Method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings

Abstract

The invention provides a method for efficiently recovering low-grade fine-grain scheelite from copper-sulfur tailings, and relates to the field of mineral separation. The method for efficiently recovering the low-grade fine-grain scheelite from the copper-sulfur tailings comprises the steps that the copper-sulfur tailings are subjected to coarse-fine grading, the coarse-grain grade is subjected to gravity separation and tailing discarding, gravity separation rough concentrate is obtained, the fine-grain grade is subjected to desliming, and cyclone settled sand is obtained; hydrocyclone settled sand and reselected rough concentrate are combined for desulfurization flotation, and sulfur concentrate and desulfurized tailings are obtained; the desulfurized tailings are subjected to normal-temperature flotation, and scheelite normal-temperature flotation concentrate and normal-temperature flotation tailings are obtained; the scheelite normal-temperature flotation concentrate is pretreated through sodium carbonate, then heating concentration is conducted, and scheelite heating flotation concentrate and heating flotation tailings are obtained; and the scheelite heating flotation concentrate is subjected to acid leaching, and acid-leached tungsten concentrate is obtained. According to the method, efficient recovery of the low-grade fine-grain scheelite in the copper-sulfur tailings is achieved, meanwhile, comprehensive recovery of the valuation sulfur concentrate is achieved, the product valuation value of the copper-sulfur tailings is increased, and application and popularization are facilitated.

Description

Technical Field

[0001] This application relates to the field of ore dressing, and particularly to a method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings. Background Art

[0002] China is rich in tungsten ore resources. However, due to the brittle and friable nature of tungsten ore, problems such as a high content of fine particles and serious slimeification often occur during the development and utilization process, making it difficult to recover and utilize tungsten resources. According to statistics, about 1 / 5 of the world's tungsten resources are lost in fine mud every year. Therefore, realizing the efficient recovery and utilization of fine-grained tungsten resources is of great strategic significance for promoting the sustainable development of resources.

[0003] Scheelite is often associated with calcium-containing gangue minerals such as fluorite and calcite. Due to their similar surface chemical properties, these calcium-containing gangue minerals are easily entrained in the scheelite concentrate during the flotation process, deteriorating the flotation effect of scheelite. For scheelite with a WO3 grade < 0.10%, an S grade > 1.50%, a proportion of easily slimeified silicate minerals and calcium-containing gangue minerals > 50%, and a proportion of -0.020mm ultra-fine particle size > 30%, due to the difficulties of high sulfide content, high content of easily slimeified silicate minerals and calcium-containing minerals, fine particle size of scheelite, and low WO3 grade, it is difficult to obtain high-quality scheelite using conventional ore dressing processes, which limits the efficient recovery of scheelite from copper-sulfur tailings.

[0004] Therefore, developing an ore dressing technology suitable for high-sulfur tungsten ratio, high-calcium, low-grade, and easily slimeified scheelite is not only of great significance for the green and efficient production of scheelite, but also of great significance for realizing the comprehensive utilization of tailings. Summary of the Invention

[0005] The purpose of this application is to provide a method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings to solve the above problems.

[0006] To achieve the above purpose, the following technical solutions are adopted in this application: A method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings, comprising: (1) Classifying the copper-sulfur tailings into coarse and fine grades, subjecting the coarse grade to gravity separation for tailing rejection to obtain a gravity separation rough concentrate, and subjecting the fine grade to desliming to obtain hydrocyclone underflow; (2) Combining the hydrocyclone underflow with the gravity separation rough concentrate and performing desulfurization flotation to obtain a sulfur concentrate and desulfurization tailings; (3) Performing normal-temperature flotation of scheelite on the desulfurization tailings to obtain a normal-temperature flotation concentrate of scheelite and normal-temperature flotation tailings; (4) Pretreating the normal-temperature flotation concentrate of scheelite with sodium carbonate, and then performing heating and cleaning to obtain a heating flotation concentrate of scheelite and heating flotation tailings; (5) Acid-leach the scheelite heating flotation concentrate with hydrochloric acid to obtain acid-leached tungsten concentrate.

[0007] According to an embodiment of the present application, the copper-sulfur tailings are ore samples with a WO3 grade <0.10%, an S grade >1.50%, a proportion of slime-forming silicate minerals and calcium-containing gangue minerals >50%, and a proportion of -0.020mm ultra-fine particle size fraction >30%; And / or, the coarse particle size fraction is treated by a combination of a spiral chute and a shaking table for heavy medium tailing discarding, and the fine particle size fraction is treated by a hydrocyclone for desliming.

[0008] According to an embodiment of the present application, the reagents used in the desulfurization flotation process in step (2) include an activator, a first collector, and a foaming agent; The activator includes at least one of sulfuric acid, oxalic acid, and copper sulfate, and the total dosage of the activator is 500-1500 g / t of raw ore; The first collector includes at least one of butyl xanthate and amyl xanthate, and the total dosage of the first collector is 50-400 g / t of raw ore; The foaming agent includes No. 2 oil, and the total dosage of the foaming agent is 20-100 g / t of raw ore.

[0009] According to an embodiment of the present application, the desulfurization flotation includes one roughing, two cleanings, and one scavenging; The reagents used in the one roughing include: the activator with a dosage of 400-1000 g / t of raw ore, the first collector with a dosage of 30-300 g / t of raw ore, and the foaming agent with a dosage of 15-70 g / t of raw ore; Both of the two cleanings are blank cleanings; The reagents used in the one scavenging include: the activator with a dosage of 100-500 g / t of raw ore, the first collector with a dosage of 20-100 g / t of raw ore, and the foaming agent with a dosage of 5-30 g / t of raw ore.

