Treatment method for hard rock of copper oxide gold ore

Abstract

The invention discloses a method for treating hard rock in copper oxide gold ore, which comprises the following steps of: reacting iron-removed hard rock with dilute sulphuric acid with the mass concentration of 10-20%, synchronously realizing copper oxide pre-recovery (the recovery rate is 5-10%) and hard rock surface softening during dump leaching for 48-72 hours, cracking the circulation bottleneck and reducing the regrinding energy consumption by 10-15%. Leached residues are returned for semi-autogenous grinding, undersize ore pulp is subjected to graded ball milling (the concentration ranges from 30% to 35%, and the fineness ranges from 75% to 85%) and then subjected to flotation, and a regulating agent 600-1000 g / t and a collecting agent 200-300 g / t are added respectively, so that the copper recovery rate reaches 60%-65%, and the gold recovery rate reaches 75%-80%; and the tailings are subjected to secondary sulfuric acid leaching (the use amount is 5-10 kg / t) to further extract copper (the leaching rate is 10-15%), and two-stage pregnant solutions are combined and recycled. And finally, the total recovery rate of copper breaks through 80%, the method is suitable for high-mud difficult-to-treat ore with the copper oxidation rate larger than 40%, and optimization of energy consumption and the metal recovery rate is achieved.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a method for processing copper oxide gold ore. Background Technology

[0002] Copper oxide gold ore refers to a mixed ore containing copper oxide minerals and gold minerals, typically exhibiting complex mineral composition and mineralogical characteristics. Its main components include copper oxide minerals (such as malachite, azurite, cuprite, etc.), copper sulfide minerals (bornite, chalcocite, etc.), and a certain amount of gold minerals, which may exist as free gold or in a composite form with other minerals (such as pyrite, copper sulfide minerals, etc.).

[0003] Oxide copper ore accounts for about a quarter of my country's copper resources. Existing copper mines mainly process copper sulfide ore in the early stages. However, with the deepening of mining and the gradual depletion of copper sulfide ore resources, the rational development and utilization of oxide copper ore is of great significance to solving the problem of my country's large demand for copper resources and high dependence on foreign sources.

[0004] There is almost no grinding and classification process for copper oxide gold ore using coarse crushing + semi-autogenous grinding + ball milling. Therefore, it is of great significance to find a way to take into account the existing grinding and classification process for sulfide ores and use the existing coarse crushing + semi-autogenous grinding + ball milling process to process copper oxide gold ore, which can significantly reduce design and infrastructure costs.

[0005] Copper oxide gold ore is relatively soft and has low hardness. The boulders produced during semi-autogenous grinding have strong toughness and hardness, making them difficult to break and dissociate when re-entering the semi-autogenous grinding mill. This results in a large volume of boulders circulating, leading to increased equipment wear, higher energy consumption, reduced grinding efficiency, and decreased throughput. Current technologies mainly focus on optimizing grinding parameters and selecting grinding media, but they have not yet effectively solved the technical bottleneck of boulder treatment. Since there is currently no solution for boulders in copper oxide gold ore, developing a method to effectively treat these boulders is of great significance for improving recovery efficiency, reducing processing costs, and minimizing equipment wear. Summary of the Invention

[0006] This invention provides a method for treating copper oxide gold ore ore with impurities. Addressing the problems of increased equipment wear, higher energy consumption, reduced grinding efficiency, and decreased throughput caused by the recirculation of impurities in the semi-autogenous grinding process of copper oxide gold ore, this invention, based on the characteristics of copper oxide gold ore, employs a dilute sulfuric acid heap leaching scheme for the impurities. This not only recovers copper oxide in advance but also softens the surface of the impurities under the action of dilute sulfuric acid, increasing the porosity and reducing the surface hardness, thus enhancing its brittleness and improving subsequent grinding efficiency.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for processing copper oxide gold ore impure stones includes the following steps: Step 1, Semi-autogenous grinding: Grind the raw ore with a copper grade of 1.0-1.5%, a gold grade of 1.5-2.5 g / t, and a copper oxidation rate of 40-60% at a grinding concentration of 56-62%, while adding 1000-2000 g / t of lime, and then screen to obtain slurry and ore. Step 2, Iron removal from stubborn rocks: Use a magnetic separator or jig to remove iron impurities from the stubborn rocks; Step 3, Heap leaching of the copper-containing precious solution: Add 10%-20% dilute sulfuric acid to the iron-removed precious rock for heap leaching for 48-72 hours, obtaining copper-containing precious solution 1 and leaching residue. The leaching residue is returned to Step 1; the leaching rate of copper-containing precious solution 1 is 5-10%. Step 4, Flotation: The slurry obtained in Step 1 is classified and ball-milled to a concentration of 30-35% and a fineness of 75-85%. A modifier of 600-1000 g / t, a collector of 200-300 g / t, and a frother of 30-50 g / t are added sequentially. After 1-2 roughing stages, 1-3 cleaning stages, and 1-2 scavenging stages, copper-gold concentrate and tailings are obtained. The copper grade in the copper-gold concentrate is 18-22%, the gold grade is 30-50 g / t, the copper recovery rate is 60-65%, and the gold recovery rate is 75-80%. Step 5, Tailings Leaching: Add 5-10 kg / t of dilute sulfuric acid (10-20% by mass) to the tailings from Step 4, with a liquid-to-solid ratio of 2.0-2.5:1.0 to obtain copper-containing precious solution 2, with a copper leaching rate of 10-15%. Step 6: Combine copper-containing precious solutions 1 and 2 for copper recovery treatment. The combined copper-containing precious solution contains Cu. 2+ Ion concentration 20-30 g / L; Preferably, the modifier in step four is a mixture of sodium hexametaphosphate and CMC at a mass ratio of 3:1.

