Beneficiation method for efficiently and comprehensively recovering tungsten-molybdenum-bismuth polymetallic ore

Abstract

The invention discloses a beneficiation method for efficiently and comprehensively recovering tungsten-molybdenum-bismuth polymetallic ore, and relates to the technical field of nonferrous metal beneficiation. Raw ore is subjected to ore grinding, grading and stirring to obtain feeding ore pulp, then bulk flotation roughing is conducted, and rough concentrate and roughing tailings are obtained; the roughing tailings are subjected to mixed flotation scavenging, and scavenged concentrate and scavenged tailings are obtained; the scavenging tailings are subjected to low-intensity magnetic separation, and iron ore concentrate and low-intensity magnetic tailings are obtained; performing strong magnetic roughing operation on the weak magnetic tailings to obtain wolframite rough concentrate and strong magnetic tailings; the wolframite rough concentrate is subjected to gravity separation to obtain wolframite concentrate and gravity separation tailings; the strong magnetic tailings are subjected to scheelite flotation, and scheelite concentrate and scheelite flotation tailings are obtained; fluorite flotation is conducted on scheelite flotation tailings, fluorite concentration first foam and fluorite scavenging tailings are obtained, the fluorite concentration first foam is subjected to repeated concentration for 2-8 times, fluorite concentrate products are obtained, and efficient multi-metal separation is achieved through the processes of molybdenum-bismuth-sulfur bulk flotation, iron low-intensity magnetic separation, wolframite high-intensity magnetic separation, wolframite gravity separation, scheelite flotation and fluorite flotation.

Description

Technical Field

[0001] The present invention relates to the technical field of non-ferrous metal beneficiation, and particularly to a beneficiation method for the efficient comprehensive recovery of tungsten, molybdenum and bismuth polymetallic ores. Background Art

[0002] The tungsten resource reserves in China account for about 50% of the global reserves, but the reserve-production ratio is only 25, which is 1 / 5 of the international tungsten resource reserve-production ratio. The resources are consumed too fast, and there are certain risks in the long-term resource guarantee. With the gradual depletion of easily beneficiated and high-grade wolframite resources, and the annual decline of the endowment of tungsten ore resources, China's tungsten industry will gradually turn to the severe situation of mainly mining complex, low-grade and lean tungsten polymetallic ores.

[0003] This type of deposit is widely distributed and has large reserves in China, and is associated with many valuable elements such as molybdenum, bismuth and fluorite. The comprehensive development and utilization has high economic value. However, due to the special geological ore-forming conditions, the mineral composition is extremely complex, and the contents of metal minerals such as tungsten, molybdenum and bismuth are low, and it is difficult to comprehensively utilize under the current beneficiation technical conditions.

[0004] At present, for the comprehensive mining and recovery of this type of complex, low-grade and lean tungsten polymetallic ores in China, the following problems mainly exist:

[0005] 1. There are many types of co-associated valuable elements, but the grades are generally low (WO3≤0.35%, Mo≤0.05%, Bi≤0.10%). The comprehensive mining cost is high, the production process is complex, the overall resource utilization rate is low, and the economic benefits of enterprises are poor.

[0006] 2. The dissemination size of tungsten minerals is extremely fine. Under the condition of coarse grinding, the monomer dissociation degree of tungsten minerals is poor, and qualified concentrate products cannot be obtained; in the case of fine grinding, tungsten minerals are easily over-ground and slime, seriously deteriorating the flotation index, resulting in serious tailing of -10 micron fine-grained tungsten minerals in the wolframite flotation tailings. Minerals such as molybdenum, bismuth and fluorite also have the same trend in the flotation process. For example, in the flotation method for tungsten-molybdenum low-grade associated fluorite ore of CN202110981534.7, a multi-step flotation process is adopted, including roughing, rough scavenging, secondary cleaning, clean scavenging and four more cleaning steps, combined with mixed alkalis of sodium carbonate and sodium hydroxide, water glass, polycarboxylic acid and organic phosphonic acid and other reagents, and through a mixed fatty acid collector of modified oleic acid and oxidized paraffin soap and an acidified water glass inhibitor, the efficient separation of fluorite and calcite is realized. To obtain a higher recovery rate and grade of fluorite. However, on the one hand, there is no molybdenum-bismuth mixed flotation process, and on the other hand, it only involves the fluorite rough concentrate obtained after roughing after the separation of tungsten and molybdenum, and does not involve the separation process of wolframite and scheelite;

[0007] 3. In the ore, WO3 exists in the form of symbiotic wolframite and scheelite. There are significant differences in the flotation characteristics and floating rates of the two. In particular, the optimal flotation pH of scheelite is in the range of 8.0 - 8.5, while the floating rate constant of wolframite reaches the maximum at pH 9.50. Usually, when floating wolframite and scheelite together, to ensure a better recovery rate of scheelite with better floatability, the roughing pH for floating wolframite is generally maintained at about 8.50, resulting in a significantly higher loss rate of wolframite in the wolframite flotation tailings than that of scheelite, and a low overall recovery rate of WO3.

[0008] Therefore, it is urgent to design and develop a beneficiation method for the efficient comprehensive recovery of tungsten, molybdenum, and bismuth polymetallic ores, break through the dual constraints of the current beneficiation technology bottleneck and economic benefits, realize the high-level comprehensive utilization of such tungsten polymetallic mineral resources, strengthen the advantageous value of China's tungsten resources, and ensure the stable and sustainable development of the tungsten industry. Summary of the Invention

[0009] In view of the problems of low comprehensive utilization rate and poor economic benefits of complex, low-grade tungsten polymetallic ores, the present invention invents a beneficiation process for the efficient comprehensive recovery of tungsten, molybdenum, and bismuth polymetallic ores, which has the characteristics of a compact process flow, stable production, low cost, high comprehensive resource recovery rate, and good beneficiation economic benefits, and realizes the high-level comprehensive utilization of such tungsten polymetallic mineral resources.

[0010] A beneficiation method for the efficient comprehensive recovery of tungsten, molybdenum, and bismuth polymetallic ores includes the following steps:

[0011] (1) The ground product obtained by grinding and classifying the -5mm high-pressure roller mill product of the raw ore is fed into a stirring tank for pulp adjustment to obtain the feed pulp.

[0012] (2) The feed pulp in step (1) is subjected to rough flotation of molybdenum and bismuth mixture to obtain a rough concentrate of molybdenum, bismuth, and sulfur and roughing tailings.

[0013] (3) The rough concentrate of molybdenum, bismuth, and sulfur obtained by flotation in step (2) is subjected to cleaning of the mixed flotation to obtain a mixed concentrate of molybdenum, bismuth, and sulfur; for the middlings in the cleaning of the mixed flotation, they are sequentially returned to the rough flotation of molybdenum and bismuth mixture again.