[0010] According to an embodiment of the present application, the reagents used in the scheelite normal temperature flotation process in step (3) include at least one of a first regulator, an inhibitor, a second collector, and an auxiliary collector; The first regulator includes at least one of sodium carbonate and sodium hydroxide, and the total dosage of the first regulator is 300-1000 g / t of raw ore; The inhibitor includes at least one of water glass, sodium hexametaphosphate, and sodium carboxymethyl cellulose, and the total dosage of the inhibitor is 1000-3000 g / t of raw ore; The second collector includes at least one of 731, 733, and BK418, and the total dosage of the second collector is 200-2000 g / t of raw ore; The auxiliary collector includes BK411, and the total dosage of the auxiliary collector is 20 - 50 g / t of raw ore.

[0011] According to the embodiment of the present application, the normal-temperature flotation of scheelite includes one rough selection, three cleaning selections, one fine scavenging selection, and two scavenging selections; The reagents used in the one rough selection include: the first regulator with a dosage of 300 - 1000 g / t of raw ore, the inhibitor with a dosage of 700 - 2400 g / t of raw ore, the second collector with a dosage of 160 - 1600 g / t of raw ore, and the auxiliary collector with a dosage of 20 - 50 g / t of raw ore; The reagents used in the one fine scavenging selection include: the second collector with a dosage of 10 - 100 g / t of raw ore; The three cleaning selections include the first cleaning selection, the second cleaning selection, and the third cleaning selection. The reagents used in the first cleaning selection include: the inhibitor with a dosage of 200 - 400 g / t of raw ore; the reagents used in the second cleaning selection include: the inhibitor with a dosage of 100 - 200 g / t of raw ore; the third cleaning selection is a blank cleaning selection; The two scavenging selections include the first scavenging selection and the second scavenging selection. The reagents used in the first scavenging selection include: the second collector with a dosage of 20 - 200 g / t of raw ore; the reagents used in the second scavenging selection include: the second collector with a dosage of 10 - 100 g / t of raw ore.

[0012] According to the embodiment of the present application, during the pretreatment process in step (4), the dosage of sodium carbonate is 500 - 2000 g / t of raw ore; After the pretreatment is completed, the method further includes: adding a second regulator and a third collector to the pulp, and performing heating and stirring; The second regulator includes at least one of water glass and sodium sulfide; The dosage of the second regulator is 4000 - 10000 g / t of raw ore; The third collector includes BK418, and the dosage of the third collector is 20 - 200 g / t of raw ore; The temperature of the heating and stirring is 95°C - 100°C, and the time of the heating and stirring is 30 - 90 min.

[0013] According to the embodiment of the present application, the second regulator includes water glass and sodium sulfide. The dosage of water glass is 4000 - 8000 g / t of raw ore, and the dosage of sodium sulfide is 500 - 2000 g / t of raw ore; And / or, after the heating and stirring is completed, the method further includes: performing heating cleaning; The reagents used in the heating cleaning include a fourth collector; The fourth collector includes BK418; The total dosage of the fourth collector is 2 - 5 g / t of raw ore.

[0014] According to the embodiments of the present application, the warm beneficiation includes one roughing, five cleaning, and two scavenging; Both the one roughing and the five cleaning are blank flotation; The two scavenging include the third scavenging and the fourth scavenging. The reagents used in the third scavenging include: the fourth collector with a dosage of 1.5 - 3.5 g / t of raw ore; the reagents used in the fourth scavenging include: the fourth collector with a dosage of 0.5 - 1.5 g / t of raw ore.

[0015] According to the embodiments of the present application, the concentration of the hydrochloric acid in step (5) is 2% - 10%; The liquid - solid ratio of the acid leaching process is (5 - 20) ml:1 g, hereinafter simply referred to as 5:1 - 20:1.

[0016] Compared with the prior art, the beneficial effects of the present application include: (1) Adopting the process of pre - classification of raw ore - combined gravity separation of coarse particles for tailing rejection - enhanced desliming of fine particles, most of the coarse - grained gangue minerals and fine - grained slimes are removed in advance, reducing the interference of easily slime - forming gangue minerals on tungsten flotation, reducing the flotation feed amount, and achieving the pre - enrichment of tungsten minerals; (2) Adopting the process of combining the gravity separation concentrate of coarse particles and the desliming sand of fine particles to enhance desulfurization, reducing the interference of easily floatable sulfide minerals such as pyrite and pyrrhotite on tungsten flotation, and obtaining a marketable sulfur concentrate product at the same time; (3) Adopting the process of normal - temperature tungsten separation from the desulfurized tailings - pretreatment of normal - temperature tungsten concentrate followed by warm beneficiation - acid leaching of warm tungsten concentrate, reducing the interference of inevitable calcium ions on tungsten flotation, optimizing the tungsten flotation environment, saving the dosage of flotation reagents, reducing the reagent cost, and obtaining high - grade scheelite concentrate. Brief Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope of the present application.

[0018] Figure 1 It is a schematic flow diagram for efficiently recovering low - grade fine - grained scheelite from copper - sulfur tailings in the embodiments of the present application; Figure 2 It is a schematic flow diagram of pre - classification of raw ore - combined gravity separation of coarse particles for tailing rejection - enhanced desliming of fine particles in the embodiments of the present application; Figure 3Schematic flow diagram of the combined enhanced desulfurization of the coarse-grained gravity separation concentrate and the fine-grained desliming underflow in the embodiments of the present application; Figure 4 Schematic flow diagram of the normal-temperature tungsten separation from the desulfurized tailings in the embodiments of the present application; Figure 5 Schematic flow diagram of the pre-treatment of the normal-temperature tungsten concentrate followed by heating and beneficiation - acid leaching of the heated tungsten concentrate in the embodiments of the present application. Detailed implementation manners

[0019] As used herein, the terms: As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0020] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, whether or not the ranges are separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0021] In these embodiments, unless otherwise specified, the parts and percentages are by mass.

