Sorting method for precious metal in low-grade copper-nickel sulfide ore

Abstract

The invention relates to the technical field of metal beneficiation, in particular to a separation method for precious metal in low-grade copper-nickel sulfide ore, and solves the problems of low recovery rate and separation efficiency of the precious metal in the low-grade copper-nickel sulfide ore at present. According to the method, ore grinding is carried out through a first ball mill, grading is carried out through a first cyclone after ore grinding, part of graded settled sand is separated out through an ore separation gate and subjected to vibrating screen coarse separation, oversize coarse particle ore of a vibrating screen returns to the first ball mill to be ground again, it is ensured that precious metal in the oversize coarse particle ore is fully dissociated, and undersize fine particle ore is subjected to gravity separation through a Nelson gravity separator; the Nelson concentrate is subjected to ore grinding through a second ball mill, precious metal minerals such as gold and platinum in the Nelson concentrate are subjected to full monomer dissociation, desliming is conducted through a second cyclone after ore grinding, deironing is conducted through a magnetic separator on settled sand, and then the ores are fed into a table concentrator, so that the precious metal concentrate with higher purity is obtained, and precious metal in low-grade raw ore is effectively enriched; and the recovery rate of gold and platinum noble metals is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal ore dressing, and in particular to a method for separating precious metals in low-grade copper-nickel sulfide ore. Background Art

[0002] In the process of mining and utilization of mineral resources, the separation technology of precious metals in low-grade copper-nickel sulfide ores has always been a key technical problem in the field of mineral processing. Due to its low grade, many impurities and complex mineral composition, the separation process of low-grade copper-nickel sulfide ores is complicated and inefficient. Traditional separation methods often fail to achieve efficient recovery of precious metals in low-grade copper-nickel sulfide ores, resulting in waste of resources and low economic benefits. In recent years, with the advancement of science and technology and the enhancement of environmental awareness, the development of efficient and environmentally friendly low-grade copper-nickel sulfide ore dressing technology has become a research hotspot in the field of mineral processing, especially in the separation of precious metals such as gold and platinum. How to achieve effective dissociation and efficient recovery of fine-grained precious metal minerals has become the key to improving overall economic benefits and reducing environmental impact. Summary of the invention

[0003] The present invention provides a method for separating precious metals from low-grade copper-nickel sulfide ore, so as to solve the problems of low precious metal recovery rate and separation efficiency in low-grade copper-nickel sulfide ore existing in the above background.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for separating precious metals from low-grade copper-nickel sulfide ore comprises the following steps: Step 1: The low-grade copper-nickel sulfide ore after crushing and screening is ground by the first ball mill, and the first cyclone is classified to produce sedimentation and overflow fine mud. The concentration of the grinding overflow fine mud is 65%-67%, and the concentration of the classified sedimentation is 78%-82%. The sedimentation produced by classification is separated into primary sedimentation through the coarse separation net and the gate.

[0005] Step 2: The primary sediment is screened through a vibrating screen to obtain coarse particles on the screen and fine particles under the screen. The coarse particles on the screen are returned to the first ball mill for further grinding.

[0006] Step 3: The fine particles under the screen flow into the Nelson gravity separator by gravity. The concentration of the fine particles under the vibrating screen is controlled at 60%-65%. The cycle time of the Nelson gravity separator is controlled at 30min-45min, and the flushing water flow rate is 40m³ / h-45m³ / h. Precious metal concentrate 1 and tailings 1 are produced. Tailings 1 are returned to the first ball mill for re-grinding.

[0007] Step 4: The precious metal concentrate 1 obtained in step 3 is ground and dissociated by a second ball mill, and desludified by a second cyclone to obtain secondary sedimentation and desludified fine mud. After grinding, the proportion of -0.074 mm particles in the desludified fine mud is 60%-70%, and the proportion of -0.074 mm particles in the secondary sedimentation is ≤10%.

[0008] Step 5: The secondary sedimentation obtained in step 4 is passed through a magnetic separator to remove iron, and the feed concentration of the magnetic separator is controlled to be 25%-30%, and the induction intensity is 80mT-92mT, to obtain magnetic concentrate and tailings 2.

