Magnesium silicate gangue combination inhibitor, method for efficient separation of low-grade magnesium silicate type copper sulfide ore

Abstract

The application discloses a magnesium silicate gangue combined inhibitor and a method for high-efficiency separation of low-grade magnesium silicate type sulfide copper ore. The combined inhibitor is composed of sodium pyrophosphate, dihexylene triamine pentamethylene phosphonic acid and sesbania gum in a mass ratio of 20:(1-10):(0.5-2). The method for high-efficiency separation of low-grade magnesium silicate type sulfide copper ore comprises the following steps: rough grinding of raw ore, copper rough separation, pre-screening and regrinding of copper rough concentrate, copper fine separation, and separate separation of copper middling. The method has the advantages of low copper loss rate, small reagent consumption, stable flotation process, small and clean flotation froth, good adaptability to slime, etc. and can realize high-efficiency separation of the difficult-to-separate ore. When the copper grade of the raw ore is 0.2%-0.8%, the method can obtain total copper concentrate with a copper grade of greater than or equal to 17% and a copper recovery rate of greater than or equal to 70%, and can significantly improve the utilization rate of copper resources.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to a magnesium silicate gangue combined inhibitor and a method for efficient separation of low-grade magnesium silicate type copper sulfide ore. BACKGROUND

[0002] Copper is a very important non-ferrous metal raw material in the national economic construction. With the rapid development of modern industry in China, the demand for copper is increasing year by year. The total amount of copper metal mineral resources in China is not small, but the endowment is poor, the grade is low, the composition of copper ore is complex and difficult to handle, and the comprehensive utilization rate of mineral resources is low, so the copper output cannot meet the domestic copper consumption demand, and more than 70% of the copper resources need to rely on imports.

[0003] More than 90% of the world's copper resources come from copper sulfide ore. During the mineralization process, the surrounding rock will also be altered while the sulfide ore body is altered. The combined action of air, water and shallow alteration of sulfide ore body leads to the chloritization, talcization and silicification of gangue minerals. Rock-forming minerals such as olivine and pyroxene are altered to form magnesium silicate gangue (mainly serpentine and talc), which is closely associated with copper sulfide ore. Magnesium silicate type copper sulfide ore is widely distributed in China, such as Xiaosigou copper mine in Chengde, Hebei (the relative content of serpentine / talc is about 42%), Dongguashan copper-sulfur ore in Tongling, Anhui (the relative content of serpentine / talc is about 16%), Yaxi copper-nickel mine in Xinjiang (the relative content of serpentine / talc is about 34%), and Dishui copper mine in Xinjiang (the relative content of serpentine / talc is about 15%), etc. These are typical magnesium silicate type copper sulfide ores. This kind of ore has the characteristics of low copper ore grade, high content of associated magnesium silicate gangue (relative content of 10%-50%), easy to be slimed in the crushing and grinding process, and fine copper dissemination size, etc., and belongs to refractory copper sulfide ore. Talc / serpentine is soft and easy to be slimed, which can easily form slime cover, leading to serious interference of this kind of gangue minerals to the flotation of copper sulfide ore in the separation process, which seriously restricts the efficient utilization of this kind of copper resources. At the same time, talc is a non-polar layered mineral with good natural hydrophobicity, which is easy to enter the concentrate product with foam, resulting in high magnesium oxide content in copper concentrate. According to the nickel metal flash smelting technology requirements, the MgO content in nickel concentrate needs to be controlled below 6.8%, and high MgO content will increase the viscosity of slag, increase the melting point of slag, and reduce the smelting recovery rate. It has important academic value and practical significance to carry out efficient flotation separation research on magnesium silicate type copper sulfide ore to improve the recovery rate of copper resources.

[0004] For the beneficiation of low-grade copper sulfide ore containing silicate, adding magnesium silicate inhibitor in the flotation system is the most direct and effective method to improve the flotation effect of copper sulfide ore. The existing technology CN 112495590A provides a magnesium silicate mineral inhibitor, which is a combination of DH and sodium hexametaphosphate, wherein DH is composed of guar gum, carboxymethyl cellulose and lignin; CN 112295728B provides a talc inhibitor composed of sulfate, polysaccharide, aluminum salt and dehydrogenase; CN103008113B provides a talc inhibitor composed of aluminum chloride and carboxymethyl starch; CN 116159680A provides a serpentine inhibitor composed of nanocellulose. The above existing magnesium silicate inhibitors are mainly dispersed inhibitors and high molecular organic inhibitors. Although the use of dispersed inhibitors can achieve the peeling of magnesium silicate minerals from the surface of copper sulfide ore and dispersion, the floatability of the peeled magnesium silicate minerals has been greatly increased, and if not captured in time, it can naturally float into the copper concentrate, resulting in excessive magnesium oxide content in the copper concentrate. At the same time, when a large amount of dispersed inhibitors are added, the beneficiation wastewater is in a stable colloidal dispersion state, which is difficult to settle and reuse; and the polar group of high molecular organic inhibitors is a large number of hydroxyl groups in the molecule, which are combined with the surface of serpentine in the form of hydrogen bond, lacking characteristic functional groups adsorbed on the surface of serpentine, so the selectivity is poor when the dosage is too large, resulting in low recovery rate of copper concentrate. At present, the inhibition effect of these two types of inhibitors in the high content magnesium silicate flotation system is limited. As can be seen from the above, it is difficult to obtain good flotation indicators by only adding magnesium silicate gangue mineral inhibitors to solve the beneficiation problem of this type of ore. Therefore, it is urgent to research from the aspects of process innovation and development of efficient magnesium silicate gangue mineral inhibitors, and to propose a new method for the beneficiation of this type of ore to realize the efficient utilization of this type of copper ore resources. SUMMARY

[0005] The present application aims to solve the beneficiation difficulties of magnesium silicate (mainly serpentine, talc, etc.) type copper sulfide ore, and provides a magnesium silicate gangue combined inhibitor and a method for efficient beneficiation of low-grade magnesium silicate type copper sulfide ore, to solve the problems of unstable process, excessive magnesium oxide in copper concentrate, low recovery rate of copper concentrate and other problems caused by the flotation system and the circulation of argillaceous gangue of this type of ore.

[0006] In order to achieve the above technical purpose, the present application designs and proposes a primary slurry flotation process, which includes: primary ore coarse grinding-copper roughing-copper rough concentrate pre-screening+regrinding-copper cleaning-copper cleaning middlings separate beneficiation, and provides a magnesium silicate gangue combined inhibitor (HMD) including sodium pyrophosphate (TSPP), dihexene triamine penta-methylene phosphonic acid (BPMPA) and sesbania gum (SG). Under the synergistic effect of the new process and the combined inhibitor, efficient beneficiation of this type of ore is achieved, and the stability of the beneficiation process is ensured.

[0007] The magnesium silicate gangue combination inhibitor provided by the application is composed of sodium pyrophosphate, dihexene triamine penta methylene phosphonic acid and sesbania gum in a mass ratio of 20: (1-10) : (0.5-2).

[0008] The dihexene triamine penta methylene phosphonic acid has a structural formula as follows:

[0009]

[0010] The sesbania gum is a high-molecular polysaccharide inhibitor composed of two monosaccharides of D-galactose and D-mannose, has a molecular weight of 20600-39100, and has a structural formula as follows:

[0011]

[0012] The TSPP is a dispersant and can play a role in dispersing the ore pulp. Meanwhile, the phosphonic acid groups in the molecules of the BPMPA and the TSPP and the hydroxyl groups in the molecule of the SG can all be combined with the Mg 2+ The selective combination enables the TSPP, the BPMPA and the SG to be adsorbed on the surface of the magnesium silicate gangue mineral, to synergistically strengthen the surface hydrophilicity, and to thus produce a strong inhibiting effect. On the other hand, the SG has a certain flocculation effect, and due to the strong coordination effect of the hydroxyl groups with the Mg 2+ The HMD has a high capturing probability for the micro-fine magnesium silicate gangue mineral in the floating ore pulp environment, and the SG is selectively adsorbed on the surface of the micro-fine gangue mineral through the bridging effect and forms a cluster, so that the particle size is increased and the gangue mineral is more easily inhibited.

