Tungsten-cobalt separation method for hard alloy grinding material

Abstract

The invention belongs to the field of waste hard alloy recovery and regeneration, and particularly relates to a tungsten-cobalt separation method for a hard alloy grinding material, which comprises the following steps: obtaining the grinding material, mixing the grinding material with alkali to obtain slurry, carrying out saponification reaction, and filtering to obtain first filtrate and first filter residue; drying and crushing the first filter residue, performing ultrasonic cleaning, and filtering to obtain a second filtrate and a second filter residue; the second filter residues and the first acid solution are mixed, then an oxidizing agent is added for cobalt dissolving, a cobalt salt solution and third filter residues are obtained through filtering, and the third filter residues comprise tungsten carbide. According to the separation method, the dissolution rate of cobalt after acid leaching of the grinding material can be increased, the dosage of a tungsten-cobalt separation agent is reduced, the reaction process of tungsten-cobalt separation is accelerated, and the clean hard alloy grinding material easy to recycle is obtained; and wastewater generated in the process can be recycled, no toxic or harmful gas is generated, and high efficiency and environmental protection are both considered.

Description

Technical Field

[0001] This application belongs to the field of recycling and regeneration of waste cemented carbide, and specifically relates to a method for separating tungsten and cobalt from cemented carbide grinding materials. Background Technique

[0002] Grinding materials are a type of high-value waste cemented carbide produced in the tungsten product processing field. Their tungsten content can reach 80% - 90%, and as powdery waste, they are suitable for recycling using hydrometallurgical methods. Currently, the common wet recycling methods for grinding materials mainly include acid method recycling and alkali method recycling: Acid method recycling is to use inorganic acids (such as sulfuric acid, nitric acid, hydrochloric acid) to leach the grinding materials, dissolve the alloy additives (such as cobalt) in the cemented carbide to obtain relatively clean tungsten carbide. The tungsten carbide obtained by this method can be used as a raw material for producing cemented carbide for a second time or further processed into other products; while alkali method recycling is to mix and roast the dried grinding materials with alkali (such as caustic soda, sodium carbonate, sodium nitrate, etc.) and then leach with water to obtain a crude sodium tungstate solution, and the alloy additives enter the slag phase.

[0003] However, most of the technologies involved in the above methods do not consider the current situation of the raw materials of cemented carbide grinding materials: During the rough grinding and finish grinding of cemented carbide, cutting fluid is often required for auxiliary processing, which results in a certain amount of grease in the produced grinding materials, and this type of grease is very difficult to clean by conventional means. Once the grease content is too high, during acid leaching, the grease coats the grinding materials, hindering the progress of the acid decomposition reaction, resulting in an increase in the dosage of reagents required for acid leaching, a long acid leaching process, and an unsatisfactory tungsten-cobalt separation effect; while during alkali method recycling, the volatilization and combustion of grease in the high-temperature roasting stage will produce a large amount of toxic and harmful flue gas and emit a foul smell, causing serious pollution to the atmospheric environment; and the grease will also consume additional roasting additives, increasing the reagent cost. In addition, grinding materials are generally temporarily stored in sedimentation ponds, and it is inevitable that large debris such as sponges, foams, sands, and branches will be mixed in, which will all have an adverse impact on the recycling of grinding materials.

[0004] In view of this situation, the Korean patent with the publication number KR101101755B1 mentions dissolving the cutting oil in the grinding material using hexane or ethanol, but does not propose any treatment for large debris. Moreover, using organic solvents for cleaning poses significant fire hazards and environmental protection problems. The Korean patent with the publication number KR20080110403A proposes first drying and sieving the sludge generated from cemented carbide processing to remove debris, and then using inorganic acid to separate tungsten carbide. It also proposes using low-temperature roasting to remove the cutting oil in the sludge. However, in actual production, the dried grinding material is often in the form of relatively hard blocks, which is not conducive to direct sieving. The main component of the grinding material is tungsten carbide. When roasting it, if the temperature is too low, the cutting oil in it cannot be fully removed; if the temperature is too high, the grinding material and the cutting oil will be ignited and finally oxidized to tungsten oxide, generating harmful gases. And at this time, the cobalt in it undergoes a transformation and the conventional method for separating tungsten and cobalt cannot be used. Summary of the Invention

[0005] The present application provides a method for separating tungsten and cobalt from cemented carbide grinding material. The separation method of the present application can improve the dissolution rate of cobalt after acid leaching of the grinding material, reduce the dosage of reagents for tungsten-cobalt separation, accelerate the reaction process of tungsten-cobalt separation, and obtain clean and easily recyclable cemented carbide grinding material.