[0022] "And / or" is used to indicate that either or both of the stated circumstances may occur. For example, A and / or B includes (A and B) and (A or B).

[0023] To better illustrate the technical solutions provided by the present application, before the embodiments, a general statement of the technical solutions is made as follows: The present application provides a method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings, comprising: (1) Classifying the copper-sulfur tailings into coarse and fine fractions, subjecting the coarse fraction to gravity separation for tailing rejection to obtain a gravity separation coarse concentrate, and subjecting the fine fraction to desliming to obtain a hydrocyclone underflow; (2) Combining the hydrocyclone underflow with the gravity separation coarse concentrate and performing desulfurization flotation to obtain a sulfur concentrate and a desulfurized tailings; (3) Subjecting the desulfurized tailings to normal-temperature scheelite flotation to obtain a normal-temperature scheelite flotation concentrate and a normal-temperature flotation tailings; (4) Pretreat the scheelite normal-temperature flotation concentrate with sodium carbonate, and then carry out heating and beneficiation to obtain a scheelite heating flotation concentrate and heating flotation tailings; (5) Leach the scheelite heating flotation concentrate with hydrochloric acid to obtain a leached tungsten concentrate.

[0024] This application realizes the efficient recovery of low-grade fine-grained scheelite in copper-sulfur tailings, and at the same time realizes the comprehensive recovery of priced sulfur concentrates, improves the product pricing value of copper-sulfur tailings, and is convenient for popularization and application.

[0025] Since the tungsten content in coarse-grained minerals is very low, most of the coarse-grained minerals are removed in advance through step (1), directly reducing the burden of subsequent flotation operations, significantly reducing the feed amount of subsequent flotation, thereby improving the efficiency of the overall treatment process, and also reducing the treatment of unnecessary materials at the source, which helps to save resources and energy. Since the slime content in fine-grained slime is very high, which is not conducive to flotation, removing the fine-grained slime in advance through step (1) can significantly reduce the interference of easily slime-forming gangue minerals on flotation, improve the flotation effect, and ensure the quality and output of the final product.

[0026] According to an embodiment of the present application, the copper-sulfur tailings are ore samples with a WO3 grade <0.10%, an S grade >1.50%, a proportion of easily slime-forming silicate minerals and calcium-containing gangue minerals >50%, and a proportion of -0.020mm extremely fine-grained fraction >30%; And / or, the coarse-grained fraction is treated by the combined method of a spiral chute and a shaking table for gravity separation tailing removal, and the fine-grained fraction is treated by a hydrocyclone for desliming.

[0027] In some embodiments, in step (1), after the copper-sulfur tailings are classified into coarse and fine fractions, the coarse-grained fraction is pre-removed of tailings by a spiral chute, and the spiral chute concentrate is secondarily removed of tailings by a shaking table to obtain the shaking table concentrate as the gravity separation rough concentrate; the fine-grained fraction is intensively deslimed by two-stage series-connected hydrocyclones to obtain hydrocyclone sand. Specifically, after the coarse-grained fraction is classified by a spiral chute, a spiral chute concentrate and a spiral chute tailings are obtained. The spiral chute concentrate is fed into a shaking table for separation to obtain a shaking table concentrate and a shaking table tailings. The spiral chute tailings and the shaking table tailings are pre-removed as gravity separation tailings, and the shaking table concentrate is the gravity separation rough concentrate; the fine-grained fraction is first deslimed by a first-stage hydrocyclone to obtain first-stage fine slime and first-stage sand. The first-stage fine slime is fed into a second-stage hydrocyclone for desliming to obtain second-stage fine slime and second-stage sand. The first-stage sand and the second-stage sand are combined as hydrocyclone sand.

[0028] In some embodiments, after the copper-sulfur tailings are classified into coarse and fine fractions, the coarse-grained ore sample with a particle size above 0.074mm can be screened out from the fine-grained ore sample with a particle size less than 0.074mm.

[0029] In some embodiments, the feed concentration of the hydrocyclone in step (1) is 20% - 25%, and the feed pressure is 0.1 MPa.

[0030] According to the embodiments of the present application, the reagents used in the desulfurization flotation process in step (2) include an activator, a first collector, and a frother; The activator includes at least one of sulfuric acid, oxalic acid, and copper sulfate, and the total dosage of the activator is 500 - 1500 g / t of raw ore; The first collector includes at least one of butyl xanthate and amyl xanthate, and the total dosage of the first collector is 50 - 400 g / t of raw ore; The frother includes No. 2 oil, and the total dosage of the frother is 20 - 100 g / t of raw ore.

[0031] In some embodiments, the total dosage of the activator can be 500 g / t of raw ore, 600 g / t of raw ore, 700 g / t of raw ore, 800 g / t of raw ore, 900 g / t of raw ore, 1000 g / t of raw ore, 1100 g / t of raw ore, 1200 g / t of raw ore, 1300 g / t of raw ore, 1400 g / t of raw ore, 1500 g / t of raw ore, or any value between 500 - 1500 g / t of raw ore.

[0032] In some embodiments, the total dosage of the first collector can be 50 g / t of raw ore, 100 g / t of raw ore, 150 g / t of raw ore, 200 g / t of raw ore, 250 g / t of raw ore, 300 g / t of raw ore, 350 g / t of raw ore, 400 g / t of raw ore, or any value between 50 - 400 g / t of raw ore.

[0033] In some embodiments, the total dosage of the frother can be 20 g / t of raw ore, 30 g / t of raw ore, 40 g / t of raw ore, 50 g / t of raw ore, 60 g / t of raw ore, 70 g / t of raw ore, 80 g / t of raw ore, 90 g / t of raw ore, 100 g / t of raw ore, or any value between 20 - 100 g / t of raw ore.