[0013] The application further provides a method for efficiently separating a low-grade magnesium silicate type copper sulfide ore, which comprises the following steps.

[0014] 1) Coarse grinding of the raw ore: the raw ore is broken and then added into a ball mill, and lime (CaO) and HMD are simultaneously added, wet ball grinding is performed, and a floating ore pulp is obtained;

[0015] 2) Copper roughing: the floating ore pulp is transferred into a flotation tank, and HMD, isopropyl ethyl sulfonamide (Z-200) and methyl isobutyl carbinol (MIBC) are added into the ore pulp, copper roughing is performed, and a copper rough concentrate and a tailing 1 are obtained respectively;

[0016] 3) Pre-screening and regrinding of the copper rough concentrate: the copper rough concentrate is pre-screened to obtain +0.038mm size fraction material and -0.038mm size fraction material; CaO and HMD are simultaneously added into the +0.038mm size fraction material, regrinding is performed, and the regrinding material and the -0.038mm size fraction material are combined as copper cleaning feed ore;

[0017] 4) Copper cleaning: CaO, HMD, Z-200, MIBC are added into the copper cleaning feed ore, and copper cleaning operation is carried out to obtain copper concentrate 1 and copper cleaning middlings 1, and other copper middlings are sequentially returned;

[0018] 5) Copper cleaning middlings separate selection: CaO, HMD, Z-200 are added into the copper cleaning middlings 1, and separate selection operation is carried out to obtain copper concentrate 2 and tailings 2.

[0019] Preferably, in the step 1), the grinding fineness of the rough grinding of the raw ore is 50% to 70% of -0.074mm.

[0020] Preferably, in the step 1), it further comprises: after the raw ore is crushed, it is added into a wet ball mill, then water is added, and then 500 to 2500g / t of lime and 100 to 600g / t of HMD are added at the same time to carry out wet ball grinding to obtain a flotation feed slurry.

[0021] Preferably, in the step 2), the copper roughing operation is two-time roughing and two-time scavenging, and specifically:

[0022] Roughing one: 10 to 200g / t of Z-200 is first added into the slurry, stirring for 2 to 3 minutes, then 7 to 28g / t of MIBC is added, stirring for 1 to 2 minutes, and after aeration and stirring, scraping for 2 to 4 minutes to obtain copper rough concentrate 1 and copper roughing one in-tank product, respectively;

[0023] Roughing two: 50 to 300g / t of HMD is first added into the copper roughing one in-tank product, stirring for 2 to 3 minutes, then 5 to 50g / t of Z-200 is added, stirring for 2 to 3 minutes, and after aeration and stirring, scraping for 2 to 3 minutes to obtain copper rough concentrate 2 and copper roughing two in-tank product, respectively;

[0024] The copper rough concentrate 1 and the copper rough concentrate 2 are combined to obtain copper rough concentrate, which enters the pre-screening operation in the step 3);

[0025] Scavenging one: 25 to 150g / t of HMD is first added into the copper roughing two in-tank product, stirring for 2 to 3 minutes, then 2.5 to 25g / t of Z-200 is added, stirring for 2 to 3 minutes, and after aeration and stirring, scraping for 1 to 3 minutes to obtain copper scavenging one concentrate (returned to roughing two) and copper scavenging one in-tank product, respectively;

[0026] Scavenging two: 1 to 12.5g / t of Z-200 is added into the copper scavenging one in-tank product, stirring for 2 to 3 minutes, and after aeration and stirring, scraping for 1 to 2 minutes to obtain copper scavenging one concentrate (returned to scavenging one), and the in-tank product is tailings 1.

[0027] Preferably, in the step 3), the addition amount of CaO is 500 to 2000g / t, and the addition amount of HMD is 50 to 300g / t.

[0028] Preferably, in step 3), the regrinding grinding fineness is 75% to 95% of -0.038mm.

[0029] Preferably, in step 4), the copper cleaning operation is 2 to 4 times of cleaning, specifically:

[0030] Cleaning 1: first add 7 to 50 g / t Z-200 to the copper cleaning feed, stir for 2 to 3 minutes, then add 7 to 50 g / t MIBC, stir for 1 to 2 minutes, after aeration and stirring, scrape the froth for 2 to 3 minutes, to obtain copper cleaning 1 concentrate (cleaning 2 feed) and copper cleaning middlings 1 (entering the copper cleaning middlings separate operation); cleaning 2: first add 0 to 1000 g / t CaO, stir for 1 to 2 minutes, then add 0 to 300 g / t HMD, stir for 2 to 3 minutes, after aeration and stirring, scrape the froth for 2 to 3 minutes, to obtain copper cleaning 2 concentrate (cleaning 3 feed) and copper cleaning middlings 2 (returning to the cleaning 1 operation); cleaning 3: first add 0 to 500 g / t CaO, stir for 1 to 2 minutes, then add 0 to 150 g / t HMD, stir for 2 to 3 minutes, after aeration and stirring, scrape the froth for 1 to 3 minutes, to obtain copper cleaning 3 concentrate (cleaning 4 feed) and copper cleaning middlings 3 (returning to the cleaning 2 operation); cleaning 4: first add 0 to 250 g / t CaO, stir for 1 to 2 minutes, then add 0 to 100 g / t HMD, stir for 2 to 3 minutes, after aeration and stirring, float and scrape the froth for 1 to 3 minutes, to obtain copper concentrate 1 and copper cleaning middlings 4 (returning to the cleaning 3 operation).

[0031] Preferably, in step 5), the copper cleaning middlings separate operation is one time of re-concentration roughing, one to two times of re-concentration scavenging, and one to two times of re-concentration cleaning, specifically:

[0032] First re-concentration roughing: first add 0 to 1000 g / t CaO to the copper cleaning middlings 1, stir for 1 to 2 minutes, then add 0 to 200 g / t HMD, stir for 2 to 3 minutes, then add 0 to 48 g / t Z-200, stir for 2 to 3 minutes, after aeration and stirring, scrape the froth for 2 to 4 minutes, to obtain middlings 1 re-concentration rough concentrate (entering the re-concentration cleaning operation) and middlings 1 re-concentration tailings (entering the re-concentration scavenging operation);

[0033] One-two times re-concentration scavenging: re-concentration scavenging one: first add 0-200 g / t HMD to the re-concentration tailings of middlings 1, stir for 2-3 minutes, then add 0-24 g / t Z-200, stir for 2-3 minutes, after aeration and stirring, scrape froth for 1-3 minutes, to obtain re-concentration scavenging one concentrate (return to re-concentration roughing operation) and re-concentration scavenging one tailings (enter re-concentration scavenging two operation); re-concentration scavenging two: first add 0-100 g / t HMD to the re-concentration scavenging one tailings, stir for 2-3 minutes, then add 0-12 g / t Z-200, stir for 2-3 minutes, after aeration and stirring, scrape froth for 1-2 minutes, to obtain re-concentration scavenging two concentrate (return to re-concentration scavenging one operation) and tailings 2;

[0034] One-two times re-concentration cleaning: re-concentration cleaning one: first add 0-1000 g / t CaO to the re-concentration rough concentrate of middlings 1, stir for 1-2 minutes, then add 0-200 g / t HMD, stir for 2-3 minutes, after aeration and stirring, scrape froth for 2-3 minutes, to obtain re-concentration cleaning one concentrate (enter re-concentration cleaning two operation) and re-concentration cleaning one middlings 1 (return to re-concentration roughing operation); re-concentration cleaning two: first add 0-500 g / t CaO to the re-concentration cleaning one concentrate, stir for 1-2 minutes, then add 0-200 g / t HMD, stir for 2-3 minutes, after aeration and stirring, scrape froth for 1-3 minutes, to obtain copper concentrate 2 and re-concentration cleaning two middlings 2 (return to re-concentration cleaning one operation).