[0014] (4) The roughing tailings in step (2) are subjected to scavenging of the mixed flotation to obtain scavenging concentrate and scavenging tailings.

[0015] (5) The scavenging concentrate in step (4) is reground, and the obtained reground product is returned to the cleaning operation of the mixed flotation.

[0016] (6) The scavenging tailings in step (4) are subjected to weak magnetic separation to obtain iron concentrate and weak magnetic tailings.

[0017] (7) Feed the weak magnetic tailings in step (6) through a "one roughing, one cleaning, and one scavenging" strong magnetic roughing operation to obtain wolframite rough concentrate and strong magnetic tailings. The strong magnetic cleaning middlings and strong magnetic scavenging concentrate are combined and returned to the strong magnetic roughing operation again.

[0018] (8) Feed the wolframite rough concentrate in step (7) to a gravity separation operation to obtain wolframite concentrate and gravity separation tailings, and return the gravity separation tailings to the strong magnetic roughing operation.

[0019] (9) Feed the strong magnetic tailings in step (7) to a scheelite flotation operation to obtain scheelite concentrate and scheelite flotation tailings.

[0020] (10) Feed the scheelite flotation tailings in step (9) to a fluorite flotation operation. Through a "one roughing, one cleaning, and one scavenging" process, obtain fluorite cleaning 1 foam and fluorite scavenging tailings. The fluorite cleaning middlings 1 and scavenging foam are combined for one-time middlings cleaning. The obtained foam product is returned to the fluorite roughing operation after regrinding, and the middlings cleaning tailings and fluorite scavenging tailings are combined and discharged into the tailings pond.

[0021] (11) Conduct 2 - 8 repeated cleaning operations on the fluorite cleaning 1 foam in step (10) to obtain fluorite concentrate products, and the cleaning middlings are returned in sequence.

[0022] For the above beneficiation method, preferably, the pulp concentration in the agitation tank in step (1) is 30% - 55%, and the fineness is such that -0.075mm accounts for 45% - 75%.

[0023] This technical solution has the following novelty features different from the prior art in terms of process combination and process optimization: Synergistic design of bulk flotation and stepwise magnetic separation / gravity separation: Through a process chain of "molybdenum-bismuth-sulfur bulk flotation - weak magnetic separation of iron - strong magnetic separation of wolframite - gravity separation of wolframite - flotation of scheelite - flotation of fluorite", efficient separation of multiple metals is achieved.

[0024] Scavenging concentrate secondary regrinding and return mechanism: In step e, the scavenging concentrate is reground twice and then returned to the bulk flotation cleaning operation, significantly improving the dissociation degree of valuable minerals.

[0025] Deep treatment system for fluorite flotation middlings: In step j, a composite process of "middlings cleaning + regrinding and return + multi-stage cleaning" is used to treat the intermediate products of fluorite flotation. Compared with the conventional single sequential return method, the grade of fluorite concentrate can be increased by 3 - 5 percentage points.

[0026] Comprehensive utilization path for strong magnetic tailings: Use the strong magnetic tailings as the raw material for scheelite flotation (step 9), and continue to recover fluorite from the scheelite flotation tailings (step 10) to achieve cascaded utilization of tailings resources.

[0027] The present invention has significant progress in terms of:

[0028] Improved recovery rate of the target substance: By means of bulk flotation, the mutual loss of molybdenum, bismuth and sulfur is reduced, and the recovery rate is increased by 5-8%. The magnetic-gravity combined separation reduces the loss of wolframite, and the recovery rate is increased by more than 10%;

[0029] Process intensification: The process that traditionally requires 6-8 independent separation systems can be compressed into a single continuous process, and the equipment investment is reduced by 30%;

[0030] Breakthrough in tailings resource utilization: The recovery rate of fluorite can reach more than 65%, achieving a high recovery effect.

[0031] For the above beneficiation method, preferably, in step (2), the rougher regulator is one or a combination of several of sodium carbonate, sodium hydroxide, sodium hexametaphosphate, sodium fluorosilicate, water glass and its modified products; the collectors include but are not limited to one or a combination of several of ethyl thionocarbamate, ethyl thionamide, xanthate series collectors, ammonium butyl dithiophosphate, kerosene, diesel oil and other products.

[0032] For the above beneficiation method, preferably, in step (3), the scavenger inhibitors include but are not limited to one or a combination of several of water glass, acidified water glass, ammonium fluorosilicate, aluminum sulfate, sodium carboxymethyl cellulose, calcium lignosulfonate.

[0033] For the above beneficiation method, preferably, in step (4), the scavenger collectors include but are not limited to long-chain xanthate, higher black drug and ester sulfide ore collectors.

[0034] For the above beneficiation method, in step (5), the fineness of the regrinding of the bulk flotation scavenger foam is -0.075mm content ≥ 85%, and the monomer dissociation of molybdenum and bismuth minerals in the regrinding product is ≥ 90%.

[0035] For the above beneficiation method, in step (9), the scheelite flotation collectors include but are not limited to one or a combination of several of styrene phosphonic acid, salicylhydroxamic acid, benzohydroxamic acid, fatty acids and their modified products, oxidized paraffin soap, etc.; the inhibitors include but are not limited to one or a combination of several of acidified water glass, water glass, sodium hexametaphosphate, aluminum sulfate, guar gum, xanthan gum.

[0036] For the above beneficiation method, in step (10), the fluorite collectors include but are not limited to one or a combination of several of oleic acid, linoleic acid, sodium oleate, oxidized paraffin soap, and various modified fatty acid collectors.

[0037] For the above beneficiation method, in step (11), the inhibitors include but are not limited to one or a combination of several of acidified water glass, water glass, sodium hexametaphosphate, aluminum sulfate, guar gum, tannin extract, caustic starch, modified polyacrylic acid.

[0038] Compared with the existing conventional technologies, the present invention has the following innovative features:

[0039] 1) In view of the uneven dissemination size of molybdenum and bismuth minerals in the raw ore, the present invention utilizes the characteristic that the floating rate of molybdenum and bismuth mineral lean intergrowths is significantly lower than that of molybdenum and bismuth monomer minerals. Under the condition of coarser grinding fineness, molybdenum and bismuth minerals with coarser dissemination size and higher monomer dissociation degree are preferentially recovered, avoiding over-grinding and over-crushing of this part of molybdenum and bismuth minerals during fine grinding, and significantly reducing the grinding energy consumption of the concentrator.

[0040] 2) The present invention strengthens the enrichment of molybdenum and bismuth intergrowth minerals with slower floating rate and higher proportion of intergrowth with gangue in the scavenging operation section. The obtained foam product realizes the efficient monomer dissociation of fine-grained molybdenum and bismuth minerals through secondary grinding, avoiding the over-grinding and slime-forming of tungsten minerals caused by fine grinding in the roughing section, and creating good conditions for the subsequent tungsten flotation operation.

