Method for recovering nickel, copper, molybdenum and tungsten from rare earth tailings by gravity separation

Abstract

This invention discloses a method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, comprising the following steps: Step 1, raw material preparation; Step 2, grinding and stirring; Step 3, centrifugal separation; Step 4, copper-nickel separation; Step 5, tungsten metal separation; Step 6, reagent flotation; Step 7, enrichment and purification. Compared with existing methods for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, this invention first employs ball milling and stirring, followed by centrifugal separation, to initially remove impurities from the raw materials, thereby improving the purity of the raw materials and facilitating subsequent separation and extraction. Simultaneously, it utilizes high-temperature alkaline leaching to separate copper and nickel, roasting alkaline leaching to separate tungsten, and reagent flotation to separate molybdenum minerals. By employing different methods for stepwise separation, the purity of the separated products is improved. The separation process is reasonable, simple to operate, requires less reagent, is environmentally friendly, and reduces production costs.

Description

Technical Field

[0001] This invention relates to the field of rare earth tailings recycling technology, specifically a method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation. Background Technology

[0002] Rare earth tailings refer to waste residues containing large amounts of rare earth elements and other valuable metals generated during rare earth mining and extraction. These tailings contain rare earth elements and other valuable metals with wide-ranging applications, necessitating their recovery and utilization. While existing methods for rare earth tailings gravity separation recovery are relatively comprehensive, they still have certain shortcomings. For example, a Chinese patent with authorization announcement number CN 110639689B, entitled "A Beneficiation Method for Comprehensive Recovery of Rare Earth, Strontium, and Molybdenum from Rare Earth Tailings," primarily employs the following recovery method: S1, magnetic separation to obtain magnetic concentrate and magnetic tailings; S2, rare earth gravity separation to obtain rare earth concentrate and shaking table tailings; S3, molybdenum flotation to obtain rougher tailings and rougher concentrate; three scavenging operations on the rougher tailings to obtain molybdenum tailings; seven cleaning operations on the rougher concentrate to obtain molybdenum concentrate; and S4, strontium flotation to obtain strontium concentrate and flotation strontium tailings. This recycling method has certain drawbacks: First, it directly performs magnetic separation on rare earth tailings without pre-treating them, resulting in a high impurity content and poor magnetic separation effect, which greatly reduces the efficiency and rate of separation. Second, the separation process mainly involves adjusting the concentration of the slurry and then adding a collector to scaveng and capture the minerals. This method yields valuable metals with low purity, many impurities, and is cumbersome to operate, requiring a large amount of reagents and resulting in high production costs. Summary of the Invention

[0003] The purpose of this invention is to provide a method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, comprising the following steps: Step 1, raw material preparation; Step 2, grinding and stirring; Step 3, centrifugal separation; Step 4, copper-nickel separation; Step 5, tungsten metal separation; Step 6, reagent flotation; Step 7, enrichment and purification.

[0005] In step one above, rare earth tailings are first selected as raw materials for gravity separation and recovery, and a small number of samples are collected for testing to determine the raw material content and physicochemical properties in the rare earth tailings.

[0006] In step two above, after the raw materials in step one are reselected and recovered, the rare earth tailings are put into a ball mill, and then an appropriate amount of water is added for ball milling. The rare earth tailings are then added into a mixer, and a dispersant is added for dispersion and stirring. After stirring, a slurry is obtained for later use.

[0007] In step three above, after the mixing in step two is completed, the mixed slurry is fed into a spiral sluice. The sluice uses centrifugal force, friction and water flow to separate the slurry. The raw material rich in heavy minerals is left on the inner side of the bottom of the sluice, while the lighter part on the outer side is discharged into a centrifuge for further separation. After separation, the clean sand and slurry are discharged into the waste liquid pool. The heavy minerals accumulated in the sluice and the solid heavy matter left by the centrifuge are left behind to obtain the screened fine tailings.