[0006] The method for separating tungsten and cobalt from the cemented carbide grinding material of the present application includes the following steps: S1. Obtain the grinding material, mix the grinding material and an alkali to form a slurry for saponification reaction, and filter to obtain a first filtrate and a first filter residue; S2. Dry and crush the first filter residue, perform ultrasonic cleaning, and filter to obtain a second filtrate and a second filter residue; S3. Mix the second filter residue with a first acid solution, then add an oxidant to dissolve cobalt, and filter to obtain a cobalt salt solution and a third filter residue, where the third filter residue includes tungsten carbide.

[0007] In the above technical solution, the alkali added in step S1 can undergo a saponification reaction with fats and oils such as cutting oil, which is beneficial to improving the dissolution rate of cobalt after acid leaching of the grinding material and reducing the dosage of chemicals for tungsten-cobalt separation. Compared with the organic solvent dissolution method, it will not additionally increase the COD treatment burden and fire risk of the waste liquid; compared with the roasting method, it is more controllable and there is no air pollution; ultrasonic cleaning in step S2 can further remove the fats and oils that were not decomposed in place in step S1, and at the same time clean the remaining alkali in the pores, which is beneficial to further reducing the dosage of chemicals for tungsten-cobalt separation; adding the first acid solution in step S3 can dissolve cobalt and make it exist in the first acid solution in the form of ions. Then adding an oxidant can promote the oxidation-reduction reaction of acid leaching and dissolution of cobalt. In this way, cobalt in the second filter residue can be dissolved in the first acid solution to the greatest extent, while tungsten will exist in the form of tungsten carbide and is not easily dissolved in the first acid solution. Therefore, cobalt and tungsten can be well separated by filtration, and the reaction process of tungsten-cobalt separation can be accelerated.

[0008] Further, the alkali in step S2 includes: NaOH, KOH or Na2CO3; the concentration of the alkali in the slurry is 0.75 - 1.5 mol / L; the mass ratio of water to the grinding material in the slurry is 1.5:1 - 2.0:1.

[0009] Further, before the saponification reaction in step S1, it also includes: screening the grinding material raw material to obtain the grinding material; preferably, high-pressure water is used to wash and screen the grinding material raw material on the sieve. This step can effectively remove impurities, improve efficiency while saving costs, and avoid dust pollution; the reaction temperature of the saponification reaction is 70 - 100 °C, and the reaction duration is 60 - 120 min.

[0010] Further, the first acid solution in step S3 includes sulfuric acid or hydrochloric acid, the second filter residue includes tungsten element and cobalt element, and the molar ratio of hydrogen ions in the first acid solution to cobalt element in the second filter residue is 2.5:1 - 4.0:1.

[0011] Further, the oxidant in step S3 includes: hydrogen peroxide or concentrated nitric acid, and the mass of the oxidant is 10% - 15% of the mass of the second filter residue. The oxidant is added to the mixed solution of the second filter residue and the first acid solution at a constant rate, and the addition duration is 4 - 6 h.

[0012] Further, the leaching rate of cobalt in step S3 reaches more than 95.5%.

[0013] Further, when the pH of the first filtrate > 12, the first filtrate is returned to step S1 for saponification reaction, otherwise it is returned for screening treatment.

[0014] Further, when the pH of the second filtrate < 12, the second filtrate is returned to step S2 for ultrasonic cleaning, otherwise it is returned for screening treatment.

[0015] Further, after step S3, the third filter residue is washed and filtered with a second acid solution to obtain a third filtrate; the second acid solution includes at least one of hydrochloric acid or sulfuric acid, and the pH of the second acid solution ≤ 2.

[0016] Further, when the pH of the third filtrate ≤ 2, the third filtrate is returned to wash the third filter residue, otherwise it is returned to step S3 to be mixed with the second filter residue as an acid solution; the liquid generated in any step of this application can be used in the next step or returned to other steps for use. In particular, the third filtrate can also be returned to step S3 as an acid solution, which can improve the utilization rate of the acid, reduce the recovery cost of cobalt, save water consumption, and reduce the burden of wastewater treatment.