[0041] 3) Based on the magnetic difference between wolframite and scheelite, the present invention uses high-intensity magnetic separation to achieve their efficient separation, avoiding the low overall recovery rate of WO3 caused by the tailing of wolframite during the bulk flotation of scheelite and wolframite, creating favorable conditions for the flotation of scheelite, simplifying the wolframite flotation reagent system, and improving the scheelite flotation index.

[0042] 4) In view of the uneven dissemination size of fluorite minerals, the present invention combines fluorite middling 1 and fluorite scavenging concentrate under coarse grinding conditions for middling cleaning. The obtained foam product is subjected to secondary re-grinding to achieve the monomer dissociation of fine-grained fluorite minerals while avoiding over-grinding of coarser-disseminated and already monomer-dissociated fluorite minerals, significantly reducing the content of fine-grained fluorite in the tailings and optimizing the fluorite flotation index.

[0043] The present invention provides a beneficiation method for the efficient comprehensive recovery of tungsten, molybdenum and bismuth polymetallic ores. Through process chain innovation, the technical effects of "reducing costs through bulk flotation - improving efficiency through magnetic and gravity separation - increasing the value of tailings in a cascade manner" are achieved, solving long-term technical problems such as long process flow, serious metal mutual loss, and waste of associated resources in the field of comprehensive recovery of polymetallic ores. It can have the characteristics of low grinding and beneficiation costs, good separation indexes, and high resource comprehensive utilization rate. This process makes full use of the characteristic of uneven dissemination size of target minerals, significantly coarsens the fineness of the first-stage grinding, and uses the differences in flotation characteristics and floating rates between different minerals to achieve refined re-grinding of intergrowth minerals, significantly reducing the grinding energy consumption while effectively avoiding over-grinding of most of the already monomer-dissociated target minerals, thus realizing the efficient comprehensive recovery of tungsten, molybdenum, bismuth and fluorite, providing a new way and idea for the recovery and utilization of such complex and low-grade tungsten polymetallic ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is the process flow diagram of the beneficiation method for the comprehensive recovery of tungsten, molybdenum and bismuth polymetallic ores of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0045] For the convenience of understanding the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings of the specification and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0046] Unless otherwise defined, all the technical terms used hereinafter have the same meanings as those commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention.

[0047] Embodiment 1:

[0048] As Figure 1 shown, an implementation scheme of the present invention includes a beneficiation method for the efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore of the present invention, which is specifically as follows:

[0049] The raw ore in this embodiment is a low-grade refractory tungsten-molybdenum-bismuth polymetallic ore. WO3 mainly exists as scheelite, followed by wolframite, and the ratio of the two is about 6:4. Mo exists in the form of single molybdenite, mostly in plate-like and blade-like shapes, with a particle size between 0.02 and 0.1 mm, regular in shape, and the intergrowth relationship with other minerals is relatively simple. In particular, its plate-like crystal form is very conducive to dissociation during the grinding process; Bi mainly exists in the form of bismuthinite and native bismuth, with a very fine particle size, generally less than 0.03 mm. The non-metallic minerals in the ore are mainly fluorite, with irregular crystal forms and uneven particle sizes. Individual coarser ones can reach more than 0.8 mm, and a small number of finer ones are less than 0.02 mm, generally between 0.03 and 0.3 mm. Some fluorite grains contain fine gangue such as calcite, mica, and feldspar, especially the intergrowth relationship with mica is very close, and some also form an extremely complex inclusion and intergrowth relationship with gangue. The gangue minerals are mainly quartz, feldspar, mica, and a small amount of amphibole, beryl, etc. The WO3 content in the ore is 0.34%, the Mo content is 0.053%, the Bi content is 0.10%, and the CaF2 content is 19.78%.

[0050] Adopt the beneficiation method for the efficient recovery of molybdenum-bismuth-sulfur by stepwise intensifying flotation as Figure 1 shown, and the specific steps are as follows:

[0051] (1) Grind and classify the -5 mm high-pressure roll mill product of the raw ore to obtain a grinding product with a particle size fraction of -0.075 mm accounting for 65%, and feed it into a stirring tank for pulp adjustment to obtain a feed pulp with a concentration of 50%;

[0052] (2) Add 80 g / t of ethyl thionocarbazide, 40 g / t of butyl xanthate, and 30 g / t of foaming agent BK205 to the feed pulp in step (1) for rough selection of molybdenum-bismuth mixed flotation to obtain a rough concentrate of molybdenum-bismuth-sulfur mixture and rough tailings;

[0053] (3) Add the molybdenum-bismuth-sulfur mixed rough concentrate in step (2) to three batches of water glass with concentrations of 200 g / t, 100 g / t, and 100 g / t in sequence, and conduct 3 times of bulk flotation cleaning to obtain a molybdenum-bismuth mixed concentrate with a yield of 0.93%, a grade of 5.25% Mo, 9.96% Bi, a recovery rate of 91.93% Mo, and 91.36% Bi. The middlings in the bulk flotation cleaning are returned in sequence;

[0054] (4) Add 30 g / t of ethyl thionocarbamate, 15 g / t of butyl xanthate, and 6 g / t of foaming agent BK205 to the rougher tailings in step (3) for bulk flotation scavenging to obtain scavenging concentrate and scavenging tailings;

[0055] (5) Feed the scavenging concentrate in step (4) into a ball mill for regrinding. The obtained grinding product has a -0.045 mm content of 85% and is returned to the bulk flotation cleaning operation;

[0056] (6) Conduct two-stage low-intensity magnetic separation on the scavenging tailings in step (5), with a roughing magnetic field intensity of 0.20 T and a cleaning magnetic field intensity of 0.16 T. The middlings in the low-intensity magnetic cleaning and the roughing tailings of the low-intensity magnetic separation are combined as low-intensity magnetic tailings to obtain an iron concentrate with a yield of 0.38% and a TFe grade of 62.08%; the TFe grade is the percentage of the total iron content in the iron ore.

