A method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation

Abstract

This invention belongs to the field of mineral processing technology, specifically disclosing a method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation. It replaces the traditional reagents used in laboratory-scale tests with a reagent combination of sodium carbonate, brine glass, and a lead nitrate-hydroxyvalerate complex. Combined with grinding, concentration, and de-removal pretreatment, this method achieves efficient recovery of scheelite and fluorite from scheelite rough concentrate under ambient temperature conditions. The recovered scheelite concentrate has a WO3 grade of over 32.95%, with an operational recovery rate of over 61.55%; the fluorite concentrate has a CaF2 grade of over 93.22%, with an operational recovery rate of over 51.25%. This method achieves comprehensive recovery and utilization of associated resources, eliminating the need for heating or acid leaching treatment and significantly reducing energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, and specifically discloses a method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation. Background Technology

[0002] Scheelite, along with fluorite and calcium carbonate, are all calcium-bearing minerals, and the three often occur together in skarn-type scheelite deposits. Because scheelite and fluorite have similar surface properties, both exhibiting high surface activity and floatability, they are difficult to separate effectively during flotation, posing a technical challenge in mineral processing.

[0003] Existing scheelite beneficiation processes mainly employ heated flotation to separate scheelite from gangue minerals. For example, the applicant's prior patent CN107790290B discloses a beneficiation method for recovering fluorite from scheelite rough concentrate. This process is typically carried out at 50℃ to 80℃, achieving separation of scheelite from gangue minerals such as fluorite by heating and destroying the reagent adsorption layer on the mineral surface. However, heated flotation has the following problems: firstly, it has high energy consumption, increasing production costs; secondly, it requires large equipment investment, necessitating a heating system; thirdly, the operating environment is harsh, which is detrimental to worker health; and fourthly, some ores are prone to mud formation under heating conditions, affecting beneficiation indicators.

[0004] In recent years, researchers have attempted to develop room temperature flotation processes, using highly selective inhibitors to separate scheelite and fluorite at room temperature. However, the WO3 grade of scheelite concentrate can only reach 20%–25%, with a recovery rate of less than 50%; the CaF2 grade of fluorite concentrate is also difficult to reach more than 90%, resulting in poor separation effect and low concentrate grade and recovery rate.

[0005] Therefore, developing a mineral processing technology that can efficiently separate scheelite and fluorite under ambient temperature conditions and obtain high-grade, high-recovery concentrates is of great significance for reducing energy consumption and improving resource utilization. Summary of the Invention

[0006] To address the problems in the background art, this invention discloses a method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation. This method achieves efficient recovery of scheelite and fluorite from scheelite rough concentrate under ambient temperature conditions. The process is simple, the reagent system is mild, no heating is required, and energy consumption is significantly reduced.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation specifically includes the following steps: Step (1): Grinding, concentration and de-removal. Take the scheelite rough concentrate and grind it to fully liberate the minerals. After grinding, remove the residual reagents from the slurry by mechanical stirring or natural sedimentation to obtain the de-removed slurry. Step (2): Room temperature scheelite flotation. The de-reagented slurry obtained in step (1) is fed into the roughing flotation cell. An adjuster is added to adjust the pH value of the slurry to 8-9. Then, inhibitors and collectors are added in sequence. Scheme roughing flotation is carried out at room temperature for 5-8 minutes. After thorough stirring, the bubbles are scraped off to obtain scheelite roughing concentrate and roughing tailings. Step (3): Scheelite Concentration. The rough concentrate obtained in Step (2) is sent to the concentrate operation for 7 rounds of concentrate. The middlings obtained in each round of concentrate are returned to the previous operation. The concentrate slurry obtained in each round of concentrate is sent to the next round of concentrate. The foam produced in the final round of concentrate is the final product, scheelite concentrate. Step (4): Scheme scavenging. The rough tailings obtained in step (2) are sent to the scavenging operation for 3 scavenging operations. The middlings obtained from each scavenging are returned to the previous operation in turn. The tailings from the third scavenging operation are sent to the subsequent fluorite re-selection process. Step (5): Fluorite re-selection. The scavenging tailings obtained in step (4) are slurried and then fed into the fluorite roughing flotation cell. An adjusting agent is added to adjust the pH value of the slurry to 8-9. Then, inhibitors, collectors and frothers are added in sequence. Fluorite roughing flotation is carried out at room temperature for 5-8 minutes. After thorough stirring, the bubbles are scraped off to obtain fluorite rough concentrate and roughing tailings. The fluorite rough concentrate is then fed into the cleaning operation for 3-5 cleaning cycles. The middlings obtained from each cleaning cycle are returned to the previous operation. The concentrate slurry obtained from each cleaning cycle is fed into the next cleaning process. The concentrate obtained from the last cleaning cycle is the fluorite concentrate. The roughing tailings are fed into the scavenging operation to recover the fluorite remaining in the tailings. The scavenging middlings are returned to the fluorite roughing process. The scavenging tailings are discharged as the final tailings.