[0017] This application proposes a method for separating tungsten and cobalt from cemented carbide grinding materials, which has the following beneficial effects: improving the dissolution rate of cobalt after acid leaching of the grinding materials; reducing the dosage of reagents for tungsten-cobalt separation; accelerating the reaction process of tungsten-cobalt separation; obtaining clean and easily recyclable cemented carbide grinding materials; and the wastewater generated during the process can be recycled, and no toxic and harmful gases are generated, taking into account both high efficiency and environmental protection. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a process flow chart of a method for recovering tungsten and cobalt from cemented carbide grinding materials; Figure 2 It is a flow chart of an embodiment of the present application.

[0020] The realization of the purpose of this application, functional characteristics and advantages will be further described in conjunction with the embodiments with reference to the drawings. Detailed Embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of them. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0022] Please refer to Figure 1 and Figure 2 , Figure 1 It is a process flow chart of a method for recovering tungsten and cobalt from cemented carbide grinding materials, Figure 2This is a flowchart of an embodiment of the present application. The technical solution proposed by the present application includes the following steps: S1. Obtain grinding material, mix the grinding material and alkali to form a slurry, carry out saponification reaction, and filter to obtain a first filtrate and a first filter residue; Specifically: rinse the grinding material raw material through a 50-100 mesh sieve with high-pressure water, and the specific gravity of the rinsing water to the grinding material raw material is 1.5:1 - 2.0:1; the added alkali includes NaOH, KOH or Na2CO3, and the concentration of alkali in the formed slurry is 0.75 - 1.5 mol / L, and the mass ratio of water to grinding material in the slurry is 1.5:1 - 2.0:1. Specifically, the concentration of alkali in the formed slurry can be any one or the range between any two of 0.75 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, and the mass ratio of water to grinding material in the slurry can be any one or the range between any two of 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1; control the reaction temperature at 70 - 100 °C and the reaction duration at 60 - 120 min; when the pH of the first filtrate > 12, return the first filtrate to step S1 for saponification reaction, otherwise return it for sieving treatment to improve the utilization rate of alkali and reduce water consumption; S2. Dry and crush the first filter residue, carry out ultrasonic cleaning, and filter to obtain a second filtrate and a second filter residue; Specifically: control the drying temperature at 100 - 120 °C and crush it to an average particle size not exceeding 2 cm; mix the crushed first filter residue with pure water for ultrasonic cleaning, and the specific gravity of pure water to the first filter residue is 1.0:1 - 1.5:1, and the ultrasonic cleaning duration is 60 min; after ultrasonic cleaning, remove the supernatant, and then filter to obtain a second filtrate and a second filter residue; the second filter residue is clean grinding material and can be directly used in step S3 or roasted with alkali to produce sodium tungstate after drying; when the pH of the second filtrate < 12, return the second filtrate to step S2 for ultrasonic cleaning, otherwise return it for sieving treatment; S3. Mix the second filter residue and a first acid solution, then add an oxidant and filter to obtain a cobalt salt solution and a third filter residue, and the third filter residue includes tungsten carbide; Specifically: the first acid solution includes hydrochloric acid or sulfuric acid, the second filter residue includes tungsten element and cobalt element, and the molar ratio of hydrogen ions in the first acid solution to cobalt element in the second filter residue is 2.5:1 to 4.0:1. Specifically, the molar ratio of hydrogen ions in the first acid solution to cobalt element in the second filter residue can be any one of 2.5:1, 3.0:1, 3.5:1, 4.0:1 or the range between any two of them; after the second filter residue is fully wetted with the acid and undergoes a preliminary reaction, an oxidant is added to the mixture of the second filter residue and the first acid solution at a constant rate. The oxidant includes hydrogen peroxide or concentrated nitric acid, and the mass of the oxidant is 10% - 15% of the mass of the second filter residue, and the addition duration is 4 - 6h. Better results can be obtained by slowly adding the oxidant. After the addition of the oxidant is completed, the reaction continues for 1h to allow the oxidant to fully participate in the reaction; then, a cobalt salt solution and a third filter residue are obtained by filtration. The third filter residue includes tungsten carbide; then, the third filter residue is washed with a second acid solution to wash away the hydrolysis products of Co and Fe elements that may be contained in the third filter residue. The second acid solution includes at least one of hydrochloric acid or sulfuric acid, the pH of the second acid solution ≤ 2, the washing duration is 30 - 60min, and the liquid-solid ratio of the washing solution is 3:1; a third filtrate and clean tungsten carbide are obtained by filtration, which can be applied to different processing fields according to their different compositions and physical properties; when the pH of the third filtrate ≤ 2, the third filtrate is returned to wash the third filter residue, otherwise it is returned to step S3 to be mixed with the second filter residue as an acid solution to improve the utilization rate of the acid, reduce the recovery cost of cobalt, save water consumption and reduce the burden of wastewater treatment; after being treated by the above steps, the leaching rate of cobalt after acid leaching of the grinding material can reach more than 95.5%.