[0035] Preferably, in steps 1), 3), 4), 5), lime is added to adjust the pH of the ore slurry to 8.0-10.5.

[0036] Preferably, the HMD is added in the following manner: first prepare TSPP, BPMPA and SG into aqueous solutions, wherein the mass concentrations of the three aqueous solutions of TSPP, BPMPA and SG are 1.0%-5.0%, 1.0%-5.0% and 0.1%-0.5% respectively, then add the three aqueous solutions together into the ore slurry.

[0037] Principle of the application

[0038] For low-grade magnesium silicate type of copper sulfide ore, the selection process is seriously disturbed by magnesium silicate gangue minerals such as talc and serpentine, etc. The existing technology usually adopts coarse and fine separation process, including pre-screening of raw ore (throwing away fine particle size slime) - coarse grinding - copper roughing - regrinding of copper rough concentrate - copper cleaning. Although pre-throwing away of fine mud of easy-to-grind magnesium silicate gangue can reduce its influence on the flotation of copper sulfide, the copper metal loss rate in the thrown away fine mud is large, resulting in low recovery rate of copper concentrate. In order to minimize the influence of argillaceous gangue on the flotation process of copper sulfide and at the same time obtain high-grade and high-recovery copper concentrate products, the present application innovatively proposes a raw pulp flotation process, including coarse grinding of raw ore - copper roughing - pre-screening + regrinding of copper rough concentrate - copper cleaning - separate selection of copper cleaning middlings. In this process, cleaning 1 is designed as open circuit flotation, and the cleaning 1 concentrate enters the subsequent cleaning operation to produce copper concentrate 1. The middlings of cleaning 1 are separately selected to obtain copper concentrate 2, and tailings 2 with low copper content (mainly argillaceous silicate gangue) can also be thrown away. Since the thrown away part of the mineral does not return to the flotation system, it will not continuously circulate and will not affect the flotation of copper sulfide, and the combined copper concentrate 1 and copper concentrate 2 become the final copper concentrate. In addition to process innovation, a high-efficiency combined depressant HMD for magnesium silicate gangue is added, which is composed of sodium pyrophosphate (TSPP), dihexene triamine pentamethylene phosphonic acid (BPMPA) and sesbania gum (SG). TSPP is a dispersant that can play a role in dispersing the slurry. The characteristic functional groups in BPMPA and TSPP molecules are phosphonic acid groups, which can selectively coordinate with the Mg 2+ of magnesium silicate gangue mineral surface. The reaction is a Lewis acid-base reaction from the coordination bonding mechanism. The phosphonic acid group is a hard Lewis base, which is easy to coordinate with hard Lewis acid, and the Mg 2+ of magnesium silicate gangue mineral surface is a hard Lewis acid, and the Cu 2+ of copper sulfide is a relatively soft acid. Therefore, according to the hard-soft acid-base theory, the phosphonic acid is more likely to selectively coordinate with the magnesium silicate gangue mineral surface, has a large adsorption density, makes the surface hydrophilic, and thus produces a strong inhibitory effect. BPMPA and TSPP are not adsorbed on the surface of copper sulfide, so as not to affect the adsorption of Z-200 on the surface of chalcopyrite, and the surface of chalcopyrite remains strongly hydrophobic, which is more conducive to the flotation separation of chalcopyrite and gangue minerals. TSPP and BPMPA are co-adsorbed on the surface of magnesium silicate gangue minerals, which synergistically enhances the hydrophilicity of the surface. The SG molecule chain has a large number of hydroxyl functional groups, which selectively coordinate with the Mg 2+ of magnesium silicate gangue mineral surface. The reaction is also a Lewis acid-base reaction in nature. That is, SG donates electrons as a Lewis base, and the Mg 2+Electron is obtained as Lewis acid; SG and dehydration condensation between surface hydroxyl of gangue, essence is acid-base reaction of Bronsted acid (SG) and Bronsted base (gangue). From coordination bonding mechanism, the combination mechanism of hydroxyl in SG and Mg 2+ of magnesium silicate gangue surface is very similar to the combination mechanism of phosphonic acid group in BPMPA, TSPP molecules and Mg 2+ of magnesium silicate gangue surface. Therefore, BPMPA, TSPP and SG combination have strong selective inhibition effect on magnesium silicate gangue minerals. On the other hand, SG has certain flocculation effect, due to strong coordination effect of hydroxyl and Mg 2+ of gangue mineral surface, the capture probability of HMD to micro-fine particle magnesium silicate gangue minerals in flotation slurry environment is improved, SG selectively adsorbs micro-fine particle gangue mineral surface by bridging effect and forms agglomerates, so that the particle size is increased, which is beneficial to be inhibited.

[0039] It can be known comprehensively that, by using the new process, the mudified gangue minerals with low copper grade are removed by separate flotation of copper cleaning middlings, so that the mudified gangue minerals are avoided from circulating in the copper flotation system; meanwhile, the magnesium silicate gangue minerals are selectively made to be hydrophilic by using the high-efficiency combined depressant HMD for magnesium silicate, so that the copper concentrate with high Cu grade and high Cu recovery rate can be obtained, and the flotation process is stable.

[0040] The beneficial effects of the present application are as follows:

[0041] 1. For the beneficiation of low-grade copper sulfide ore containing magnesium silicate, the present application provides a raw slurry flotation process, which comprises: raw ore coarse grinding-copper roughing-copper rough concentrate pre-screening+regrinding-copper cleaning-copper cleaning middlings separate flotation, and HMD is used as a combined depressant for magnesium silicate gangue, so that the high-efficiency beneficiation of the ore can be realized. When the copper grade of the raw ore is 0.2% to 0.8%, by using the new beneficiation method provided by the present application, the copper concentrate (copper concentrate 1+copper concentrate 2) with copper grade ≥17% and copper recovery rate ≥70% can be obtained.

[0042] 2. The new combined depressant HMD provided by the present application is composed of organic phosphonic acid BPMPA, inorganic phosphate TSPP and organic high molecular polysaccharide inhibitor SG, has high selectivity and inhibition performance, and the preparation of the reagent is simple, easy to add in industry, and BPMPA is also an excellent water treatment agent, which can complex heavy metal ions in beneficiation wastewater, so that the difficulty of wastewater reuse is greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is the flotation process flow chart of Example 1;

[0044] Figure 2 It is the flotation process flow chart of Comparative Example 9;

[0045] Figure 3 A schematic flow sheet for Example 2;

[0046] Figure 4 A flotation process flow sheet for Example 2;

[0047] Figure 5 A flotation process flow sheet for Comparative Example 16. DETAILED DESCRIPTION

[0048] In the following examples and comparative examples, the reagents used are all commercially available.