[0057] (7) Subject the low-intensity magnetic tailings in step (6) to "1 roughing, 1 cleaning, 1 scavenging" high-intensity magnetic separation, with the roughing, cleaning, and scavenging field intensities being 1.2 T, 1.5 T, and 1.0 T in sequence to obtain wolframite rough concentrate and high-intensity magnetic tailings. The middlings in the high-intensity magnetic cleaning and the scavenging concentrate of the high-intensity magnetic separation are combined and returned to the high-intensity magnetic roughing operation;

[0058] (8) Obtain wolframite concentrate with a yield of 0.15%, a WO3 grade of 60.75%, and a WO3 recovery rate of 27.11% by tabling the wolframite rough concentrate in (7). The tailings from the tabling are returned to the high-intensity magnetic roughing operation;

[0059] (9) Feed the strong magnetic tailings from step (7) into scheelite flotation. Through a separation process of "one roughing, two scavengings, and four cleanings", the flotation reagent regime is as follows: for roughing, 591 g / t of salinized water glass, 788 g / t of lead nitrate, 591 g / t of collector benzohydroxamic acid, and 6 g / t of frother BK205; for the first scavenging, 49 g / t of collector benzohydroxamic acid and 6 g / t of frother BK205; for the second scavenging, 25 g / t of collector benzohydroxamic acid; for the first cleaning, 49 g / t of salinized water glass; for the second cleaning, 30 g / t of salinized water glass; for the third cleaning, 20 g / t of salinized water glass; for the fourth cleaning, 20 g / t of salinized water glass; the flotation middlings are returned in sequence. Obtain scheelite concentrate with a yield of 0.39%, WO3 grade of 46.42%, and WO3 recovery rate of 53.86% and scheelite flotation tailings; among them, the first scavenging refers to the first scavenging operation, and the second scavenging refers to the second scavenging operation; the first cleaning refers to the first cleaning operation, and so on.

[0060] (10) Add 1472 g / t of sodium carbonate, 982 g / t of water glass, and 785 g / t of collector CYS-7 (modified fatty acid) to the scheelite flotation tailings from step (9) for rough fluorite separation to obtain rough fluorite concentrate and rough fluorite separation tailings;

[0061] (11) Add 393 g / t of water glass to the rough fluorite concentrate from step (10) to obtain fluorite first cleaning foam and fluorite first cleaning middlings 1; the fluorite first cleaning foam refers to the foam product in the first stage during the fluorite flotation process, which means the foam layer containing fluorite minerals obtained after one roughing or cleaning operation in the flotation operation. The fluorite first cleaning middlings 1 is the middling product in the first stage during the fluorite flotation process, which means the intermediate product obtained after one roughing or cleaning operation in the flotation operation.

[0062] (12) Add 393 g / t of collector CYS-7 (modified fatty acid) to the rough fluorite separation tailings from step (10) for fluorite scavenging to obtain fluorite scavenging concentrate and fluorite scavenging tailings;

[0063] (13) Combine the fluorite first cleaning middlings 1 from step (11) and the fluorite scavenging concentrate from step (12), add 147 g / t of acidified water glass for flotation to obtain middling concentrate foam, and the tailings obtained from the middling cleaning are discharged into the tailings pond;

[0064] (14) Feed the middling concentrate foam obtained in step (13) into a ball mill and grind it to a grinding fineness where the proportion of -0.030 mm accounts for 90%, and then return it to the rough fluorite separation operation;

[0065] (15) The fluorite concentrate 1 foam in step (11) is subjected to the 2nd to 7th stage of concentration. The inhibitor added in the concentration reagent is acidified water glass, and the dosages are 294 g / t, 196 g / t, 147 g / t, 98 g / t, 49 g / t, and 49 g / t in sequence. The middlings in the concentration are returned in sequence, obtaining a fluorite concentrate product with a yield of 16.64%, a CaF₂ grade of 97.26%, and a CaF₂ recovery rate of 81.84%.

[0066] Using the above beneficiation method to process tungsten polymetallic associated ores with a WO₃ content of 0.34%, a Mo content of 0.053%, a Bi content of 0.10%, and a CaF₂ content of 19.78% in the raw ore, obtaining a molybdenum-bismuth mixed concentrate with a yield of 0.93%, a Mo grade of 5.25%, a Bi grade of 9.96%, a Mo recovery rate of 91.93%, and a Bi recovery rate of 91.36%; an iron concentrate with a yield of 0.38% and a TFe grade of 62.08%; a tungsten comprehensive concentrate with a yield of 0.54%, a WO₃ grade of 50.40%, and a WO₃ recovery rate of 80.97%; a fluorite concentrate with a yield of 16.64%, a CaF₂ grade of 97.26%, and a CaF₂ recovery rate of 81.84%.

[0067] Example 2:

[0068] Another beneficiation method for the efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ores of the present invention, compared with the parameter distribution in Example 1, is as follows:

[0069] The raw ore in this example is a low-grade, complex, and difficult-to-dress mixed scheelite and wolframite ore, with a WO₃ content of 0.26%, a Mo content of 0.027%, a Bi content of 0.06%, and a CaF₂ content of 16.22% in the ore. The WO₃ in the ore is mainly scheelite, followed by wolframite, and the ratio of the two is about 7:3; Mo and Bi are associated in the form of molybdenite and bismuthinite respectively; the non-metallic minerals in the ore are mainly fluorite, followed by quartz, and a small amount of sericite, feldspar, chlorite, and beryl, etc. The fluorite is generally coarser in particle size and more regular in shape, and only a few are closely intergrown with gangue such as quartz, feldspar, mica, and chlorite.

[0070] Using the beneficiation method for the efficient recovery of molybdenum-bismuth-sulfur by stepwise strengthening flotation as Figure 1 shown, the specific steps are as follows:

[0071] (1) Grind and classify the products of the raw ore -5 mm high-pressure roll mill to obtain a grinding product with a particle size fraction of -0.075 mm accounting for 60%, and feed it into a stirring tank for pulp mixing to obtain a feed pulp with a concentration of 50%.

[0072] (2) Add 60 g / t of ethyl dithiocarbamate, 30 g / t of butyl xanthate, and 20 g / t of frother BK205 to the ore pulp in step (1), and conduct rough flotation for molybdenum-bismuth bulk flotation to obtain a rough concentrate of molybdenum-bismuth-sulfur and rough flotation tailings;

[0073] (3) Add 150 g / t, 80 g / t, and 60 g / t of water glass to the rough concentrate of molybdenum-bismuth-sulfur in step (2) in sequence, and conduct 3 times of bulk flotation cleaning to obtain a molybdenum-bismuth bulk concentrate with a yield of 0.68%, a grade of 3.62% Mo and 7.98% Bi, and a recovery rate of 90.03% Mo and 90.47% Bi. The middlings in the bulk flotation cleaning are returned in sequence;

[0074] (4) Add 20 g / t of ethyl dithiocarbamate, 10 g / t of butyl xanthate, and 6 g / t of frother BK205 to the rough flotation tailings in step (3), and conduct bulk flotation scavenging to obtain scavenging concentrate and scavenging tailings;

[0075] (5) Feed the scavenging concentrate in step (4) into a ball mill for regrinding. The obtained grinding product has a -0.045 mm content of 85%, and is returned to the bulk flotation cleaning operation;

[0076] (6) Conduct two-stage weak magnetic separation on the scavenging tailings in step (5). The roughing magnetic field intensity is 0.20 T, and the cleaning magnetic field intensity is 0.16 T. The middlings in the weak magnetic cleaning are combined with the weak magnetic roughing tailings to form weak magnetic tailings, and an iron concentrate with a yield of 0.25% and a TFe grade of 63.32% is obtained;