[0008] Preferably, the collector in step four is selected from at least one of butyl xanthate, pentyl xanthate, isopentyl xanthate, and butylammonium black powder.

[0009] Preferably, the foaming agent in step four is No. 2 oil or MIBC.

[0010] Preferably, the mass concentration of the dilute sulfuric acid in step three is 10-20%, and the amount of dilute sulfuric acid used in step five is 5-10 kg / t.

[0011] Preferably, in step four, the amount of the modifier is 800 g / t, and the collector is a mixture of butyl xanthate and butylammonium black powder in a 1:1 ratio.

[0012] Preferably, the copper recycling process in step six includes: iron filings replacement to produce sponge copper, sodium sulfide precipitation to produce copper sulfide, or extraction of electrodes to produce cathode copper.

[0013] Compared with the prior art, the present invention has the following advantages: (1) This invention innovatively uses dilute sulfuric acid heap leaching to treat the ore discharged from the semi-autogenous grinding process. While achieving the initial recovery of copper oxide, the chemical softening effect of acid on the mineral surface significantly increases the ore gaps, reduces hardness and increases brittleness, directly eliminating the inherent problem of repeated circulation of ore in the grinding system, reducing the energy consumption of subsequent re-grinding, and solving the problem of blockage in the high-mud oxide ore process from the source.

[0014] (2) The heap leaching pretreatment of the present invention increases the proportion of copper sulfide in the ore and optimizes the copper-gold flotation efficiency of the flotation stage. Under the combined action of the modifier and the composite collector, the copper recovery rate of flotation is stable at 60-65% and the gold recovery rate is 75-80%. The tailings secondary leaching further extracts residual copper oxide (leaching rate 10-15%), forming a multi-stage recovery system. Finally, the total copper recovery rate exceeds 80%, realizing the maximum utilization of resources.

[0015] (3) The design of directly returning the leaching residue to the grinding mill and centrally treating the precious liquor in this invention not only significantly reduces grinding costs and steel ball consumption, but also achieves process compatibility by utilizing the subsequent copper oxide leaching process. It is especially suitable for refractory deposits with copper oxidation rate ≥40% and mud content ≥15%, providing a solution with both technical feasibility and economic competitiveness for similar mines. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to specific embodiments.

[0018] Example 1 A copper-gold ore deposit in Xinjiang (copper grade 1.2%, gold grade 2.0 g / t, copper oxidation rate 50%) was semi-autogenous milled (concentration 60%, lime addition 1500 g / t) and screened to remove impurities. After magnetic separation to remove iron, it was heap leached with 15% dilute sulfuric acid (60 hours) to obtain copper-containing precious solution 1 (copper recovery rate 8%) and leaching residue (returned to the semi-autogenous mill). The undersize slurry was ball-milled to a concentration of 32% and a fineness of 80%. 800 g / t of modifier (sodium hexametaphosphate:CMC=3:1), 250 g / t of butyl xanthate, and 40 g / t of No. 2 oil were added. After one roughing, two cleaning, and two scavenging processes, a copper-gold concentrate (copper grade 20%, gold grade 40 g / t, copper recovery rate 62%, gold grade 40 g / t, gold recovery rate 78%) was obtained. 7.5 g / t of 15% dilute sulfuric acid was added to the tailings. Leaching at a rate of kg / t (liquid-to-solid ratio 2:1) yields copper-containing precious solution 2 (copper leaching rate 15%); combine precious solutions 1 and 2, and extract-electrodegrade to produce cathode copper.

[0019] Example 2 A mine in Gansu Province (copper grade 1.0%, gold grade 1.5 g / t, copper oxidation rate 40%) produced copper-containing precious solution 1 (copper recovery rate 50%) through semi-autogenous grinding (concentration 56%, lime 1000 g / t). After iron removal by jigging, the solution was heap leached with 10% dilute sulfuric acid for 48 hours. The resulting solution was copper-containing precious solution 1 (copper recovery rate 5%). The slurry was ground to a concentration of 30% and a fineness of 75%. 600 g / t of modifier (sodium hexametaphosphate:CMC=3:1), 200 g / t of pentyl xanthate, and 30 g / t of MIBC were added. After one roughing, one cleaning, and one scavenging process, a copper concentrate (copper grade 18%, gold grade 30 g / t, copper recovery rate 65%, gold recovery rate 75%) was obtained. The tailings were leached with 5 kg / t of 10% dilute sulfuric acid (liquid-to-solid ratio 2.2:1) to obtain copper-containing precious solution 2 (copper leaching rate 10%). The two precious solutions were combined, and sodium sulfide was precipitated to produce copper sulfide.