[0008] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (3), the WO3 grade in the scheelite concentrate is not less than 32.95%, and the operating recovery rate is not less than 61.55%.

[0009] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (5), the CaF2 grade in the fluorite concentrate is not less than 93.22%, and the operating recovery rate is not less than 51.25%.

[0010] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, steps (2), (3), (4) and (5) are all carried out at ambient temperature, and the flotation temperature is controlled between 10℃ and 30℃.

[0011] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, the grinding fineness in step (1) is -0.074 mm particle size with a mass ratio of 70% to 80%.

[0012] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (2), the modifier is sodium carbonate, the amount of sodium carbonate is 2000-2500 g / ton, the inhibitor is salinized water glass, the amount of salinized water glass is 1500-2000 g / ton, and the collector is lead nitrate hydrovalerate complex, the amount of lead nitrate hydrovalerate complex is 1000-1500 g / ton.

[0013] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (3), sulphurized water glass and lead nitrate hydrovalerate complex are added to the first and second selection stages, respectively; sulphurized water glass is added to the third, fourth, and fifth selection stages, respectively; no reagents are added to the sixth and seventh selection stages; and the concentrate grade is further improved by stirring and skimming. The amounts of sulphurized water glass used in the first, second, third, fourth, and fifth selection stages are 1400–1600 g / ton, 700–800 g / ton, 500–600 g / ton, 300–400 g / ton, and 300–400 g / ton, respectively; and the amounts of lead nitrate hydrovalerate complex used in the first and second selection stages are 500–700 g / ton and 200–300 g / ton, respectively.

[0014] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (4), lead nitrate hydrovalerate complex is added to scavenging processes one, two, and three respectively, and the amounts of lead nitrate hydrovalerate complex used in scavenging processes one, two, and three are 600 g / ton, 400 g / ton, and 200 g / ton, respectively.

[0015] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (5), the modifier is sodium carbonate, the amount of sodium carbonate is 1000-2000 g / ton, the inhibitor is salinized water glass, the amount of salinized water glass is 500-1500 g / ton, the collector is oleic acid, the amount of oleic acid is 200-500 g / ton, and the frother is No. 2 oil, the amount of No. 2 oil is 20-40 g / ton.

[0016] Furthermore, in the method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, in step (5), 500-1000 g / ton of saline water glass is added during each refining process to enhance the inhibition of residual gangue, and 50-200 g / ton of oleic acid and No. 2 oil is added during the scavenging process.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a reagent combination of saline water glass and lead nitrate hydroxyvalerate to replace the traditional reagents in laboratory small-scale tests. Combined with grinding, concentration and de-drug pretreatment, it achieves efficient recovery of scheelite and fluorite from scheelite rough concentrate under normal temperature conditions, without the need for heating or acid leaching treatment, and significantly reduces energy consumption. 2. The present invention recovers scheelite concentrate with a WO3 grade of over 32.95% and an operating recovery rate of over 61.55%; and fluorite concentrate with a CaF2 grade of over 93.22% and an operating recovery rate of over 51.25%, thus realizing the comprehensive recovery and utilization of associated resources. 3. The process of this invention is simple, easy to operate and control, and easy to promote industrially. Attached Figure Description