[0077] (7) Conduct "1 roughing, 1 cleaning, 1 scavenging" high-intensity magnetic separation on the weak magnetic tailings in step (6). The roughing, cleaning, and scavenging field intensities are 1.2 T, 1.5 T, and 1.0 T in sequence to obtain a wolframite rough concentrate and high-intensity magnetic tailings. The middlings in the high-intensity magnetic cleaning are combined with the high-intensity magnetic scavenging concentrate and returned to the high-intensity magnetic roughing operation;

[0078] (8) Conduct shaking table gravity separation on the wolframite rough concentrate in step (7) to obtain a wolframite concentrate with a yield of 0.08%, a WO3 grade of 61.36%, and a WO3 recovery rate of 18.63%. The tailings from the shaking table gravity separation are returned to the high-intensity magnetic roughing operation;

[0079] (9) Feed the strong magnetic tailings in step (7) into scheelite flotation, and through a separation process of "one roughing, two scavenging, and four cleaning", the flotation reagent system is as follows: for roughing, 594 g / t of salinized water glass, 792 g / t of lead nitrate, 495 g / t of collector benzohydroxamic acid, and 6 g / t of frother BK205; for scavenging 1, 49 g / t of collector benzohydroxamic acid and 6 g / t of frother BK205; for scavenging 2, 25 g / t of collector benzohydroxamic acid; for cleaning 1, 49 g / t of salinized water glass; for cleaning 2, 30 g / t of salinized water glass; for cleaning 3, 20 g / t of salinized water glass; for cleaning 4, 15 g / t of salinized water glass; the flotation middlings are returned in sequence, obtaining scheelite concentrate with a yield of 0.34%, WO3 grade of 47.71%, and WO3 recovery rate of 61.57% and scheelite flotation tailings;

[0080] (10) Add 1480 g / t of sodium carbonate, 987 g / t of water glass, and 789 g / t of collector CYS-7 (modified fatty acid) to the scheelite flotation tailings in step (9) for rough fluorite separation, obtaining rough fluorite concentrate and rough fluorite separation tailings;

[0081] (11) Add 345 g / t of water glass to the rough fluorite concentrate in step (10) to obtain fluorite cleaning 1 foam and fluorite cleaning middlings 1;

[0082] (12) Add 296 g / t of collector CYS-7 (modified fatty acid) to the rough fluorite separation tailings in step (10) for fluorite scavenging, obtaining fluorite scavenging concentrate and fluorite scavenging tailings;

[0083] (13) Combine the fluorite cleaning middlings 1 in step (11) and the fluorite scavenging concentrate in step (12), add 148 g / t of acidified water glass for flotation to obtain middling concentrate foam, and the tailings obtained from middling cleaning are discharged into the tailings pond;

[0084] (14) Feed the middling concentrate foam obtained in step (13) into a ball mill and grind it to a grinding fineness where the proportion of -0.038 mm accounts for 92%, and then return it to the rough fluorite separation operation;

[0085] (15) Conduct the 2nd to 7th cleaning on the fluorite cleaning 1 foam in step (11). The inhibitors added in the cleaning reagents are all acidified water glass, with dosages of 296 g / t, 197 g / t, 98 g / t, 98 g / t, 39 g / t, and 39 g / t in sequence. The cleaning middlings are returned in sequence, obtaining fluorite concentrate product with a yield of 13.25%, CaF2 grade of 98.11%, and CaF2 recovery rate of 80.17%.

[0086] Using the above beneficiation method to process a low-grade, complex and refractory black-and-white tungsten mixed ore with an original ore containing 0.26% WO3, 0.027% Mo, 0.06% Bi, and 16.22% CaF2, a molybdenum-bismuth mixed concentrate with a yield of 0.68%, a grade of 3.62% Mo and 7.98% Bi, a recovery rate of 90.03% Mo and 90.47% Bi is obtained; an iron concentrate with a yield of 0.25% and a TFe grade of 63.32%; a tungsten comprehensive concentrate with a yield of 0.42%, a WO3 grade of 50.31%, and a WO3 recovery rate of 80.20%; a fluorite concentrate with a yield of 13.25%, a CaF2 grade of 98.11%, and a CaF2 recovery rate of 80.17%.

[0087] Comparative Example 1:

[0088] Using Figure 1 The shown process flow to process the tungsten-molybdenum-bismuth polymetallic ore. The original ore is the same as that in Example 1. The main difference from Example 1 is that in step (1), the grinding fineness is increased to 90% of the -0.075mm particle size fraction, and the regrinding operations in steps (5) and (14) are cancelled. The specific steps are as follows:

[0089] (1) Grind and classify the -5mm high-pressure roller mill product of the original ore to obtain a grinding product with 90% of the -0.075mm particle size fraction, and feed it into a stirring tank for pulp adjustment to obtain a feed pulp with a concentration of 50%;

[0090] (2) Add 80g / t of ethyl thionocarbazide, 40g / t of butyl xanthate, and 30g / t of foaming agent BK205 to the feed pulp in step (1) for rough flotation of molybdenum-bismuth mixture to obtain a rough concentrate of molybdenum-bismuth-sulfur mixture and a roughing tailings;

[0091] (3) Add 200g / t, 100g / t, and 100g / t of water glass in sequence to the rough concentrate of molybdenum-bismuth-sulfur mixture in step (2) for 3 times of cleaning in mixed flotation to obtain a molybdenum-bismuth mixed concentrate with a yield of 0.78%, a grade of 5.99% Mo and 11.33% Bi, a recovery rate of 87.97% Mo and 87.16% Bi. The middlings in the cleaning of mixed flotation are returned in sequence;

[0092] (4) Add 30g / t of ethyl thionocarbazide, 15g / t of butyl xanthate, and 6g / t of foaming agent BK205 to the roughing tailings in step (3) for scavenging in mixed flotation to obtain a scavenging concentrate and a scavenging tailings;

[0093] (5) Return the scavenging concentrate in step (4) to the roughing operation of mixed flotation;

[0094] (6) The scavenged tailings in step (5) are subjected to two-stage weak magnetic separation, namely one roughing and one cleaning. The magnetic field intensity for roughing is 0.20 T, and for cleaning is 0.16 T. The middlings from weak magnetic cleaning are combined with the tailings from weak magnetic roughing to form weak magnetic tailings. An iron concentrate with a yield of 0.32% and a TFe grade of 63.55% is obtained.

[0095] (7) The weak magnetic tailings in step (6) are subjected to "one roughing, one cleaning, and one scavenging" high-intensity magnetic separation. The magnetic field intensities for roughing, cleaning, and scavenging are 1.2 T, 1.5 T, and 1.0 T respectively, to obtain wolframite rough concentrate and high-intensity magnetic tailings. The middlings from high-intensity magnetic cleaning are combined with the concentrate from high-intensity magnetic scavenging and returned to the high-intensity magnetic roughing operation.

