Beneficiation method for improving recycling effect of micro-fine particle copper-nickel sulfide ore in acid environment

Abstract

The invention discloses a beneficiation method for improving the recovery effect of micro-fine particle copper-nickel sulfide ore in an acid environment, and belongs to the technical field of beneficiation. Aiming at the limitation of slime covering, mineral oxidation and micro-fine particle recovery which are difficult to solve in the traditional alkaline flotation, the method comprises the following steps: grinding and grading first-section flotation tailings by virtue of an Aisand mill, adding sulfuric acid diluted to 30-40% into overflow ore pulp, adjusting the pH value to 4.0-5.0, adding medicaments such as butyl xanthate and ammonium sulfate, treating middlings by virtue of rough flotation, fine flotation and a plurality of flotation columns, and separating the middlings by virtue of an alkaline separation method. The closed-loop process of scavenging and middling returning and regrinding is combined, the influence of slime such as serpentine is eliminated, and micro-fine particle mineral recycling is enhanced. The nickel recovery rate can reach 88.12%, the copper recovery rate can reach 89.56%, and the beneficiation technical index of the copper-nickel sulfide ore is remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to a mineral processing method for improving the recovery effect of micro-fine particle sulfide copper-nickel ore in an acidic environment. BACKGROUND

[0002] With the surge in demand for nickel metal, high-grade sulfide nickel ore is consumed in large quantities, resulting in the characteristics of "poor, fine and complex" of exploitable resources, i.e., ore grade reduction, mineral particle size miniaturization and composition complication. The traditional alkaline medium flotation process faces fundamental limitations when processing such ores: low recovery rate of micro-fine particle minerals; particle size reduction leads to increased mineral surface energy, which easily causes slime covering phenomenon; serious gangue mineral interference; magnesium-containing gangue minerals such as serpentine cover the surface of sulfide minerals, hindering effective separation; and the problem of mineral oxidation is prominent; the surface of sulfide copper-nickel minerals is prone to form an oxidation film, reducing its hydrophobicity and floatability.

[0003] Although a large number of optimizations (such as reagent formula adjustment and process structure improvement) have been made to the alkaline flotation process at home and abroad, the technical index improvement space has tended to be saturated: inherent defects of alkaline environment; under high pH conditions, gangue minerals such as serpentine are easily slimed and adsorbed on the surface of target minerals, aggravating slime interference; insufficient micro-fine particle recovery technology; conventional flotation machines have low recovery efficiency for micro-fine particle minerals with-200 mesh content of 90% or more, which easily causes metal loss.

[0004] In view of the above problems, it is urgent to develop a new process that breaks through the limitations of alkaline medium. SUMMARY

[0005] The present application mainly aims at the partial oxidation problem of sulfide copper-nickel ore, the slime covering problem and the equipment characteristics of the flotation column, and provides a mineral processing method for improving the recovery effect of micro-fine particle sulfide copper-nickel ore in an acidic environment, which eliminates the influence of magnesium-containing gangue mineral slime such as serpentine on flotation while strengthening the recovery effect of micro-fine particle minerals, and further improves the technical index of sulfide copper-nickel ore dressing.

[0006] A mineral processing method for improving the recovery effect of micro-fine particle sulfide copper-nickel ore in an acidic environment, comprising the following steps: (1) After one-time roughing of the raw ore, the roughing concentrate is subjected to two-time cleaning, one-time roughing obtains a first roughing tailing, one-time cleaning obtains a first cleaning tailing, and the first roughing tailing and the first cleaning tailing are mixed to form a first flotation tailing; the first flotation tailing slurry is subjected to grinding operation by a Ai sand mill, and the overflow slurry is introduced into a 1# acid adding stirring barrel after grading. The grinding slurry has a fineness of-200 mesh of 85%; and the overflow slurry has a fineness of-200 mesh of 90%.

[0007] (2) adding dilute sulfuric acid to the 1# acid stirring tank, adjusting the pH of the ore pulp to 4.0-5.0, the concentration being ≥20%, and then adding dispersant ammonium sulfate, collector butyl xanthate and frother into the dosing and stirring tank to obtain the first ore pulp; The amount of butyl xanthate is 68 g / t, the amount of ammonium sulfate is 328 g / t, and the amount of frother BQ-622 is 12 g / t.

[0008] (3) the first ore pulp is subjected to primary roughing to obtain first roughing concentrate and first roughing tailings.

[0009] (4) the first roughing concentrate is subjected to secondary acid addition in the 2# acid stirring tank to obtain the second ore pulp; the acid addition is adding dilute sulfuric acid to adjust the pH of the ore pulp to 4.0-5.0, the concentration being ≥20%.

[0010] (5) the second ore pulp is subjected to primary concentration to obtain primary concentration concentrate and primary concentration middlings; the primary concentration middlings are subjected to flotation column 1 selection for 5-10 minutes to obtain flotation column 1 concentrate and flotation column 1 middlings.

