0; specifically, it can be 1:0.8 or 1:1.

[0054] In step B):

[0055] In an inert atmosphere, the first green body is heated to 1300-1600° C. and melted into a melt. After heat preservation, the slag is removed to obtain a stable melt.

[0056] In some embodiments of the present invention, the gas forming the inert atmosphere includes argon or nitrogen.

[0057] In certain embodiments of the present invention, the first blank is heated to 1300-1600° C. and melted in a graphite crucible; the first blank occupies 25%-80% of the volume of the graphite crucible, specifically 60%, 70%, or 80%.

[0058] In some embodiments of the present invention, the heating rate of the first green body to 1300-1600° C. is 5-15° C. / min, specifically, 10° C. / min.

[0059] In some embodiments of the present invention, the first body is melted at a temperature of 1450°C.

[0060] In some embodiments of the present invention, after melting into a melt, the method further includes: adding the second green body into the melt.

[0061] In some embodiments of the present invention, the second green body is added to the melt at one time; in some embodiments of the present invention, the second green body is added to the melt in multiple times; specifically, it can be added in two times, and the mass ratio of the second green body added in each time is 1:0.5~1.

[0062] In certain embodiments of the present invention, the insulation temperature is 1300-1600° C., specifically, 1450° C.; the insulation time is 1-3 hours, specifically, 2 hours.

[0063] In step C):

[0064] The stable melt is cooled to obtain an alloy ingot enriched with valuable metals.

[0065] In certain embodiments of the present invention, cooling the stable melt comprises:

[0066] First cool down to 800-1200°C at 2-5°C / min, and then cool down to room temperature at 5-10°C / min.

[0067] Specifically, the temperature is first lowered at a rate of 3°C / min, then lowered to 1000°C, and then lowered at a rate of 7.5°C / min.

[0068] In certain embodiments of the present invention, in the alloy ingot enriched with valuable metals, the mass content of W is 20% to 40%, the mass content of Co is 10% to 38%, the mass content of Ta is 5% to 20%, and the mass content of Nb is 2% to 10%.

[0069] In certain embodiments of the present invention, the alloy mass recovery rate in the waste tungsten slag is not less than 80%.

[0070] In order to further illustrate the present invention, a method for recovering valuable metals in waste tungsten slag provided by the present invention is described in detail below with reference to examples, but it should not be understood as limiting the scope of protection of the present invention.

[0071] Example 1

[0072] The waste tungsten slag powder contains 6% W by mass, 36% SiO2 by mass, 4.5% Co by mass, 1.5% Nb by mass, 3% Ta by mass, 15% S by mass, and 34% organic matter by mass. The waste tungsten slag powder has a particle size of 1 to 10 μm.

[0073] A method for recovering valuable metals from waste tungsten slag comprises the following steps:

[0074] 1) 5 kg of the first portion of dry waste tungsten slag powder, a slag forming agent (including CaCO3, SiO2 and CaF2, with a mass ratio of 1:0.6:0.04) and a metal additive (including Fe, Co and Ni, with a mass ratio of 1:0.2:0.5) were mixed and then cold isostatically pressed at a pressure of 190 MPa to obtain a first green body;

[0075] The mass ratio of the first part of dry waste tungsten slag powder, slag forming agent and metal additive is 1:0.35:0.04; 2) the second part of dry waste tungsten slag powder is pressed to obtain a second green body; the mass ratio of the first part of dry waste tungsten slag powder to the second part of dry waste tungsten slag powder is 1:0.8; the tap density of the second green body is 1.0 g / cm 3 ;

[0076] 3) placing the first green body in a graphite crucible, wherein the first green body occupies 70% of the volume of the graphite crucible, heating the first green body at a rate of 10°C / min to 1450°C and melting the first green body in a nitrogen atmosphere, adding the second green body to the melted melt at once, maintaining the temperature at 1450°C for 2 hours, and removing the slag to obtain a stable melt;

[0077] 4) first cooling the stable melt to 1000° C. at a rate of 3° C. / min, and then cooling to room temperature at a rate of 7.5° C. / min to obtain an alloy ingot enriched with valuable metals.

[0078] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 27%, the Co content was 30%, the Ta content was 12.5%, and the Nb content was 6%. The alloy mass recovery rate in the waste tungsten slag reached 90%.

[0079] Example 2

[0080] The difference between this embodiment and embodiment 1 is that:

[0081] The waste tungsten slag powder contains 4% by mass of W, 40% by mass of SiO2, 4% by mass of Co, 1% by mass of Nb, 3% by mass of Ta, 14% by mass of S, and 34% by mass of organic matter. The waste tungsten slag powder has a particle size of 1 to 10 μm.

[0082] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 28%, the Co content was 33%, the Ta content was 12%, and the Nb content was 4%. The alloy mass recovery rate in the waste tungsten slag reached 89%.