[0023] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0024] The raw materials used in each example and comparative example are the grinding material raw materials produced in the fine grinding process of cemented carbide. The grinding material raw materials are composed of 20wt% water, 3wt% grease and 77wt% grinding material. After detection, the main components of the grinding material are shown in Table 1 as follows: Table 1 Main components of the grinding material Example 1 Take 500 g of grinding material raw materials, wash and sieve them with 1000 mL of high-pressure water. Stir the obtained grinding material and washing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping warm for 120 min, carry out solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then carry out solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt in the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide. And use 200 mL of 1% mass fraction dilute sulfuric acid to wash the third filter residue to obtain the third filtrate and clean tungsten carbide. After detection, the Co content in the obtained tungsten carbide is 0.15%. After calculation, the leaching rate of Co reaches 98.9%; the total water consumption is 1750 mL.

[0025] Example 2 Take 500 g of grinding material raw materials, wash and sieve them with 750 mL of high-pressure water. Stir the obtained grinding material and washing water evenly and pour them into a decomposition kettle. Add 45 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping warm for 120 min, carry out solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then carry out solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt in the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0026] The difference between this embodiment and Embodiment 1 is that: the amount of water for flushing and sieving is reduced from a liquid-solid ratio of 2:1 to 1.5:1, that is, the mass ratio of water to abrasive in the slurry is reduced to 1.5:1, and the remaining conditions are the same as those in Embodiment 1. The Co content in the tungsten carbide obtained through detection is 0.19%, and through calculation, the leaching rate of Co reaches 98.6%.

[0027] Embodiment 3 Take 500 g of abrasive raw materials and rinse and sieve them with 1000 mL of high-pressure water. Stir the obtained abrasive and rinsing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 70 °C and start heating and decomposing. After maintaining the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven and dry it at 100 °C, then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Place the beaker in an ultrasonic cleaner and perform ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt in the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0028] The difference between this embodiment and Embodiment 1 is that: the saponification reaction temperature is reduced from 100 °C to 70 °C, and the remaining conditions are the same as those in Embodiment 1. The Co content in the tungsten carbide obtained through detection is 0.35%, and through calculation, the leaching rate of Co reaches 97.4%.

[0029] Embodiment 4 Take 500 g of the grinding material raw material, wash and screen it with 1000 mL of high-pressure water. Stir the obtained grinding material and the washing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping the temperature for 60 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining material to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0030] The difference between this example and Example 1 is that: the holding time of alkali dissolution of the grinding material is reduced from 120 min to 60 min, and the other conditions are the same as those in Example 1. The Co content in the tungsten carbide obtained by detection is 0.23%, and the leaching rate of Co reaches 98.3% after calculation.

[0031] Example 5 Take 500 g of the grinding material raw material, without washing and screening, only use 1000 mL of water to make a slurry, stir evenly and pour it into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining material to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0032] The difference between this embodiment and Embodiment 1 is that the grinding material is not rinsed and screened. The Co content in the obtained tungsten carbide is 0.59%, and the leaching rate of Co is 95.5%. The untreated impurities affect the decomposition reaction, resulting in a worse tungsten-cobalt separation effect than Embodiment 1, and the hard impurities therein cause a certain degree of wear on the decomposition equipment.

[0033] Embodiment 6 Take 500 g of the grinding material raw material and rinse and screen it with 1000 mL of high-pressure water. Stir the obtained grinding material and the rinsing water evenly and pour them into the decomposition kettle. Add 50 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After holding for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven and dry it at 100 °C, then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner and perform ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue the reaction for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0034] The difference between this embodiment and Embodiment 1 is that the concentration of sodium hydroxide during the alkaline dissolution of the grinding material is reduced from 60 g / L to 50 g / L. The Co content in the obtained tungsten carbide is 0.48%, and the leaching rate of Co is 96.1%, which is lower than that of Embodiment 1. Reducing the concentration of sodium hydroxide will make the cleaning effect of the pretreatment worse, thus affecting the tungsten-cobalt separation effect.

