A method for pretreatment and beneficiation of copper-nickel sulfide lean ore

Abstract

The present invention belongs to the technical field of mineral processing of non-ferrous metal ores, and specifically relates to a method for pretreatment and mineral processing of copper-nickel sulfide lean ore, the method comprising the following steps: S1, grinding operation: grinding the copper-nickel sulfide lean ore to a fineness of 200 mesh with a content of 80%-85% and a mass concentration of 28%-32% of the original ore pulp; adding a sludge dispersant sodium phytate during grinding; S2, roughing operation: roughing the original ore pulp to obtain a roughing concentrate and a roughing tailing, the roughing concentrate is the copper-nickel sulfide lean ore obtained by pretreatment; adding an inhibitor sodium gluconate and a collector during roughing. The present invention can shorten the beneficiation process of copper-nickel lean ore, and compared with the conventional two-milling and two-selection process, the amount of ore entering the second stage is reduced by more than 70%, thereby reducing production costs. The use of a new and efficient sludge dispersant and a sludge inhibitor has a significant effect on copper, nickel and magnesium reduction, achieving the purpose of "reducing costs and increasing efficiency" in lean ore production.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal ore dressing, and in particular relates to a method for pretreating and dressing lean copper-nickel sulfide ore. Background Art

[0002] Copper and nickel are strategic metal resources widely used in the national defense industry and civilian industry, with the characteristics of large import volume, high external dependence and urgent demand. The Northwest region is the concentrated area of ​​copper and nickel mines in my country. With the development and utilization of copper and nickel mines in the western region, the ore has become impoverished, and the production of impoverished ore has gradually faced technical difficulties such as long process, unsatisfactory comprehensive recovery indicators and poor economic efficiency.

[0003] The resource endowment of difficult-to-process copper-nickel sulfide lean ore is poor. The lean ore and rich ore use the same two-grinding and two-selection process. The second-stage grinding volume of the lean ore is large, and the economic efficiency is poor. The main two-grinding and two-selection process can no longer meet the needs of economical utilization of lean ore resources. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for beneficiating difficult-to-treat sulfide copper-nickel lean ore by using a process of one-stage grinding-pre-tailings discarding-middling batch regrinding and reselection. The method can shorten the beneficiation process of copper-nickel lean ore. Compared with the conventional two-grinding and two-selection process, the amount of ore entering the second stage is reduced by 70%, thereby reducing production costs. The use of a new and efficient ore dispersant and ore slime inhibitor can significantly increase copper, nickel and reduce magnesium, achieving the purpose of "reducing costs and increasing efficiency" in lean ore production.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A method for pretreating lean copper-nickel sulfide ore, the method comprising the following steps:

[0007] S1. Grinding operation: Grinding the copper-nickel sulfide lean ore to a raw ore slurry with a fineness of -200 mesh, a content of 80%-85%, and a mass concentration of 28%-32%;

[0008] Wherein, a pH adjuster and a sludge dispersant are also added during the grinding, wherein the pH adjuster is one or more of sodium carbonate, ammonium sulfate, lime, and sodium bicarbonate, and the sludge dispersant is sodium phytate;

[0009] S2, roughing operation: roughing the raw ore pulp to obtain roughing concentrate and roughing tailings, wherein the roughing concentrate is the copper-nickel sulfide lean ore obtained by pretreatment;

[0010] Wherein, an inhibitor and a collector are added during the rough selection, the inhibitor is sodium gluconate, and the collector is composed of butyl xanthate and butyl ammonium xanthate.

[0011] Further, in step S1, the amount of the pH adjuster is 1000 g / t-1500 g / t based on the amount of the original ore;

[0012] And / or, in step S1, the amount of the sludge dispersant is 100 g / t-220 g / t based on the amount of the original ore;

[0013] And / or, in step S2, the dosage of the inhibitor is 300 g / t-500 g / t based on the amount of the original ore;

[0014] And / or, in step S2, based on the amount of the original ore, the amount of the collector used is 200g / t-270g / t.

[0015] Furthermore, in step S2, the mass ratio of butyl xanthate to butyl ammonium black medicine in the collector is 3-5:1-1.5.

[0016] Furthermore, the nickel grade of the copper-nickel sulfide lean ore is 0.4%-0.7%.

[0017] The present invention also provides a method for beneficiation of copper-nickel sulfide lean ore, the method comprising the above-mentioned method for pretreating copper-nickel sulfide lean ore, and further comprising the following steps:

[0018] S3, beneficiation operation: the rougher concentrate is beneficiated three times or more to obtain beneficiated concentrate, beneficiated tailings and middlings, wherein the beneficiated concentrate is a low-magnesium high-grade copper-nickel mixed concentrate; the beneficiated tailings after the third time are returned to the first beneficiation operation to form a closed loop;

[0019] Among them, the inhibitor sodium gluconate is added during the selection, and the addition amount of the inhibitor sodium gluconate is 8g / t-12g / t based on the amount of original ore.