[0083] Example 3

[0084] The difference between this embodiment and embodiment 1 is that:

[0085] In the slagging agent, the mass ratio of CaCO3, SiO2 and CaF2 is 1:0.8:0.05.

[0086] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 28%, the Co content was 28%, the Ta content was 12%, and the Nb content was 6%. The alloy mass recovery rate in the waste tungsten slag reached 87%.

[0087] Example 4

[0088] The difference between this embodiment and embodiment 1 is that:

[0089] In the slagging agent, the mass ratio of CaCO3, SiO2 and CaF2 is 1:0.4:0.02.

[0090] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 29%, the Co content was 29%, the Ta content was 13%, and the Nb content was 6%. The alloy mass recovery rate in the waste tungsten slag reached 89%.

[0091] Example 5

[0092] The difference between this embodiment and embodiment 1 is that:

[0093] The amount of the first portion of dried waste tungsten slag powder is the same, but the mass ratio of the first portion of dried waste tungsten slag powder to the second portion of dried waste tungsten slag powder is 1:1.

[0094] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 32%, the Co content was 24%, the Ta content was 15%, and the Nb content was 6%. The alloy mass recovery rate in the waste tungsten slag reached 88%.

[0095] Example 6

[0096] The difference between this embodiment and embodiment 1 is that:

[0097] In step 1), the first portion of waste tungsten slag powder, slag forming agent, and metal additive were mixed according to the mass ratios of each test example in Table 1. ICP-AES was used to analyze the W, Co, Ta, and Nb components of the valuable metal-enriched alloy ingots obtained in each test example of this embodiment, and the alloy mass recovery rate in the waste tungsten slag was calculated. The results are recorded in Table 1.

[0098] Table 1: Alloy mass recovery rate in waste tungsten slag of each test example in Example 6

[0099]

[0100] Example 7

[0101] The difference between this embodiment and embodiment 1 is that:

[0102] In step 1), the metal additives were prepared according to the mass ratios of the respective test examples in Table 2. The W, Co, Ta, and Nb compositions of the valuable metal-enriched alloy ingots obtained in each test example of this embodiment were analyzed by ICP-AES, and the alloy mass recovery rate in the waste tungsten slag was calculated. The results are recorded in Table 2.

[0103] Table 2: Alloy mass recovery rate in waste tungsten slag of each test example in Example 7

[0104]

[0105] Example 8

[0106] The difference between this embodiment and embodiment 1 is that:

[0107] In step 1), the metal additives are Fe and Ni in a mass ratio of 1:1.

[0108] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 30%, the Co content was 28%, the Ta content was 10%, and the Nb content was 5.5%. The alloy mass recovery rate in the waste tungsten slag reached 87%.

[0109] Example 9

[0110] The difference between this embodiment and embodiment 1 is that:

[0111] The metal additives in step 1) of Example 1 were replaced with Fe and Co in a mass ratio of 2:1.

[0112] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 25%, the Co content was 35%, the Ta content was 8%, and the Nb content was 3%. The alloy mass recovery rate in the waste tungsten slag reached 82%.

[0113] Example 10

[0114] The difference from Example 1 is:

[0115] The metal auxiliary agent in step 1) of Example 1 was replaced with Fe.

[0116] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 36%, the Co content was 20%, the Ta content was 12%, and the Nb content was 4%. The alloy mass recovery rate in the waste tungsten slag reached 85%.

[0117] Example 11

[0118] The difference between this embodiment and embodiment 1 is that:

[0119] In step 1), the metal additive is Ni.

[0120] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 32%, the Co content was 25%, the Ta content was 12%, and the Nb content was 5%. The alloy mass recovery rate in the waste tungsten slag reached 84%.

[0121] Example 12

[0122] The difference between this embodiment and embodiment 1 is that:

[0123] The slag-forming agent in Example 1 was replaced by CaO and SiO2, and the mass ratio of CaO to SiO2 was 1:0.6.

[0124] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 28%, the Co content was 30%, the Ta content was 12%, and the Nb content was 6%. The alloy mass recovery rate in the waste tungsten slag reached 89%.

[0125] Example 13

[0126] The waste tungsten slag powder used in this embodiment is the same as that used in Example 1.

[0127] A method for recovering valuable metals from waste tungsten slag comprises the following steps:

[0128] 1) 5 kg of the first portion of dry waste tungsten slag powder, a slag forming agent (including CaCO3, SiO2 and CaF2, with a mass ratio of 1:0.6:0.04) and a metal additive (including Fe, Co and Ni, with a mass ratio of 1:0.2:0.5) were mixed and then cold isostatically pressed (at a pressure of 190 MPa) to obtain a first green body;

[0129] The mass ratio of the first part of dry waste tungsten slag powder, slag forming agent and metal additive is 1:0.35:0.04;

[0130] 3) placing the first green body in a graphite crucible (the first green body accounts for 70% of the volume of the graphite crucible), heating the first green body to 1450° C. at a rate of 10° C. / min in an inert atmosphere (the gas forming the inert atmosphere is nitrogen) to melt the first green body into a melt, holding the temperature for 2 hours, and removing the slag to obtain a stable melt;

[0131] 4) first cooling the stable melt to 1000° C. at a rate of 3° C. / min, and then cooling to room temperature at a rate of 7.5° C. / min to obtain an alloy ingot enriched with valuable metals.