[0034] According to the embodiments of the present application, the desulfurization flotation includes one roughing, two cleanings, and one scavenging; The reagents used in the one roughing include: the activator with a dosage of 400 - 1000 g / t of raw ore, the first collector with a dosage of 30 - 300 g / t of raw ore, and the frother with a dosage of 15 - 70 g / t of raw ore; In some embodiments, the dosage of the activator during the first rough selection can be 400 g / t of raw ore, 500 g / t of raw ore, 600 g / t of raw ore, 700 g / t of raw ore, 800 g / t of raw ore, 900 g / t of raw ore, 1000 g / t of raw ore, or any value between 400 and 1000 g / t of raw ore; the dosage of the first collector during the first rough selection can be 30 g / t of raw ore, 50 g / t of raw ore, 100 g / t of raw ore, 150 g / t of raw ore, 200 g / t of raw ore, 250 g / t of raw ore, 300 g / t of raw ore, or any value between 30 and 300 g / t of raw ore; the dosage of the foaming agent during the first rough selection can be 15 g / t of raw ore, 20 g / t of raw ore, 30 g / t of raw ore, 40 g / t of raw ore, 48 g / t of raw ore, 50 g / t of raw ore, 60 g / t of raw ore, 70 g / t of raw ore, or any value between 15 and 70 g / t of raw ore.

[0035] Both of the two scavenging processes are blank scavenging; The reagents used in the first scavenging include: the activator with a dosage of 100 - 500 g / t of raw ore, the first collector with a dosage of 20 - 100 g / t of raw ore, and the foaming agent with a dosage of 5 - 30 g / t of raw ore.

[0036] In some embodiments, the dosage of the activator during the first scavenging can be 100 g / t of raw ore, 200 g / t of raw ore, 300 g / t of raw ore, 400 g / t of raw ore, 500 g / t of raw ore, or any value between 100 and 500 g / t of raw ore; the dosage of the first collector during the first scavenging can be 20 g / t of raw ore, 30 g / t of raw ore, 40 g / t of raw ore, 50 g / t of raw ore, 60 g / t of raw ore, 70 g / t of raw ore, 80 g / t of raw ore, 90 g / t of raw ore, 100 g / t of raw ore, or any value between 20 and 100 g / t of raw ore; the dosage of the foaming agent during the first scavenging can be 5 g / t of raw ore, 10 g / t of raw ore, 15 g / t of raw ore, 20 g / t of raw ore, 24 g / t of raw ore, 30 g / t of raw ore, or any value between 5 and 30 g / t of raw ore.

[0037] Through step (2), sulfides in the copper-sulfur tailings can be removed.

[0038] According to the embodiments of the present application, the reagents used in the scheelite normal-temperature flotation process in step (3) include at least one of a first regulator, an inhibitor, a second collector, and an auxiliary collector; The first regulator includes at least one of sodium carbonate and sodium hydroxide, and the total dosage of the first regulator is 300 - 1000 g / t of raw ore; The inhibitor includes at least one of sodium silicate, sodium hexametaphosphate, and sodium carboxymethylcellulose, and the total dosage of the inhibitor is 1000 - 3000 g / t of raw ore; The second collector includes at least one of 731, 733, and BK418 (a mixture of fatty acid soaps), and the total dosage of the second collector is 200 - 2000 g / t of raw ore; The auxiliary collector includes BK411, and the total dosage of the auxiliary collector is 20 - 50 g / t of raw ore.

[0039] In some embodiments, the total dosage of the first regulator can be 300 g / t of raw ore, 400 g / t of raw ore, 500 g / t of raw ore, 600 g / t of raw ore, 700 g / t of raw ore, 800 g / t of raw ore, 900 g / t of raw ore, 1000 g / t of raw ore, or any value between 300 - 1000 g / t of raw ore; In some embodiments, the total dosage of the inhibitor can be 1000 g / t of raw ore, 1500 g / t of raw ore, 2000 g / t of raw ore, 2500 g / t of raw ore, 3000 g / t of raw ore, or any value between 1000 - 3000 g / t of raw ore; In some embodiments, the total dosage of the second collector can be 200 g / t of raw ore, 500 g / t of raw ore, 700 g / t of raw ore, 1000 g / t of raw ore, 1200 g / t of raw ore, 1500 g / t of raw ore, 1700 g / t of raw ore, 2000 g / t of raw ore, or any value between 200 - 2000 g / t of raw ore.

[0040] In some embodiments, the total dosage of the auxiliary collector can be 20 g / t of raw ore, 25 g / t of raw ore, 30 g / t of raw ore, 36 g / t of raw ore, 40 g / t of raw ore, 45 g / t of raw ore, 50 g / t of raw ore, or any value between 20 - 50 g / t of raw ore.

[0041] According to the embodiments of the present application, the scheelite normal-temperature flotation includes one roughing, three cleanings, one scavenging of the concentrate, and two scavengings; The reagents used in the one roughing include: the first regulator with a dosage of 300 - 1000 g / t of raw ore, the inhibitor with a dosage of 700 - 2400 g / t of raw ore, the second collector with a dosage of 160 - 1600 g / t of raw ore, and the auxiliary collector with a dosage of 20 - 50 g / t of raw ore; In some embodiments, the dosage of the first regulator during the first rough selection can be 300 g / t of raw ore, 400 g / t of raw ore, 500 g / t of raw ore, 600 g / t of raw ore, 700 g / t of raw ore, 800 g / t of raw ore, 900 g / t of raw ore, 1000 g / t of raw ore, or any value between 300 and 1000 g / t of raw ore; the dosage of the inhibitor during the first rough selection can be 700 g / t of raw ore, 1000 g / t of raw ore, 1500 g / t of raw ore, 1600 g / t of raw ore, 2000 g / t of raw ore, 2400 g / t of raw ore, or any value between 700 and 2400 g / t of raw ore; the dosage of the second collector during the first rough selection can be 160 g / t of raw ore, 200 g / t of raw ore, 500 g / t of raw ore, 600 g / t of raw ore, 700 g / t of raw ore, 1000 g / t of raw ore, 1200 g / t of raw ore, 1500 g / t of raw ore, 1600 g / t of raw ore, or any value between 160 and 1600 g / t of raw ore; the dosage of the auxiliary collector during the first rough selection can be 20 g / t of raw ore, 25 g / t of raw ore, 30 g / t of raw ore, 36 g / t of raw ore, 40 g / t of raw ore, 45 g / t of raw ore, 50 g / t of raw ore, or any value between 20 and 50 g / t of raw ore.