[0035] Embodiment 7 Take 500 g of grinding material raw materials, wash and screen them with 900 mL of high-pressure water. Stir the obtained grinding material and washing water evenly and pour them into a decomposition kettle. Add 54 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After holding for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant. Then perform solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0036] The difference between this example and Example 1 is that the amount of water for washing and screening is reduced from a liquid-solid ratio of 2:1 to 1.8:1, that is, the mass ratio of water to grinding material in the slurry is reduced to 1.8:1, and the other conditions are the same as in Example 1. The Co content in the obtained tungsten carbide is 0.22% by detection, and the leaching rate of Co reaches 98.4% by calculation.

[0037] Example 8 Take 500 g of grinding material raw materials, wash and screen them with 1000 mL of high-pressure water. Stir the obtained grinding material and washing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 80 °C and start heating and decomposing. After holding for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant. Then perform solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0038] The difference between this example and Example 1 is that the saponification reaction temperature is reduced from 100 °C to 80 °C, and the remaining conditions are the same as those in Example 1. The Co content in the tungsten carbide obtained by detection is 0.29%, and the calculated leaching rate of Co reaches 97.9%.

[0039] Example 9 Take 500 g of grinding material raw materials and rinse and screen them with 1000 mL of high-pressure water. Stir the obtained grinding material and rinsing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start the stirring of the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 70 °C and start heating and decomposing. After keeping warm for 80 min, carry out solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven and dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Place the beaker in an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then carry out solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt in the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, a cobalt salt solution and a third filter residue including tungsten carbide are obtained.

[0040] The difference between this example and Example 1 is that the alkali dissolution holding time of the grinding material is reduced from 120 min to 80 min, and the remaining conditions are the same as those in Example 1. The Co content in the tungsten carbide obtained by detection is 0.18%, and the calculated leaching rate of Co reaches 98.6%.

[0041] Example 10 Take 500 g of grinding material raw materials and rinse and screen them with 1000 mL of high-pressure water. Stir the obtained grinding material and rinsing water evenly and pour them into a decomposition kettle. Add 30 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping the temperature for 120 min, carry out solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. Put the first filter residue into a blast drying oven and dry it at 100 °C, then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then carry out solid-liquid separation on the remaining materials to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, a cobalt salt solution and a third filter residue including tungsten carbide are obtained.

[0042] The difference between this example and Example 1 is that the concentration of sodium hydroxide during the alkaline dissolution of the grinding material is reduced from 60 g / L to 30 g / L. The Co content in the obtained tungsten carbide is 0.68%, and the leaching rate of Co is 95.6%, which is not as good as that in Example 1. Reducing the concentration of sodium hydroxide will make the cleaning effect of the pretreatment worse, thus affecting the tungsten-cobalt separation effect.