[0020] Furthermore, the method further comprises the following steps:

[0021] S4, scavenging operation: the rougher tailings are scavenged twice or more to obtain scavenged concentrate and scavenged tailings, and the scavenged tailings are the final tailings;

[0022] Wherein, during the sweeping, a sludge dispersant sodium phytate and a collector butyl xanthate are added;

[0023] S5, vertical mill operation: grinding the middlings and scavenged concentrates by a vertical mill to a middling ore slurry with a fineness of -325 mesh, a content of 90%-95%, and a mass concentration of 23%-26%;

[0024] Wherein, the pH adjuster and the mineral mud dispersant sodium phytate are added in the vertical mill operation;

[0025] S6, middling ore flotation operation: subjecting the middling ore pulp to a coarse, fine and sweep flotation operation.

[0026] Further, in step S4, the amount of the sludge dispersant sodium phytate is 30 g / t-50 g / t based on the amount of the original ore;

[0027] And / or, in step S4, the amount of the collector butyl xanthate is 40 g / t-60 g / t based on the amount of the original ore;

[0028] And / or, in step S5, the amount of the pH adjuster is 100 g / t-150 g / t based on the amount of the original ore;

[0029] And / or, in step S5, based on the amount of original ore, the amount of sodium phytate as the sludge dispersant is 20 g / t-40 g / t.

[0030] Furthermore, in step S6, when the middling ore pulp is subjected to middling roughing, middling roughing concentrate and middling roughing tailings are obtained;

[0031] The middling rougher concentrate is used as the feed material for the middling scavenging, and the middling scavenging concentrate and the middling scavenging tailings are obtained. The middling scavenging concentrate is returned to the vertical mill operation, and the middling scavenging tailings are returned to the grinding operation;

[0032] The middling rougher tailings are used as feed materials for middling beneficiation, and middling beneficiation obtains middling beneficiation concentrate and middling beneficiation tailings. The middling beneficiation concentrate is a low-magnesium and high-grade copper-nickel mixed concentrate, and the middling beneficiation tailings are returned to the vertical mill operation.

[0033] Furthermore, in step S6, the inhibitor sodium gluconate and the collector butyl xanthate are added to the rough selection of the middling ore, and the amount of the inhibitor sodium gluconate is 30g / t-50g / t, and the amount of the collector butyl xanthate is 50g / t-80g / t based on the amount of the original ore;

[0034] And / or, in step S6, the inhibitor sodium gluconate and the collector butyl xanthate are added to the middling ore during scavenging, and the amount of the inhibitor sodium gluconate is 30g / t-50g / t, and the amount of the collector butyl xanthate is 40g / t-60g / t based on the amount of the original ore;

[0035] And / or, in step S6, the inhibitor sodium gluconate is added to the middling ore concentration, and the amount of the inhibitor sodium gluconate is 2g / t-5g / t based on the amount of the original ore.

[0036] The present invention also provides the application of the above-mentioned method for pretreating copper-nickel sulfide lean ore and / or the above-mentioned method for beneficiating copper-nickel sulfide lean ore in the beneficiation process of copper-nickel sulfide lean ore.

[0037] The beneficial effects of the present invention are:

[0038] 1. The present invention adopts a one-stage grinding-pre-tailing flotation pretreatment process, and uses a green and efficient sludge dispersant sodium phytate and an inhibitor sodium gluconate to discard more than 70% of the tailings, obtain a low-magnesium high-grade copper-nickel mixed concentrate, and reduce the influence of sludge on subsequent separation. Then most of the intermediates in the first-stage flotation process are combined for re-grinding, classification, and deep flotation, so that the second-stage grinding amount is reduced by 70%, and there is no interference from sludge, and a low-magnesium low-grade copper-nickel mixed concentrate can be stably obtained, thereby reducing the total concentrate magnesium oxide content, improving the copper-nickel concentrate grade and recovery rate. The present invention is aimed at difficult-to-process extremely low-grade copper-nickel sulfide ores, adopts a one-stage grinding-pre-tailing process, removes sludge and obtains high-quality copper-nickel mixed concentrate, and introduces the intermediate ore re-grinding and re-selection process into the copper-nickel lean ore beneficiation, so as to achieve the purpose of removing sludge in advance, improving the efficiency of each stage of flotation operation, reducing process energy consumption, improving copper-nickel selection indicators, and reducing the magnesium oxide content of the concentrate.

