Efficient Utilization Method of Fine-grained Refractory Weathered Scheelite

Abstract

The present invention provides a method for efficiently utilizing fine-grained, refractory weathered scheelite. The method comprises the following steps: first, crushing and wet-grinding the ore particles to be processed, and then adding water and stirring to obtain a slurry of a preset concentration; then passing the slurry through a high-gradient magnetic separator to remove some gangue, thereby obtaining a coarse magnetic concentrate and a magnetic tailings; then, concentrating the magnetic tailings, first pumping them into a first-stage stirring barrel, adding a dispersing agent and stirring them, then pumping them into a second-stage stirring barrel, adding a coagulant and stirring them; then pumping them into a third-stage stirring barrel, adding a first preset agent and performing a primary flotation to obtain a first concentrate and a first tailings; then, pumping the first concentrate into a fourth-stage stirring barrel, adding activated carbon and stirring them, and then adding a second preset agent and performing a secondary flotation to obtain a scheelite concentrate and a second tailings. The present invention obtains a high-grade, high-recovery scheelite concentrate through a magnetic separation-flotation process, utilizing the coagulant effect of the coagulant, the synergistic effect of the inhibitor, and the efficient capture of modified fatty acid CK.

Description

Technical Field

[0001] The present invention relates to the technical field of scheelite beneficiation, and in particular to a method for efficiently utilizing fine-grained, refractory weathered scheelite. Background Art

[0002] With the continuous development and consumption of mineral resources, the availability of rich and easily processed ores is dwindling. The challenge is to efficiently and economically utilize low-grade, finely distributed, and complex ores. Tungsten is a key resource in my country, with reserves accounting for 68% of the world's total, ranking first. However, with my country's rapid economic development, easily processed tungsten ore (wolframite, which is easily enriched by gravity separation) has been nearly depleted. In stark contrast to the overexploitation of easily processed resources, my country's abundant, complex, and difficult-to-process tungsten resources (fine-grained skarn-type scheelite) remain largely underutilized.

[0003] Scheelite is brittle and prone to over-crushing, and large particles can easily become fine particles (-20μm), making its development difficult. The main reasons for the difficulty in flotation of fine scheelite are: (1) the small mass and high specific surface energy of fine scheelite, the low probability of effective collision between scheelite and collector, resulting in slow flotation rate; (2) fine gangue easily adheres to flotation bubbles, resulting in serious flotation inclusions, low flotation concentrate grade, and difficulty in enrichment; (3) fine minerals inevitably produce more ions in the slurry, affecting the floatability of some minerals.

[0004] Currently, scheelite beneficiation primarily involves high-concentration pulp shear flocculation and agitation, or the traditional fatty acid method, which involves prolonged interaction between flotation reagents and the scheelite to capture fine-grained weathered scheelite. However, the WO3 grade of the scheelite concentrate obtained by these two methods generally ranges from 5% to 15%, with a WO3 recovery rate of 10% to 30%. Both these low grades and recoveries result in a significant waste of scheelite resources. Furthermore, low-grade scheelite concentrates are difficult to generate economic benefits. Consequently, a significant amount of weathered scheelite in my country remains untapped and unutilized.

[0005] In view of this, it is necessary to design an improved method for efficiently utilizing fine-grained refractory weathered scheelite to solve the above problems. Summary of the Invention

[0006] The object of the present invention is to provide a method for efficiently utilizing fine-grained, difficult-to-select, weathered scheelite. Through a magnetic separation-flotation process, a coagulant is first used to aggregate small particles of scheelite through a "bridging" effect to form large and dense particles. Subsequently, a flotation operation is performed. The synergistic effect of water glass and a composite inhibitor CF, as well as the synergistic effect of various substances in the composite inhibitor CF, is utilized to effectively inhibit muddy gangue. At the same time, a modified fatty acid CK is selected as a collector to reduce the entrainment and flotation of fine mud during the collection process. Through two consecutive flotation processes, a high-grade, high-recovery scheelite concentrate is obtained.

