Flotation process for improving enrichment content of associated gold and silver in copper-containing iron ore

Abstract

The invention discloses a flotation process for improving the enrichment content of associated gold and silver in copper-containing iron ore. The flotation process sequentially comprises the procedures of coarse grinding and slurry mixing, roughing, scavenging, concentration, regrinding and grading and re-concentration. By the adoption of the flotation process, the associated low-grade gold and silver in the copper-containing iron ore can be comprehensively recycled, and waste of metal resources is eradicated. After the flotation process is adopted by a Dahongshan three-separation plant, the copper concentrate copper-containing, gold-containing and silver-containing accumulative sales grade is obviously improved, and the proportion of the silver-containing pricing quantity of the concentrates to the sales volume of the copper concentrates is obviously increased.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to a flotation process for increasing the enrichment content of associated gold and silver in copper-containing iron ore. Background Art

[0002] The copper-containing iron ore reserves of the third concentrator of Dahongshan Mining Company are 16.3688 million tons, copper metal reserves are 71,300 tons, and associated gold is 15.97 tons, silver is 141.02 tons, and platinum and palladium are 2.07 tons. The content of gold and silver in the copper ore is relatively low (gold grade is 0.1g / t, silver grade is 0.9g / t), and the gold and silver minerals in the ore are fine in size, and have a close and complex symbiotic relationship with sulfide minerals such as chalcopyrite and pyrite. It is difficult to completely dissociate from iron minerals, copper minerals and gangue minerals to obtain independent products, and can only be enriched in copper concentrate for comprehensive recovery. Since it was put into production in 2011, the copper concentrate grade has been 20-21% over the years, of which the associated gold content is 3.4-3.6g / t, which has been able to be sold at a pricing coefficient of 78%; the associated silver content is 14-18g / t, which has not reached the Yunnan industry pricing standard of 20g / t. The silver in the copper concentrate has never been able to be sold at a pricing, resulting in the added value of the copper concentrate sales not being fully reflected. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a flotation process for increasing the enrichment content of associated gold and silver in copper-containing iron ore, so as to improve the recovery rate of gold and silver in copper concentrate and make the associated gold and silver in the copper concentrate reach the pricing standard.

[0004] The object of the present invention is achieved in that a flotation process for increasing the enrichment content of associated gold and silver in copper-containing iron ore is achieved by the following steps: 1) Coarse grinding and slurry mixing: After the copper ore is coarsely ground, it is put into a stirring tank for stirring; the collector xanthate, black medicine and the foaming agent pine oil are successively added into the stirring tank; 2) Roughing: The slurry obtained in step 1) is fed into a roughing flotation machine for roughing operation to obtain roughing concentrate and roughing tailings; 3) Scavenging: Adding the collector xanthate, black powder and frother pine oil to the roughing tailings obtained in step 2) to carry out scavenging flotation operation, and the scavenging concentrate obtained enters the ball mill pump pool for regrinding and grading operation; the scavenging tailings are directly discarded; 4) Concentration: The rough concentrate obtained in step 2) enters the concentrating flotation machine for three times of concentrating to obtain copper concentrate, and the concentrating tailings enter the ball mill for further grinding and classification; 5) Regrinding and classifying: Regrinding and classifying the mixed ore of the scavenged concentrate obtained in step 3) and the selected tailings obtained in step 4) using a ball mill and a matching cyclone; 6) Secondary concentration: After adding the collector xanthate, black powder and frother pine oil to the mixed ore of the concentrated tailings obtained by regrinding and classification in step 5), the mixed ore enters the secondary concentration flotation machine for three concentrations to obtain copper concentrate, and the concentrated tailings are returned to the roughing operation; 7) The copper concentrates obtained in step 4) and step 6) are mixed as final concentrate.

[0005] The beneficial effects of the present invention are as follows: the flotation process of the present invention can realize the comprehensive recovery and utilization of low-grade gold and silver associated with copper-containing iron ore, thus eliminating the waste of metal resources. After the Dahongshan Third Concentrator adopted the flotation process, the cumulative sales grade of copper concentrate, gold concentrate and silver concentrate was significantly improved, and the proportion of the silver content in the concentrate to the sales volume of copper concentrate increased significantly. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a flotation process flow chart of Example 1 of the present invention; Figure 2 It is a schematic diagram of the flotation process device of the present invention. DETAILED DESCRIPTION

[0007] The present invention is further described below in conjunction with the embodiments and drawings, but the present invention is not limited in any way. Any changes made based on the present invention belong to the protection scope of the present invention.