[0043] Example 11 The first tungsten-cobalt separation: Take 500 g of grinding material raw materials, rinse and sieve them with 1000 mL of high-pressure water. Stir the obtained grinding material and rinsing water evenly and pour them into a decomposition kettle. Add 60 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping warm for 120 min, carry out solid-liquid separation on the slurry to obtain the first filter residue and 980 mL of the first filtrate, and recycle the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then carry out solid-liquid separation on the remaining materials to obtain the second filter residue and 300 mL of the second filtrate, and recycle the second filtrate; Use 250 mL of water and 57.3 g of concentrated sulfuric acid to prepare a solution to separate tungsten and cobalt from the second filter residue. Add 30 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide. And use 200 mL of 1% mass fraction dilute sulfuric acid to wash the third filter residue to obtain 200 mL of the third filtrate and clean tungsten carbide, and recycle the third filtrate. After detection, the Co content in the obtained tungsten carbide is 0.15%. After calculation, the leaching rate of Co reaches 98.9%. The total water consumption for this tungsten-cobalt separation is 1750 mL; It is detected that the pH of the first filtrate in the first tungsten-cobalt separation > 12, the pH of the second filtrate > 12, and the pH of the third filtrate < 2, and carry out the second tungsten-cobalt separation; Second tungsten-cobalt separation: Take 500 g of abrasive raw materials and wash and sieve them under high pressure with 300 mL of the second filtrate from the first tungsten-cobalt separation and 450 mL of water. Stir the obtained abrasive and the washing water evenly and pour them into a decomposition kettle. Then add 250 mL of the first filtrate from the first tungsten-cobalt separation and 50 g of NaOH, and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After maintaining the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and 980 mL of the first filtrate, and recycle the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant. Then perform solid-liquid separation on the remaining material to obtain the second filter residue and 300 mL of the second filtrate, and recycle the second filtrate; Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the second filter residue. Add 30 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide. And use the third filtrate from the first tungsten-cobalt separation to wash the third filter residue to obtain 200 mL of the third filtrate and clean tungsten carbide, and recycle the third filtrate. After detection, the Co content in the obtained tungsten carbide is 0.20%, and after calculation, the leaching rate of Co reaches 98.2%; Detect that the pH of the first filtrate in the second tungsten-cobalt separation is <12, the pH of the second filtrate is >12, and the pH of the third filtrate is >2; The new water consumption in the second tungsten-cobalt separation includes: 450 mL of water for washing and sieving, 300 mL of water for ultrasonic cleaning, and 250 mL of water for preparing the acid solution. And other water used is recycled water recovered from the first tungsten-cobalt separation. The new water consumption is reduced from 1750 mL to 1000 mL. The consumption of acid and alkali is reduced during the process, which improves the utilization rate of acid and alkali to a certain extent. And the filtrate recovered from the second tungsten-cobalt separation can also be continuously used in the subsequent tungsten-cobalt separation steps.

[0044] Example 12 The first tungsten-cobalt separation: Take 500 g of grinding material raw materials and rinse and screen them with 1000 mL of high-pressure water. Stir the obtained grinding material and rinsing water evenly and pour them into a decomposition kettle. Add 30 g of NaOH and start stirring the decomposition kettle to make a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After maintaining the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and 980 mL of the first filtrate, and recycle the first filtrate. Put the first filter residue into a blast drying oven and dry it at 100 °C, then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add 300 mL of pure water and stir appropriately. Place the beaker in an ultrasonic cleaner and perform ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining material to obtain the second filter residue and 300 mL of the second filtrate, and recycle the second filtrate; Use 250 mL of water and 57.3 g of concentrated sulfuric acid to prepare a solution for tungsten-cobalt separation of the second filter residue. Add 30 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, a cobalt salt solution and a third filter residue including tungsten carbide are obtained. And use 200 mL of dilute sulfuric acid with a mass fraction of 0.5% to wash the third filter residue to obtain 200 mL of the third filtrate and clean tungsten carbide, and recycle the third filtrate. After detection, the Co content in the obtained tungsten carbide is 0.68%, and the leaching rate of Co is 95.5%. The total water consumption for this tungsten-cobalt separation is 1750 mL; it is detected that the pH of the first filtrate in the first tungsten-cobalt separation is <12, the pH of the second filtrate is <12, and the pH of the third filtrate is >2, and perform the second tungsten-cobalt separation; Second tungsten-cobalt separation: Take 500 g of grinding material raw materials, use the first filtrate from the first tungsten-cobalt separation and 20 mL of water for high-pressure rinsing and sieving. Stir the obtained grinding material and rinsing water evenly and pour them into a decomposition kettle. Add 30 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After maintaining the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and 980 mL of the first filtrate, and recycle the first filtrate. Put the first filter residue into a blast drying oven, dry it at 100 °C, and then crush it into small pieces with a particle size not exceeding 2 cm. Take 200 g of the crushed first filter residue and place it in a beaker, add the second filtrate from the first tungsten-cobalt separation and stir appropriately. Put the beaker into an ultrasonic cleaner for ultrasonic cleaning for 60 min, then let it stand for 30 min and separate part of the supernatant, and then perform solid-liquid separation on the remaining materials to obtain the second filter residue and 300 mL of the second filtrate, and recycle the second filtrate; Use the third filtrate from the first tungsten-cobalt separation, 50 mL of water and 57.3 g of concentrated sulfuric acid to prepare a solution for tungsten-cobalt separation of the second filter residue. Add 30 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide. And use 200 mL of dilute sulfuric acid with a mass fraction of 0.5% to wash the third filter residue to obtain 200 mL of the third filtrate and clean tungsten carbide, and recycle the third filtrate. After detection, the Co content in the obtained tungsten carbide is 0.67%, and after calculation, the leaching rate of Co reaches 95.9%; Detect that the pH of the first filtrate in the second tungsten-cobalt separation is <12, the pH of the second filtrate is <12, and the pH of the third filtrate is >2; The new water consumption in the second tungsten-cobalt separation includes: 20 mL of water for rinsing and sieving, 50 mL of water for preparing the acid solution and 200 mL of dilute sulfuric acid for washing, and other water used is recycled water recovered in the first tungsten-cobalt separation. The new water consumption is reduced from 1750 mL to 270 mL, and the filtrate recovered in the second tungsten-cobalt separation can also be continuously used in subsequent tungsten-cobalt separation steps.