[0096] (8) The wolframite rough concentrate in step (7) is subjected to tabling gravity separation to obtain wolframite concentrate with a yield of 0.13%, a WO3 grade of 61.08%, and a WO3 recovery rate of 23.62%. The tailings from tabling gravity separation are returned to the high-intensity magnetic roughing operation.

[0097] (9) The high-intensity magnetic tailings in step (7) are fed into scheelite flotation, which undergoes a separation process of "one roughing, two scavengings, and four cleanings". The flotation reagent regime is as follows: for roughing, sodium silicate (salted) 591 g / t, lead nitrate 788 g / t, collector benzohydroxamic acid 591 g / t, and frother BK205 6 g / t; for scavenging 1, collector benzohydroxamic acid 49 g / t and frother BK205 6 g / t; for scavenging 2, collector benzohydroxamic acid 25 g / t; for cleaning 1, sodium silicate (salted) 49 g / t; for cleaning 2, sodium silicate (salted) 30 g / t; for cleaning 3, sodium silicate (salted) 20 g / t; for cleaning 4, sodium silicate (salted) 20 g / t. The middlings from flotation are returned in sequence to obtain scheelite concentrate with a yield of 0.40%, a WO3 grade of 41.88%, and a WO3 recovery rate of 49.84% and scheelite flotation tailings.

[0098] (10) Sodium carbonate 1472 g / t, sodium silicate 982 g / t, and collector CYS-7 (modified fatty acid) 785 g / t are added to the scheelite flotation tailings in step (9) for fluorite roughing to obtain fluorite rough concentrate and fluorite roughing tailings.

[0099] (11) Sodium silicate 393 g / t is added to the fluorite rough concentrate in step (10) to obtain fluorite cleaning 1 foam and fluorite cleaning middlings 1.

[0100] (12) Collector CYS-7 (modified fatty acid) 393 g / t is added to the fluorite roughing tailings in step (10) for fluorite scavenging to obtain fluorite scavenging concentrate and fluorite scavenging tailings.

[0101] (13) The fluorite cleaning middlings 1 in step (11) are combined with the fluorite scavenging concentrate in step (12), and then 147 g / t of acidified sodium silicate is added for flotation to obtain middling concentrate foam. The tailings obtained from middling cleaning are discharged into the tailings pond.

[0102] (14) Return the middling concentrate foam obtained in step (13) to the fluorite roughing operation;

[0103] (15) Conduct the 2nd to 7th stage of concentration on the fluorite concentrate foam in step (11). The inhibitor added in the concentration agent is acidified water glass, and the dosages are 294 g / t, 196 g / t, 147 g / t, 98 g / t, 49 g / t, and 49 g / t in sequence. The middlings in the concentration are returned in sequence to obtain a fluorite concentrate product with a yield of 15.76%, a CaF₂ grade of 97.74%, and a CaF₂ recovery rate of 77.89%.

[0104] Compared with the beneficiation method of Example 1, directly raising the grinding fineness to a -0.075 mm particle size content of 90% using the above process not only leads to a more than 30% significant increase in the grinding energy consumption of the concentrator, but also causes the WO₃ grade of the tungsten comprehensive concentrate to decrease by 3.81 percentage points, the WO₃ recovery rate to decrease by 7.51 percentage points, the recovery rates of Mo and Bi in the molybdenum-bismuth mixed concentrate to decrease by 3.96 and 4.20 percentage points respectively, and the CaF₂ recovery rate of the fluorite concentrate to decrease by 3.95 percentage points. The overall resource comprehensive utilization rate declines, and the economic benefits of the enterprise are also significantly affected.

[0105] Comparative Example 2:

[0106] Adopt Figure 1 The shown process flow to process the tungsten-molybdenum-bismuth polymetallic ore. The original ore is the same as that in Example 1. The main difference from Example 1 is to cancel the strong magnetic recovery of wolframite operation in steps (7) and (8), and adopt the combined flotation process of scheelite and wolframite for the comprehensive recovery of tungsten minerals. The specific steps are as follows:

[0107] (1) Grind and classify the -5 mm high-pressure roller mill product of the original ore to obtain a grinding product with a -0.075 mm particle size content of 65%, and feed it into a stirring tank for pulp adjustment to obtain a feed pulp with a concentration of 50%;

[0108] (2) Add 80 g / t of ethyl thionocarbazide, 40 g / t of butyl xanthate, and 30 g / t of foaming agent BK205 to the feed pulp in step (1) for the rough flotation of molybdenum-bismuth mixed flotation to obtain a molybdenum-bismuth-sulfur mixed rough concentrate and a roughing tailing;

[0109] (3) Add 200 g / t, 100 g / t, and 100 g / t of water glass to the molybdenum-bismuth-sulfur mixed rough concentrate in step (2) in sequence for 3 stages of mixed flotation concentration to obtain a molybdenum-bismuth mixed concentrate with a yield of 0.93%, a grade of Mo of 5.25%, a grade of Bi of 9.96%, a recovery rate of Mo of 91.93%, and a recovery rate of Bi of 91.36%. The middlings in the mixed flotation concentration are returned in sequence;

[0110] (4) Add 30 g / t of ethyl thionocarbamate, 15 g / t of butyl xanthate, and 6 g / t of frother BK205 to the rougher tailings in step (3), and conduct bulk flotation scavenging to obtain scavenging concentrate and scavenging tailings;

[0111] (5) Feed the scavenging concentrate in step (4) into a ball mill for regrinding. The content of the obtained grinding product with a particle size of -0.045 mm accounts for 85%, and it is returned to the bulk flotation cleaning operation;

[0112] (6) Conduct two-stage weak magnetic separation on the scavenging tailings in step (5). The magnetic field intensity for the rougher separation is 0.20 T, and the magnetic field intensity for the cleaner separation is 0.16 T. The middlings from the weak magnetic cleaning are combined with the tailings from the weak magnetic rougher to form weak magnetic tailings, and iron concentrate with a yield of 0.38% and a TFe grade of 62.08% is obtained;

[0113] (7) Feed the weak magnetic tailings in step (6) into the combined flotation of scheelite and wolframite. Through a separation process of "one rougher, two scavengers, and four cleaners", the flotation reagent regime is as follows: for the rougher separation, add 592 g / t of salinized water glass, 790 g / t of lead nitrate, 790 g / t of collector benzohydroxamic acid, and 6 g / t of frother BK205; for scavenging 1, add 59 g / t of collector benzohydroxamic acid and 6 g / t of frother BK205; for scavenging 2, add 25 g / t of collector benzohydroxamic acid; for cleaning 1, add 79 g / t of salinized water glass; for cleaning 2, add 49 g / t of salinized water glass; for cleaning 3, add 30 g / t of salinized water glass; for cleaning 4, add 30 g / t of salinized water glass; the middlings from the flotation are sequentially returned. Scheelite concentrate with a yield of 0.70%, a WO3 grade of 35.26%, and a WO3 recovery rate of 73.43% and scheelite flotation tailings are obtained;