[0007] To achieve the above-mentioned object of the invention, the present invention provides a method for efficiently utilizing fine-grained refractory weathered scheelite, comprising the following steps:

[0008] S1. crushing the ore particles to a particle size of less than 2 mm to obtain ore powder, then wet-grinding the ore powder to obtain a first slurry, and then adding water to the first slurry and stirring to obtain a slurry of a predetermined concentration; more than 80% of the ore particles to be processed have a particle size of less than 20 μm;

[0009] S2. The slurry to be processed in step S1 is subjected to magnetic separation by a high gradient magnetic separator to remove part of the gangue to obtain a magnetically separated coarse concentrate and magnetically separated tailings;

[0010] S3. The magnetic tailings of step S2 are concentrated to a pulp mass concentration of 30%-35%, and then pumped into a first-level stirring barrel, a dispersant is added, and stirred for a preset time; then pumped into a second-level stirring barrel, a coagulant is added, and stirred for a preset time; then pumped into a third-level stirring barrel, a first preset reagent is added, and a flotation is performed once to obtain a first concentrate and a first tailing; the first preset reagent includes an inhibitor and a collector; the inhibitor includes water glass and a composite inhibitor CF, and the composite inhibitor CF is obtained by compounding xanthan gum, dextrin, starch, and aluminum sulfate;

[0011] S4. The first concentrate of step S3 is pumped into a four-stage stirring tank, activated carbon is added and stirred for 5-10 minutes at a stirring speed of 500-700 r / min, and then a second preset reagent is added for secondary flotation to obtain scheelite concentrate and second tailings.

[0012] As a further improvement of the present invention, the mass ratio of xanthan gum, dextrin, starch and aluminum sulfate in the composite inhibitory CF is (0.5-1.5):(1.5-2.5):(1.5-2.5):(1.5-2.5).

[0013] As a further improvement of the present invention, in step S3, the coagulant aid is 1000-3000 g / t of lime, stirred for 5-10 minutes, and the stirring speed is 100-300 r / min; the dispersing agent is 1000-3000 g / t of sodium carbonate and 200-400 g / t of sodium hexametaphosphate, stirred for 5-10 minutes, and the stirring speed is 100-300 r / min.

[0014] As a further improvement of the present invention, the collector is a modified fatty acid CK; the modified fatty acid CK is obtained by reacting tall oil with concentrated sulfuric acid in a mass ratio of 4-6:1 in a reactor at 20-30°C for 0.5-1.5h, and then adjusting the pH to 7.5-8.5 with 30wt%-50wt% sodium hydroxide solution.

[0015] As a further improvement of the present invention, in the first ore pulp of step S1, the mineral powder with a particle size less than 0.074 mm accounts for 80%-85% of the mass of the ore particles to be processed; and the mass concentration of the ore pulp to be processed is 20%-25%.

[0016] As a further improvement of the present invention, in step S2, the magnetic field strength of the high gradient magnetic separator is 10000-12000 GS.

[0017] As a further improvement of the present invention, in step S3, the first flotation includes a roughing separation, a cleaning separation and a scavenging separation, and finally the first concentrate and the first tailings are obtained.

[0018] As a further improvement of the present invention, the first preset reagent includes: 500-1500g / t of composite inhibitor CF, 2000-4000g / t of water glass and 500-1500g / t of modified fatty acid CK as roughing reagent, stirring for 30-40min, and the stirring speed is 100-300r / min; 300-500g / t of modified fatty acid CK as scavenging reagent, stirring for 30-40min, and the stirring speed is 100-300r / min.

[0019] As a further improvement of the present invention, in step S4, the secondary flotation includes one fine roughing separation, four fine cleaning separations and one fine scavenging separation, and finally the scheelite concentrate and the second tailings are obtained.

[0020] As a further improvement of the present invention, the second preset reagents include: 100-300g / t of sodium hydroxide, 3000-5000g / t of water glass and 200-400g / t of composite inhibitor CF as fine and rough selection reagents; 500-1500g / t of water glass and 300-600g / t of composite inhibitor CF as the first selection reagent, 100-200g / t of water glass and 100-200g / t of composite inhibitor CF as the second, third and fourth selection reagents; 50-150g / t of modified fatty acid CK as the fine sweeping reagent.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention provides a method for efficiently utilizing fine-grained, difficult-to-select, weathered scheelite, which combines magnetic separation with flotation. Magnetic separation is performed before flotation to remove magnetic gangue minerals such as limonite, hematite, magnetite, and garnet, thereby reducing the interference of these gangue minerals with the subsequent flotation of the scheelite.