[0018] Figure 1 This is a flowchart of the experimental process for recovering scheelite from scheelite rough concentrate by ambient temperature flotation according to the present invention; Figure 2 This is a flowchart of the experimental process for recovering fluorite from scavenging tailings in this invention. Detailed Implementation Example 1

[0019] In this embodiment, the experimental raw material was scheelite concentrate provided by Luoyang Molybdenum Group, which mainly contains minerals such as WO3, fluorite CaF2 and calcium carbonate. The grade of WO3 was 1.24%, the grade of CaF2 was 13.14%, and the grade of CaCO3 was 46.29%. Other reagents used in the experiment were commercially available.

[0020] A method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation specifically includes the following steps: Grinding, Concentration and Reagent Removal: The scheelite rough concentrate is ground to a fineness of -0.074mm with a mass ratio of 80%, so that the minerals are fully liberated. The slurry after grinding enters the concentration and reagent removal process. The mass concentration of the concentrated slurry is 40%. The residual reagents in the slurry are removed by mechanical stirring or natural sedimentation to obtain the reagent-removed slurry. Room temperature scheelite flotation: The de-reagented slurry is fed into the roughing flotation cell. Sodium carbonate is added as a modifier to adjust the pH of the slurry to 8. The amount of sodium carbonate is 2250 g / ton. Then, the inhibitor AlSBL (alkaline water glass) and the collector GYP (lead nitrate hydrovalerate complex) are added sequentially. The amount of alkaline water glass is 1875 g / ton and the amount of lead nitrate hydrovalerate complex is 1200 g / ton. Scheme roughing flotation is carried out at 30°C for 8 minutes. After thorough stirring, the bubbles are skimmed off to obtain scheelite roughing concentrate and roughing tailings. Scheelite Refinement: Under 30℃ conditions, the scheelite rougher concentrate obtained from room temperature scheelite flotation is subjected to seven refinement processes. Refinement Process 1 involves adding 1500 g / t of saline water glass and 600 g / t of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 6 minutes; Refinement Process 2 involves adding 750 g / t of saline water glass and 300 g / t of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 5 minutes; Refinement Process 3 involves adding 562.5 g / t of saline water glass, with a flotation time of approximately 5 minutes; Refinement Process 4 involves adding 375 g / t of saline water glass. 375 g / ton of saline water glass is added in the fifth stage of the process, with a flotation time of approximately 4 minutes. No reagents are added in the sixth and seventh stages; instead, stirring and skimming are used to further improve the concentrate grade. The middlings obtained from each stage are returned to the previous stage, and the concentrate slurry from each stage enters the next stage of the process. The foam produced in the final stage of the seventh stage is the final product, scheelite concentrate, with a WO3 grade of 32.95% and an operating recovery rate of 61.55%. Scheelite Scavenging: Under 30℃ conditions, the roughing tailings obtained from room temperature scheelite flotation are subjected to three scavenging operations. Scavenging 1 involves adding 600 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 6 minutes; Scavenging 2 involves adding 400 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 5 minutes; Scavenging 3 involves adding 200 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 4 minutes. The middlings obtained from each scavenging are returned to the previous operation sequentially. The tailings from Scavenging 3 are then used in the subsequent fluorite reprocessing. The fluorite CaF2 grade in the tailings is approximately 13.14%, the calcium carbonate content is approximately 46.29%, the WO3 grade in the tailings is 0.044%, and the WO3 loss rate is only 2.43%. Fluorite Re-concentration: The obtained scavenged tailings are slurry-adjusted and fed into the fluorite rougher flotation cell. Sodium carbonate is added to adjust the pH of the slurry to 8 (1800 g / ton). Then, depressant, collector, and frother are added sequentially. The depressant is brine glass (1000 g / ton), the collector is oleic acid (300 g / ton), and the frother is No. 2 oil (30 g / ton). Fluorite rougher flotation is carried out at 30°C for 8 minutes. After thorough stirring, the froth is skimmed off to obtain fluorite rough concentrate and rougher tailings. The fluorite rough concentrate then undergoes five stages of cleaning, progressively improving its quality. High-grade concentrate is produced by adding 800 g / t of saline water glass during each beneficiation process to enhance the inhibition of residual gangue. The middlings obtained from each beneficiation are returned to the previous operation, and the concentrate slurry obtained from each beneficiation enters the next beneficiation process. The concentrate obtained from the final beneficiation is the fluorite concentrate, with a CaF2 grade of 93.22% and an operation recovery rate of 51.25%. The roughing tailings enter the scavenging operation, where 100 g / t of oleic acid and No. 2 oil are added to recover the residual fluorite in the tailings. The scavenged middlings are returned to the fluorite roughing process, and the scavenged tailings are discharged as the final tailings, with a CaF2 grade of 1.82% and a recovery rate of 3.20%. Example 2