[0009] Step 6: The tailings 2 obtained in step 5 are sorted on a shaking table, and the feed concentration of the shaking table is controlled to be 15%-20% to obtain precious metal concentrate 2, middlings and tailings 3. The precious metal concentrate 2 is directly smelted.

[0010] Step 7: Finally, the overflow fine mud in step 1, the magnetic separation concentrate in step 5 and the tailings 3 in step 6 are combined and enter the flotation process to complete the separation of platinum Pt and gold Au precious metals in the low-grade copper-nickel sulfide ore.

[0011] Furthermore, the particle diameter of the low-grade copper-nickel sulfide ore in step 1 is ≤10 mm and the mass proportion is ≥85%.

[0012] Furthermore, in the precious metal concentrate 1 of step 3, the purity of platinum Pt is 50g / t-80g / t, and the purity of gold Au is 20g / t-30g / t; in the precious metal concentrate of step 6, the purity of platinum Pt is 180g / t-230g / t, and the purity of gold Au is 100g / t-150g / t.

[0013] The present invention has the following beneficial effects: The present invention uses multi-stage ball mills and cyclones for grinding and grading, so that precious metals such as platinum and gold in low-grade copper-nickel sulfide ore can be effectively screened and enriched by Nelson gravity separation machines and shaking tables, thereby improving the collection efficiency of precious metals such as platinum and gold.

[0014] The present invention optimizes the ore feeding cycle time and flushing water flow of the Nelson gravity separator, thereby improving the matching of the gravity separation characteristics of the Nelson gravity separator and the particles under the vibrating screen, and further magnetically separating the graded sediment, thereby effectively reducing the failure rate of the Nelson gravity separator and improving the overall economy and efficiency of the mineral separation operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0017] Example 1 A low-grade copper-nickel sulfide ore with a Pt grade of 1.20 g / t and an Au grade of 0.13 / t is subjected to ore dressing using the ore dressing method of the present invention: Step 1: The low-grade copper-nickel sulfide ore with a particle diameter of ≤10mm and a mass proportion of ≥85% in the original ore is crushed and screened, and then ground by the first ball mill. The first cyclone is classified to produce sedimentation and overflow fine mud. The concentration of the grinding overflow fine mud is 65%, and the concentration of the classified sedimentation is 78%. The sedimentation produced by classification is separated into primary sedimentation through a coarse separation net and a gate.

[0018] Step 2: The primary sediment is screened through a vibrating screen to obtain coarse particles on the screen and fine particles under the screen. The coarse particles on the screen are returned to the first ball mill for further grinding.

[0019] Step 3: The fine particle ore under the screen flows into the Nelson gravity separator by gravity. The concentration of the fine particle ore under the vibrating screen is controlled to 60%. The cycle time of the Nelson gravity separator is controlled to 30 minutes, and the flushing water flow rate is 40m³ / h. Precious metal concentrate 1 and tailings 1 are produced. Tailings 1 are returned to the first ball mill for re-grinding. The purity of platinum Pt in the precious metal concentrate 1 is 50g / t, and the purity of gold Au is 20g / t.

[0020] Step 4: The precious metal concentrate 1 obtained in step 3 is ground and dissociated by a second ball mill, and desludified by a second cyclone to obtain secondary sedimentation and desludified fine mud. After grinding, the desludified fine mud accounts for 60% of the -0.074 mm particles, and the secondary sedimentation accounts for 10% of the -0.074 mm particles.

[0021] Step 5: The secondary sediment obtained in step 4 is passed through a magnetic separator to remove iron, and the feed concentration of the magnetic separator is controlled to be 25%, and the induction intensity is 80mT, to obtain magnetic concentrate and tailings 2.

[0022] Step 6: The tailings 2 obtained in step 5 are sorted on a shaking table, and the feed concentration of the shaking table is controlled to be 15% to obtain precious metal concentrate 2, middlings and tailings 3. The precious metal concentrate 2 is directly smelted, and the purity of 2 platinum Pt in the precious metal concentrate is 192g / t, and the purity of gold Au is 105g / t.

[0023] Step 7: Finally, the overflow fine mud in step 1, the magnetic separation concentrate in step 5 and the tailings 3 in step 6 are combined and enter the flotation process to complete the separation of platinum Pt and gold Au precious metals in the low-grade copper-nickel sulfide ore.