[0042] The reagents used in the first scavenging include: the second collector with a dosage of 10 - 100 g / t of raw ore; In some embodiments, the dosage of the second collector during the first scavenging can be 10 g / t of raw ore, 50 g / t of raw ore, 100 g / t of raw ore, or any value between 10 and 100 g / t of raw ore.

[0043] The three-stage cleaning includes the first cleaning, the second cleaning, and the third cleaning. The reagents used in the first cleaning include: the inhibitor with a dosage of 200 - 400 g / t of raw ore; the reagents used in the second cleaning include: the inhibitor with a dosage of 100 - 200 g / t of raw ore; the third cleaning is blank cleaning; In some embodiments, the dosage of the inhibitor during the first cleaning can be 200 g / t of raw ore, 300 g / t of raw ore, 400 g / t of raw ore, or any value between 200 and 400 g / t of raw ore; the dosage of the inhibitor during the second cleaning can be 100 g / t of raw ore, 150 g / t of raw ore, 200 g / t of raw ore, or any value between 100 and 200 g / t of raw ore.

[0044] The two-stage scavenging includes the first scavenging and the second scavenging. The reagents used in the first scavenging include: the second collector with a dosage of 20 - 200 g / t of raw ore; the reagents used in the second scavenging include: the second collector with a dosage of 10 - 100 g / t of raw ore.

[0045] In some embodiments, the dosage of the second collector during the first scavenging can be 20 g / t of raw ore, 100 g / t of raw ore, 200 g / t of raw ore, or any value between 20 and 200 g / t of raw ore; the dosage of the second collector during the second scavenging can be 10 g / t of raw ore, 50 g / t of raw ore, 100 g / t of raw ore, or any value between 10 and 100 g / t of raw ore.

[0046] In some embodiments, during the normal-temperature flotation of tungsten in step (3), the concentration of the roughing pulp is 25% - 45%.

[0047] According to the embodiments of the present application, during the pretreatment process in step (4), the dosage of sodium carbonate is 500 - 2000 g / t of raw ore. Within this dosage range, tungsten concentrate indexes with both high tungsten grade and high tungsten recovery rate can be obtained. When the dosage of sodium carbonate is too small, it is not conducive to the improvement of the tungsten concentrate grade. When the dosage of sodium carbonate is too large, both the tungsten concentrate grade and recovery rate indexes are poor. By adding sodium carbonate during the pretreatment process in step (4), on the one hand, the slightly soluble calcium sulfate covering the mineral surface can be transformed into insoluble calcium carbonate precipitate, reducing the dissolution of calcium ions. On the other hand, the dissolved calcium ions and the original calcium ions in the pulp can form calcium carbonate precipitate, reducing the interference of calcium ions. After the acid leaching step in step (5), acid leached tungsten concentrate and leaching solution are obtained. Calcium carbonate reacts with hydrochloric acid to form soluble calcium ions, which are then transferred to the leaching solution, thereby obtaining high-grade tungsten concentrate.

[0048] In some embodiments, during the pretreatment process in step (4), the dosage of sodium carbonate can be 500 g / t of raw ore, 1000 g / t of raw ore, 1500 g / t of raw ore, 2000 g / t of raw ore, or any value between 500 and 2000 g / t of raw ore.

[0049] After the pretreatment is completed, the method further includes: adding a second regulator and a third collector to the pulp, and performing heating and stirring. The second regulator includes at least one of water glass and sodium sulfide. The dosage of the second regulator is 4000 - 10000 g / t of raw ore; for example, the dosage of the second regulator can be 4000 g / t of raw ore, 5000 g / t of raw ore, 6000 g / t of raw ore, 7000 g / t of raw ore, 8000 g / t of raw ore, 9000 g / t of raw ore, 10000 g / t of raw ore, or any value between 4000 and 10000 g / t of raw ore. The third collector includes BK418, and the dosage of the third collector is 20 - 200 g / t of raw ore; for example, the dosage of the third collector can be 20 g / t of raw ore, 50 g / t of raw ore, 70 g / t of raw ore, 100 g / t of raw ore, 120 g / t of raw ore, 150 g / t of raw ore, 170 g / t of raw ore, 200 g / t of raw ore, or any value between 20 - 200 g / t of raw ore.

[0050] The temperature of the heating and stirring is 95°C - 100°C, and the time of the heating and stirring is 30 - 90 min.

[0051] For example, the temperature of the heating and stirring can be 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, or any value between 95°C - 100°C; the time of the heating and stirring can be 30 min, 60 min, 90 min, or any value between 30 - 90 min.

[0052] According to an embodiment of the present application, the second regulator includes water glass and sodium sulfide. The dosage of the water glass is 4000 - 8000 g / t of raw ore, and the dosage of the sodium sulfide is 500 - 2000 g / t of raw ore; For example, the dosage of the water glass can be 4000 g / t of raw ore, 5000 g / t of raw ore, 6000 g / t of raw ore, 7000 g / t of raw ore, 8000 g / t of raw ore, or any value between 4000 - 8000 g / t of raw ore, and the dosage of the sodium sulfide can be 500 g / t of raw ore, 1000 g / t of raw ore, 1500 g / t of raw ore, 2000 g / t of raw ore, or any value between 500 - 2000 g / t of raw ore.