[0021] This embodiment uses scheelite rough concentrate from another mining area as raw material, with WO3 grade of 1.56% and CaF2 grade of 15.82%.

[0022] The specific operating steps are the same as in Example 1, except that the process parameters and reagent formulation are as follows: Grinding, Concentration, and Reagent Removal: The scheelite rough concentrate is ground to a fineness of -0.074mm particles with a mass ratio of 75%, which fully liberates the minerals. The slurry after grinding enters the concentration and reagent removal process. Through mechanical stirring and natural sedimentation, the residual reagents in the slurry are fully removed to obtain the reagent-removed slurry. If this reagent removal step is not carried out, the residual reagents will seriously interfere with the separation of scheelite and fluorite, resulting in a significant decrease in concentrate grade and recovery rate. Room temperature scheelite flotation: The de-reagented slurry is fed into the roughing flotation cell. Sodium carbonate is added as a modifier to adjust the pH of the slurry to 8. The amount of sodium carbonate is 2000 g / ton. Then, the inhibitor AlSBL (alkaline water glass) and the collector GYP (lead nitrate hydrovalerate complex) are added in sequence. The amount of alkaline water glass is 1550 g / ton and the amount of lead nitrate hydrovalerate complex is 1000 g / ton. Scheme roughing flotation is carried out at 30℃ for 5 minutes. After thorough stirring, the bubbles are skimmed off to obtain scheelite roughing concentrate and roughing tailings. Scheelite Refinement: Under 30℃ conditions, the scheelite rougher concentrate obtained from room temperature scheelite flotation is subjected to seven refinement processes. Refinement Process 1 involves adding 1400 g / ton of saline water glass and 500 g / ton of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 4 minutes; Refinement Process 2 involves adding 700 g / ton of saline water glass and 220 g / ton of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 4 minutes; Refinement Process 3 involves adding 500 g / ton of saline water glass, with a flotation time of approximately 3 minutes; Refinement Process 4 involves adding 300 g / ton of saline water glass... The flotation time is approximately 3 minutes for each ton of saline water glass. In the fifth stage, 300 grams of saline water glass are added, and the flotation time is approximately 3 minutes. In the sixth and seventh stages, no reagents are added; the concentrate grade is further improved through stirring and skimming. The middlings obtained from each stage are returned to the previous stage, and the concentrate slurry from each stage enters the next stage of the process. The foam produced in the final stage (stage 7) is the final product, scheelite concentrate, with a WO3 grade of 33.21% and an operating recovery rate of 62.34%. Scheelite scavenging: Under 30℃ conditions, the roughing tailings obtained from room temperature scheelite flotation are subjected to scavenging operations for three scavenging processes. In scavenging process one, 600 g / t of lead nitrate hydrovalerate complex is added, and the scavenging time is about 4 minutes. In scavenging process two, 400 g / t of lead nitrate hydrovalerate complex is added, and the scavenging time is about 4 minutes. In scavenging process three, 200 g / t of lead nitrate hydrovalerate complex is added, and the scavenging time is about 3 minutes. The middlings obtained from each scavenging process are returned to the previous operation in sequence, and the tailings from scavenging process three are used in the subsequent fluorite reprocessing. Fluorite Re-concentration: The obtained scavenged tailings are slurry-adjusted and then fed into the fluorite rougher flotation cell. Sodium carbonate is added to adjust the pH of the slurry to 8 (1100 g / ton). Subsequently, depressant, collector, and frother are added sequentially. The depressant is brine glass (500 g / ton), the collector is oleic acid (200 g / ton), and the frother is No. 2 oil (20 g / ton). Fluorite rougher flotation is carried out at 30°C for 5 minutes. After thorough stirring, the froth is skimmed off to obtain fluorite rough concentrate and rougher tailings. The fluorite rough concentrate then undergoes five stages of cleaning, progressively improving its quality. High-grade concentrate is produced by adding 500 g / ton of saline water glass during each beneficiation process to enhance the inhibition of residual gangue. The middlings obtained from each beneficiation are returned to the previous operation, and the concentrate slurry obtained from each beneficiation enters the next beneficiation process. The concentrate obtained from the final beneficiation is the fluorite concentrate, with a CaF2 grade of 93.85% and an operation recovery rate of 52.17%. The roughing tailings enter the scavenging operation, where 50 g / ton of oleic acid and No. 2 oil are added to recover the residual fluorite in the tailings. The scavenged middlings are returned to the fluorite roughing process, and the scavenged tailings are discharged as the final tailings, with a CaF2 grade of 1.82% and a recovery rate of 3.20%. Example 3