[0039] 2. The sludge dispersant sodium phytate used in the present invention, also known as sodium inositol hexaphosphate, is an organic phosphorus compound extracted from pure natural plant seeds. The unique molecular structure of sodium phytate determines the characteristics of high negative charge density. After adsorption, the magnesium-containing gangue sludge particles are surrounded by negative charges, which prevents the magnesium-containing gangue sludge particles from aggregating with each other, improves the fluidity and dispersion of the slurry, and thus reduces the influence of the magnesium-containing gangue sludge on the flotation of copper-nickel minerals. Compared with inorganic dispersants, the dispersibility of sodium phytate is not affected by the pH value of the slurry. It is a new type of efficient dispersant suitable for the flotation of magnesium-rich sulfide copper-nickel lean ores, which is beneficial to improving the flotation index of copper and nickel.

[0040] 3. The mineral slime inhibitor sodium gluconate used in the present invention is an organic substance with a chemical formula of C 6 H 11 NaO 7 , which is widely used in industry. Sodium gluconate can be used as a high-efficiency chelating agent in the construction, textile printing and dyeing, metal surface treatment and water treatment industries, a steel surface cleaning agent, a glass bottle cleaning agent, an electroplating industrial aluminum oxide coloring agent, and a high-efficiency retarder in the concrete industry. The present invention introduces sodium gluconate into the copper-nickel ore dressing to inhibit magnesium-containing gangue. Because the polar group (-OH) in the inhibitor molecule is easy to react with the metal ion Mg with larger metallicity, 2+ It reacts to form ionic chemical bonds and chemical reactions, and with the metal ions Fe with higher negative charge 2+ Their action ability is weak, so their action ability on the surface of magnesium-containing gangue is significantly stronger than that on the surface of copper-nickel sulfide ore, so they have the effect of selectively reducing magnesium.

[0041] 4. After the pre-treatment of the first-stage grinding-pre-tailing flotation, more than 70% of the magnesium-containing gangue can be removed in advance, thereby greatly reducing the amount of second-stage grinding, reducing the circulation amount of magnesium-containing gangue in the flotation system, improving the flotation environment, and innovatively adopting the method of returning the flotation medium in batches (the tailings of the selected ore and the scavenged ore of the ore are combined and returned to the vertical mill of the ore for grinding, the scavenged ore tailings of the ore are returned to the ball mill for grinding, and the third selected tailings are returned to the first selected operation to form a closed loop), extending the sorting time of the ore, effectively improving the sorting efficiency of the ore, thereby improving the recovery rate of copper and nickel, and reducing the magnesium oxide content of the copper-nickel concentrate. The method has strong adaptability to lean ores, simple process, easy control, high sorting efficiency, excellent method indicators, and the obtained copper-nickel mixed concentrate is of high quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0044] Example 1

[0045] This embodiment provides a method for beneficiating a difficult-to-treat copper-nickel sulfide lean ore by a one-stage grinding-pre-tailings discarding process, wherein the copper grade of the copper-nickel lean ore is 0.36%, the nickel grade is 0.63%, and the magnesium oxide content is as high as 23.1%. 2 , O 2 The mineral components of the entire ore deposit are subjected to varying degrees of alteration, including serpentinization, chloritization and talc-carbonation of the ore-bearing rock mass. Serpentinization and chloritization are what we often call weak alteration, while talc-carbonation is strong alteration. The alteration makes the mineral composition of the entire ore deposit very complex: the ore is soft and brittle, and the particle size of the metal sulfide is very uneven; the copper-nickel minerals are poorly crystallized, low in content, and fine inlaid in size; the secondary purple sulfide nickel content is high, and the floatability is poor. The sulfide minerals in the lean ore mainly include pentlandite, pyrrhotite, chalcopyrite, chalcopyrite, pyrrhotite, pyrite, as well as a small amount of blackthorn ore and rare and precious metal minerals such as platinum and palladium; the gangue minerals mainly include olivine, pyroxene and its alteration products serpentine, chlorite, talc, and a small amount of magnesium-containing silicate minerals such as carbonate and biotite; the ore also contains a certain amount of iron oxides such as magnetite and chromite.

[0046] The flow diagram of the mineral processing method is as follows: Figure 1 As shown, the following steps are included: the grinding operation includes grinding of raw ore with a ball mill and grinding of intermediate ore with a vertical mill; the flotation operation includes roughing, scavenging, and concentrating of intermediate ore, roughing, scavenging, and concentrating of intermediate ore.