[0049] Example 1

[0050] A low-grade magnesium silicate type copper sulfide ore from Hebei was obtained. The chemical multi-element analysis of the raw ore showed that the main element copper grade in the raw ore was 0.55%, containing Zn 0.056%, Pb 0.040%, Fe 5.50%, Au 0.89 g / t, and Ag 13.25 g / t. The contents of valuable elements such as Pb, Zn, Au, and Ag were low, and the comprehensive recycling value was not great. The main gangue components that needed to be excluded from the ore through beneficiation were SiO2, MgO, and CaO, with contents of 43.36%, 20.02%, and 16.38%, respectively. Copper was mainly in the form of copper sulfide, accounting for 83.13% (primary copper sulfide and secondary copper sulfide). Mineral composition analysis showed that the metallic minerals in the ore were mainly pyrite, chalcopyrite, bornite, and magnetite; the gangue minerals were mainly talc, serpentine, and carbonate (calcite), with a small amount of quartz, feldspar, and mica, among which the relative content of the easily argillized magnesium silicate mineral (talc / serpentine) was as high as 46%. The copper minerals were finely disseminated and closely associated with other minerals.

[0051] After the raw ore was crushed, wet ball milling was performed, with the addition of CaO 1000 g / t and HMD 200 g / t during the milling process. The grinding fineness was 65% passing 0.074 mm. Then the ground ore slurry was sent to the flotation tank for flotation test. The flotation test process and reagent system were as follows: Figure 1 , and were as follows:

[0052] In this example, HMD was composed of TSPP, BPMPA, and SG in a mass ratio of 20:4:1. Before adding HMD to the ore slurry, TSPP was prepared into a TSPP aqueous solution with a mass concentration of 5%, BPMPA was prepared into a BPMPA aqueous solution with a mass concentration of 2%, and SG was prepared into a SG aqueous solution with a mass concentration of 0.5%. Then the three aqueous solutions were added to the ore slurry together. MIBC was added to the ore slurry as a raw solution.

[0053] 1) Copper roughing: the ground ore slurry was subjected to two-stage roughing and two-stage scavenging, which included the following steps:

[0054] Second roughing: roughing one: 48 g / t Z-200 was first added to the slurry, stirred for 2 minutes, 14 g / t MIBC was then added, stirred for 1 minute, and after aeration and stirring, the froth was scraped for 3 minutes to obtain roughing one concentrate (entering the pre-screening operation), and the tank was the feed of roughing two; roughing two: 60 g / t HMD was added to the product in the roughing one tank, stirred for 2 minutes, 7 g / t Z-200 was then added, stirred for 2 minutes, and after aeration and stirring, the froth was scraped for 2.5 minutes to obtain roughing two concentrate (entering the pre-screening operation), and the tank was the feed of scavenging one;

[0055] Second scavenging: scavenging one: 40 g / t HMD was first added to the product in the roughing two tank, stirred for 2 minutes, 7 g / t Z-200 was then added, stirred for 2 minutes, and after aeration and stirring, the froth was scraped for 1.5 minutes to obtain scavenging one concentrate (returned to the roughing two operation), and the tank was the feed of scavenging two; scavenging two: 3.5 g / t Z-200 was added to the product in the scavenging one tank, stirred for 2 minutes, and after aeration and stirring, the froth was scraped for 1 minute to obtain scavenging two concentrate (returned to the scavenging one operation), and the tank was the tailings 1.

[0056] 2) The roughing one concentrate and the roughing two concentrate were combined as copper rough concentrate, and pre-screening was performed thereon to obtain +0.038 mm size fraction rough concentrate and -0.038 mm size fraction rough concentrate; the +0.038 mm size fraction rough concentrate was re-ground in a re-grinding mill, 1000 g / t CaO and 60 g / t HMD were simultaneously added to the re-grinding mill before re-grinding, and the re-ground fineness was -0.038 mm accounting for 85%. The re-ground rough concentrate and the -0.038 mm size fraction rough concentrate were combined as the feed of cleaning;

[0057] 3) The re-ground rough concentrate and the -0.038 mm size fraction rough concentrate were subjected to four times of cleaning, specifically including the following steps:

[0058] Four cleaning: cleaning 1 : first add 14 g / t Z-200 to the rough concentrate, stir for 2 minutes, then add 7 g / t MIBC, stir for 1 minute, and after aeration and froth scraping for 2 minutes, obtain cleaning 1 concentrate (cleaning 2 feed) and copper cleaning middlings 1 (enter copper cleaning middlings separate selection operation); cleaning 2: first add 500 g / t CaO, stir for 1 minute, then add 30 g / t HMD, stir for 2 minutes, and after aeration and froth scraping for 2 minutes, obtain cleaning 2 concentrate (cleaning 3 feed) and cleaning middlings 2 (return to cleaning 1 operation); cleaning 3: first add 250 g / t CaO, stir for 1 minute, then add 15 g / t HMD, stir for 2 minutes, and after aeration and froth scraping for 1.5 minutes, obtain cleaning 3 concentrate (cleaning 4 feed) and cleaning middlings 3 (return to cleaning 2 operation); cleaning 4: first add 125 g / t CaO, stir for 1 minute, then add 10 g / t HMD, stir for 2 minutes, and after aeration and froth scraping for 1.5 minutes, obtain copper concentrate 1 and cleaning middlings 4 (return to cleaning 3 operation).

[0059] 4) Once re-concentration rough cleaning twice re-concentration scavenging twice re-concentration cleaning is performed on the copper cleaning middlings 1, specifically including the following steps:

[0060] Once re-concentration rough cleaning: first add 500 g / t CaO to the copper cleaning middlings 1, stir for 1 minute, then add 50 g / t HMD, stir for 2 minutes, then add 7 g / t Z-200, stir for 2 minutes, and after aeration and froth scraping for 2.5 minutes, obtain middlings 1 re-concentration rough concentrate (enter re-concentration cleaning operation) and copper middlings 1 re-concentration rough cleaning tailings (enter re-concentration scavenging operation);

[0061] Twice re-concentration scavenging: re-concentration scavenging 1 : first add 50 g / t HMD to the middlings 1 re-concentration rough cleaning tailings, stir for 2 minutes, then add 4 g / t Z-200, stir for 2 minutes, and after aeration and froth scraping for 1.5 minutes, obtain re-concentration scavenging 1 concentrate (return to re-concentration rough cleaning operation) and re-concentration scavenging 1 tailings (enter re-concentration scavenging 2 operation); re-concentration scavenging 2: add 2 g / t Z-200 to the re-concentration scavenging 1 tailings, stir for 2 minutes, and after aeration and froth scraping for 1 minute, obtain re-concentration scavenging 2 concentrate (return to re-concentration scavenging 1 operation) and tailings 2;

[0062] Secondary cleaning: cleaning 1 : to the rough cleaning middlings 1, first add 500g / t CaO, stirring for 1 minute, then add 50g / t HMD, stirring for 2 minutes, after aeration and froth scraping for 2 minutes, obtain cleaning 1 concentrate (entering cleaning 2 operation) and cleaning 1 middlings 1 (returning to rough cleaning operation); cleaning 2: to the cleaning 1 concentrate, first add 250g / t CaO, stirring for 1 minute, then add 50g / t HMD, stirring for 2 minutes, after aeration and froth scraping for 1.5 minutes, obtain copper concentrate 2 product and cleaning 2 middlings 2 (returning to cleaning 1 operation).

[0063] The middlings in the above three flotation cycle operations are returned in sequence, the flotation process is executed for six times, and after reaching equilibrium, the mass and grade of the concentrate and tailings obtained in each test are basically unchanged. The concentrate and tailings after stabilization are sampled and sent for chemical analysis. The closed-circuit test results are shown in Table 1.