[0045] Comparative Example 1 Take 250 g of grinding material raw materials without any pretreatment. Use a solution prepared from 250 mL of water and 114.6 g of concentrated sulfuric acid for tungsten-cobalt separation, add 60 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 7 h, and then continue to react for 1 h.

[0046] The difference between this comparative example and Example 1 is that the grinding material is directly subjected to acid leaching without any treatment, and the amount of acid used is doubled, and the amount of oxidant used is doubled. When sampling and testing after 6 hours of acid leaching, the Co content in the tungsten carbide obtained is 8.73%. The leaching is not complete, so the acid leaching time is extended by 2 hours, approximately 33%. After detection, the Co content in the tungsten carbide obtained is 4.53%, and the leaching rate of Co is only 62.5%. It shows that when using the process of the present application to separate tungsten and cobalt from high-fat hard alloy grinding materials, the amount of acid leaching agent used can be reduced by 1 time, and at the same time, only 6 hours of acid leaching is required to achieve a cobalt dissolution effect far higher than that of direct acid leaching for 8 hours.

[0047] Comparative Example 2 Take 250 g of grinding material raw materials, and only wash and screen them with high-pressure water. A solution prepared with 250 mL of water and 114.6 g of concentrated sulfuric acid is used to separate tungsten and cobalt from the obtained grinding material. Add 60 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 7 hours, and then continue to react for 1 hour.

[0048] The difference between this comparative example and Example 1 is that the grinding material is directly subjected to acid leaching after only being washed and screened, and the amount of acid used is doubled, the amount of oxidant used is doubled, and the acid leaching time is extended by 2 hours, approximately 33%. After detection, the Co content in the tungsten carbide obtained is 3.98%, and the leaching rate of Co is only 67.1%. The tungsten-cobalt separation effect is slightly better than that of Comparative Example 1.

[0049] Comparative Example 3 Take 250 g of grinding material raw materials, wash and screen them with 500 mL of high-pressure water. Stir the obtained grinding material and washing water evenly and pour them into a decomposition kettle. Add 30 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping warm for 120 minutes, carry out solid-liquid separation on the slurry. Use a solution prepared with 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt from the obtained filter residue. Add 30 g of hydrogen peroxide as an oxidant, control the dropping time of hydrogen peroxide to be 5 hours, and then continue to react for 1 hour. After filtration, a cobalt salt solution and a filter residue including tungsten carbide are obtained.

[0050] The difference between this comparative example and Example 1 is that the grinding material does not go through the steps of drying, crushing and ultrasonic cleaning. After detection, the Co content in the tungsten carbide obtained is 0.74%, and the leaching rate of Co is 94.4%. The tungsten-cobalt separation effect is significantly inferior to that of Example 1.

[0051] Comparative Example 4 Take 250 g of abrasive raw materials, rinse and sieve them with 500 mL of high-pressure water. Stir the obtained abrasive and rinsing water evenly and pour them into a decomposition kettle. Add 30 g of NaOH and start stirring the decomposition kettle to form a slurry. Set the heating temperature of the decomposition kettle to 100 °C and start heating and decomposing. After keeping the temperature for 120 min, perform solid-liquid separation on the slurry to obtain the first filter residue and the first filtrate. The first filter residue is directly added with 300 mL of pure water, stirred appropriately, and ultrasonically cleaned for 60 min, then left to stand for 30 min and part of the supernatant is separated. Then, perform solid-liquid separation on the remaining material to obtain the second filter residue and the second filtrate. Use a solution prepared by mixing 250 mL of water and 57.3 g of concentrated sulfuric acid to separate tungsten and cobalt in the second filter residue. Here, the molar ratio of hydrogen ions in the acid solution to cobalt elements in the second filter residue is 3:1. Add 30 g of hydrogen peroxide as an oxidant. Here, the weight of hydrogen peroxide is 15% of the weight of the second filter residue. Control the dropping time of hydrogen peroxide to be 5 h, and then continue to react for 1 h. After filtration, obtain a cobalt salt solution and a third filter residue including tungsten carbide.