[0023] Then, a dispersant is added to disperse the small particles evenly, and a coagulant is added to aggregate the small particles of scheelite through a "bridging" effect to form large and dense particles, thereby increasing the collision probability between the scheelite and the collector.

[0024] The flotation process then proceeds. By adding the traditional depressant water glass and the self-made composite depressant CF, the synergistic effects of the water glass, the composite depressant CF, and the various components within the composite depressant CF achieve highly selective suppression of silicates, carbonates, and other minerals, effectively inhibiting argillaceous gangue. Furthermore, a modified fatty acid CK is used as a collector. Modified tall oil increases selectivity compared to fatty acids, brittles and ruptures the flotation foam, reducing the carryover of fine mud during the collection process. The resulting scheelite concentrate is of higher grade than that obtained with a traditional fatty acid collector.

[0025] Furthermore, the present invention realizes efficient recovery of scheelite through two consecutive flotation processes.

[0026] (2) The method for efficiently utilizing fine-grained refractory weathered scheelite provided by the present invention realizes efficient recovery of scheelite, improves the grade and recovery rate of scheelite, can achieve economic benefits, effectively avoids waste of resources, and provides a new idea for the mining of refractory scheelite. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a process flow chart of the method for efficiently utilizing fine-grained refractory weathered scheelite according to the present invention. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] It should also be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0030] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0031] See also Figure 1 As shown, the present invention provides a method for efficiently utilizing fine-grained refractory weathered scheelite, comprising the following steps:

[0032] S1. Pulping:

[0033] The ore particles to be processed are crushed to a particle size of less than 2mm to obtain ore powder. The ore powder is then wet-milled to obtain a first slurry. Water is then added to the first slurry and stirred to obtain a slurry with a mass concentration of 20%-25%. More than 80% of the ore particles to be processed have a particle size of less than 20μm.

[0034] In the first ore pulp, the mineral powder with a particle size of less than 0.074mm accounts for 80%-85% of the mass of the ore particles to be processed; controlling the mineral powder in the ore pulp to be processed to a certain fineness is more conducive to separating and purifying the various substances in the mineral powder and improving the recovery rate.

[0035] S2. Magnetic separation:

[0036] The ore pulp obtained in step S1 is subjected to magnetic separation in a high-gradient magnetic separator to remove some gangue, thereby obtaining a magnetically separated coarse concentrate and magnetically separated tailings. The magnetically separated coarse concentrate consists of magnetic gangue minerals such as limonite, hematite, magnetite, and garnet. These easily argillized gangue minerals are discarded through magnetic separation, thereby reducing their interference with subsequent scheelite flotation.

[0037] Among them, the magnetic field strength of the high gradient magnetic separator is 10000-12000GS.

[0038] S3. Multi-stage stirring and primary flotation:

[0039] The magnetic tailings obtained in step S2 are concentrated to a pulp mass concentration of 30%-35% and then pumped into a primary mixing tank. Dispersants (1000-3000g / t sodium carbonate and 200-400g / t sodium hexametaphosphate) are added and stirred for 5-10 minutes at a speed of 100-300r / min. The addition of the dispersant disperses the particles in the magnetic tailings as much as possible, facilitating the flotation of the scheelite.

[0040] The slurry, containing a dispersant, is then pumped from the primary mixing tank into the secondary mixing tank. Lime, a coagulant aid, is added at a rate of 1,000-3,000 g / t and stirred for 5-10 minutes at a speed of 100-300 rpm. Due to the fine particle size of weathered scheelite, the addition of lime as a coagulant aid can aggregate these fine particles through a "bridging" effect, forming large, dense particles. This increases the probability of collision between the scheelite and the collector, effectively capturing the scheelite and improving its recovery rate. Furthermore, after adding the lime, stirring is performed at a medium-to-low speed to prevent strong stirring from disrupting the lime's "bridging" effect, allowing the "enlarged" scheelite agglomerates to resolve.