[0023] This embodiment uses the same raw materials as in Example 1, with WO3 grade 1.24% and CaF2 grade 13.14%. The difference is that the scheelite flotation and fluorite flotation processes are both carried out at a low temperature of 15°C to verify the adaptability of the process of this invention in a lower ambient temperature environment.

[0024] Grinding, thickening, and de-removal: The scheelite rough concentrate is ground to a fineness of -0.074mm with a mass ratio of 80%, which fully liberates the minerals. The slurry after grinding enters the thickening and de-removal process. It is then thickened and de-removed in a thickener. The slurry mass concentration after thickening is 40%. The residual reagents in the slurry are removed by mechanical stirring or natural sedimentation to obtain the de-removed slurry. Room temperature scheelite flotation: The de-reagented slurry is fed into the roughing flotation cell. Sodium carbonate is added as a modifier to adjust the pH of the slurry to 9. The amount of sodium carbonate is 2500 g / ton. Then, the inhibitor AlSBL (alkaline water glass) and the collector GYP (lead nitrate hydrovalerate complex) are added sequentially. The amount of alkaline water glass is 2000 g / ton and the amount of lead nitrate hydrovalerate complex is 1500 g / ton. Scheme roughing flotation is carried out at 15℃ for 8 minutes. After thorough stirring, the bubbles are skimmed off to obtain scheelite roughing concentrate and roughing tailings. Scheelite Refinement: Under 15℃ conditions, the scheelite rougher concentrate obtained from room temperature scheelite flotation is subjected to seven refinement processes. Refinement Process 1 involves adding 1600 g / ton of saline water glass and 700 g / ton of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 4 minutes; Refinement Process 2 involves adding 800 g / ton of saline water glass and 300 g / ton of lead nitrate-hydroxyvalerate complex, with a flotation time of approximately 5 minutes; Refinement Process 3 involves adding 600 g / ton of saline water glass, with a flotation time of approximately 5 minutes; Refinement Process 4 involves adding 400 g / ton of saline water glass. The flotation time is approximately 4 minutes for each ton of saline water glass added; in the fifth stage, 400 grams of saline water glass are added, and the flotation time is approximately 4 minutes; in the sixth and seventh stages, no reagents are added, and the concentrate grade is further improved by stirring and skimming. The middlings obtained from each stage are returned to the previous operation, and the concentrate slurry obtained from each stage enters the next stage of the purification process. Finally, the foam produced in the seventh stage is the final product, scheelite concentrate, with a WO3 grade of 32.18% and an operation recovery rate of 60.22%. Scheelite Scavenging: Under 15℃ conditions, the rougher tailings obtained from room temperature scheelite flotation are subjected to three scavenging operations. Scavenging 1 involves adding 600 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 6 minutes; Scavenging 2 involves adding 400 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 5 minutes; Scavenging 3 involves adding 200 g / t of lead nitrate hydrovalerate complex and scavenging for approximately 4 minutes. The middlings obtained from each scavenging are returned to the previous operation sequentially. The tailings from Scavenging 3 are then used in the subsequent fluorite reprocessing. The fluorite CaF2 grade in the tailings is approximately 13.14%, the calcium carbonate content is approximately 46.29%, the WO3 grade in the tailings is 0.044%, and the WO3 loss rate is only 2.43%. Fluorite reprocessing: The obtained scavenged tailings are slurry-adjusted and then fed into the fluorite roughing flotation cell. Sodium carbonate is added to adjust the pH of the slurry to 9 (2000 g / ton). Subsequently, depressant, collector, and frother are added sequentially. The depressant is brine glass (1500 g / ton), the collector is oleic acid (500 g / ton), and the frother is No. 2 oil (40 g / ton). Fluorite roughing flotation is carried out at 15°C for 5-8 minutes. After thorough stirring, the froth is skimmed off to obtain fluorite rough concentrate and roughing tailings. The fluorite rough concentrate is then fed into… The fine-graining process involves five rounds of fine-graining to progressively improve the concentrate grade. During each fine-graining process, 1000 g / ton of saline water glass is added to enhance the inhibition of residual gangue. The middlings obtained from each fine-graining process are returned to the previous process. The concentrate slurry obtained from each fine-graining process enters the next fine-graining process. The concentrate obtained from the final fine-graining process is the fluorite concentrate, with a CaF2 grade of 92.56% and an operation recovery rate of 50.38%. The roughing tailings enter the scavenging process. During the scavenging process, 180 g / ton of oleic acid and No. 2 oil are added to recover residual fluorite in the tailings. The scavenged middlings are returned to the fluorite roughing process, and the scavenged tailings are discharged as the final tailings.