[0064] Comparative Example 1

[0065] The process flow and reagent system are basically the same as those of Example 1, except that the magnesium silicate-containing inhibitor is replaced by a conventional inhibitor sodium silicate, and the dosage of sodium silicate is the same as that of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0066] Comparative Example 2

[0067] The process flow and reagent system are basically the same as those of Example 1, except that the magnesium silicate-containing inhibitor is replaced by a conventional inhibitor carboxymethyl cellulose (CMC), and the dosage of CMC is the same as that of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0068] Comparative Example 3

[0069] The process flow and reagent system are basically the same as those of Example 1, except that the magnesium silicate-containing inhibitor is replaced by a single component TSPP, and the dosage of TSPP is the same as that of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0070] Comparative Example 4

[0071] The process flow and reagent system are basically the same as those of Example 1, except that the magnesium silicate-containing inhibitor is replaced by a single component BPMPA, and the dosage of BPMPA is the same as that of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0072] Comparative Example 5

[0073] The process flow and reagent system are basically the same as those of Example 1, except that the magnesium silicate-containing inhibitor is replaced by a single component SG, and the dosage of SG is the same as that of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0074] Comparative Example 6

[0075] The process flow and reagent system are basically the same as those in Example 1, except that the magnesium silicate-containing inhibitor is a combined reagent composed of TSPP and BPMPA at a mass ratio of 4:1, the combined reagent is used in the same amount as HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0076] Comparative Example 7

[0077] The process flow and reagent system are basically the same as those in Example 1, except that the magnesium silicate-containing inhibitor is a combined reagent composed of TSPP and SG at a mass ratio of 24:1, the combined reagent is used in the same amount as HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0078] Comparative Example 8

[0079] The process flow and reagent system are basically the same as those in Example 1, except that the magnesium silicate-containing inhibitor is a combined reagent composed of BPMPA and SG at a mass ratio of 24:1, the combined reagent is used in the same amount as HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 1.

[0080] Comparative Example 9

[0081] A rough and fine separation process in a production site is used, which includes pre-screening of raw ore (tailings of fine particles) - grinding of coarse particles - rough copper separation - regrinding of rough copper concentrate - copper cleaning, and a low-grade magnesium silicate-containing copper sulfide ore in Hebei in Example 1 is separated, the mass ratio of the three components in the depressant HMD remains the same as in Example 1, and the specific process is shown in Figure 2 The separation steps are as follows:

[0082] 1) Pre-screening of raw ore and grinding of coarse particles: the raw ore is pre-screened to obtain +0.038 mm size material and -0.038 mm size material; 1000 g / t lime and 200 g / t HMD are added to the +0.038 mm size material, which is wet ball milled to a grinding fineness of -0.074 mm accounting for 65%, to obtain a slurry; the -0.038 mm size material is directly discarded.

[0083] 2) Copper rough separation: the slurry is subjected to secondary rough separation and secondary scavenging, which includes the following steps:

[0084] Secondary roughing: Roughing 1 : Add 50 g / t Z-200 to the pulp, stir for 2 minutes, then add 14 g / t MIBC, stir for 1 minute, and after aeration and stirring, scrape froth for 3 minutes to obtain roughing 1 concentrate (go to pre- sizing operation), and the tank is the feed for roughing 2; Roughing 2: Add 100 g / t HMD to the roughing 1 tank, stir for 2 minutes, then add 7 g / t Z-200, stir for 2 minutes, and after aeration and stirring, scrape froth for 2 minutes to obtain roughing 2 concentrate (go to pre- sizing operation), and the tank is the feed for scavenging 1.

[0085] Secondary scavenging: Scavenging 1 : Add 80 g / t HMD to the roughing 2 tank, stir for 2 minutes, then add 7 g / t Z-200, stir for 2 minutes, and after aeration and stirring, scrape froth for 1.5 minutes to obtain scavenging 1 concentrate (return to roughing 2 operation), and the tank is the feed for scavenging 2; Scavenging 2: Add 3.5 g / t Z-200 to the scavenging 1 tank, stir for 2 minutes, and after aeration and stirring, scrape froth for 1 minute to obtain scavenging 1 concentrate (return to scavenging 1 operation), and the tank is the tailings.

[0086] 3) Combine the roughing 1 concentrate and the roughing 2 concentrate into copper rough concentrate, and pre-size it to obtain +0.038 mm size fraction rough concentrate and -0.038 mm size fraction rough concentrate; regrind the +0.038 mm size fraction rough concentrate, add 1000 g / t CaO and 100 g / t HMD simultaneously, and the regrind fineness is -0.038 mm 85%. Combine the regrind product and the -0.038 mm size fraction rough concentrate to be the feed for copper cleaning.

[0087] 4) Use four cleaning processes to clean the copper from the above regrind product and -0.038 mm size fraction rough concentrate, which includes the following steps:

[0088] Four cleaning: Cleaning 1 : Add 14 g / t Z-200 to the above rough concentrate, stir for 2 minutes, then add 7 g / t MIBC, stir for 1 minute, and after aeration and stirring, float and scrape froth for 2 minutes to obtain cleaning 1 concentrate (cleaning 2 feed) and middlings 1 (return to roughing 2 operation); Cleaning 2: Add 500 g / t CaO to the cleaning 1 concentrate, stir for 1 minute, then add 60 g / t HMD, stir for 2 minutes, and after aeration and stirring, scrape froth for 2 minutes to obtain cleaning 2 concentrate (cleaning 3 feed) and middlings 2 (return to cleaning 1 operation); Cleaning 3: Add 250 g / t CaO, stir for 1 minute, then add 30 g / t HMD, stir for 2 minutes, and after aeration and stirring, scrape froth for 1.5 minutes to obtain cleaning 3 concentrate (cleaning 4 feed) and middlings 3 (return to cleaning 2 operation); Cleaning 4: Add 125 g / t CaO, stir for 1 minute, then add 15 g / t HMD, stir for 2 minutes, and after aeration and stirring, scrape froth for 1.5 minutes to obtain copper concentrate product and middlings 4 (return to cleaning 3 operation). The closed-circuit test results are shown in Table 1.

[0089] Table 1: Closed-circuit test results of Example 1 and Comparative Examples 1-9

[0090]

[0091]

[0092] As shown in Table 1, the new process flow of raw slurry flotation is adopted, and the combined depressant HMD is added (Example 1), and the copper grade of the combined total copper concentrate is 17.76%, and the copper recovery rate is 72.03%; the new process flow is also adopted, and the conventional depressants water glass (Comparative Example 1), CMC (Comparative Example 2), or one of the three components of HMD, TSPP (Comparative Example 3), BPMPA (Comparative Example 4), and SG (Comparative Example 5) are added, due to the interference of argillaceous serpentine and talc minerals on the flotation of copper sulfide, it is difficult to obtain a high-grade copper concentrate product, and the loss of copper in the tailings is large, and the copper grade and copper recovery rate of the copper concentrate are not high, the copper grade of the total copper concentrate is 7.65-13.52%, and the copper recovery rate is 26.37-48.94%; when two of the three components of HMD, TSPP and BPMPA combination (Comparative Example 6), TSPP and SG combination (Comparative Example 7), and BPMPA and SG combination (Comparative Example 8) are added, the depression effect is better than that of a single component, but the depression effect is still not good, the copper grade of the total copper concentrate is 10.09-13.28%, and the copper recovery rate is 55.71-62.38%; the on-site production process flow is adopted, and the argillaceous magnesium silicate gangue is thrown away in advance, and the gangue depressant HMD is added (Comparative Example 9), obviously, the copper grade of the copper concentrate is increased to 17.42%, but due to direct desliming of the raw ore, the loss of copper metal is large, and the loss rate of copper in the desliming product is as high as 25.05%, the copper recovery rate in the copper concentrate is not high, and is only 51.93%, which is 20.1 percentage points lower than that of Example 1.