[0041] The slurry, containing the reagents added to the secondary mixing tank, is then pumped into the tertiary mixing tank, where the first pre-set reagent is added for flotation to produce the first concentrate and the first tailings. The first pre-set reagent includes an inhibitor and a collector; specifically, the inhibitor includes water glass and a composite inhibitor CF. The composite inhibitor CF is a mixture of xanthan gum, dextrin, starch, and aluminum sulfate in a mass ratio of (0.5-1.5):(1.5-2.5):(1.5-2.5):(1.5-2.5). The composite inhibitor CF can better selectively inhibit silicates, carbonates, and other minerals, thereby effectively suppressing muddy gangue.

[0042] The collector is modified fatty acid CK. Modified fatty acid CK is prepared by reacting tall oil with concentrated sulfuric acid in a 4-6:1 mass ratio in a reactor at 20-30°C for 0.5-1.5 hours, then adjusting the pH to 7.5-8.5 with 30-50 wt% sodium hydroxide solution. This modified tall oil collector exhibits higher selectivity than unmodified conventional fatty acids. It also makes the flotation foam brittle and easily breakable, reducing the carryover of fine mud. The resulting scheelite concentrate is higher grade than that obtained with conventional fatty acid collectors.

[0043] The first preset reagents include: 500-1500g / t of composite inhibitor CF as a roughing agent, 2000-4000g / t of water glass and 500-1500g / t of modified fatty acid CK, stirring for 30-40min at a stirring speed of 100-300r / min; 300-500g / t of modified fatty acid CK as a scavenging agent, stirring for 30-40min at a stirring speed of 100-300r / min.

[0044] A flotation process includes a roughing process, a cleaning process, and a scavenging process, ultimately obtaining the first concentrate and the first tailings. Specifically, it includes the following steps:

[0045] S31. The slurry in the three-stage mixing barrel is subjected to roughing of scheelite concentrate to obtain roughing concentrate and roughing tailings of scheelite;

[0046] S32. The scheelite rougher concentrate obtained in step S31 is subjected to a blank selection to obtain a first concentrate and scheelite concentrate tailings; wherein the scheelite concentrate tailings are returned to the scheelite concentrate roughing step of step S31;

[0047] S33. The scheelite rougher tailings obtained in step S31 are subjected to a scavenging process to obtain a scheelite scavenging concentrate and a first tailing; wherein the scheelite scavenging concentrate is returned to the scheelite concentrate roughing process in step S31, and the first tailing is directly discarded.

[0048] S4. Secondary flotation

[0049] The first concentrate obtained in step S32 is pumped into a four-stage mixing tank. 300-400g / t of activated carbon is added and stirred for 5-10 minutes at a stirring speed of 500-700r / min. The activated carbon adsorbs the reagent on the surface of the first concentrate, thereby removing the reagent. A second predetermined reagent is then added for secondary flotation to obtain scheelite concentrate and a second tailings.

[0050] The second preset reagents include: 100-300g / t of sodium hydroxide, 3000-5000g / t of water glass and 400-600g / t of composite inhibitor CF as roughing reagents, stirring for 30-40min at a stirring speed of 100-300r / min; 500-1500g / t of water glass and 200-400g / t of composite inhibitor CF as the first cleaning reagent, stirring for 30-40min at a stirring speed of 100-300r / min; 100-200g / t of water glass and 100-200g / t of composite inhibitor CF as the second, third and fourth cleaning reagents, stirring for 30-40min at a stirring speed of 100-300r / min; 50-150g / t of modified fatty acid CK as a scavenging reagent, stirring for 30-40min at a stirring speed of 100-300r / min.