[0024] Example 2 A low-grade copper-nickel sulfide ore with a Pt grade of 1.38 g / t and an Au grade of 0.15 g / t is subjected to ore dressing using the ore dressing method of the present invention: Step 1: The low-grade copper-nickel sulfide ore with a particle diameter of ≤10mm and a mass proportion of ≥85% in the original ore is crushed and screened, and then ground by the first ball mill. The first cyclone is classified to produce sedimentation and overflow fine mud. The concentration of the grinding overflow fine mud is 66%, and the concentration of the classified sedimentation is 80%. The sedimentation produced by classification is separated into primary sedimentation through a coarse separation net and a gate.

[0025] Step 2: The primary sediment is screened through a vibrating screen to obtain coarse particles on the screen and fine particles under the screen. The coarse particles on the screen are returned to the first ball mill for further grinding.

[0026] Step 3: The fine particles under the screen flow into the Nelson gravity separator by gravity. The concentration of the fine particles under the vibrating screen is controlled to 63%. The cycle time of the Nelson gravity separator is controlled to 40 minutes, and the flushing water flow rate is 43m³ / h. Precious metal concentrate 1 and tailings 1 are produced. Tailings 1 are returned to the first ball mill for re-grinding. The purity of platinum Pt in precious metal concentrate 1 is 70g / t, and the purity of gold Au is 25g / t.

[0027] Step 4: The precious metal concentrate 1 obtained in step 3 is ground and dissociated by a second ball mill, and desludified by a second cyclone to obtain secondary sedimentation and desludified fine mud. After grinding, the desludified fine mud accounts for 65% of the -0.074 mm particles, and the secondary sedimentation accounts for 9% of the -0.074 mm particles.

[0028] Step 5: The secondary sediment obtained in step 4 is passed through a magnetic separator to remove iron, and the feed concentration of the magnetic separator is controlled to be 27%, and the induction intensity is controlled to be 85mT, to obtain magnetic concentrate and tailings 2.

[0029] Step 6: The tailings 2 obtained in step 5 are sorted on a shaking table, and the feed concentration of the shaking table is controlled to be 17% to obtain precious metal concentrate 2, middlings and tailings 3. The precious metal concentrate 2 is directly smelted, and the purity of 2 platinum Pt in the precious metal concentrate is 211g / t, and the purity of gold Au is 122g / t.

[0030] Step 7: Finally, the overflow fine mud in step 1, the magnetic separation concentrate in step 5 and the tailings 3 in step 6 are combined and enter the flotation process to complete the separation of platinum Pt and gold Au precious metals in the low-grade copper-nickel sulfide ore.

[0031] Example 3 A low-grade copper-nickel sulfide ore with a Pt grade of 1.30 g / t and an Au grade of 0.28 g / t is subjected to ore dressing using the ore dressing method of the present invention: Step 1: The low-grade copper-nickel sulfide ore with a particle diameter of ≤10mm and a mass proportion of ≥85% in the original ore is crushed and screened, and then ground by the first ball mill. The first cyclone is classified to produce sedimentation and overflow fine mud. The concentration of the grinding overflow fine mud is 67%, and the concentration of the classified sedimentation is 82%. The sedimentation produced by classification is separated into primary sedimentation through a coarse separation net and a gate.

[0032] Step 2: The primary sediment is screened through a vibrating screen to obtain coarse particles on the screen and fine particles under the screen. The coarse particles on the screen are returned to the first ball mill for further grinding.

[0033] Step 3: The fine particle ore under the screen flows into the Nelson gravity separator by gravity. The concentration of the fine particle ore under the vibrating screen is controlled to 65%. The cycle time of the Nelson gravity separator is controlled to 45min, and the flushing water flow rate is 45m³ / h. Precious metal concentrate 1 and tailings 1 are produced. Tailings 1 are returned to the first ball mill for re-grinding. The purity of platinum Pt in precious metal concentrate 1 is 80g / t, and the purity of gold Au is 30g / t.