[0011] (6) the flotation column 1 middlings are subjected to flotation column 2 selection for 5-10 minutes to obtain flotation column 2 concentrate and flotation column 2 middlings.

[0012] (7) the primary concentration concentrate and the flotation column 1 concentrate are combined to perform secondary concentration to obtain secondary concentration concentrate and secondary concentration middlings; the secondary concentration middlings are subjected to flotation column 3 selection for 5-10 minutes to obtain flotation column 3 concentrate and flotation column 3 middlings.

[0013] (8) the flotation column 2 concentrate and the flotation column 3 middlings are returned to the primary concentration operation; the secondary concentration concentrate is the final concentrate.

[0014] (9) the first roughing tailings obtained in step (3) are subjected to sweeping stirring in a sweeping stirring tank to obtain the third ore pulp by adding collector butyl xanthate and dispersant ammonium sulfate; the amount of butyl xanthate is 24 g / t, and the amount of ammonium sulfate is 96 g / t.

[0015] (10) the third ore pulp is subjected to two times of sweeping, and the secondary sweeping tailings are the final tailings; the secondary sweeping middlings are returned to the primary sweeping, and the primary sweeping middlings and the flotation column 2 middlings are returned to the sand mill for regrinding.

[0016] The H2S generated in the mineral processing process is absorbed by the diluted liquid caustic, and the exhaust gas meets the environmental protection requirements before being discharged.

[0017] Beneficial Effects: The mineral processing method for improving the recovery of fine-grained copper-nickel sulfide ores under acidic conditions provided by this invention involves first grinding the flotation tailings through an azin mill, then adding sulfuric acid to adjust the flotation environment to acidic conditions. This prevents the formation of oxide films on the surface of copper-nickel sulfide minerals and eliminates the influence of magnesium gangue mineral slime, such as serpentine, on flotation. At the same time, a large amount of dispersant is added to prevent the fine slime from re-aggregating. Combined with the azin milling process, fine-grained minerals are liberated. The flotation column is used to enhance the separation of fine-grained minerals. Through a closed-loop process of roughing, cleaning, scavenging, and middlings return for regrinding, the mineral processing technical indicators are significantly improved. The nickel recovery rate can reach 88.12%, and the copper recovery rate can reach 89.56%. This effectively solves the limitations of traditional alkaline flotation in the separation of "lean, fine, and impure" copper-nickel sulfide ores and improves resource utilization. Attached Figure Description

[0018] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0020] Example 1 The raw ore is a slurry sample from a nickel sulfide mine in Jinchuan, with a nickel grade of 1.30% and a copper grade of 1.15%. The process adopts a traditional one-stage roughing and two-stage cleaning process. After one roughing of the raw ore, the roughing concentrate undergoes two cleaning processes. The first roughing process yields a roughing tailings, and the first cleaning process yields a cleaning tailings. The roughing tailings and the cleaning tailings are mixed to form a flotation tailings.

[0021] like Figure 1 As shown, a beneficiation method for improving the recovery efficiency of fine-grained copper-nickel sulfide ore under acidic conditions includes the following steps: (1) The first flotation tailings slurry is ground by an abrasive mill. After the slurry is classified, the overflow slurry is fed into the No. 1 acid mixing tank. The portion of the grinding slurry with a fineness of less than 200 mesh ≥ 85%; the portion of the overflow slurry with a fineness of less than 200 mesh ≥ 90%; (2) Dilute 98% concentrated sulfuric acid to 35% by adding water through a graphite diluent, then introduce it into the No. 1 acid mixing tank, adjust the pH of the slurry to 4.0~5.0, adjust the slurry concentration to 25%, and introduce it into the dosing tank for slurry preparation and dosing to obtain the first slurry; The added reagents are butyl xanthate as a collector, ammonium sulfate as a dispersant, and BQ-622 as a foaming agent. The dosage of butyl xanthate is 68 g / t, the dosage of ammonium sulfate is 328 g / t, and the dosage of BQ-622 as a foaming agent is 12 g / t. (3) the first roughing concentrate obtained in step (3) is subjected to a second roughing operation to obtain a second roughing concentrate and a second roughing tailing; (4) the first roughing concentrate obtained in step (3) is subjected to a second roughing operation to obtain a second roughing concentrate and a second roughing tailing; (5) the second roughing concentrate obtained in step (4) is subjected to a first cleaning operation to obtain a first cleaning concentrate and a first cleaning middling; the first cleaning middling is introduced into a flotation column 1 for a first cleaning to obtain a flotation column 1 concentrate and a flotation column 1 middling; the cleaning time of the flotation column is 8 minutes; (6) the flotation column 1 middling obtained in step (5) is introduced into a flotation column 2 for a first cleaning to obtain a flotation column 2 concentrate and a flotation column 2 middling; the cleaning time of the flotation column is 8 minutes; (7) the first cleaning concentrate obtained in step (5) and the flotation column 1 concentrate are subjected to a second cleaning operation to obtain a second cleaning concentrate and a second cleaning middling; the second cleaning middling is introduced into a flotation column 3 for a first cleaning to obtain a flotation column 3 concentrate and a flotation column 3 middling; the cleaning time of the flotation column is 8 minutes; (8) the flotation column 2 concentrate obtained in step (6) and the flotation column 3 middling obtained in step (7) are returned to the first cleaning operation; the second cleaning concentrate obtained in step (7) is taken as a final concentrate product; (9) the first roughing tailing obtained in step (3) is introduced into a scavenging stirring tank to obtain a third roughing concentrate after pulp conditioning and reagent addition; The reagents added in the scavenging stirring tank are a collector butyl xanthate and a dispersant ammonium sulfate, wherein the butyl xanthate is used in an amount of 24 g / t and the ammonium sulfate is used in an amount of 96 g / t; (10) the third roughing concentrate obtained in step (9) is subjected to two scavenging operations in sequence, and a second scavenging tailing is taken as a final product; a second scavenging middling is returned to a first scavenging operation; a first scavenging middling and the flotation column 2 middling obtained in step (6) are returned to a sand mill for regrinding; The H2S generated in the beneficiation process is absorbed by the diluted liquid caustic, and the exhaust gas meets the environmental protection requirements before being discharged.