[0051] Secondary flotation includes one roughing separation, four cleaning separations and one scavenging separation, ultimately obtaining scheelite concentrate and secondary tailings. Specifically, it includes the following steps:

[0052] S41. The slurry in the four-stage mixing barrel is subjected to scheelite concentrate roughing to obtain scheelite roughing concentrate and scheelite roughing tailings;

[0053] S42. The scheelite rougher concentrate obtained in step S41 is subjected to a first beneficiation to obtain a first scheelite concentrate and a first scheelite tailing; wherein the first scheelite tailing is returned to the scheelite concentrate rougher step of step S41;

[0054] S43. The first scheelite concentrate obtained in step S42 is subjected to a second concentration to obtain a second scheelite concentrate and a second scheelite tailing; wherein the second scheelite tailing is returned to the first concentration step of step S42;

[0055] S44. The second scheelite concentrate obtained in step S43 is subjected to a third concentration to obtain a third scheelite concentrate and a third scheelite tailings; wherein the third scheelite tailings are returned to the second concentration step of step S43;

[0056] S45. The third scheelite concentrate obtained in step S44 is subjected to a fourth concentration to obtain a scheelite concentrate and a fourth scheelite tailing; wherein the fourth scheelite tailing is returned to the third concentration step of step S44;

[0057] S46. The scheelite rougher tailings obtained in step S41 are subjected to a scavenging process to obtain a first scheelite scavenging concentrate and a second scheelite tailings; wherein the first scheelite scavenging concentrate is returned to the scheelite rougher step of step S41; the second tailings are directly discarded.

[0058] When the WO3 content of the original ore is 0.9%, the present invention can obtain scheelite concentrate containing WO3 of 28.25%, and the recovery rate is 55.60%. The entire mineral processing process is low in cost and has obvious economic benefits.

[0059] The present invention will be described below by means of specific embodiments:

[0060] Example 1

[0061] In terms of mass percentage, the WO3 content in the ore particles to be processed used in this embodiment is 0.90%.

[0062] A method for efficiently utilizing fine-grained refractory weathered scheelite comprises the following steps:

[0063] S1. Pulping:

[0064] The ore particles to be processed are crushed to a particle size of less than 2 mm to obtain ore powder to be processed, and then the ore powder to be processed is wet-ground to obtain a first ore pulp, and then water is added to the first ore pulp and stirred to obtain an ore pulp to be processed with a mass concentration of 23%.

[0065] In the first slurry, the mineral powder with a particle size of less than 0.074 mm accounts for 83% of the mass of the ore particles to be processed.

[0066] S2. Magnetic separation:

[0067] The slurry obtained in step S1 is subjected to magnetic separation in a high gradient magnetic separator to remove part of the gangue, thereby obtaining a magnetically separated coarse concentrate and magnetically separated tailings. The magnetic field strength of the high gradient magnetic separator is 11000 GS.

[0068] S3. Multi-stage stirring and primary flotation:

[0069] The magnetically separated tailings obtained in step S2 are concentrated to a pulp mass concentration of 33% and then pumped into a primary mixing tank. Dispersants (2000 g / t sodium carbonate and 300 g / t sodium hexametaphosphate) are added, and stirred for 8 minutes at a stirring speed of 200 r / min. Next, a coagulant (2000 g / t lime) is added, and stirred for 8 minutes at a stirring speed of 200 r / min. Finally, a first pre-set reagent is added for a primary flotation, yielding a first concentrate and a first tailing.

[0070] The first preset agent includes an inhibitor and a collector; specifically, the inhibitor includes water glass and a composite inhibitor CF, and the composite inhibitor CF is prepared by compounding xanthan gum, dextrin, starch, and aluminum sulfate in a mass ratio of 1:2:2:2; the collector is a modified fatty acid CK, and the modified fatty acid CK is obtained by reacting tall oil with a mass ratio of 5:1 with concentrated sulfuric acid in a reactor at 25°C for 1 hour, and then adjusting the pH to 8 with a 40wt% sodium hydroxide solution.