[0020] Example 3 A foreign mine (copper grade 1.5%, gold grade 2.5 g / t, copper oxidation rate 60%) underwent semi-autogenous grinding (concentration 62%, lime 2000 g / t) to separate impurities. After magnetic separation-jigging combined iron removal, it was heap leached with 20% dilute sulfuric acid (mass concentration) for 72 hours to produce copper-containing precious solution 1 (copper recovery rate 15%). The slurry was adjusted to a concentration of 35% and a fineness of 85%, and 1000 g / t of modifier (sodium hexametaphosphate:CMC=3:1), 300 g / t of isoamyl xanthate, and 50 g / t of No. 2 oil were added. After two roughing, three cleaning, and two scavenging processes, a copper concentrate (copper grade 22%, gold grade 50 g / t, copper recovery rate 60%, gold recovery rate 80%) was obtained. The tailings were treated with 10 g / t of 20% dilute sulfuric acid. Leaching at a rate of kg / t (liquid-to-solid ratio 2.5:1) produces copper-containing precious liquor 2 (copper leaching rate 12%); the precious liquor is then combined and iron filings are used to replace the copper to produce sponge copper.

[0021] The product yield and analysis results are shown in Table 1.

[0022] Table 1 Product Yield and Analysis Results serial number Copper grade (%) Gold grade (g / t) Copper recovery rate (%) Gold recovery rate (%) Example 1 20 40 85 78 Example 2 18 30 80 75 Example 3 22 50 87 80 As shown in Table 1, this process achieves a copper recovery rate of ≥80% and a gold recovery rate of 75-80%, which is 8.0-15% higher than conventional processes and 10-15% higher for both. It also reduces power consumption by 10-15% and steel ball usage by 10-15%.

Claims

1. A method for processing copper oxide gold ore, characterized in that, Includes the following steps: Step 1, Semi-autogenous grinding: Grind the raw ore with a copper grade of 1.0-1.5%, a gold grade of 1.5-2.5 g / t, and a copper oxidation rate of 40-60% at a grinding concentration of 56-62%, while adding 1000-2000 g / t of lime, and then screen to obtain slurry and ore. Step 2, Iron removal from stubborn rocks: Use a magnetic separator or jig to remove iron impurities from the stubborn rocks; Step 3, Heap leaching of the copper-containing precious solution: Add 10%-20% dilute sulfuric acid to the iron-removed precious rock for heap leaching for 48-72 hours, obtaining copper-containing precious solution 1 and leaching residue. The leaching residue is returned to Step 1; the leaching rate of copper-containing precious solution 1 is 5-10%. Step 4, Flotation: The slurry obtained in Step 1 is classified and ball-milled to a concentration of 30-35% and a fineness of 75-85%. A modifier of 600-1000 g / t, a collector of 200-300 g / t, and a frother of 30-50 g / t are added sequentially. After 1-2 roughing stages, 1-3 cleaning stages, and 1-2 scavenging stages, copper-gold concentrate and tailings are obtained. The copper grade in the copper-gold concentrate is 18-22%, the gold grade is 30-50 g / t, the copper recovery rate is 60-65%, and the gold recovery rate is 75-80%. Step 5, Tailings Leaching: Add 5-10 kg / t of dilute sulfuric acid (10-20% by mass) to the tailings from Step 4, with a liquid-to-solid ratio of 2.0-2.5:1.0 to obtain copper-containing precious solution 2, with a copper leaching rate of 10-15%. Step 6: Combine copper-containing precious solutions 1 and 2 for copper recovery treatment. The combined copper-containing precious solution contains Cu. 2+ Ion concentration 20-30 g / L.

2. The method for processing copper oxide gold ore impure as described in claim 1, characterized in that, The modifier mentioned in step four is a mixture of sodium hexametaphosphate and CMC at a mass ratio of 3:

1.

3. The method for processing copper oxide gold ore impurities according to claim 2, characterized in that, The collector mentioned in step four is selected from at least one of butyl xanthate, pentyl xanthate, isopentyl xanthate, and butylammonium black powder.

4. The method for processing copper oxide gold ore impurities according to claim 3, characterized in that, The foaming agent mentioned in step four is No. 2 oil or MIBC.

5. The method for processing copper oxide gold ore impurities according to claim 4, characterized in that, The mass concentration of the dilute sulfuric acid mentioned in step three is 10-20%, and the amount of dilute sulfuric acid used in step five is 5-10 kg / t.

6. The method for processing copper oxide gold ore impurities according to claim 5, characterized in that, In step four, the dosage of the modifier is 800 g / t, and the collector is a mixture of butyl xanthate and butylammonium black powder in a 1:1 ratio.

7. The method for processing copper oxide gold ore impure as described in claim 6, characterized in that, Step six describes copper recycling processes including: iron filings replacement to produce sponge copper, sodium sulfide precipitation to produce copper sulfide, or extraction of electrodes to produce cathode copper.

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