[0047] Ball mill grinding of raw ore: before the roughing, the raw ore is ball milled to obtain raw ore with a fineness of -200 mesh, a content of 82%, and a mass concentration of 31%. During the ball mill grinding operation, a pH adjuster and a sludge dispersant are added to the raw ore; preferably, the pH adjuster is ammonium sulfate and the sludge dispersant is sodium phytate, and the addition amounts of the two are preferably 1200g / t and 150g / t, respectively, based on the amount of raw ore.

[0048] Roughing: adding inhibitors to the slurry to inhibit gangue, adding collectors to collect copper-nickel minerals, and obtaining roughing concentrate and roughing tailings; the roughing tailings are used as feed for the scavenging, and the roughing concentrate is used as feed for the concentrating; preferably, the gangue inhibitor is sodium gluconate, and the collector is composed of butyl xanthate and butyl ammonium black medicine, and the addition amounts of the two are preferably 400g / t and 250g / t, respectively, based on the amount of original ore; more preferably, the mass ratio of the collector butyl xanthate to butyl ammonium black medicine is 3:1.

[0049] Scavenging: The scavenging is carried out twice. During each scavenging process, dispersant sodium phytate and collector butyl xanthate are added to the feed ore to obtain scavenging concentrate and scavenging tailings. In addition to the scavenging concentrate, the second scavenging also obtains the final tailings. Preferably, based on the amount of original ore, the addition amounts of the dispersant sodium phytate and collector butyl xanthate in each scavenging process are 30 g / t and 40 g / t, respectively.

[0050] Concentration: The concentrating is carried out three times, and during each concentrating process, an inhibitor, sodium gluconate, is added to the feed ore for concentrating to obtain a concentrated ore and a concentrated tailing. In addition to the concentrated tailings, the third concentrating also obtains a low-magnesium and high-grade copper-nickel mixed concentrate and a third concentrated tailings. The third concentrated tailings are returned to a concentrating operation to form a closed loop. Preferably, based on the amount of original ore, the amount of the inhibitor sodium gluconate added during each concentrating process is 12 g / t.

[0051] Vertical mill grinding of medium ore: The medium ore is ground by a vertical mill. During the vertical mill grinding operation, a pH adjuster and a sludge dispersant are added to the medium ore to obtain a medium ore slurry with a fineness of -325 mesh, a content of 92%, and a mass concentration of 24%. Preferably, the pH adjuster is sodium carbonate and the sludge dispersant is sodium phytate. Based on the amount of original ore, the addition amounts of the two are preferably 150g / t and 40g / t, respectively.

[0052] Roughing of middlings: adding sodium gluconate as an inhibitor and butyl xanthate as a collector to the ore pulp to obtain a roughing concentrate and a roughing tailing of middlings; the roughing tailings of middlings are used as feed for the scavenging of middlings, and the roughing concentrate of middlings is used as feed for the beneficiation of middlings; preferably, the sodium gluconate as an inhibitor and the butyl xanthate as a collector are preferably added in an amount of 30 g / t and 50 g / t, respectively, based on the amount of the original ore.

[0053] Middling ore scavenging: the middling ore scavenging is carried out once, and a collector butyl xanthate is added during the middling ore scavenging process to obtain a middling ore scavenging concentrate and a middling ore scavenging tailings, the middling ore scavenging concentrate is returned to the middling ore vertical mill for grinding to form a closed loop, and the middling ore scavenging tailings are returned to the original ore ball mill for grinding to form a closed loop; preferably, based on the amount of original ore, the addition amounts of the dispersant sodium phytate and the collector butyl xanthate in the middling ore scavenging process are 30 g / t and 40 g / t, respectively.

[0054] Middling beneficiation: Middling beneficiation is carried out once, during which sodium gluconate, an inhibitor, is added to carry out beneficiation to obtain a low-magnesium, high-grade copper-nickel mixed concentrate and middling beneficiation tailings, which are returned to the middling vertical mill for grinding to form a closed-loop circulation; preferably, based on the amount of original ore, the amount of sodium gluconate, an inhibitor, added during the middling beneficiation process is 3 g / t.

[0055] The test results of Example 1 are shown in the following table.

[0056]

[0057] Example 2

[0058] This embodiment provides a method for beneficiating difficult-to-treat sulfide copper-nickel lean ore using a one-stage grinding-pre-tailings discarding process. The copper grade of the extremely low-grade copper-nickel ore is 0.15%, the nickel grade is 0.51%, and the magnesium oxide content is as high as 24.3%. The mineral composition of the lean ore is relatively complex. The copper minerals mainly include chalcopyrite, trace amounts of bornite and arsenopyrite; the nickel minerals mainly include pentlandite, trace amounts of arsenopyrite and pyrite; the iron minerals mainly include pyrrhotite, magnetite, ilmenite and pyrite; in addition, it also contains a small amount or trace amount of sphalerite, galena, monoclinic green copper zinc ore, stannite and other metal minerals; the gangue minerals are mainly composed of talc, pyroxene, mica, feldspar, chlorite, olivine, etc., and there are also a small amount or trace amount of quartz, calcite, amphibole, serpentine and other minerals. In addition, the primary particle size of chalcopyrite and pentlandite in the ore is uneven, with particle sizes below 20 microns accounting for more than 20%, and the nickel silicate content is high. The ore is a difficult-to-process low-grade copper-nickel ore.