[0052] The difference between this comparative example and Example 1 is that the abrasive after alkaline dissolution is directly ultrasonically cleaned without drying and crushing. The Co content in the obtained tungsten carbide is 0.70%, and the leaching rate of Co is 94.7%. The tungsten-cobalt separation effect is close to that of Comparative Example 3 and is significantly inferior to that of Example 1, indicating that ultrasonic cleaning of dried and crushed materials has a better cleaning effect than cleaning wet materials.

[0053] The process flows of each example and comparative example are shown in Table 2: Table 2 Summary of the process flows of examples and comparative examples By comparing the above examples and comparative examples, it can be seen that the tungsten-cobalt separation method for cemented carbide abrasives proposed in this application can improve the dissolution rate of cobalt after acid leaching of abrasives, reduce the dosage of agents for tungsten-cobalt separation, accelerate the reaction process of tungsten-cobalt separation, and obtain clean and easily recyclable cemented carbide abrasives; and the wastewater generated during the process can be recycled, and no toxic and harmful gases are generated, taking into account both high efficiency and environmental protection.

[0054] The above are only the preferred embodiments of this application, and do not limit the patent scope of this application accordingly. Any equivalent structural transformation made using the content of the specification of this application under the inventive concept of this application, or direct / indirect application in other related technical fields, is included in the patent protection scope of this application.

Claims

1. A method for separating tungsten and cobalt from cemented carbide grinding materials, characterized in that, It includes the following steps: S1. Obtain abrasive, mix the abrasive and alkali to form a slurry for saponification reaction, and filter to obtain a first filtrate and a first filter residue; S2. Dry and crush the first filter residue, perform ultrasonic cleaning, and filter to obtain a second filtrate and a second filter residue; S3. Mix the second filter residue with a first acid solution, then add an oxidant for cobalt dissolution, and filter to obtain a cobalt salt solution and a third filter residue, where the third filter residue includes tungsten carbide.

2. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 1, characterized in that, The alkali in step S1 includes: NaOH, KOH or Na2CO3; the concentration of the alkali in the slurry is 0.75 - 1.5 mol / L; the mass ratio of water to the abrasive in the slurry is 1.5:1 - 2.0:

1.

3. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 1, characterized in that, Before performing the saponification reaction in step S1, it also includes: screening the abrasive raw material to obtain the abrasive, the reaction temperature of the saponification reaction is 70 - 100 °C, and the reaction duration is 60 - 120 min.

4. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 1, characterized in that, The first acid solution in step S3 includes at least one of sulfuric acid or hydrochloric acid, the second filter residue includes tungsten element and cobalt element, and the molar ratio of hydrogen ions in the first acid solution to cobalt element in the second filter residue is 2.5:1 - 4.0:

1.

5. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 1, characterized in that, The oxidant in step S3 includes: hydrogen peroxide or concentrated nitric acid, and the mass of the oxidant is 10% - 15% of the mass of the second filter residue. The oxidant is added to the mixture of the second filter residue and the first acid solution at a constant rate, and the addition duration is 4 - 6 h.

6. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 1, characterized in that, The leaching rate of cobalt in step S3 reaches over 95.5%.

7. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 3, characterized in that, When the pH of the first filtrate > 12, return the first filtrate to step S1 for saponification reaction, otherwise return it for the screening process.

8. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 3, characterized in that, When the pH of the second filtrate < 12, return the second filtrate to step S2 for ultrasonic cleaning, otherwise return it for the screening process.

9. The method for separating tungsten and cobalt from the cemented carbide grinding material according to claim 3, characterized in that, After step S3, wash and filter the third filter residue with a second acid solution to obtain a third filtrate; the second acid solution includes at least one of hydrochloric acid or sulfuric acid, and the pH of the second acid solution ≤ 2.

10. The tungsten-cobalt separation method of the cemented carbide grinding material according to claim 9, characterized in that, When the pH of the third filtrate ≤ 2, return the third filtrate to wash the third filter residue, otherwise return it to step S3 to be mixed with the second filter residue as an acid solution.

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