[0071] A flotation process includes a roughing process, a cleaning process, and a scavenging process, ultimately obtaining the first concentrate and the first tailings. Specifically, it includes the following steps:

[0072] S31. Add 1000g / t of composite inhibitor CF, 3000g / t of water glass and 1000g / t of modified fatty acid CK to the slurry in the three-stage mixing barrel, stir for 35min at a stirring speed of 200r / min, and perform roughing of scheelite concentrate to obtain rougher scheelite concentrate and rougher scheelite tailings;

[0073] S32. The scheelite rougher concentrate obtained in step S31 is subjected to a blank selection to obtain a first concentrate and scheelite concentrate tailings; wherein the scheelite concentrate tailings are returned to the scheelite concentrate roughing step of step S31;

[0074] S33. Add 400 g / t modified fatty acid CK to the scheelite roughing tailings obtained in step S31, stir for 35 minutes at a stirring speed of 200 r / min, and perform a scavenging to obtain a scheelite scavenging concentrate and a first tailing; wherein the scheelite scavenging concentrate is returned to the scheelite concentrate roughing step of step S31, and the first tailing is directly discarded.

[0075] S4. Secondary flotation

[0076] The first concentrate obtained in step S32 is pumped into a four-stage mixing tank, where 350g / t activated carbon is added and stirred for 8 minutes at a stirring speed of 600r / min to remove the reagents on the surface of the ore particles. A second predetermined reagent is then added for secondary flotation to obtain scheelite concentrate and a second tailing.

[0077] Secondary flotation includes one roughing separation, four cleaning separations and one scavenging separation, ultimately obtaining scheelite concentrate and secondary tailings. Specifically, it includes the following steps:

[0078] S41. Add 200g / t of sodium hydroxide, 4000g / t of water glass and 500g / t of composite inhibitor CF to the four-stage mixing barrel and stir for 35min at a stirring speed of 200r / min to perform roughing of scheelite concentrate to obtain roughing concentrate and roughing tailings of scheelite concentrate;

[0079] S42. Add 1000 g / t of water glass and 300 g / t of a composite depressant CF to the scheelite rougher concentrate obtained in step S41 and stir for 35 min at a stirring speed of 200 r / min to perform a first concentration to obtain a first scheelite concentrate and a first scheelite tailing; wherein the first scheelite tailing is returned to the scheelite concentrate rougher concentration step of step S41;

[0080] S43. Add 150 g / t of water glass and 150 g / t of composite depressant CF to the first scheelite concentrate obtained in step S42 and stir for 35 min at a stirring speed of 200 r / min for a second concentration to obtain a second scheelite concentrate and a second scheelite tailing; wherein the second scheelite tailing is returned to the first concentration step of step S42;

[0081] S44. Add 150 g / t of water glass and 150 g / t of composite inhibitor CF to the second scheelite concentrate obtained in step S43 and stir for 35 min at a stirring speed of 200 r / min for a third concentration to obtain a third scheelite concentrate and a third scheelite tailing; wherein the third scheelite tailing is returned to the second concentration step of step S43;

[0082] S45. Add 150 g / t of water glass and 150 g / t of composite depressant CF to the third scheelite concentrate obtained in step S44 and stir for 35 min at a stirring speed of 200 r / min for a fourth concentration to obtain a scheelite concentrate and a fourth scheelite tailing; wherein the fourth scheelite tailing is returned to the third concentration step of step S44;

[0083] S46. Add 100 g / t of modified fatty acid CK to the scheelite roughing tailings obtained in step S41, stir for 35 minutes, and perform a fine scavenging at a stirring speed of 200 r / min to obtain a first scheelite scavenging concentrate and a second scheelite tailings; wherein, the first scheelite scavenging concentrate is returned to the scheelite roughing step of step S41; the second tailings are directly discarded.

[0084] The WO3 content of the obtained scheelite concentrate is 28.25%, and the recovery rate is 55.60%.

[0085] Examples 2-3 and Comparative Examples 1-5

[0086] A method for efficiently utilizing fine-grained refractory weathered scheelite is provided. Compared with Example 1, the difference lies in that the proportions of the various substances in the composite inhibitor CF are different. The rest is substantially the same as Example 1 and will not be repeated here.

[0087] Table 1 Tungsten content and recovery rate of scheelite concentrates obtained in Examples 1-3 and Comparative Examples 1-5

[0088]

[0089] It can be seen from Table 1 that with the change of the content of each substance in the composite inhibitor CF, the grade and recovery rate of the obtained scheelite concentrate vary, but the overall recovery rate is relatively high.