[0059] The flow diagram of the mineral processing method is as follows: Figure 1As shown, the following steps are included: the grinding operation includes grinding of raw ore with a ball mill and grinding of intermediate ore with a vertical mill; the flotation operation includes roughing, scavenging, and concentrating of intermediate ore, roughing, scavenging, and concentrating of intermediate ore.

[0060] Ball mill grinding of raw ore: before the roughing, the raw ore is ball milled to obtain raw ore with a fineness of -200 mesh, a content of 85%, and a mass concentration of 29%. During the ball mill grinding operation, a pH adjuster and a sludge dispersant are added to the raw ore; preferably, the pH adjuster is sodium bicarbonate and the sludge dispersant is sodium phytate, and the addition amounts of the two are preferably 1500g / t and 220g / t, respectively, based on the amount of raw ore.

[0061] Roughing: adding inhibitors to the slurry to inhibit gangue, adding collectors to collect copper-nickel minerals, and obtaining roughing concentrate and roughing tailings; the roughing tailings are used as feed for the scavenging, and the roughing concentrate is used as feed for the concentrating; preferably, the gangue inhibitor is sodium gluconate, and the collector is composed of butyl xanthate and butyl ammonium black medicine, and the addition amounts of the two are preferably 500g / t and 270g / t, respectively, based on the amount of original ore; more preferably, the mass ratio of the collector butyl xanthate to butyl ammonium black medicine is 5:1.5.

[0062] Scavenging: The scavenging is carried out twice. During each scavenging process, dispersant sodium phytate and collector butyl xanthate are added to the feed ore to obtain scavenging concentrate and scavenging tailings. In addition to the scavenging concentrate, the second scavenging also obtains the final tailings. Preferably, based on the amount of original ore, the addition amounts of the dispersant sodium phytate and collector butyl xanthate in each scavenging process are 50g / t and 60g / t, respectively.

[0063] Concentration: The concentrating is carried out three times, and during each concentrating process, an inhibitor, sodium gluconate, is added to the feed ore for concentrating to obtain a concentrated ore and a concentrated tailing. In addition to the concentrated tailings, the third concentrating also obtains a low-magnesium and high-grade copper-nickel mixed concentrate and a third concentrated tailings. The third concentrated tailings are returned to a concentrating operation to form a closed loop. Preferably, based on the amount of original ore, the amount of the inhibitor sodium gluconate added during each concentrating process is 12 g / t.

[0064] Vertical mill grinding of medium ore: The medium ore is ground by a vertical mill. During the vertical mill grinding operation, a pH adjuster and a sludge dispersant are added to the medium ore to obtain a medium ore slurry with a fineness of -325 mesh, a content of 94%, and a mass concentration of 23%. Preferably, the pH adjuster is sodium carbonate and the sludge dispersant is sodium phytate. Based on the amount of original ore, the addition amounts of the two are preferably 150g / t and 40g / t, respectively.

[0065] Roughing of middlings: adding sodium gluconate, an inhibitor, and butyl xanthate, a collector, to the ore pulp to obtain a roughing concentrate of middlings and a roughing tailing of middlings; the roughing tailings of middlings are used as feed for the scavenging of middlings, and the roughing concentrate of middlings is used as feed for the beneficiation of middlings; preferably, the sodium gluconate, an inhibitor, and butyl xanthate, a collector, are added in an amount of 50 g / t and 80 g / t, respectively, based on the amount of the original ore.

[0066] Middling ore scavenging: the middling ore scavenging is carried out once, and a collector butyl xanthate is added during the middling ore scavenging process to obtain a middling ore scavenging concentrate and a middling ore scavenging tailing. The middling ore scavenging concentrate is returned to the middling ore vertical mill for grinding to form a closed loop, and the middling ore scavenging tailing is returned to the original ore ball mill for grinding to form a closed loop; preferably, based on the amount of original ore, the addition amounts of the dispersant sodium phytate and the collector butyl xanthate in the middling ore scavenging process are 50 g / t and 60 g / t, respectively.