[0093] In summary, in the new process of Example 1, the cleaning operation is open-circuit separation, and the middlings are separately selected to remove part of the copper-containing low-content argillaceous serpentine and talc gangue minerals, so as to avoid the circulation of the argillaceous gangue in the flotation system and the interference with the flotation of the copper sulfide ore, and the new combined depressant HMD is used to simultaneously obtain the copper concentrate product with high grade and high recovery rate; when one component or any two components of the new process are added, the separation effect of the copper sulfide ore and the magnesium silicate mineral is poor; compared with the coarse and fine separation process used in the field production, the new process using the combined depressant HMD can also reduce the loss rate of copper in the desliming operation. It is shown that the new process used in cooperation with the high-efficiency magnesium silicate gangue depressant HDM can effectively ensure the grade and recovery rate of the copper concentrate and obtain good separation indexes. Due to the timely removal of part of the argillaceous gangue in the new process, the flotation reagent consumption is normal, the process is stable and easy to operate, the foam mineralization effect is good, the foam is clean and the entrainment is small, and the process is easy to implement in industry.

[0094] Example 2

[0095] A low-grade magnesium silicate type copper-nickel sulfide ore in Yunnan is obtained, and through chemical multi-element analysis, it is obtained that the valuable elements in the raw ore are mainly copper and nickel, the copper grade is 0.41%, and the nickel grade is 0.34%. The raw ore also contains sulfur 0.85%, iron 9.49%, silicon 7.89%, magnesium 4.41%, and calcium 3.11%, and sulfur and iron can be used as associated valuable metals for comprehensive recovery. The copper-containing minerals are mainly chalcopyrite, and the nickel-containing minerals are mainly nickel pyrite. It can be known from the mineral composition analysis that the main purpose minerals in the raw ore are chalcopyrite, nickel pyrite and pyrrhotite, and the main gangue minerals are serpentine and talc, and the gangue has good floatability and seriously interferes with the flotation process of copper and nickel minerals.

[0096] In this embodiment, the principle process of preferentially floating copper and then floating nickel is used, as shown in Figure 3 . In this embodiment, the recovery of copper is focused on, so in Example 2, only the recovery of copper is considered, and the recovery of nickel is not considered.

[0097] The raw ore is first crushed and then ball milled, and 500 g / t of lime and 120 g / t of HMD are added during the grinding process, and the two are added at the same time. The grinding fineness is 63% of -0.074 mm, and then the ground ore slurry is sent to the flotation tank for flotation test, and the test process and reagent system are as shown in Figure 4 , and the specific conditions are as follows:

[0098] In the present embodiment, the HMD is composed of TSPP, BPMPA and SG in a mass ratio of 20:6:1.5. Before adding the HMD into the ore pulp, the TSPP is prepared into a TSPP aqueous solution with a mass concentration of 5%, the BPMPA is prepared into a BPMPA aqueous solution with a mass concentration of 2%, and the SG is prepared into a SG aqueous solution with a mass concentration of 0.5%, and then the three aqueous solutions are added into the ore pulp together. The MIBC is added into the ore pulp in the form of a stock solution.

[0099] 1) Copper roughing: the above ore pulp is subjected to secondary roughing and secondary scavenging, which specifically includes the following steps:

[0100] Secondary roughing: roughing 1: 35 g / t Z-200 is first added into the ore pulp, stirring for 2 minutes, then 7 g / t MIBC is added, stirring for 1 minute, and after aeration and stirring, froth scraping is performed for 2.5 minutes to obtain roughing 1 concentrate (entering a pre-screening operation), and the tank is used as roughing 2 feed; roughing 2: 60 g / t HMD is first added into the roughing 1 tank, stirring for 2 minutes, then 14 g / t Z-200 is added, stirring for 2 minutes, and after aeration and stirring, froth scraping is performed for 2 minutes to obtain roughing 2 concentrate (entering a pre-screening operation), and the tank is used as scavenging 1 feed;

[0101] Secondary scavenging: scavenging 1: 60 g / t HMD is first added into the roughing 2 tank, stirring for 2 minutes, then 7 g / t Z-200 is added, stirring for 2 minutes, and after aeration and stirring, flotation froth scraping is performed for 1.5 minutes to obtain scavenging 1 concentrate (returning to the roughing 2 operation), and the tank is used as scavenging 2 feed; scavenging 2: 3.5 g / t Z-200 is added into the product in the scavenging 1 tank, stirring for 2 minutes, and after aeration and stirring, froth scraping is performed for 1 minute to obtain scavenging 2 concentrate (returning to the scavenging 1 operation), and the tank is used as tailings 1;

[0102] 2) The roughing 1 concentrate and the roughing 2 concentrate are combined as copper rough concentrate, and a pre-screening operation is performed thereon to obtain +0.038 mm size fraction of rough concentrate and -0.038 mm size fraction of rough concentrate; the +0.038 mm size fraction of rough concentrate is subjected to regrinding, 1000 g / t CaO and 50 g / t HMD are added, both of which are added at the same time, and the regrinding fineness is -0.038 mm accounting for 80%, and the regrinded rough concentrate and the -0.038 mm size fraction of copper rough concentrate are combined as concentration feed;

[0103] 3) The regrinded rough concentrate and the -0.038 mm size fraction of rough concentrate are subjected to three times of concentration, which specifically includes the following steps:

[0104] Third cleaning: cleaning 1 : 14 g / t Z-200 was first added to the rough concentrate, stirring for 2 minutes, then 7 g / t MIBC was added, stirring for 1 minute, and after aeration and froth scraping for 2 minutes, cleaning 1 concentrate (cleaning 2 feed) and copper cleaning middlings 1 (entering copper cleaning middlings separate operation) were obtained; cleaning 2: 25 g / t HMD was added, stirring for 2 minutes, and after aeration and froth scraping for 2 minutes, cleaning 2 concentrate (cleaning 3 feed) and middlings 2 (returning to cleaning 1 operation) were obtained; cleaning 3: blank cleaning, after aeration and froth scraping for 1.5 minutes, copper concentrate 1 and middlings 3 (returning to cleaning 2 operation) were obtained;

[0105] 4) The copper cleaning middlings 1 were subjected to one-time re-concentration rough cleaning, two-time re-concentration scavenging and one-time re-concentration cleaning, specifically including the following steps:

[0106] One-time re-concentration rough cleaning: 500 g / t CaO was first added to the copper cleaning middlings 1, stirring for 1 minute, then 50 g / t HMD was added, stirring for 2 minutes, and then 7 g / t Z-200 was added, stirring for 2 minutes, and after aeration and flotation scraping for 2.5 minutes, re-concentration rough concentrate (entering re-concentration cleaning operation) and re-concentration tailings (entering re-concentration scavenging operation) were obtained;

[0107] One-time re-concentration scavenging: 30 g / t HMD was first added to the re-concentration tailings, stirring for 2 minutes, then 4 g / t Z-200 was added, stirring for 2 minutes, and after aeration and froth scraping for 1.5 minutes, re-concentration scavenging 1 concentrate (returning to re-concentration rough cleaning operation) and tailings 2 were obtained;

[0108] Two-time re-concentration cleaning: re-concentration cleaning 1 : 250 g / t CaO was added to the re-concentration rough concentrate, stirring for 1 minute, then 40 g / t HMD was added, stirring for 2 minutes, and after aeration and froth scraping for 2 minutes, re-concentration cleaning 1 concentrate (entering re-concentration cleaning 2 operation) and re-concentration middlings 1 (returning to re-concentration rough cleaning operation) were obtained; re-concentration cleaning 2: 130 g / t CaO was added to the re-concentration cleaning 1 concentrate, stirring for 1 minute, then 20 g / t HMD was added, stirring for 2 minutes, and after aeration and froth scraping for 1.5 minutes, copper concentrate 2 and re-concentration middlings 2 (returning to re-concentration cleaning 1 operation) were obtained.