[0008] A flotation process for increasing the concentration of associated gold and silver in copper-containing iron ore is implemented by the following steps: 1) Coarse grinding and slurry mixing: After the copper ore is coarsely ground, it is put into a stirring tank for stirring; the collector xanthate, black medicine and the foaming agent pine oil are successively added into the stirring tank; 2) Roughing: The slurry obtained in step 1) is fed into a roughing flotation machine for roughing operation to obtain roughing concentrate and roughing tailings; 3) Scavenging: Adding the collector xanthate, black powder and frother pine oil to the roughing tailings obtained in step 2) to carry out scavenging flotation operation, and the scavenging concentrate obtained enters the ball mill pump pool for regrinding and grading operation; the scavenging tailings are directly discarded; 4) Concentration: The rough concentrate obtained in step 2) enters the concentrating flotation machine for three times of concentrating to obtain copper concentrate, and the concentrating tailings enter the ball mill for further grinding and classification; 5) Regrinding and classifying: Regrinding and classifying the mixed ore of the scavenged concentrate obtained in step 3) and the selected tailings obtained in step 4) using a ball mill and a matching cyclone; 6) Secondary concentration: After adding the collector xanthate, black powder and frother pine oil to the mixed ore of the concentrated tailings obtained by regrinding and classification in step 5), the mixed ore enters the secondary concentration flotation machine for three concentrations to obtain copper concentrate, and the concentrated tailings are returned to the roughing operation; 7) The copper concentrates obtained in step 4) and step 6) are mixed as final concentrate.

[0009] In step 1), the amount of the collecting agent xanthate is 45-55 g / t, the amount of the collecting agent black medicine is 6-10 g / t, and the amount of the foaming agent pine oil is 20-30 g / t.

[0010] In step 1), the copper ore is coarsely ground to a particle size of -200 mesh, accounting for 75-78%; the mass concentration of the ore pulp is 38-42%.

[0011] In step 2), the roughing flotation time is 7-8 minutes.

[0012] In step 3), the amount of the collecting agent xanthate is 35-45 g / t, the amount of the collecting agent black medicine is 4-6 g / t, and the amount of the foaming agent pine oil is 8-12 g / t.

[0013] In step 3), the time of scavenging flotation is 5-6 minutes.

[0014] In step 4), the copper concentrate grade is controlled at 23.0-24.0%, and the concentration flotation time is 4-5 minutes.

[0015] In step 5), the mixed ore of the selected tailings is ground to a particle size of -200 mesh accounting for more than 95%.

[0016] In step 6), the amount of collector black medicine is 5-8g / t, the amount of frother pine oil is 8-10g / t; the concentrate grade is controlled at 22.0-23.0%, and the time of concentration flotation is 4-5 minutes. The concentrate grade control can be achieved by reducing the amount of aeration, reducing the amount of scraping foam, lowering the liquid level and other measures.

[0017] The concentration of the collector yellow medicine is 14-15%, the concentration of the collector black medicine is 4.8-5.1%, and the concentration of the foaming agent pine oil is 89-91%.

[0018] Example 1 After production stabilizes in 2022, flotation practice will be carried out on a low-grade copper-bearing iron ore of the Dahongshan No. 3 Concentrator. The raw ore belongs to a single deep underground copper mine, with a copper content of 0.344%, a gold grade of <0.1g / t, and a silver grade of 0.9g / t. The main metal minerals such as magnetite, hematite, and chalcopyrite have a fine particle size, accounting for about 70% below 0.07mm. Iron minerals and chalcopyrite are mostly single crystals and closely interlocked with gangue minerals, which have a great influence on the dissociation of useful minerals and gangue.

[0019] The specific flotation method mainly includes the following steps: 1. The raw ore is fully crushed and ground to obtain a slurry with a concentration of 41% and a particle size of -200 accounting for 76%. 6g / t butylamine black medicine, 40g / t butyl xanthate and 20g / t pine oil are added successively. The slurry after adding and stirring enters the roughing flotation machine to obtain roughing concentrate and roughing tailings.