[0067] Middling beneficiation: Middling beneficiation is carried out once, during which sodium gluconate, an inhibitor, is added to carry out beneficiation to obtain a low-magnesium, high-grade copper-nickel mixed concentrate and middling beneficiation tailings, which are returned to the middling vertical mill for grinding to form a closed-loop circulation; preferably, based on the amount of original ore, the amount of sodium gluconate, an inhibitor, added during the middling beneficiation process is 5 g / t.

[0068] The test results of Example 2 are shown in the following table.

[0069]

[0070] Comparative Example 1

[0071] Comparative Example 1 uses the same raw ore as Example 1, and the "two-grinding and two-selection process" described in the background technology. The specific method of the process is copper-nickel mixed flotation, and all sulfides are enriched into concentrate products through two-stage grinding and two-stage selection. Among them, the first stage of selection is divided into one roughing selection and two selections. The selected concentrate is a high-grade concentrate, and the roughing tailings enter the second stage of grinding; the second stage of selection is divided into one roughing selection, two selections, and two scavenging selections. The selected concentrate is a low-grade concentrate, and the scavenging tailings are used as the final tailings; the closed-circuit middling return form is a step-by-step return. The reagent system adopted is: the first stage is rough selection of ammonium sulfate (as pH adjuster and inhibitor) 300g / t, ethyl xanthate 300g / t and butyl ammonium black powder 50g / t, and blank selection; the second stage grinding fineness is -0.074mm accounting for 86.7%, rough selection of ethyl xanthate 150g / t, and butyl ammonium black powder 20g / t, the first scavenging of the second stage adds ethyl xanthate 75g / t, and the second scavenging does not add any reagent, and blank selection is performed.

[0072] The test results of Comparative Example 1 are shown in the following table.

[0073]

[0074] Comparing the data of Example 1 with Comparative Example 1, it can be seen that the difference between Comparative Example 1 and Example 1 is that the process and reagents are different. The comparison of experimental data shows that the new process can reduce the amount of second-stage grinding, improve the copper and nickel grades of two concentrates (high and low), and reduce the content of magnesium oxide in the concentrate. It can be concluded that the process and reagents of the present invention have the effect of reducing the amount of second-stage grinding (load) and improving quality and reducing magnesium.

[0075] Comparative Example 2

[0076] Comparative Example 2 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding and roughing steps, the only difference is that no sludge dispersant is used when grinding the raw ore in the ball mill of Comparative Example 2 (for verifying the effect of the sludge dispersant sodium phytate when grinding the raw ore in the ball mill). The test results of Comparative Example 2 are shown in Table 1 below, and Table 2 is the roughing test results of grinding with 200g / t sodium phytate added.

[0077] Table 1

[0078]

[0079] Table 2

[0080]

[0081] Comparing the data in Table 1 with Table 2, it can be seen that the difference between Table 1 and Table 2 is that Table 1 does not use a sludge dispersant. The comparison of experimental data shows that the addition of the dispersant sodium phytate improves the grade and recovery rate of copper and nickel in the rough concentrate, reduces the magnesium oxide content, and reduces the content of the target metal copper and nickel in the tailings. It can be concluded that when sodium gluconate is used as an inhibitor, the sludge dispersant sodium phytate has an excellent dispersing effect of improving the quality of the concentrate in the present invention.

[0082] Comparative Example 3

[0083] Comparative Example 3 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding and roughing steps. The only difference is that the sludge dispersant used in the raw ore ball mill grinding of Comparative Example 3 is water glass (that is, this comparative example uses an inorganic dispersant to verify the effect of the sludge dispersant sodium phytate in the raw ore ball mill grinding), and the dosage is the same as that of Example 1. The test results of Comparative Example 3 are shown in the following table.

[0084]

[0085] Comparing the data in Table 2 with Comparative Example 3, it can be seen that the difference between Table 2 and Comparative Example 3 is that the inorganic dispersant water glass is used in Comparative Example 3. The comparison of experimental data shows that the sodium phytate under the same dosage has a more obvious effect on the improvement of concentrate indicators (copper-nickel grade, recovery rate). At the same time, the state of water glass in the ore pulp is greatly affected by pH (while the state of sodium phytate is relatively stable in the ore pulp), so the requirement of water glass as a dispersant for pH is relatively strict. It can be concluded that when sodium gluconate is used as an inhibitor, sodium phytate has a more excellent dispersing effect in the present invention compared to the general inorganic dispersant water glass when sodium phytate is added in the grinding.

[0086] Comparative Example 4

[0087] Comparative Example 4 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding and roughing steps. The only difference is that the sludge dispersant used in the raw ore ball mill grinding of Comparative Example 4 is sodium hexametaphosphate (that is, this comparative example uses an inorganic dispersant to verify the effect of the sludge dispersant sodium phytate in the raw ore ball mill grinding), and the dosage is the same as that of Example 1. The test results of Comparative Example 4 are shown in the following table.