[0008] In step four above, after the tailings in step three are screened, the tailings are put into a mixer. An appropriate amount of water is added to the mixer to ensure that the concentration of the tailings is 40-50% after adding water. After adding water, the mixer is started to mix. Then sodium carbonate is added to the tailings slurry. At this time, high-temperature steam is introduced into the mixer to heat and stir. After completion, the copper sediment is filtered at the bottom. Then lime is added to adjust the pH. Nickel precipitate is generated at the bottom. The precipitate is removed to separate nickel and copper. The filtrate is then used for later use.

[0009] In step five above, after the copper and nickel are separated in step four, the filtrate is filtered by plate and frame pressing to remove water. Then, the filtered solid is put into an electric furnace for roasting. After roasting, the solid is put into a saturated sodium carbonate solution for leaching to dissolve the tungsten in the solid. The solid is then filtered, leaving the filtrate. Sodium bisulfite is then added to the filtrate for reduction treatment to obtain tungsten metal, thus achieving the separation of tungsten.

[0010] In step six above, after the tungsten separation in step five is completed, the remaining filtrate is put into the flotation cell. Flotation reagents are then added to the cell, and air is introduced into the flotation cell. The air bubbles will react with the molybdenum minerals in the ore to form flotation foam, causing them to float. Impurities will settle to the bottom of the flotation cell. The flotation material is then filtered and dehydrated to separate the molybdenum minerals, thus achieving the separation of molybdenum minerals.

[0011] In step seven above, after the molybdenum minerals are separated in step six, the separated tungsten, nickel, copper and molybdenum minerals are dried and evaporated respectively to further enrich the products. After completion, the heavy separation and recovery of nickel, copper and molybdenum and tungsten in rare earth tailings are achieved.

[0012] Preferably, in step two, the dispersant is a mixture of soda ash, water glass and tripolyphosphate in a mass ratio of 1:1:1.

[0013] Preferably, in step two, the ball milling time is 36-48 hours, the mixing time of the mixer is 2-3 hours, and the mixing speed is 200-240 r / min.

[0014] Preferably, in step three, the centrifuge is a low-speed centrifuge with a rotation speed of 3000 rpm to 5000 rpm.

[0015] Preferably, in step four, the mixer speed is 240-300 r / min, the mixing time is 10-20 min, and the slurry temperature is 67-75℃ after steam is introduced.

[0016] Preferably, in step four, the pH for separating copper is 6-7.5, and the pH for separating nickel is 8.1-10.

[0017] Preferably, in step five, the roasting temperature is 700-750℃ and the roasting time is 60-70 minutes.

[0018] Preferably, in step five, the immersion temperature is 85-90℃ and the immersion time is 80-90 minutes.

[0019] Preferably, in step six, the flotation reagent is a mixture of sodium chloride, sodium cyanide, and lead oxide.

[0020] Preferably, in step seven, the evaporation temperature is 110-120℃ and the evaporation time is 30-40 minutes.

[0021] Compared with existing technologies, the beneficial effects of this invention are as follows: Compared with existing methods for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, this invention first employs ball milling and stirring, followed by centrifugal separation to initially remove impurities from the raw materials, thereby improving the purity of the raw materials and facilitating subsequent separation and extraction. Simultaneously, it utilizes high-temperature alkaline leaching to separate copper and nickel, roasting alkaline leaching to separate tungsten, and reagent flotation to separate molybdenum minerals. By employing different methods for stepwise separation, the purity of the separated products is improved. The separation process is reasonable, the operation is simple, and less reagent is added, which is environmentally friendly and reduces production costs. Attached Figure Description

[0022] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 The present invention provides an embodiment of a method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, comprising the following steps: Step 1, raw material preparation; Step 2, grinding and stirring; Step 3, centrifugal separation; Step 4, copper-nickel separation; Step 5, tungsten metal separation; Step 6, reagent flotation; Step 7, enrichment and purification.

[0025] In step one above, rare earth tailings are first selected as raw materials for gravity separation and recovery, and a small number of samples are collected for testing to determine the raw material content and physicochemical properties in the rare earth tailings.