[0025] The results of Example 1 show that by using a reagent combination of saline water glass and lead nitrate hydroxyvalerate complex to replace the traditional reagents in the laboratory pilot test, and combined with grinding, concentration and de-removal pretreatment, the WO3 grade of tungsten concentrate reached 32.95% and the CaF2 grade of fluorite concentrate reached 93.22% under normal temperature conditions, verifying the feasibility of the reagent system of the present invention.

[0026] The results of Example 2 show that the reagent combination of saline water glass and lead nitrate hydrovalerate, combined with grinding, concentration and de-reagent pretreatment, has good adaptability to scheelite rough concentrate from different sources and the separation index is stable.

[0027] The results of Example 3 show that the present invention can still maintain good beneficiation indicators under the relatively low ambient temperature of 15℃, with the WO3 grade of scheelite concentrate maintained above 32% and the CaF2 grade of fluorite concentrate maintained above 92%.

[0028] The results of Examples 1-3 demonstrate that the reagent system using the salt-treated water glass and lead nitrate hydroxyvalerate complex exhibits excellent separation selectivity and adaptability over a wide temperature range of 10℃ to 30℃, with broad process temperature adaptability, significantly superior to traditional flotation processes that require heating to above 50℃.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation, characterized in that, Specifically, the following steps are included: Step (1): Grinding, concentration and de-removal. Take the scheelite rough concentrate and grind it to fully liberate the minerals. After grinding, remove the residual reagents from the slurry by mechanical stirring or natural sedimentation to obtain the de-removed slurry. Step (2): Room temperature scheelite flotation. The de-reagented slurry obtained in step (1) is fed into the roughing flotation cell. An adjuster is added to adjust the pH value of the slurry to 8-9. Then, inhibitors and collectors are added in sequence. Scheme roughing flotation is carried out at room temperature for 5-8 minutes. After thorough stirring, the bubbles are scraped off to obtain scheelite roughing concentrate and roughing tailings. Step (3): Scheelite Concentration. The rough concentrate obtained in Step (2) is sent to the concentrate operation for 7 rounds of concentrate. The middlings obtained in each round of concentrate are returned to the previous operation. The concentrate slurry obtained in each round of concentrate is sent to the next round of concentrate. The foam produced in the final round of concentrate is the final product, scheelite concentrate. Step (4): Scheme scavenging. The rough tailings obtained in step (2) are sent to the scavenging operation for 3 scavenging operations. The middlings obtained from each scavenging are returned to the previous operation in turn. The tailings from the third scavenging operation are sent to the subsequent fluorite re-selection process. Step (5): Fluorite re-selection. The scavenging tailings obtained in step (4) are slurried and then fed into the fluorite roughing flotation cell. An adjusting agent is added to adjust the pH value of the slurry to 8-9. Then, inhibitors, collectors and frothers are added in sequence. Fluorite roughing flotation is carried out at room temperature for 5-8 minutes. After thorough stirring, the bubbles are scraped off to obtain fluorite rough concentrate and roughing tailings. The fluorite rough