[0088]

[0089] Comparing the data in Tables 1 and 2 with Comparative Example 4, it can be seen that the difference between Tables 2 and Comparative Example 4 is that the inorganic dispersant sodium hexametaphosphate is used in Comparative Example 4. The experimental data comparison shows that the addition of sodium hexametaphosphate to grinding has a certain improvement effect on the copper and nickel indicators of the coarse concentrate compared to not adding a dispersant, but it is still insufficient compared to sodium phytate at the same dosage. It can be concluded that when sodium gluconate is used as an inhibitor, the same amount of sodium phytate has a more significant dispersing effect in the present invention compared to the general inorganic dispersant sodium hexametaphosphate.

[0090] Comparative Example 5

[0091] Comparative Example 5 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding and roughing steps, the only difference is that no inhibitor is used in the raw ore ball mill grinding of Comparative Example 5 (for verifying the effect of the slime inhibitor sodium gluconate in roughing). The test results of Comparative Example 5 are shown in the following table.

[0092]

[0093] Comparing the data in Table 2 with Comparative Example 5, it can be seen that the difference between Table 2 and Comparative Example 5 is that no inhibitor is used in Comparative Example 5. The comparison of experimental data shows that the inhibitor sodium gluconate can significantly reduce the magnesium oxide content and improve the copper-nickel index. It can be concluded that when sodium phytate is used as a dispersant, sodium gluconate has the effect of significantly inhibiting magnesium oxide and improving the quality of the concentrate in the present invention.

[0094] Comparative Example 6

[0095] Comparative Example 6 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding and roughing steps, the only difference is that the inhibitor used in the roughing in Comparative Example 6 is sodium carboxymethyl cellulose (used to verify that the slime inhibitor sodium gluconate and the slime dispersant sodium phytate have a synergistic effect in the roughing), and the dosage is the same as that in Example 1. The test results of Comparative Example 6 are shown in the following table.

[0096]

[0097] Comparing the data in Table 2 with Comparative Example 6, it can be seen that the difference between Table 2 and Comparative Example 6 is that the inhibitor used in Comparative Example 6 is sodium carboxymethyl cellulose, and the comparison of experimental data shows that sodium phytate has a greater effect on improving the copper and nickel grades than sodium carboxymethyl cellulose. It can be concluded that compared with the general inhibitor carboxymethyl cellulose, the inhibitor effect of sodium gluconate in the present invention has a more suitable synergistic effect with the dispersant sodium phytate.

[0098] Comparative Example 7

[0099] Comparative Example 7 uses the same raw ore as Example 1 for raw ore ball mill grinding and roughing steps, the only difference is that the inhibitor used in the roughing step of Comparative Example 7 is guar gum (used to verify that the slime inhibitor sodium gluconate and the slime dispersant sodium phytate have a synergistic effect in roughing), and the dosage is the same as that of Example 1. The test results of Comparative Example 7 are shown in the following table.

[0100]

[0101] Comparing the data in Table 2 with Comparative Example 7, it can be seen that the difference between Table 2 and Comparative Example 7 is that the inhibitor used in Comparative Example 7 is guar gum. The comparison of experimental data shows that the inhibitory effect of guar gum on magnesium oxide at the same dosage is not as good as that of sodium gluconate, and the copper-nickel concentrate index is not as good as that of sodium gluconate. It can be concluded that when sodium phytate is added to the grinding as a dispersant, sodium gluconate has a better synergistic effect than guar gum, a general inhibitor, at the same dosage.

[0102] Comparative Example 8

[0103] Comparative Example 8 uses the same raw ore as Example 1 to carry out raw ore ball mill grinding, roughing and concentrating steps, without scavenging, medium ore vertical mill grinding, medium ore roughing, medium ore scavenging and medium ore concentrating steps. The roughing tailings and concentrating tailings obtained from the roughing and the first two concentrating steps are the final tailings (used to verify the effects of the medium ore grinding and medium ore flotation steps).

[0104]

[0105] Comparing the data of Example 1 with Comparative Example 8, it can be seen that the difference between Comparative Example 8 and Example 1 is that Comparative Example 8 does not adopt the steps of grinding and flotation of middlings. The comparison of experimental data shows that if only one stage of grinding and one stage of separation are carried out without re-grinding and re-selection of middlings, a large part of the copper and nickel metals will enter the tailings, resulting in a low total recovery rate of the concentrate. It can be concluded that the steps of grinding and flotation of middlings have the effect of improving the flotation recovery rate in the present invention.