[0026] In step two above, after the raw materials in step one are recovered by gravity separation, the rare earth tailings are fed into a ball mill, and then an appropriate amount of water is added for ball milling. The rare earth tailings are then added to a mixer, and a dispersant is added. The dispersant is a mixture of soda, water glass and tripolyphosphate in a mass ratio of 1:1:1. The mixture is dispersed and stirred. The ball milling time is 48 hours, the stirring time of the mixer is 3 hours, and the stirring speed is 200 r / min. After stirring, the slurry is obtained for later use.

[0027] In step three above, after the mixing in step two is completed, the mixed slurry is fed into a spiral sluice. Centrifugal separation is carried out using the centrifugal force, friction, and water flow of the sluice. The raw material rich in heavy minerals is left on the inner side of the lower part of the sluice, while the lighter part on the outer side is discharged into a centrifuge for further separation. The centrifuge is a low-speed centrifuge with a rotation speed of 3000 rpm. After separation, the clean sand and slurry are discharged into the waste liquid pool, while the heavy minerals accumulated in the sluice and the solid heavy matter left by the centrifuge are left behind, resulting in the screened and refined tailings.

[0028] In step four above, after the tailings in step three are screened, the tailings are fed into a mixer. An appropriate amount of water is added to the mixer to ensure that the concentration of the tailings is 40-50% after adding water. The mixer is then started to mix the tailings. Sodium carbonate is then added to the tailings slurry. High-temperature steam is then introduced into the mixer to heat and stir the slurry. The mixer speed is 300 r / min and the stirring time is 20 min. After the steam is introduced, the slurry temperature is 75℃. After completion, the bottom copper is filtered. Then, lime is added to adjust the pH, and nickel precipitate is generated at the bottom. The precipitate is then removed to separate nickel and copper. The pH for separating copper is 7.5 and the pH for separating nickel is 9. The filtrate is then set aside.

[0029] In step five above, after the separation of copper and nickel in step four is completed, the filtrate is then filtered using a plate and frame filter press to remove moisture. The filtered solid is then placed in an electric furnace for roasting at 750°C for 60 minutes. The roasted solid is then leached in a saturated sodium carbonate solution at 90°C for 90 minutes to dissolve the tungsten in the solid. The solid is then filtered, leaving the filtrate. Sodium bisulfite is then added to the filtrate for reduction treatment to obtain tungsten metal, thus achieving the separation of tungsten.

[0030] In step six above, after the tungsten separation in step five is completed, the remaining filtrate is fed into a flotation cell. Flotation reagents, a mixture of sodium chloride, sodium cyanide, and lead oxide, are then added to the cell. Air is then introduced into the flotation cell, and the bubbles react with the molybdenum minerals in the ore to form flotation foam, causing them to float. Impurities settle to the bottom of the flotation cell. The flotation material is then filtered and dehydrated to separate the molybdenum minerals, thus achieving the separation of molybdenum minerals.

[0031] In step seven above, after the molybdenum minerals are separated in step six, the separated tungsten, nickel, copper and molybdenum minerals are dried and evaporated respectively. The evaporation temperature is 120℃ and the evaporation time is 40 minutes to further enrich the products. After completion, the heavy separation and recovery of nickel, copper and molybdenum and tungsten in rare earth tailings are achieved.