[0034] Step 4: The precious metal concentrate 1 obtained in step 3 is ground and dissociated by a second ball mill, and desludified by a second cyclone to obtain secondary sedimentation and desludified fine mud. After grinding, the desludified fine mud accounts for 70% of the -0.074 mm particles, and the secondary sedimentation accounts for 8% of the -0.074 mm particles.

[0035] Step 5: The secondary sediment obtained in step 4 is passed through a magnetic separator to remove iron, and the feed concentration of the magnetic separator is controlled to be 30%, and the induction intensity is controlled to be 92mT, to obtain magnetic concentrate and tailings 2.

[0036] Step 6: The tailings 2 obtained in step 5 are sorted on a shaking table, and the feed concentration of the shaking table is controlled to be 20% to obtain precious metal concentrate 2, middlings and tailings 3. The precious metal concentrate 2 is directly smelted, and the purity of 2 platinum Pt in the precious metal concentrate is 220g / t, and the purity of gold Au is 136g / t.

[0037] Step 7: Finally, the overflow fine mud in step 1, the magnetic separation concentrate in step 5 and the tailings 3 in step 6 are combined and enter the flotation process to complete the separation of platinum Pt and gold Au precious metals in the low-grade copper-nickel sulfide ore.

[0038] The comparative data of platinum and gold purity obtained in the above three embodiments are shown in Table 1: Table 1

Claims

1. A method for separating precious metals from low-grade copper-nickel sulfide ore, characterized in that: The following steps are involved: Step 1: The low-grade copper-nickel sulfide ore after crushing and screening is ground by the first ball mill, and the first cyclone is classified to produce sediment and overflow fine mud. The concentration of the grinding overflow fine mud is 65%-67%, and the concentration of the classified sediment is 78%-82%. The sediment produced by classification is separated into primary sediment through the coarse separation net and the gate plate; Step 2: The primary sediment is screened through a vibrating screen to obtain coarse particles on the screen and fine particles under the screen, and the coarse particles on the screen are returned to the first ball mill for re-grinding; Step 3: The fine particles under the screen flow into the Nelson gravity separator by gravity, the concentration of the fine particles under the vibrating screen is controlled to be 60%-65%, the cycle time of the Nelson gravity separator is controlled to be 30min-45min, the flushing water flow rate is 40m³ / h-45m³ / h, and precious metal concentrate 1 and tailings 1 are produced. The tailings 1 are returned to the first ball mill for re-grinding; Step 4: The precious metal concentrate 1 obtained in step 3 is subjected to grinding and dissociation in a second ball mill, and subjected to graded desludging in a second cyclone to obtain secondary sedimentation and desludging fine mud. After grinding, the proportion of -0.074 mm particles in the desludging fine mud is 60%-70%, and the proportion of -0.074 mm particles in the secondary sedimentation is ≤10%; Step 5: The secondary sedimentation obtained in step 4 is passed through a magnetic separator to remove iron, and the feed concentration of the magnetic separator is controlled to be 25%-30%, and the induction intensity is 80mT-92mT, to obtain magnetic concentrate and tailings 2; Step 6: The tailings 2 obtained in step 5 are sorted by a shaking table, and the feed concentration of the shaking table is controlled to be 15%-20% to obtain precious metal concentrate 2, middlings and tailings 3. The precious metal concentrate 2 is directly smelted; Step 7: Finally, the overflow fine mud in step 1, the magnetic separation concentrate in step 5 and the tailings 3 in step 6 are combined and enter the flotation process to complete the separation of platinum Pt and gold Au precious metals in the low-grade copper-nickel sulfide ore.

2. The method for separating precious metals from low-grade copper-nickel sulfide ore according to claim 1, characterized in that: The particle diameter of the low-grade copper-nickel sulfide ore in step 1 is ≤10 mm and the mass proportion is ≥85%.

3. The method for separating precious metals from low-grade copper-nickel sulfide ore according to claim 1, characterized in that: In the step 3, the purity of platinum Pt in the precious metal concentrate 1 is 50g / t-80g / t, and the purity of gold Au is 20g / t-30g / t. In the step 6, the purity of platinum Pt in the precious metal concentrate 2 is 180g / t-230g / t, and the purity of gold Au is 100g / t-150g / t.

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