[0090] However, when any component of the composite inhibitor CF is missing or the ratios of the various substances in the composite inhibitor CF are inappropriate, the grade and / or recovery rate of the resulting scheelite concentrate decreases significantly. This demonstrates that only when xanthan gum, dextrin, starch, and aluminum sulfate are combined in the appropriate ratios can they achieve a good inhibitory effect.

[0091] Examples 4-5 and Comparative Examples 6-7

[0092] A method for efficiently utilizing fine-grained refractory weathered scheelite is provided. Compared with Example 1, the difference lies in that the addition amounts of the composite inhibitor CF and water glass in step S31 are different. The rest is substantially the same as Example 1 and will not be repeated here.

[0093] Table 2 Tungsten content and recovery rate of scheelite concentrate obtained in Examples 4-5 and Comparative Examples 6-7

[0094]

[0095] It can be seen from Table 2 that the addition of composite inhibitor CF and water glass has some influence on the grade and recovery rate of scheelite concentrate, but the overall recovery rate is relatively high.

[0096] However, when only one of the composite depressants, CF or water glass, was used, the grade and / or recovery rate of the resulting scheelite concentrate decreased significantly, indicating the synergistic effect of the two depressants.

[0097] Comparative Example 8

[0098] A method for efficiently utilizing fine-grained, refractory weathered scheelite was described. This method differs from Example 1 in that the magnetic separation step S2 is omitted. The remaining steps are generally the same as Example 1 and are not described here. The resulting scheelite concentrate contained 23.55% WO3 and had a recovery rate of 46.20%, significantly reducing both grade and recovery.

[0099] Comparative Example 9

[0100] A method for efficiently utilizing fine-grained, refractory, weathered scheelite is described. Compared to Example 1, this method differs in that lime, a coagulant aid, is not added in step S3. The remaining steps are substantially the same as in Example 1 and are not further described here. The resulting scheelite concentrate contains 14.45% WO3, with a recovery rate of 14.52%.

[0101] Comparative Example 10

[0102] A method for efficiently utilizing fine-grained, refractory, weathered scheelite is described. This method differs from Example 1 in that, in step S31, the magnetically separated tailings are concentrated to a slurry concentration of 45% by mass and then subjected to shear flocculation and stirring without the addition of lime to aid coagulation. The remaining steps are substantially the same as in Example 1 and are not further described here. The resulting scheelite concentrate contains 16.45% WO3, with a recovery rate of 30.88%.

[0103] Comparative Example 11

[0104] A method for efficiently utilizing fine-grained, refractory, weathered scheelite is described. This method differs from Example 1 in that unmodified tall oil, i.e., a conventional fatty acid, is used as the collector. All other aspects are largely the same as in Example 1 and are not further described here. The resulting scheelite concentrate contains 14.30% WO3, with a recovery rate of 57.28%.

[0105] Comparative Example 12

[0106] A method for efficiently utilizing fine-grained, refractory, weathered scheelite is described. Compared to Comparative Example 11, this method differs in that the collector duration is extended by 30 minutes. Other aspects of the method are generally similar to Comparative Example 11 and are not further described here. The resulting scheelite concentrate contains 10.45% WO3, with a recovery rate of 58.33%.