concentrate is then fed into the cleaning operation for 3-5 cleaning cycles. The middlings obtained from each cleaning cycle are returned to the previous operation. The concentrate slurry obtained from each cleaning cycle is fed into the next cleaning process. The concentrate obtained from the last cleaning cycle is the fluorite concentrate. The roughing tailings are fed into the scavenging operation to recover the fluorite remaining in the tailings. The scavenging middlings are returned to the fluorite roughing process. The scavenging tailings are discharged as the final tailings.

2. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (3), the WO3 grade in the scheelite concentrate is not less than 32.95%, and the recovery rate is not less than 61.55%.

3. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (5), the CaF2 grade in the fluorite concentrate shall not be less than 93.22%, and the recovery rate shall not be less than 51.25%.

4. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, Steps (2), (3), (4) and (5) are all carried out at room temperature, and the flotation temperature is controlled between 10℃ and 30℃.

5. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (1), the grinding fineness is -0.074 mm and the mass ratio of the particles is 70% to 80%.

6. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (2), the modifier is sodium carbonate, and the amount of sodium carbonate used is 2000-2500 g / ton. The inhibitor is salinized water glass, and the amount of salinized water glass used is 1500-2000 g / ton. The collector is lead nitrate hydrovalerate complex, and the amount of lead nitrate hydrovalerate complex used is 1000-1500 g / ton.

7. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (3), chlorinated water glass and lead nitrate hydrovalerate complex are added to Selected 1 and Selected 2 respectively, chlorinated water glass is added to Selected 3, Selected 4 and Selected 5 respectively, and no reagents are added to Selected 6 and Selected 7. The concentrate grade is further improved by stirring and skimming. The amount of chlorinated water glass used in Selected 1, Selected 2, Selected 3, Selected 4 and Selected 5 is 1400-1600 g / ton, 700-800 g / ton, 500-600 g / ton, 300-400 g / ton and 300-400 g / ton respectively. The amount of lead nitrate hydrovalerate complex used in Selected 1 and Selected 2 is 500-700 g / ton and 200-300 g / ton respectively.

8. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (4), lead nitrate hydrovalerate complex is added to scavenging processes one, two, and three respectively. The amounts of lead nitrate hydrovalerate complex added to scavenging processes one, two, and three are 600 g / ton, 400 g / ton, and 200 g / ton, respectively.

9. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (5), the modifier is sodium carbonate, and the amount of sodium carbonate is 1000-2000 g / ton; the inhibitor is saline water glass, and the amount of saline water glass is 500-1500 g / ton; the collector is oleic acid, and the amount of oleic acid is 200-500 g / ton; and the foaming agent is No. 2 oil, and the amount of No. 2 oil is 20-40 g / ton.

10. The method for recovering scheelite and fluorite from scheelite rough concentrate by ambient temperature flotation according to claim 1, characterized in that, In step (5), 500-1000 g / ton of saline water glass is added during each selection process to enhance the inhibition of residual gangue. 50-200 g / ton of oleic acid and No. 2 oil are added during the scavenging process.

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