[0109] All the middlings in the above three flotation cycles were sequentially returned, and after the flotation process was performed six times, the mass and grade of the flotation concentrate and the flotation tailings obtained in each test were basically unchanged, and the stable concentrate and tailings were sampled and sent for chemical analysis. The results of the closed-circuit test are shown in Table 2.

[0110] Comparative Example 10

[0111] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a single TSPP, the amount of TSPP is the same as the amount of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 2.

[0112] Comparative Example 11

[0113] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a single BPMPA, the amount of BPMPA is the same as the amount of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 2.

[0114] Comparative Example 12

[0115] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a single SG, the amount of SG is the same as the amount of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 2.

[0116] Comparative Example 13

[0117] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a combination of TSPP and SG in a mass ratio of 26:1.5, the amount of the combination reagent is the same as the amount of HMD, and other conditions remain unchanged. The closed-circuit test results are shown in Table 2.

[0118] Comparative Example 14

[0119] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a combination of BPMPA and SG in a mass ratio of 26:1.5, the amount of the combination reagent is the same as the amount of HMD. The closed-circuit test results are shown in Table 2.

[0120] Comparative Example 15

[0121] The process flow and reagent system are basically the same as those in Example 2, except that the magnesium silicate-containing inhibitor is a combination of TSPP and BPMPA in a mass ratio of 4:1.5, the amount of the combination reagent is the same as the amount of HMD. The closed-circuit test results are shown in Table 2.

[0122] Comparative Example 16

[0123] The on-site production copper direct flotation process flow includes ore grinding-copper roughing-copper rough concentrate regrinding-copper cleaning, and a low-grade magnesium silicate-containing copper-nickel sulfide ore in Yunnan is beneficiated in the same way as in Example 2. The specific flow chart is shown in Figure 5 .

[0124] In this comparative example, the mass ratio of the three components in the magnesium silicate inhibitor HMD remains the same as in Example 2.

[0125] (1) The raw ore is crushed and then wet ball-milled, and the grinding fineness is 63% passing 0.074 mm, to obtain the flotation feed slurry.

[0126] (2) The copper roughing is carried out by using the process flow of twice roughing, twice scavenging and thrice cleaning, and the details are as follows:

[0127] The second roughing: roughing one: 500 g / t lime is added to the slurry, stirring for 1 minute, then 120 g / t HMD is added, stirring for 2 minutes, then 35 g / t Z-200 is added, stirring for 2 minutes, 7 g / t MIBC is added, stirring for 1 minute, and after aeration and stirring, scraping for 2.5 minutes to obtain the roughing one concentrate (entering the regrinding operation), and the tank is the feed of roughing two; roughing two: 60 g / t HMD is added to the tank of roughing one, stirring for 2 minutes, then 14 g / t Z-200 is added, stirring for 2 minutes, and after aeration and stirring, scraping for 2 minutes to obtain the roughing two concentrate (entering the regrinding operation), and the tank is the feed of scavenging one.

[0128] The second scavenging: scavenging one: 60 g / t HMD is added to the tank of roughing two, stirring for 2 minutes, then 7 g / t Z-200 is added, stirring for 2 minutes, and after aeration and stirring, scraping for 1.5 minutes to obtain the scavenging one concentrate (returning to the roughing one operation), and the tank is the feed of scavenging two; scavenging two: 3.5 g / t Z-200 is added to the tank of scavenging one, stirring for 2 minutes, and after aeration and stirring, scraping for 1 minute to obtain the copper scavenging one concentrate (returning to the scavenging one), and the tank is the tailings (nickel pyrrhotite flotation feed).

[0129] The copper rough concentrate regrinding: the roughing one concentrate and the roughing two concentrate are combined into the copper rough concentrate, and the regrinding is carried out, and the regrinding fineness is 80% passing 0.038 mm.

[0130] The third cleaning: cleaning one: 1000 g / t CaO is added to the regrinding copper rough concentrate, stirring for 1 minute, then 50 g / t HMD is added, stirring for 2 minutes, then 14 g / t Z-200 is added, stirring for 2 minutes, 7 g / t MIBC is added, stirring for 1 minute, and after aeration and stirring, scraping for 2 minutes to obtain the concentrate one (the feed of cleaning two) and the middlings 1 (returning to the roughing one operation); cleaning two: 300 g / t CaO is added first, stirring for 1 minute, then 25 g / t HMD is added, stirring for 2 minutes, and after aeration and stirring, scraping for 2 minutes to obtain the concentrate two (the feed of cleaning three) and the copper middlings 2 (returning to the cleaning one operation); cleaning three: blank cleaning, and after aeration and stirring, scraping for 1.5 minutes to obtain the copper concentrate and the middlings 3 (returning to the cleaning two operation). The closed-circuit test results are shown in Table 2.

[0131] Table 2 Closed-circuit test results of Example 2 and Comparative Examples 10-16 / %

[0132]

[0133]

[0134] Note: Tailings 1 in Example 2 and Comparative Examples 10-15 and tailings in Comparative Example 16 refer to the feed of nickel pyrite separation.

[0135] As shown in Table 2, the new slurry flotation process proposed in the present application is adopted, and the combined depressant HMD (Example 2) is added, the copper grade of the combined total copper concentrate is 17.33%, and the copper recovery rate is 71.47%; when the new process is adopted, and one of the three components TSPP (Comparative Example 10), BPMPA (Comparative Example 11), and SG (Comparative Example 12) in HMD is added, due to the interference of argillaceous serpentine and talc on the flotation of copper sulfide, it is difficult to obtain a high-grade copper concentrate product, and the loss of copper in the tailings is large, the copper grade and copper recovery rate of the copper concentrate are not high, the copper grade of the total copper concentrate is 9.37%-14.48%, and the copper recovery rate is 39.10%-50.86%; when any two components (TSPP and BPMPA combination (Comparative Example 15), BPMPA and SG combination (Comparative Example 14), and TSPP and SG combination (Comparative Example 13)) in HMD are added, although the inhibition effect on argillaceous gangue is better than that of a single component, the inhibition effect on argillaceous serpentine and talc is still not good, the copper grade of the total copper concentrate is 11.12%-15.37%, and the copper recovery rate is 53.39%-58.40%; the copper direct flotation process and the new depressant HMD (Comparative Example 16) are adopted in the field production, due to the serious interference of argillaceous magnesium silicate gangue, the copper grade of the copper concentrate is only 9.33%, and the copper recovery rate is only 39.54%, compared with Example 2, the copper grade of the copper concentrate is reduced by 8 percentage points, and the copper recovery rate is reduced by 31.93 percentage points.

[0136] In summary, in Example 2, the new process is used for open-circuit separation in the cleaning operation, and part of the argillaceous serpentine and talc and other gangue minerals with low copper content are separated from the cleaning middlings, which avoids the continuous circulation of argillaceous gangue in the flotation system, avoids its interference with the flotation of copper sulfide ore, and simultaneously uses the new combined depressant HMD to obtain a copper concentrate product with high grade and high recovery rate; when one component or any two components in HMD are added in the new process, the separation effect of copper sulfide ore and magnesium silicate minerals is not good; similarly, the combined depressant HMD is used, compared with the copper direct separation process used in the field production, the new process greatly avoids the adverse effects of the circulation of argillaceous gangue in direct flotation on copper flotation, and the grade and recovery rate of the copper concentrate are significantly improved. Due to the timely removal of part of the argillaceous gangue in the new process, the entire flotation reagent consumption is normal, the process is stable and easy to operate, the foam mineralization effect is good, the foam is clean and has little entrainment, and the process is easy to implement in industry.