[0132] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy layer was 30%, the Co content was 35%, the Ta content was 10%, and the Nb content was 4%. The alloy mass recovery rate in the waste tungsten slag reached 85%.

[0133] Comparative Example 1

[0134] The difference between this comparative example and Example 1 is:

[0135] The metal adjuvant in step 2) of Example 1 was omitted.

[0136] After smelting, a very thin alloy layer forms at the bottom of the crucible. The slag phase contains a large number of metal droplets. ICP-AES analysis shows that the mass recovery rate of the valuable metals W, Co, Ta, and Nb alloy in the waste tungsten slag is only 10%.

[0137] Comparative Example 2

[0138] The difference from Example 1 is:

[0139] The Fe in the metal additive in step 1) of Example 1 was replaced with Cu.

[0140] The obtained alloy ingot enriched with valuable metals was analyzed. ICP-AES test showed that the W content in the alloy ingot was 28%, the Co content was 24%, the Ta content was 6%, and the Nb content was 2%. The alloy mass recovery rate in the waste tungsten slag reached 75%.

[0141] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for recovering valuable metals from waste tungsten slag, comprising the following steps: A) mixing the first portion of waste tungsten slag powder, a slag-forming agent, and a metal additive, and performing cold isostatic pressing to obtain a first green body; The slag-forming agent includes CaCO3 and SiO2; the metal additive includes at least one of Fe, Co and Ni; B) In an inert atmosphere, heating the first green body to 1300-1600°C to melt it into a melt, holding the temperature, and removing the slag to obtain a stable melt; C) cooling the stable melt to obtain an alloy ingot enriched with valuable metals.

2. The recycling method according to claim 1, wherein: The metal additives include Fe, Co and Ni, and the mass ratio of Fe, Co and Ni is 1:0.03~0.5:0.1~1; Or the metal additive includes Fe and Ni in a mass ratio of 0.8 to 1.5:1; Or the metal additive includes Fe and Co in a mass ratio of 1.5 to 2.5:1; Or the metal additive includes Fe or Ni.

3. The recycling method according to claim 1, wherein: The mass ratio of the first part of waste tungsten slag powder, slag-forming agent and metal additive is 1:0.2~0.6:0.02~0.

08.

4. The recycling method according to claim 1, characterized in that In step A), the waste tungsten slag powder has a W content of 4% to 10% by mass, a SiO2 content of 30% to 40% by mass, a Co content of 1% to 5% by mass, a Nb content of 0.5% to 2% by mass, a Ta content of 1% to 5% by mass, a S content of 10% to 15% by mass, and an organic matter content of 20% to 40% by mass; the sum of the mass contents of each component is 100%.

5. The recycling method according to claim 1, wherein: In step A), the particle size of the waste tungsten slag powder is 1-10 μm.

6. The recycling method according to claim 1, characterized in that In step A), the mass ratio of CaCO3 to SiO2 is 1:0.4-0.

8.

7. The recycling method according to claim 1, characterized in that: In step A), the slag-forming agent further comprises CaF2, and the mass ratio of CaCO3 to SiO2 to CaF2 is 1:0.4-0.8:0.02-0.

05.

8. The recycling method according to claim 1, characterized in that Step A) further includes: The second part of waste tungsten slag powder is pressed to obtain a second green body; the mass ratio of the first part of waste tungsten slag powder to the second part of waste tungsten slag powder is 1:0.6~1.

0.

9. The recycling method according to claim 8, characterized in that: The tap density of the second green body is 0.6-1.0 g / cm 3 ; In step B), after the melt is formed into a molten body, the method further comprises: adding the second green body into the melt.

10. The recycling method according to claim 1, characterized in that: In step B), the first green body is heated to 1300-1600° C. and melted in a graphite crucible; The first green body occupies 25% to 80% of the volume of the graphite crucible.

11. The recycling method according to claim 1, characterized in that: In step B), the first green body is heated to 1300-1600° C. at a heating rate of 5-15° C. / min.

12. The recycling method according to claim 1, characterized in that: In step C), cooling the stable melt comprises: First cool down to 800~1200℃ at 2~5℃ / min, then cool down to room temperature at 5~10℃ / min.

13. The recycling method according to claim 1, characterized in that: In step C), in the alloy ingot enriched with valuable metals, the mass content of W is 20% to 40%, the mass content of Co is 10% to 38%, the mass content of Ta is 5% to 20%, and the mass content of Nb is 2% to 10%.

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