[0032] Based on the above, the advantages of this invention are that the method is simple, the process is straightforward and standardized, and it is highly operable. Before the raw materials are recycled, the mixture is first ball-milled and stirred to form a slurry. Then, the impurities in the slurry are separated by centrifugal sluice and centrifuge to remove the impurities and obtain refined tailings. This effectively improves the purity of the raw materials, facilitates subsequent processing, and improves work efficiency. During the separation and recycling, copper and nickel are separated by high-temperature alkaline leaching, tungsten is separated by roasting alkaline leaching, and molybdenum minerals are separated by reagent flotation. The raw materials are separated in steps, which improves the purity of the separated products and the separation efficiency. The separation process is reasonable, the operation is simple, and the amount of reagents added is small, which is beneficial to environmental protection and reduces production costs.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation, comprising the following steps: Step 1, raw material preparation; Step 2, grinding and stirring; Step 3, centrifugal separation; Step 4, copper-nickel separation; Step 5, tungsten metal separation; Step 6, reagent flotation; Step 7, enrichment and purification; characterized in that: In step one above, rare earth tailings are first selected as raw materials for gravity separation and recovery, and a small number of samples are collected for testing to determine the raw material content and physicochemical properties in the rare earth tailings. In step two above, after the raw materials in step one are reselected and recovered, the rare earth tailings are put into a ball mill, and then an appropriate amount of water is added for ball milling. The rare earth tailings are then added into a mixer, and a dispersant is added for dispersion and stirring. After stirring, a slurry is obtained for later use. In step three above, after the mixing in step two is completed, the mixed slurry is fed into a spiral sluice. The sluice uses centrifugal force, friction and water flow to separate the slurry. The raw material rich in heavy minerals is left on the inner side of the bottom of the sluice, while the lighter part on the outer side is discharged into a centrifuge for further separation. After separation, the clean sand and slurry are discharged into the waste liquid pool. The heavy minerals accumulated in the sluice and the solid heavy matter left by the centrifuge are left behind to obtain the screened fine tailings. In step four above, after the tailings in step three are screened, the tailings are put into a mixer. An appropriate amount of water is added to the mixer to ensure that the concentration of the tailings is 40-50% after adding water. After adding water, the mixer is started to mix. Then sodium carbonate is added to the tailings slurry. At this time, high-temperature steam is introduced into the mixer to heat and stir. After completion, the copper sediment is filtered at the bottom. Then lime is added to adjust the pH. Nickel precipitate is generated at the bottom. The precipitate is removed to separate nickel and copper. The filtrate is then used for later use. In step five above, after the copper and nickel are separated in step four, the filtrate is filtered by plate and frame pressing to remove water. Then, the filtered solid is put into an electric furnace for roasting. After roasting, the solid is put into a saturated sodium carbonate solution for leaching to dissolve the tungsten in the solid. The solid is then filtered, leaving the filtrate. Sodium bisulfite is then added to the filtrate for reduction treatment to obtain tungsten metal, thus achieving the separation of tungsten. In step six above, after the tungsten separation in step five is completed, the remaining filtrate is put into the flotation cell. Flotation reagents are then added to the cell, and air is introduced into the flotation cell. The air bubbles will react with the molybdenum minerals in the ore to form flotation foam, causing them to float. Impurities will settle to the bottom of the flotation cell. The flotation material is then filtered and dehydrated to separate the molybdenum minerals, thus achieving the separation of molybdenum minerals. In step seven above, after the molybdenum minerals are separated in step six, the separated tungsten, nickel, copper and molybdenum minerals are dried and evaporated respectively to further enrich the products. After completion, the heavy separation and recovery of nickel, copper and molybdenum and tungsten in rare earth tailings are achieved.

2. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step two, the dispersant is a mixture of soda ash, water glass and tripolyphosphate in a mass ratio of 1:1:

1.

3. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step two, the ball milling time is 36-48 hours, the mixing time of the mixer is 2-3 hours, and the mixing speed is 200-240 r / min.

4. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step three, the centrifuge is a low-speed centrifuge with a rotation speed of 3000rpm-5000rpm.

5. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step four, the mixer speed is 240-300 r / min, the mixing time is 10-20 min, and the slurry temperature is 67-75℃ after steam is introduced.

6. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step four, the pH for separating copper is 6-7.5, and the pH for separating nickel is 8.1-10.

7. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step five, the roasting temperature is 700-750℃ and the roasting time is 60-70 minutes.

8. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step five, the immersion temperature is 85-90℃ and the immersion time is 80-90 minutes.

9. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step six, the flotation reagent is a mixture of sodium chloride, sodium cyanide, and lead oxide.

10. The method for recovering nickel, copper, molybdenum, and tungsten from rare earth tailings by gravity separation according to claim 1, characterized in that: In step seven, the evaporation temperature is 110-120℃ and the evaporation time is 30-40 minutes.

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