[0114] (10) Add 1472 g / t of sodium carbonate, 981 g / t of water glass, and 785 g / t of collector CYS-7 (modified fatty acid) to the scheelite flotation tailings in step (9) for rougher flotation of fluorite to obtain fluorite rougher concentrate and fluorite rougher tailings;

[0115] (11) Add 392 g / t of water glass to the fluorite rougher concentrate in step (10) to obtain fluorite cleaning 1 foam and fluorite cleaning middlings 1;

[0116] (12) Add 392 g / t of collector CYS-7 (modified fatty acid) to the fluorite rougher tailings in step (10) for scavenging of fluorite to obtain fluorite scavenging concentrate and fluorite scavenging tailings;

[0117] (13) Combine the fluorite cleaning middlings 1 in step (11) and the fluorite scavenging concentrate in step (12), add 147 g / t of acidified water glass for flotation to obtain middlings concentrate foam, and the tailings obtained from the cleaning of the middlings are discharged into the tailings pond;

[0118] (14) Feed the middling concentrate foam obtained in step (13) into a ball mill for regrinding until the grinding fineness of -0.030 mm accounts for 90%, and then return it to the fluorite roughing operation;

[0119] (15) Conduct the 2nd to 7th stage of concentration on the fluorite concentrate 1 foam in step (11). The inhibitor added in the concentration agent is acidified water glass, and the dosages are 294 g / t, 196 g / t, 147 g / t, 98 g / t, 49 g / t, and 49 g / t in sequence. The middlings in the concentration are returned in sequence to obtain a fluorite concentrate product with a yield of 15.73%, a CaF2 grade of 92.46%, and a CaF2 recovery rate of 73.55%.

[0120] Compared with the beneficiation method of Example 1, the operation of strongly magnetic recovery of wolframite is cancelled, and the WO3 grade of the tungsten comprehensive concentrate obtained by using the combined flotation of scheelite and wolframite is reduced by 15.14 percentage points, and the WO3 recovery rate is reduced by 7.54 percentage points. In addition, the CaF2 grade and recovery rate in the fluorite concentrate are reduced by 4.80 and 8.29 percentage points respectively.

[0121] Comparative Example 3:

[0122] Adopt Figure 1 The shown process flow to treat the tungsten-molybdenum-bismuth polymetallic ore. The original ore is the same as that in Example 1. The main difference from Example 1 is that the regrinding operation of the fluorite middling re-election foam in step (14) is cancelled. The specific steps are as follows:

[0123] (1) Grind and classify the -5 mm high-pressure roller mill product of the original ore to obtain a grinding product with a particle size content of -0.075 mm accounting for 65%, and feed it into a stirring tank for pulp adjustment to obtain a feed pulp with a concentration of 50%;

[0124] (2) Add 80 g / t of ethyl thionocarbazide, 40 g / t of butyl xanthate, and 30 g / t of foaming agent BK205 to the feed pulp in step (1) for the rough flotation of molybdenum-bismuth mixed flotation to obtain a molybdenum-bismuth-sulfur mixed rough concentrate and a rough flotation tailing;

[0125] (3) Add 200 g / t, 100 g / t, and 100 g / t of water glass to the molybdenum-bismuth-sulfur mixed rough concentrate in step (2) in sequence for 3 times of mixed flotation concentration to obtain a molybdenum-bismuth mixed concentrate with a yield of 0.93%, a Mo grade of 5.25%, a Bi grade of 9.96%, a Mo recovery rate of 91.93%, and a Bi recovery rate of 91.36%. The middlings in the mixed flotation concentration are returned in sequence;

[0126] (4) Add 30 g / t of ethyl thionocarbazide, 15 g / t of butyl xanthate, and 6 g / t of foaming agent BK205 to the rough flotation tailing in step (3) for mixed flotation scavenging to obtain a scavenging concentrate and a scavenging tailing;

[0127] (5) Feed the scavenging concentrate in step (4) into a ball mill for regrinding. The content of the grinding product with a particle size of less than 0.045 mm accounts for 85%, and it is returned to the bulk flotation and cleaning operation;

[0128] (6) Conduct two weak magnetic separations of one roughing and one cleaning on the scavenging tailings in step (5). The magnetic field intensity for roughing is 0.20 T, and the magnetic field intensity for cleaning is 0.16 T. The middlings from the weak magnetic cleaning are combined with the tailings from the weak magnetic roughing to form the weak magnetic tailings, and iron concentrate with a yield of 0.38% and a TFe grade of 62.08% is obtained;

[0129] (7) Conduct "one roughing, one cleaning, and one scavenging" high-intensity magnetic separation on the weak magnetic tailings in step (6). The magnetic field intensities for roughing, cleaning, and scavenging are 1.4 T, 1.6 T, and 1.2 T in sequence, obtaining wolframite rough concentrate and high-intensity magnetic tailings. The middlings from the high-intensity magnetic cleaning are combined with the scavenging concentrate from the high-intensity magnetic separation and returned to the high-intensity magnetic roughing operation;

[0130] (8) Conduct tabling on the wolframite rough concentrate in step (7) to obtain wolframite concentrate with a yield of 0.15%, a WO3 grade of 60.75%, and a WO3 recovery rate of 27.11%. The tailings from the tabling are returned to the high-intensity magnetic roughing operation;

[0131] (9) Feed the high-intensity magnetic tailings in step (7) into scheelite flotation, and conduct a separation process of "one roughing, two scavengings, and four cleanings". The flotation reagent regime is as follows: for roughing, 591 g / t of salinized water glass, 788 g / t of lead nitrate, 591 g / t of collector benzohydroxamic acid, and 56 g / t of frother BK205; for scavenging 1, 49 g / t of collector benzohydroxamic acid and 6 g / t of frother BK205; for scavenging 2, 25 g / t of collector benzohydroxamic acid; for cleaning 1, 49 g / t of salinized water glass; for cleaning 2, 30 g / t of salinized water glass; for cleaning 3, 20 g / t of salinized water glass; for cleaning 4, 20 g / t of salinized water glass; the middlings from the flotation are returned in sequence, obtaining scheelite concentrate with a yield of 0.39%, a WO3 grade of 46.42%, and a WO3 recovery rate of 53.86% and scheelite flotation tailings;

[0132] (10) Add 1472 g / t of sodium carbonate, 982 g / t of water glass, and 785 g / t of collector CYS-7 (modified fatty acid) to the scheelite flotation tailings in step (9) for fluorite roughing, obtaining fluorite rough concentrate and fluorite roughing tailings;