[0053] And / or, after the heating and stirring is completed, the method further includes: performing heating concentration; The reagent used for the heating concentration includes a fourth collector; The fourth collector includes BK418; The total dosage of the fourth collector is 2 - 5 g / t of raw ore. For example, the total dosage of the fourth collector can be 2 g / t of raw ore, 3 g / t of raw ore, 4 g / t of raw ore, 5 g / t of raw ore, or any value between 2 - 5 g / t of raw ore.

[0054] According to an embodiment of the present application, the heating concentration includes one roughing, five cleanings, and two scavengings; Both the one roughing and the five cleanings are blank flotation; The two-stage scavenging includes the third scavenging and the fourth scavenging. The reagents used in the third scavenging include: the fourth collector with a dosage of 1.5 - 3.5 g / t of the original ore; the reagents used in the fourth scavenging include: the fourth collector with a dosage of 0.5 - 1.5 g / t of the original ore.

[0055] In some embodiments, the dosage of the fourth collector during the third scavenging can be 1.5 g / t of the original ore, 2 g / t of the original ore, 2.5 g / t of the original ore, 3 g / t of the original ore, 3.5 g / t of the original ore, or any value between 1.5 - 3.5 g / t of the original ore; the dosage of the fourth collector during the fourth scavenging can be 0.5 g / t of the original ore, 1 g / t of the original ore, 1.5 g / t of the original ore, or any value between 0.5 - 1.5 g / t of the original ore.

[0056] According to the embodiments of the present application, the concentration of the hydrochloric acid in step (5) is 2% - 10%; for example, the concentration of the hydrochloric acid in step (5) can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any value between 2% - 10%. The liquid-solid ratio of the acid leaching process is (5 - 20) ml:1 g, hereinafter simply referred to as 5:1 - 20:1. For example, the liquid-solid ratio of the acid leaching process can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, or any value between 5:1 - 20:1.

[0057] The implementation solutions of the present application will be described in detail below in conjunction with specific embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0058] Taking a certain copper-sulfur tailing in China as an example, the WO3 grade in this copper-sulfur tailing is 0.087%, mainly existing in the form of scheelite, the S grade is 2.36%, the proportion of easily slime-forming silicate minerals such as muscovite, biotite, chlorite, etc. and calcium-containing gangue minerals such as calcite, grossularite - andradite is 58%, and the proportion of the extremely fine particle size of -0.020 mm is 35%. It is a high sulfur-tungsten ratio, high calcium, low grade, and easily slime-forming scheelite.

[0059] Example 1 In this example, the above copper-sulfur tailing is used as the feed ore, and the beneficiation process is as Figure 1 shown, specifically including the following steps: (1)Pre-tailing: Screen the copper-sulfur tailings into +0.074mm coarse fraction and -0.074mm fine fraction. After the +0.074mm coarse fraction is classified by a spiral chute, spiral chute concentrate and spiral chute tailings are obtained. Feed the spiral chute concentrate into a shaking table for separation to obtain shaking table concentrate and shaking table tailings. The spiral chute tailings and the shaking table tailings are pre-discarded as gravity separation tailings, and the shaking table concentrate is the gravity separation rough concentrate. The -0.074mm fine fraction is first deslimed by a first-stage hydrocyclone to obtain first-stage fine slime and first-stage sand. Feed the first-stage fine slime into a second-stage hydrocyclone for desliming to obtain second-stage fine slime and second-stage sand. The first-stage sand and the second-stage sand are combined into hydrocyclone sand, as shown in Figure 2 shown.

[0060] (2)Enhanced desulfurization: Combine the gravity separation rough concentrate obtained in step (1) and the hydrocyclone sand as the feed for desulfurization, and conduct sulfide flotation. After one roughing, two cleanings, and one scavenging, sulfur concentrate and desulfurized tailings are obtained. The reagents used in one roughing are: sulfuric acid 600g / t, butyl xanthate 200g / t, No. 2 oil 48g / t. Both cleanings are blank cleanings. The reagents used in one scavenging are: sulfuric acid 300g / t, butyl xanthate 80g / t, No. 2 oil 24g / t, as shown in Figure 3 shown.

[0061] (3)Scheelite normal-temperature flotation: Use the desulfurized tailings as the feed for scheelite normal-temperature flotation. After one roughing, three cleanings, one cleaning scavenging, and two scavengings, scheelite normal-temperature flotation concentrate, normal-temperature flotation tailings (i.e., tailing I and tailing II) are obtained. Among them, the feed for cleaning scavenging is the tailings of the first cleaning. The remaining product in the cell obtained from cleaning scavenging is tailing II. The remaining product in the cell obtained after two scavengings is tailing I. The froth product obtained after three cleanings is scheelite normal-temperature flotation concentrate. The reagents used in one roughing are: sodium carbonate 600g / t, water glass 1600g / t, BK418 (collector) 600g / t, BK411 (auxiliary collector) 36g / t. The reagents used in one cleaning are: water glass 300g / t. The reagents used in one cleaning scavenging are: BK418 (50g / t). The reagents used in the second cleaning are: water glass 150g / t. The third cleaning is a blank cleaning. The reagents used in one scavenging are: BK418 (100g / t). The reagents used in the second scavenging are: BK418 (50g / t), as shown in Figure 4 shown.

[0062] (4)Post-treatment heating and beneficiation of scheelite: The scheelite concentrate obtained by normal-temperature flotation is used as the feed for heating flotation. First, 1500 g / t of sodium carbonate is added for pretreatment. After pretreatment, 5000 g / t of water glass, 1500 g / t of sodium sulfide, and BK418 (50 g / t) are added to the pulp, and the pulp is heated to 95 °C - 100 °C, stirred and kept warm for 60 min, and then heating beneficiation is carried out. The heating beneficiation includes one rough selection, five fine selections, and two scavenging selections. Both the first rough selection and the five fine selections are blank flotation. The reagents used for the first scavenging selection include: BK418 (2 g / t), and the reagents used for the second scavenging selection include: BK418 (1 g / t). The foam product obtained after five fine selections is the scheelite heating flotation concentrate, and the remaining product in the cell obtained after two scavenging selections is the heating flotation tailings (i.e., tailings Ⅲ), as Figure 5 shown.