[0020] 2. The rougher tailings are pumped to the scavenging flotation operation through a foam pump, and 35g / t of sodium butyl xanthate, 4g / t of butylamine black medicine and 4g / t of pine oil are added successively to obtain scavenging concentrate. The scavenging concentrate is pumped to the regrinding and grading pump pool through a slurry pump. The scavenging tailings enter the subsequent process for iron selection, and the copper tailings obtained have a grade of 0.029%.

[0021] 3. The rougher concentrate enters 4 BF-8 flotation machines for primary concentration, the primary concentrated concentrate enters 2 BF-8 flotation machines for secondary concentration, the secondary concentrated concentrate enters 2 BF-8 flotation machines for tertiary concentration, and the concentrated tailings are returned to the previous process in sequence, and after being collected, they are pumped to the regrinding and grading pump pool through a slurry pump to obtain a copper concentrate with a grade of 23.97%.

[0022] 4. Use ball mill and supporting cyclone to grind the mixed ore of scavenged concentrate and selected tailings to a particle size of -200 mesh accounting for 96.8%; 5. The rougher concentrate enters 7 BF-4 flotation machines for primary concentration, the primary concentrated concentrate enters 3 BF-4 flotation machines for secondary concentration, the secondary concentrated concentrate enters 2 BF-4 flotation machines for tertiary concentration, and the concentrated tailings are returned to the previous process in sequence, and after being collected, they are pumped to the rougher operation through a slurry pump to obtain a copper concentrate grade of 22.16%; 6. The copper concentrate obtained in step 3 is mixed with the copper concentrate obtained in step 5 as the final concentrate. The comprehensive copper concentrate yield is 1.39%, the copper grade is 22.68%, the gold content is 4.26g / t, which is greater than 3g / t and reaches the sales pricing grade; the silver content is 20.09g / t, which is greater than 20g / t and reaches the sales pricing grade.

[0023] Example 2 After production stabilizes in 2022, flotation practice is carried out on a low-grade copper-containing iron ore of the Dahongshan No. 3 Concentrator. The ore dressing object of this embodiment is different from that of Example 1. Example 1 is all copper sulfide ore, and the original ore of Example 2 belongs to open-pit copper-containing iron oxide ore. The original ore contains 0.285% copper, gold grade <0.1g / t, and silver grade 0.4g / t. Among them, the distribution law of combined copper oxide is 25%, the distribution law of free copper oxide is 20%, and the distribution law of copper sulfide and other copper is 55%. The main metal mineral chalcopyrite is partly independent particles, partly coexisting with magnetite and pyrite, and scattered and impregnated among the gangue mineral particles. Chalcopyrite and magnetite are mutually wrapped or fine chalcopyrite is wrapped in transparent gangue minerals. The particle size is generally between 0.01 and 0.6 mm.

[0024] The main difference between the ore dressing method of Example 2 and Example 1 is: Step 1: The raw ore is fully crushed and ground to obtain a slurry with a concentration of 39% and a particle size of -200 accounting for 78%, and 8g / t butylamine black medicine, 45g / t butyl xanthate and 22g / t pine alcohol oil are added successively.

[0025] Step 2: Sweep flotation operation, add 35g / t sodium butyl xanthate, 4g / t butylamine black medicine and 4g / t pine oil successively, and the copper tailings grade is 0.032%.

[0026] Step 3: The rougher concentrate enters the tertiary concentration operation to obtain a copper concentrate with a grade of 23.16%.

[0027] Step 4: Use a ball mill and a matching cyclone to grind the mixed ore of the scavenged concentrate and the selected tailings to a particle size of -200 mesh accounting for 96.8%; Step 5: The mixed ore enters the tertiary concentration operation for re-concentration to obtain a copper concentrate with a grade of 22.48%; Step 6: The copper concentrate obtained in step 3 is mixed with the copper concentrate obtained in step 5 as the final concentrate. The comprehensive copper concentrate yield is 1.11%, the copper grade is 22.74%, the gold content is 4.23g / t, which is greater than 3g / t and reaches the sales pricing grade; the silver content is 21.80g / t, which is greater than 20g / t and reaches the sales pricing grade.