[0107] In summary, the present invention provides a method for efficiently utilizing fine-grained refractory weathered scheelite. Through the magnetic separation-flotation process, a coagulant is first used to aggregate small particles of scheelite through a "bridging" effect to form large and dense particles. Subsequently, a flotation operation is performed. The synergistic effect of water glass and the composite inhibitor CF and the synergistic effect of each substance in the composite inhibitor CF are utilized to achieve effective inhibition of muddy gangue. At the same time, modified fatty acid CK is selected as a collector to reduce the entrainment and flotation of fine mud during the collection process. Through two consecutive flotation processes, efficient recovery of scheelite is achieved, the grade and recovery rate of scheelite are improved, economic benefits can be achieved, and the waste of resources is effectively avoided, providing a new idea for the mining of refractory scheelite.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for efficiently utilizing fine-grained refractory weathered scheelite, characterized in that: The steps include: S1. crushing the ore particles to a particle size of less than 2 mm to obtain ore powder, then wet-grinding the ore powder to obtain a first slurry, and then adding water to the first slurry and stirring to obtain a slurry of a predetermined concentration; wherein more than 80% of the scheelite particles to be selected have a particle size of less than 20 μm; S2. The slurry to be processed in step S1 is subjected to magnetic separation by a high gradient magnetic separator to remove part of the gangue to obtain a magnetically separated coarse concentrate and magnetically separated tailings; S3. The magnetic tailings of step S2 are concentrated to a pulp mass concentration of 30%-35%, and then pumped into a first-level stirring barrel, a dispersant is added, and stirred for a preset time; then pumped into a second-level stirring barrel, a coagulant is added, and stirred for a preset time; then pumped into a third-level stirring barrel, a first preset reagent is added, and a flotation is performed to obtain a first concentrate and a first tailing; the first preset reagent includes an inhibitor and a collector; the inhibitor includes water glass and a composite inhibitor CF, and the composite inhibitor CF is composed of xanthan gum, dextrin, starch, and aluminum sulfate. The mass ratio of xanthan gum, dextrin, starch and aluminum sulfate in the composite inhibitor CF is (0.5-1.5):(1.5-2.5):(1.5-2.5):(1.5-2.5); the collector is a modified fatty acid CK, which is prepared by reacting tall oil with concentrated sulfuric acid at a mass ratio of 4-6:1 in a reactor at 20-30°C for 0.5-1.5h, and then adjusting the pH to 7.5-8.5 with 30wt%-50wt% sodium hydroxide solution; S4. The first concentrate of step S3 is pumped into a four-stage stirring tank, activated carbon is added and stirred for 5-10 minutes at a stirring speed of 500-700 r / min, and then a second preset reagent is added for secondary flotation to obtain scheelite concentrate and second tailings.

2. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 1, characterized in that: In step S3, the coagulant aid is 1000-3000 g / t of lime, stirred for 5-10 minutes, and the stirring speed is 100-300 r / min; the dispersant is 1000-3000 g / t of sodium carbonate and 200-400 g / t of sodium hexametaphosphate, stirred for 5-10 minutes, and the stirring speed is 100-300 r / min.

3. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 1, characterized in that: In the first ore pulp of step S1, the ore powder with a particle size of less than 0.074 mm accounts for 80%-85% of the mass of the ore particles to be processed; the mass concentration of the ore pulp to be processed is 20%-25%.

4. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 1, characterized in that: In step S2, the magnetic field strength of the high gradient magnetic separator is 10000-12000 GS.

5. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 1, characterized in that: In step S3, the first flotation includes a roughing separation, a cleaning separation and a scavenging separation, and finally obtains the first concentrate and the first tailings.

6. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 5, characterized in that: The first preset reagent includes: 500-1500g / t of composite inhibitor CF, 2000-4000g / t of water glass and 500-1500g / t of modified fatty acid CK as roughing reagent, stirring for 30-40min, and the stirring speed is 100-300r / min; 300-500g / t of modified fatty acid CK as scavenging reagent, stirring for 30-40min, and the stirring speed is 100-300r / min.

7. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 1, characterized in that: In step S4, the secondary flotation includes one fine roughing separation, four fine cleaning separations and one fine scavenging separation, and finally obtains the scheelite concentrate and the second tailings.

8. The method for efficiently utilizing fine-grained refractory weathered scheelite according to claim 7, characterized in that: The second preset reagents include: 100-300g / t of sodium hydroxide, 3000-5000g / t of water glass and 200-400g / t of composite inhibitor CF as fine and rough selection reagents; 500-1500g / t of water glass and 300-600g / t of composite inhibitor CF as the first selection reagent, 100-200g / t of water glass and 100-200g / t of composite inhibitor CF as the second, third and fourth selection reagents; 50-150g / t of modified fatty acid CK as the fine sweeping reagent.

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