[0063] (5)Acid leaching: The scheelite heating flotation concentrate is used as the feed for acid leaching. Hydrochloric acid with a concentration of 5% is added until the liquid-solid ratio is 8:1. After stirring for 30 min, filtration operation is used to remove the leachate to obtain acid-leached tungsten concentrate, as Figure 5 shown.

[0064] The beneficiation process indexes of Example 1 are shown in Table 1.

[0065] Table 1 Beneficiation process indexes of Example 1

[0066] Note: The Fe grade in the sulfur concentrate is 40.27%, and the grade of (S + Fe) is 68.23%, reaching the pricing standard.

[0067] Example 2 Referring to the method of Example 1, low-grade fine-grained scheelite is efficiently recovered from copper-sulfur tailings. Other conditions are the same as those in Example 1, except that: in step (4) of Example 2, the dosage of sodium carbonate is 500 g / t of the original ore.

[0068] The beneficiation process indexes of Example 2 are shown in Table 2.

[0069] Table 2 Beneficiation process indexes of Example 2

[0070] Example 3 Referring to the method of Example 1, low-grade fine-grained scheelite is efficiently recovered from copper-sulfur tailings. Other conditions are the same as those in Example 1, except that: in step (4) of Example 3, the dosage of sodium carbonate is 2000 g / t of the original ore.

[0071] The beneficiation process indexes of Example 3 are shown in Table 3.

[0072] Table 3 Beneficiation process indexes of Example 3

[0073] Comparative Example 1 Other conditions were the same as those in Example 1, except that: the whole particle size of copper-sulfur tailings entered the hydrocyclone for desliming. After desliming by two-stage series-connected hydrocyclones, the hydrocyclone sand directly entered the sulfide flotation, and the sulfide flotation process and reagent regime were the same as those in Example 1.

[0074] The comparison results of the desulfurization indexes between Comparative Example 1 and Example 1 are shown in Table 4. Compared with Example 1, the yield of desulfurized tailings obtained in Comparative Example 1 with the whole particle size selected was 91.10%, which was much higher than the yield of desulfurized tailings obtained in Example 1 (50.00%), greatly increasing the feed amount for subsequent tungsten flotation and being unfavorable to the stability of the tungsten flotation process. This further illustrates that the particle size classification selection process adopted in Example 1 is very necessary.

[0075] Table 4 Comparison Table of Desulfurization Indexes between Comparative Example 1 and Example 1

[0076] Comparative Example 2 Other conditions were the same as those in Example 1, except that: the scheelite concentrate at normal temperature was directly subjected to heating flotation without pretreatment with sodium carbonate, and the heating flotation process and reagent regime were the same as those in Example 1.

[0077] The comparison results of the product indexes between Comparative Example 2 and Example 1 are shown in Table 5. Compared with Example 1, the grade and operating recovery rate of WO3 in the scheelite heating flotation concentrate obtained in Comparative Example 2 were both lower, which further confirmed the necessity of the sodium carbonate pretreatment method adopted in Example 1 for tungsten heating flotation.

[0078] Table 5 Comparison Table of Product Indexes between Comparative Example 2 and Example 1

[0079] Comparative Example 3 Referring to the method of Example 1 to efficiently recover low-grade fine-grained scheelite from copper-sulfur tailings, other conditions were the same as those in Example 1, except that: in step (4) of Comparative Example 3, the dosage of sodium carbonate was 200 g / t of raw ore.

[0080] The comparison results of the product indexes between Comparative Example 3 and Example 1 are shown in Table 6. Compared with Example 1, the grade of WO3 and the operating recovery rate in the scheelite heating flotation concentrate obtained in Comparative Example 3 were both lower than the corresponding indexes in Example 1, indicating that when the dosage of sodium carbonate is too small, it is not conducive to the improvement of the grade and recovery rate of tungsten concentrate.

[0081] Table 6 Comparison Table of Product Indexes between Comparative Example 3 and Example 1

[0082] Comparative Example 4 Referring to the method of Example 1, low-grade fine-grained scheelite was efficiently recovered from copper-sulfur tailings. Other conditions were the same as those in Example 1, except that: in step (4) of Comparative Example 4, the dosage of sodium carbonate was 3000 g / t of raw ore.

[0083] The comparison results of the product indexes between Comparative Example 4 and Example 1 are shown in Table 7. Compared with Example 1, the WO3 grade and the operation recovery rate in the scheelite heating flotation concentrate obtained in Comparative Example 4 are lower than the corresponding indexes of Example 1, indicating that when the dosage of sodium carbonate is too much, it is also not conducive to the improvement of the grade and recovery rate of tungsten concentrate.

[0084] Table 7 Comparison Table of Product Indexes between Comparative Example 4 and Example 1

[0085] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

[0086] In addition, those skilled in the art can understand that although some of the embodiments herein include some features included in other embodiments but not other features, the combination of the features of different embodiments means within the scope of the present application and forms different embodiments. For example, in the above claims, any one of the claimed embodiments can be used in any combination. The information disclosed in this background section is only intended to deepen the understanding of the overall background technology of the present application, and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those skilled in the art.