[0028] During the debugging stage of the flotation method of the present invention in 2021, its main production indicators are as follows: the cumulative sales grades of copper, gold and silver in copper concentrate of the Dahongshan Third Concentrator were 22.63%, 4.102 g / ton and 20.40 g / ton, respectively, which were 2.051% (20.579% before implementation), 0.536 g / ton (3.566 g / ton before implementation) and 1.75 g / ton (18.65 g / ton before implementation) higher than the cumulative grades before implementation. The proportion of silver in copper concentrate to copper concentrate sales volume increased from 9.3% before implementation to 79.01%, an increase of 69.71%.

[0029] It will tend to operate stably in 2022-2023. In 2022-2023, the gold content and silver content of copper concentrate of Dahongshan No. 3 Concentrator will meet the sales pricing requirements (Table 1), realizing the comprehensive recovery and utilization of low-grade gold and silver associated with copper-containing iron ore, and eliminating the waste of metal resources.

[0030] Table 1 Statistics of copper selection indexes of the three concentrators in recent years .

Claims

1. A flotation process for increasing the concentration of associated gold and silver in copper-containing iron ore, characterized in that: To do this, follow these steps: 1) Coarse grinding and slurry mixing: After the copper ore is coarsely ground, it is put into a stirring tank for stirring; the collector xanthate, black medicine and the foaming agent pine oil are successively added into the stirring tank; 2) Roughing: The slurry obtained in step 1) is fed into a roughing flotation machine for roughing operation to obtain roughing concentrate and roughing tailings; 3) Scavenging: Adding the collector xanthate, black powder and frother pine oil to the roughing tailings obtained in step 2) to carry out scavenging flotation operation, and the scavenging concentrate obtained enters the ball mill pump pool for regrinding and classification operation; The tailings are directly discarded after scavenging; 4) Concentration: The rough concentrate obtained in step 2) enters the concentrating flotation machine for three times of concentrating to obtain copper concentrate, and the concentrating tailings enter the ball mill for further grinding and classification; 5) Regrinding and classifying: Regrinding and classifying the mixed ore of the scavenged concentrate obtained in step 3) and the selected tailings obtained in step 4) using a ball mill and a matching cyclone; 6) Secondary concentration: After adding the collector xanthate, black powder and frother pine oil to the mixed ore of the concentrated tailings obtained by regrinding and classification in step 5), the mixed ore enters the secondary concentration flotation machine for three concentrations to obtain copper concentrate, and the concentrated tailings are returned to the roughing operation; 7) The copper concentrates obtained in step 4) and step 6) are mixed as final concentrate.

2. The flotation process according to claim 1, characterized in that: In step 1), the amount of the collecting agent xanthate is 45-55 g / t, the amount of the collecting agent black medicine is 6-10 g / t, and the amount of the foaming agent pine oil is 20-30 g / t.

3. The flotation process according to claim 1, characterized in that: In step 1), the copper ore is coarsely ground to a particle size of -200 mesh, accounting for 75-78%; the mass concentration of the ore pulp is 38-42%.

4. The flotation process according to claim 1, characterized in that: In step 2), the roughing flotation time is 7-8 minutes.

5. The flotation process according to claim 1, characterized in that: In step 3), the amount of the collecting agent xanthate is 35-45 g / t, the amount of the collecting agent black medicine is 4-6 g / t, and the amount of the foaming agent pine oil is 8-12 g / t.

6. The flotation process according to claim 1, characterized in that: In step 3), the time of scavenging flotation is 5-6 minutes.

7. The flotation process according to claim 1, characterized in that: In step 4), the copper concentrate grade is controlled at 23.0-24.0%, and the concentration flotation time is 4-5 minutes.

8. The flotation process according to claim 1, characterized in that: In step 5), the mixed ore of the selected tailings is ground to a particle size of -200 mesh accounting for more than 95%.

9. The flotation process according to claim 1, characterized in that: In step 6), the dosage of the collector black medicine is 5-8 g / t, and the dosage of the foaming agent pine oil is 8-10 g / t; the concentrate grade is controlled at 22.0-23.0%, and the concentration flotation time is 4-5 minutes.

10. The flotation process according to claim 1, characterized in that: The concentration of the collector yellow medicine is 14-15%, the concentration of the collector black medicine is 4.8-5.1%, and the concentration of the foaming agent pine oil is 89-91%.

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