Claims

1. A magnesium silicate gangue combined inhibitor HMD, characterized in that: The HMD is composed of sodium pyrophosphate, dihexylenetriamine penta methylene phosphonic acid and sesbania gum in a mass ratio of 20: (1-10): (0.5-2); The structural formula of the dihexylenetriaminepentamethylenephosphonic acid is: The sesbania gum is a high molecular weight polysaccharide inhibitor with a molecular weight of 20600 to 39100 and a structural formula as follows:

2. A method for efficiently separating low-grade magnesium-containing silicate-type copper sulfide ore, comprising the following steps: 1) Coarse grinding of raw ore: crush the raw ore and add it into a ball mill, then add lime and the HMD as claimed in claim 1 at the same time, and perform wet ball milling to obtain a flotation slurry; 2) Copper roughing: The flotation pulp is transferred to the flotation tank, and HMD, Z-200, and MIBC are added to the pulp to perform copper roughing operations to obtain copper rough concentrate and tailings 1 respectively; 3) Copper coarse concentrate pre-screening + regrinding: The copper coarse concentrate is pre-screened to obtain +0.038 mm particle size material and -0.038 mm particle size material; CaO and HMD are simultaneously added to the +0.038 mm particle size material, and regrinding is performed. The regrinded material and the -0.038 mm particle size material are combined as copper concentrate feed; 4) Copper concentration: CaO, HMD, Z-200, and MIBC are added to the copper concentration feed to perform copper concentration operations, thereby obtaining copper concentrate 1 and copper concentrated midd 1, and the remaining copper midds are returned in sequence; 5) Separate separation of copper concentrate middlings: CaO, HMD and Z-200 are added to the copper concentrate middlings 1 for separate separation to obtain copper concentrate 2 and tailings 2.

3. The method according to claim 2, characterized in that In the step 1), the grinding fineness of the raw ore is -0.074 mm, accounting for 50% to 70%.

4. The method according to claim 2, characterized in that The step 1) further comprises: crushing the raw ore, adding it into a wet ball mill, then adding water, and then adding 500-2500g / t of lime and 100-600g / t of HMD, and wet ball milling to obtain a flotation slurry.

5. The method according to claim 2, characterized in that: In step 2), the copper roughing operation is a secondary roughing and secondary sweeping operation, specifically: Roughing 1: first add 10-200g / t Z-200 to the slurry, stir for 2-3 minutes, then add 7-28g / t MIBC, stir for 1-2 minutes, aerate and stir, then scrape for 2-4 minutes to obtain copper rough concentrate 1 and the product in the copper roughing 1 tank respectively; Roughing 2: First add 50-300g / t HMD to the product in the copper roughing tank 1, stir for 2-3 minutes, then add 5-50g / t Z-200, stir for 2-3 minutes, aerate and stir, then scrape for 2-3 minutes to obtain copper rough concentrate 2 and the product in the copper roughing tank 2 respectively; The copper rough concentrate 1 and the copper rough concentrate 2 are combined to obtain a copper rough concentrate, and the concentrate is subjected to the pre-screening operation in step 3); Scavenging 1: first add 25-150g / t HMD to the product in the copper roughing 2 tank, stir for 2-3 minutes, then add 2.5-25g / t Z-200, stir for 2-3 minutes, aerate and stir, then scrape for 1-3 minutes to obtain copper scavenging 1 concentrate and copper scavenging 1 tank product respectively; Scavenging 2: Add 1-12.5g / t Z-200 to the product in the copper scavenging tank, stir for 2-3 minutes, aerate and stir, and then scrape for 1-2 minutes to obtain copper scavenging concentrate. The product in the tank is tailings 1.

6. The method according to claim 2, characterized in that: In step 3), the amount of CaO added is 500-2000 g / t, and the amount of HMD added is 50-300 g / t; the grinding fineness of the regrinding is -0.038 mm, accounting for 75%-95%.

7. The method according to claim 2, characterized in that: In step 4), the copper concentrating operation is 2 to 4 times of concentrating, specifically: Concentration 1: first add 7-50g / t Z-200 to the copper concentrate feed, stir for 2-3 minutes, then add 7-50g / t MIBC, stir for 1-2 minutes, aerate and stir, and then scrape for 2-3 minutes to obtain copper concentrate 1 concentrate and copper concentrate middling 1; Concentration 2: first add 0-1000g / t CaO, stir for 1-2 minutes, then add 0-300g / t HMD, stir for 2-3 minutes, aerate and stir, and then scrape for 2-3 minutes to obtain copper concentrate 2 concentrate and copper concentrate middling 2; Concentration 3: first add 0-500g / t CaO, stir for 1-2 minutes, then add 0-150g / t HMD, stir for 2-3 minutes, aerate and stir, and then scrape for 1-3 minutes to obtain copper concentrate 3 concentrate and copper concentrate middling 3; Concentration 4: first add 0-250g / t CaO, stirred for 1 to 2 minutes, then added 0 to 100 g / t HMD, stirred for 2 to 3 minutes, aerated and stirred, and then flotation and frothing for 1 to 3 minutes to obtain copper concentrate 1 and copper concentrated midd ore 4.

8. The method according to claim 2, characterized in that: In step 5), the copper concentrate middlings are separated into one roughing selection, one to two scavenging selections, and one to two concentrating selections, specifically: Primary reselection roughing: first add 0-1000g / t CaO to the copper concentrate middling 1, stir for 1-2 minutes, then add 0-200g / t HMD, stir for 2-3 minutes, then add 0-48g / t Z-200, stir for 2-3 minutes, aerate and stir, then scrape for 2-4 minutes to obtain the reselected rough concentrate of middling 1 and the reselected tailings of middling 1; One to two reselection and scavenging: Reselection and scavenging 1: first add 0-200g / t HMD to the reselected tailings of the middling ore 1, stir for 2-3 minutes, then add 0-24g / t Z-200, stir for 2-3 minutes, aerate and stir, and then scrape for 1-3 minutes to obtain the reselection and scavenging 1 concentrate and the reselection and scavenging 1 tailings; Reselection and scavenging 2: first add 0-100g / t HMD to the reselection and scavenging 1 tailings, stir for 2-3 minutes, then add 0-12g / t Z-200, stir for 2-3 minutes, aerate and stir, and then scrape for 1-2 minutes to obtain the reselection and scavenging 2 concentrate and tailings 2; One to two reselection and concentration: Reselection and concentration 1: first add 0-1000g / t CaO to the reselected coarse concentrate of middling ore 1, stir for 1-2 minutes, then add 0-200g / t HMD, stir for 2-3 minutes, aerate and stir, and then scrape for 2-3 minutes to obtain reselection and concentration 1 concentrate and reselection and concentration 1 middling ore 1; Reselection and concentration 2: first add 0-500g / t CaO to the reselection and concentration 1 concentrate, stir for 1-2 minutes, then add 0-200g / t HMD, stir for 2-3 minutes, aerate and stir, and then scrape for 1-3 minutes to obtain copper concentrate 2 and reselection and concentration 2 middling ore 2.

9. The method according to claim 2, characterized in that: In the steps 1), 3), 4) and 5), lime is added to adjust the pH of the slurry to 8.0-10.5.

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