[0106] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for beneficiation of copper-nickel sulfide lean ore, characterized in that: The method comprises the following steps: S1. Grinding operation: Grinding the copper-nickel sulfide lean ore to a raw ore slurry with a fineness of -200 mesh, a content of 80%-85%, and a mass concentration of 28%-32%; S2, roughing operation: roughing the raw ore pulp to obtain roughing concentrate and roughing tailings, wherein the roughing concentrate is the copper-nickel sulfide lean ore obtained by pretreatment; S3, beneficiation operation: beneficiating the rougher concentrate three times or more to obtain beneficiated concentrate, beneficiated tailings and middlings, wherein the beneficiated concentrate is a low-magnesium high-grade copper-nickel mixed concentrate; S4, scavenging operation: the rougher tailings are scavenged twice or more to obtain scavenged concentrate and scavenged tailings, and the scavenged tailings are the final tailings; S5, vertical mill operation: grinding the middlings and scavenged concentrates by a vertical mill to a middling ore slurry with a fineness of -325 mesh, a content of 90%-95%, and a mass concentration of 23%-26%; S6, flotation of middlings: subjecting the middling pulp to a coarse, fine and sweep flotation operation; Wherein, a pH adjuster and a sludge dispersant are also added during the grinding, wherein the pH adjuster is one or more of sodium carbonate, ammonium sulfate, lime, and sodium bicarbonate, and the sludge dispersant is sodium phytate; During the roughing, an inhibitor and a collector are added, wherein the inhibitor is sodium gluconate, and the collector is composed of butyl xanthate and butyl ammonium black medicine; The inhibitor sodium gluconate is added during the concentration, and the addition amount of the inhibitor sodium gluconate is 8g / t-12g / t based on the amount of the original ore; During the sweeping, a sludge dispersant sodium phytate and a collector butyl xanthate are added; The pH adjuster and the sludge dispersant sodium phytate are added to the vertical mill operation; In step S1, the amount of the pH adjuster is 1000 g / t-1500 g / t based on the amount of the original ore; In step S1, the amount of the sludge dispersant is 100 g / t-220 g / t based on the amount of the original ore; In step S2, the dosage of the inhibitor is 300 g / t-500 g / t based on the amount of the original ore; In step S2, the amount of the collector is 200 g / t-270 g / t based on the amount of the original ore; In step S4, the amount of sodium phytate as a sludge dispersant is 30 g / t-50 g / t based on the amount of the original ore; In step S4, the amount of the collector butyl xanthate is 40 g / t-60 g / t based on the amount of the original ore; In step S5, the amount of the pH adjuster is 100 g / t-150 g / t based on the amount of the original ore; In step S5, based on the amount of the original ore, the amount of sodium phytate as the sludge dispersant is 20 g / t-40 g / t.

2. A method for beneficiation of copper-nickel sulfide lean ore according to claim 1, characterized in that: In step S2, the mass ratio of butyl xanthate to butyl ammonium black medicine in the collector is 3-5:1-1.

5.

3. A method for beneficiation of copper-nickel sulfide lean ore according to claim 1, characterized in that: The nickel grade of the copper-nickel sulfide lean ore is 0.4%-0.7%.

4. A method for beneficiation of copper-nickel sulfide lean ore according to claim 1, characterized in that: In step S6, when the middling ore pulp is subjected to middling roughing, middling roughing concentrate and middling roughing tailings are obtained; The middling rougher concentrate is used as the feed material for the middling scavenging, and the middling scavenging concentrate and the middling scavenging tailings are obtained. The middling scavenging concentrate is returned to the vertical mill operation, and the middling scavenging tailings are returned to the grinding operation; The middling rougher tailings are used as feed materials for middling beneficiation, and middling beneficiation obtains middling beneficiation concentrate and middling beneficiation tailings. The middling beneficiation concentrate is a low-magnesium and high-grade copper-nickel mixed concentrate, and the middling beneficiation tailings are returned to the vertical mill operation.

5. A method for beneficiation of copper-nickel sulfide lean ore according to claim 1, characterized in that: In step S6, the inhibitor sodium gluconate and the collector butyl xanthate are added to the rough selection of the middling ore. Based on the amount of the original ore, the amount of the inhibitor sodium gluconate is 30g / t-50g / t, and the amount of the collector butyl xanthate is 50g / t-80g / t; In step S6, the inhibitor sodium gluconate and the collector butyl xanthate are added to the middling ore during scavenging. Based on the amount of the original ore, the amount of the inhibitor sodium gluconate is 30 g / t-50 g / t, and the amount of the collector butyl xanthate is 40 g / t-60 g / t. In step S6, the inhibitor sodium gluconate is added to the middling ore for concentration, and the dosage of the inhibitor sodium gluconate is 2 g / t-5 g / t based on the amount of the original ore.

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