[0022] Example 2 The raw ore is a certain ore slurry sample of Jinchuan nickel sulfide ore, the nickel grade of the raw ore is 1.32%, and the copper grade of the raw ore is 1.13%; the beneficiation method is the same as that in Example 1.

[0023] The technical indexes after the treatment of Example 1 and Example 2 are shown in Table 1

Claims

1. A beneficiation method for improving the recovery effect of fine-grained copper sulfide nickel ore in an acidic environment, characterized in that, It comprises the following steps: (1) a section of flotation tailings slurry is ground by the Aisan mill, and after the ground slurry is classified, the overflow slurry is fed into a 1# acid adding and stirring tank; (2) dilute sulfuric acid with a concentration of 30-40% is added to the 1# acid adding and stirring tank, the pH of the slurry is adjusted to 4.0-5.0, and the concentration is greater than or equal to 20%, and then the dispersant ammonium sulfate, the collector butyl xanthate and the foaming agent are added into a dosing and stirring tank to obtain a first slurry; (3) the first slurry is subjected to one-time roughing to obtain first roughing concentrate and first roughing tailings; (4) the first roughing concentrate is subjected to secondary acid adding and stirring in a 2# acid adding and stirring tank to obtain a second slurry; the acid adding and stirring is adding dilute sulfuric acid with a concentration of 30-40%, adjusting the pH of the slurry to 4.0-5.0, and the concentration is greater than or equal to 20%; (5) the second slurry is subjected to one-time cleaning to obtain one-time cleaning concentrate and one-time cleaning middlings; the one-time cleaning middlings are fed into a flotation column 1 for one-time separation to obtain flotation column 1 concentrate and flotation column 1 middlings; (6) the flotation column 1 middlings are fed into a flotation column 2 for one-time separation to obtain flotation column 2 concentrate and flotation column 2 middlings; (7) the one-time cleaning concentrate and the flotation column 1 concentrate are combined for two-time cleaning to obtain two-time cleaning concentrate and two-time cleaning middlings; the two-time cleaning middlings are fed into a flotation column 3 for one-time separation to obtain flotation column 3 concentrate and flotation column 3 middlings; (8) the flotation column 2 concentrate and the flotation column 3 middlings are returned to the one-time cleaning operation; the two-time cleaning concentrate is the final concentrate; (9) the first roughing tailings obtained in step (3) are fed into a scavenging stirring tank, and the collector butyl xanthate and the dispersant ammonium sulfate are added to obtain a third slurry; (10) the third slurry is subjected to two-time scavenging in sequence, and the two-time scavenging tailings are the final tailings; the two-time scavenging middlings are returned to the one-time scavenging, and the one-time scavenging middlings and the flotation column 2 middlings are returned to the Aisan mill for regrinding.

2. The method of claim 1, wherein: In step (1), the roughing concentrate is subjected to two-time cleaning after the one-time roughing, and the one-time roughing tailings and the one-time cleaning tailings are mixed to form the one-section flotation tailings.

3. The method of claim 1, wherein: In step (1), the fineness of the ground slurry is greater than or equal to 85% of -200 mesh; and the fineness of the overflow slurry is greater than or equal to 90% of -200 mesh.

4. The method of claim 1, wherein: In step (2), the dosage of butyl xanthate is 68 g / t, the dosage of ammonium sulfate is 328 g / t, and the dosage of foaming agent BQ-622 is 12 g / t.

5. The method of claim 1, wherein: In step (9), the dosage of butyl xanthate is 24 g / t, and the dosage of ammonium sulfate is 96 g / t.

6. The method of claim 1, wherein: In steps (5)-(7), the separation time of the flotation column is controlled to be 5-10 minutes.

7. The method of claim 1, wherein: The H2S waste gas generated in the mineral processing process is treated by dilute liquid alkali absorption and discharged after reaching the standard.

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