Claims

1. A method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings, characterized in that: include: (1) The copper-sulfur tailings are subjected to coarse and fine classification, the coarse particles are subjected to gravity separation and tailings are discarded to obtain gravity separation coarse concentrate, and the fine particles are subjected to desludging to obtain cyclone sand settling; (2) combining the cyclone sedimentation sand with the gravity separation rough concentrate, and performing desulfurization flotation to obtain sulfur concentrate and desulfurization tailings; (3) subjecting the desulfurized tailings to room-temperature scheelite flotation to obtain room-temperature scheelite flotation concentrate and room-temperature flotation tailings; (4) pre-treating the scheelite room temperature flotation concentrate with sodium carbonate, and then performing heating concentration to obtain scheelite heated flotation concentrate and heated flotation tailings; (5) The heated scheelite flotation concentrate is acid-leached with hydrochloric acid to obtain an acid-leached tungsten concentrate.

2. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 1, characterized in that: The copper-sulfur tailings are ore samples with a WO3 grade of <0.10%, a S grade of >1.50%, a proportion of easily sludged silicate minerals and calcium-containing gangue minerals of >50%, and a proportion of -0.020 mm ultra-fine particles of >30%; And / or, the coarse particle size fraction is subjected to gravity selection and tailings discarding by adopting a spiral chute combined with a shaking table, and the fine particle size fraction is subjected to desludging by adopting a cyclone.

3. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 1, characterized in that: The reagents used in the desulfurization flotation process of step (2) include an activator, a first collector, and a frother; The activator comprises at least one of sulfuric acid, oxalic acid and copper sulfate, and the total amount of the activator is 500-1500 g / t of raw ore; The first collector comprises at least one of butyl xanthate and amyl xanthate, and the total dosage of the first collector is 50-400 g / t of the raw ore; The foaming agent includes No. 2 oil, and the total amount of the foaming agent is 20-100 g / t of raw ore.

4. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 3 is characterized in that: The desulfurization flotation includes one roughing selection, two cleaning selections and one scavenging selection; The reagents used in the primary roughing include: the activator in an amount of 400-1000 g / t of raw ore, the first collector in an amount of 30-300 g / t of raw ore, and the frother in an amount of 15-70 g / t of raw ore; The two selections mentioned above are both blank selections; The reagents used in the first sweep include: the activator in an amount of 100-500 g / t of raw ore, the first collector in an amount of 20-100 g / t of raw ore, and the frother in an amount of 5-30 g / t of raw ore.

5. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 1, characterized in that: The reagents used in the room temperature flotation process of scheelite in step (3) include at least one of a first adjusting agent, a suppressant, a second collecting agent, and an auxiliary collecting agent; The first adjusting agent includes at least one of sodium carbonate and sodium hydroxide, and the total amount of the first adjusting agent is 300-1000 g / t of raw ore; The inhibitor comprises at least one of water glass, sodium hexametaphosphate and sodium carboxymethyl cellulose, and the total dosage of the inhibitor is 1000-3000 g / t of raw ore; The second collector includes at least one of 731, 733, and BK418, and the total dosage of the second collector is 200-2000 g / t of raw ore; The auxiliary collector includes BK411, and the total dosage of the auxiliary collector is 20-50 g / t of raw ore.

6. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 5, characterized in that: The room temperature flotation of scheelite includes one roughing selection, three cleaning selections, one fine scavenging selection and two scavenging selections; The reagents used in the primary roughing include: the first adjusting agent in an amount of 300-1000 g / t of raw ore, the depressant in an amount of 700-2400 g / t of raw ore, the second collector in an amount of 160-1600 g / t of raw ore, and the auxiliary collector in an amount of 20-50 g / t of raw ore; The reagents used in the primary fine sweeping include: the second collector in an amount of 10-100 g / t of the raw ore; The three concentrations include the first concentration, the second concentration and the third concentration. The reagents used in the first concentration include: the inhibitor in an amount of 200-400 g / t of the original ore; the reagents used in the second concentration include: the inhibitor in an amount of 100-200 g / t of the original ore; the third concentration is blank concentration; The two sweeps include a first sweep and a second sweep, wherein the reagents used in the first sweep include: the second collector in an amount of 20-200 g / t of original ore; and the reagents used in the second sweep include: the second collector in an amount of 10-100 g / t of original ore.

7. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 1, characterized in that: In the pretreatment process of step (4), the amount of sodium carbonate used is 500-2000 g / t of raw ore; After the pretreatment is completed, the method further comprises: adding a second adjusting agent and a third collecting agent to the slurry, and heating and stirring the slurry; The second adjusting agent includes at least one of water glass and sodium sulfide; The dosage of the second adjusting agent is 4000-10000 g / t of raw ore; The third collector includes BK418, and the dosage of the third collector is 20-200 g / t of raw ore; The temperature of the heating and stirring is 95° C. to 100° C., and the time of the heating and stirring is 30 to 90 minutes.

8. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 7, characterized in that: The second adjusting agent includes water glass and sodium sulfide, the amount of the water glass is 4000-8000 g / t of the original ore, and the amount of the sodium sulfide is 500-2000 g / t of the original ore; And / or, after the heating and stirring is completed, the method further comprises: performing heating and selection; The reagent used for the heating and concentration includes a fourth collector; The fourth collector includes BK418; The total dosage of the fourth collector is 2-5 g / t of raw ore.

9. The method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to claim 8, characterized in that: The heating selection includes one rough selection, five selections and two sweeping selections; The first roughing and the five cleanings are blank flotation; The two sweeps include a third sweep and a fourth sweep. The reagents used in the third sweep include: the fourth collector in an amount of 1.5-3.5 g / t of original ore; the reagents used in the fourth sweep include: the fourth collector in an amount of 0.5-1.5 g / t of original ore.

10. A method for efficiently recovering low-grade fine-grained scheelite from copper-sulfur tailings according to any one of claims 1 to 9, characterized in that: The concentration of hydrochloric acid in step (5) is 2% to 10%; The liquid-to-solid ratio of the acid leaching process is (5-20) ml:1 g.

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