[0133] (11) Add 393 g / t of water glass to the fluorite rough concentrate in step (10) to obtain fluorite cleaning 1 foam and fluorite cleaning middlings 1;

[0134] (12) Add 393 g / t of collector CYS-7 (modified fatty acid) to the fluorite roughing tailings in step (10) for fluorite scavenging, obtaining fluorite scavenging concentrate and fluorite scavenging tailings;

[0135] (13) Combine the fluorite beneficiation middlings 1 in step (11) with the fluorite scavenging concentrate in step (12), add 147 g / t of acidified water glass, and perform flotation to obtain the middling concentrate foam. The tailings obtained from the middling beneficiation are discharged into the tailings pond;

[0136] (14) Return the middling concentrate foam obtained in step (13) to the fluorite roughing operation;

[0137] (15) Perform the 2nd to 7th beneficiations on the fluorite beneficiation 1 foam in step (11). The inhibitors added in the beneficiation agents are all acidified water glass, and the dosages are 294 g / t, 294 g / t, 147 g / t, 147 g / t, 98 g / t, and 49 g / t in sequence. The middlings obtained from the beneficiation are returned in sequence to obtain a fluorite concentrate product with a yield of 16.15%, a CaF2 grade of 91.89%, and a CaF2 recovery rate of 75.04%.

[0138] Compared with the beneficiation method of Example 1, the regrinding of the middling beneficiation foam is cancelled. Some fluorite-vein intergrown minerals with poor floatability are inhibited and lost in the flotation tailings in the fluorite beneficiation section, while another part of the fluorite-vein intergrown minerals with good floatability enter the fluorite concentrate product, affecting the CaF2 grade and ultimately resulting in a 5.37 and 6.80 percentage point reduction in the CaF2 grade and recovery rate of the fluorite concentrate respectively.

[0139] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0140] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore, characterized in that, It includes the following steps: (1) Feed the grinding product obtained by grinding and classifying the -5mm high-pressure roller mill product of the original ore into a stirring tank for pulp mixing to obtain the feed pulp; (2) Conduct rough flotation of molybdenum and bismuth mixed flotation on the feed pulp in step (1) to obtain the rough concentrate of molybdenum, bismuth and sulfur and the rough flotation tailings; (3) Conduct cleaning flotation on the rough concentrate of molybdenum, bismuth and sulfur mixed flotation in step (2) to obtain the mixed concentrate of molybdenum, bismuth and sulfur; for the middlings in the cleaning flotation of mixed flotation, return them in sequence to the rough flotation of molybdenum and bismuth mixed flotation again; (4) Conduct scavenging flotation on the rough flotation tailings in step (2) to obtain the scavenging concentrate and the scavenging tailings; (5) Conduct secondary regrinding on the scavenging concentrate in step (4), and return the obtained regrinding product to the cleaning flotation operation of mixed flotation; (6) Conduct weak magnetic separation on the scavenging tailings in step (4) to obtain iron concentrate and weak magnetic tailings; (7) Conduct "1 roughing, 1 cleaning, 1 scavenging" strong magnetic roughing operation on the weak magnetic tailings in step (6) to obtain the rough concentrate of wolframite and the strong magnetic tailings, and merge the middlings in the strong magnetic cleaning and the scavenging concentrate of strong magnetic separation and return them to the strong magnetic roughing operation again; (8) For the rough concentrate of wolframite in step (7), obtain wolframite concentrate and gravity separation tailings through gravity separation, and return the gravity separation tailings to the strong magnetic roughing operation; (9) Feed the strong magnetic tailings in step (7) into scheelite flotation to obtain scheelite concentrate and scheelite flotation tailings; (10) Conduct fluorite flotation on the scheelite flotation tailings in step (9), and through the "1 roughing, 1 cleaning, 1 scavenging" process, obtain the fluorite cleaning 1 foam and the fluorite scavenging tailings. Merge the middlings 1 in the fluorite cleaning and the scavenging foam for one-time middlings cleaning. The obtained foam product returns to the fluorite roughing operation after regrinding. Merge the tailings of the middlings cleaning and the fluorite scavenging tailings and discharge them into the tailings pond; (11) Conduct 2 - 8 times of repeated cleaning operations on the fluorite cleaning 1 foam in step (10) to obtain fluorite concentrate products, and return the cleaning middlings in sequence; 2. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that: In step (1), the original ore is pre-ground in a coarse grinding manner, and when the fineness is 45% - 75% of -0.075mm, first recover molybdenum and bismuth minerals with coarser embedded particle size and higher monomer dissociation degree.

3. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, wherein In step (2), a roughing regulator and a collector are added in the rough flotation of molybdenum and bismuth mixed flotation. The roughing regulator is one or a combination of sodium carbonate, sodium hydroxide, sodium hexametaphosphate, sodium fluorosilicate, and water glass; the collector includes one or a combination of ethyl xanthate, ethyl thionocarbamate, xanthate, ammonium dibutyl dithiophosphate, kerosene, and diesel.

4. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (3), a cleaning inhibitor is added in the cleaning flotation of mixed flotation. The cleaning inhibitor includes one or a combination of water glass, acidified water glass, ammonium fluorosilicate, aluminum sulfate, sodium carboxymethyl cellulose, and calcium lignosulfonate.

5. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (4), a scavenging collector is added in the scavenging flotation of mixed flotation. The scavenging collector includes xanthate, black medicine, and ester sulfide ore collectors.

6. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (6), the magnetic field intensity of the weak magnetic separation is 0.10T - 0.20T.

7. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (7), the magnetic field intensity of the strong magnetic separation is 0.50T - 2.0T.

8. The ore dressing method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (8), the gravity separation includes one or several of a shaking table, a centrifugal concentrator, and a rotary vibrating conical concentrator.

9. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (9), a collector and an inhibitor are added in scheelite flotation. The scheelite flotation collector includes one or several combinations of styrene phosphonic acid, salicylhydroxamic acid, benzohydroxamic acid, fatty acids and their modified products, oxidized paraffin soap, etc.; the inhibitor includes one or several combinations of acidified sodium silicate, sodium silicate, sodium hexametaphosphate, aluminum sulfate, guar gum, xanthan gum.

10. The beneficiation method for efficient comprehensive recovery of tungsten-molybdenum-bismuth polymetallic ore according to claim 1, characterized in that, In step (10), a collector is added in fluorite flotation. The fluorite collector includes one or several combinations of oleic acid, linoleic acid, sodium oleate, oxidized paraffin soap, and various modified fatty acid collectors. In step (11), an inhibitor is added in cleaning. The inhibitor includes one or several combinations of acidified sodium silicate, sodium silicate, sodium hexametaphosphate, aluminum sulfate, guar gum, tannin extract, caustic starch, modified polyacrylic acid.

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