Zinc hydrometallurgy process for oxygen-sulfur mixed zinc concentrate

Abstract

The invention discloses a zinc hydrometallurgy process for oxygen-sulfur mixed zinc concentrate, and belongs to the technical field of hydrometallurgy. The oxygen-sulfur mixed zinc concentrate is subjected to ore grinding treatment, and the particle size of ore powder is smaller than 500 meshes; then the mineral powder and concentrated sulfuric acid are mixed and cured, the liquid-solid mass ratio of the concentrated sulfuric acid to the mineral powder is (0.4-1.2): 1, the curing temperature is 100-300 DEG C, and the curing time is 1.5-4 h. The liquid-solid mass ratio of water to the material is (4-7): 1, and the leaching temperature is 50-80 DEG C; the leaching time is 1-4 hours, and leaching liquid and leaching residues are obtained after solid-liquid separation. And the leaching liquid is subjected to iron removal and purification, and a zinc product is obtained after electrodeposition. According to the zinc hydrometallurgy process, zinc oxide and zinc sulfide can be efficiently treated, the technical bottleneck problem that the mixed ore treatment efficiency of a traditional process is low is solved, the leaching rate of the mixed zinc concentrate is increased to 92% or above, meanwhile, the energy consumption of reaction is greatly reduced, and the operation cost has more advantages.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, specifically relating to a hydrometallurgical zinc smelting process for oxygen-sulfur mixed zinc concentrate. Background Technology

[0002] Lead and zinc are widely used in metallurgy, building materials, batteries, chemicals, and pharmaceuticals, and are essential non-ferrous metal raw materials for the national economy. After years of mining, many mining areas have accumulated large quantities of low-grade oxygen-sulfur mixed lead-zinc ore, leading to a decline in overall resource utilization and the occupation of land resources.

[0003] Based on years of prior research, obtaining oxygen-sulfur mixed concentrate from low-grade oxygen-sulfur mixed stockpiled ore through mixed flotation has good economic efficiency and process stability. However, there are two key technical challenges in the smelting application of this mixed concentrate: (1) due to its oxygen-sulfur mixture, it is difficult to incorporate into existing smelting processes; (2) after mixed flotation, the oxidized ore is coated with reagents and sulfided, making oxygen-sulfur separation difficult with existing beneficiation techniques. The carbonates in the mixed concentrate and the surface flotation reagents will rapidly foam during the leaching stage, causing a large amount of foam to overflow with slurry, leading to overflowing. The continuously accumulating foam will hinder the continuous addition of sulfuric acid and waste electrolyte, and the relative content of sulfides in the mixed concentrate is approximately 12-16%. Under the influence of multiple factors, the leaching rate of the mixed concentrate is difficult to stabilize within the target range.

[0004] Based on this, the present invention aims to provide a hydrometallurgical zinc smelting process for oxygen-sulfur mixed zinc concentrate, so as to achieve efficient utilization of complex polymetallic ores and harmless treatment of waste residue, thereby maximizing resource value while ensuring resource supply. Summary of the Invention

[0005] The purpose of this invention is to provide a hydrometallurgical zinc smelting process for oxygen-sulfur mixed zinc concentrate.

[0006] The objective of this invention is achieved as follows: the hydrometallurgical zinc smelting process for the oxygen-sulfur mixed zinc concentrate includes the following steps: Grinding: The oxygen-sulfur mixed zinc concentrate is ground to make the mineral powder particle size <500 mesh; Maturation: The mineral powder is mixed with concentrated sulfuric acid for maturation. The liquid-solid mass ratio of concentrated sulfuric acid to mineral powder is 0.4~1.2:1. The maturation temperature is 100~300℃ and the maturation time is 1.5~4h. Leaching: The matured material is stirred and leached, with a water-to-solid mass ratio of 4~7:1, a leaching temperature of 50~80℃, and a leaching time of 1~4h. After solid-liquid separation, leachate and leachate residue are obtained. Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0007] The technical solution described in this invention has the following advantages compared with the prior art: The technical solution described in this invention can efficiently process zinc oxide and zinc sulfide, solving the technical bottleneck problem of low processing efficiency of mixed ore in traditional processes, and increasing the leaching rate of mixed zinc concentrate to over 92%.

[0008] During the curing stage, the reaction between concentrated sulfuric acid and zinc oxide is highly efficient. Under high-temperature curing conditions, concentrated sulfuric acid can convert zinc in sulfides that are difficult to leach into soluble zinc sulfate. The sulfur element is left in the residue, and the generated sulfur dioxide gas can be used to produce acid, making the single leaching rate of zinc much higher than that of the traditional direct leaching method.

[0009] Most sulfur exists in the leaching residue as solid elemental sulfur, greatly reducing the pressure of sulfur-containing gas treatment at the source. Furthermore, grinding refines the ore powder, increasing the specific surface area and making the ripening reaction more uniform and thorough. The heat generated by the reaction can maintain the required ripening temperature, requiring only a small amount of additional heat energy, significantly reducing energy consumption and making the operating cost more advantageous. Attached Figure Description

[0010] Figure 1 This is a process flow diagram of the technical solution described in this invention. Detailed Implementation

[0011] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the scope of protection of the present invention.

[0012] The hydrometallurgical zinc smelting process for the oxygen-sulfur mixed zinc concentrate includes the following steps: Grinding: The oxygen-sulfur mixed zinc concentrate is ground to make the mineral powder particle size <500 mesh; Maturation: The mineral powder is mixed with concentrated sulfuric acid for maturation. The liquid-solid mass ratio of concentrated sulfuric acid to mineral powder is 0.4~1.2:1. The maturation temperature is 100~300℃ and the maturation time is 1.5~4h. Leaching: The matured material is stirred and leached, with a water-to-solid mass ratio of 4~7:1, a leaching temperature of 50~80℃, and a leaching time of 1~4h. After solid-liquid separation, leachate and leachate residue are obtained. Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0013] The grinding process is a dry ball mill. The dry ball mill operates at a speed of 300-400 rpm for 0.5-1 hour.

[0014] The liquid-solid mass ratio of concentrated sulfuric acid to mineral powder is preferably 0.8~0.9:1.

[0015] The preferred curing temperature is 200~250℃.

[0016] The preferred curing time is 2 hours.

[0017] The preferred liquid-to-solid mass ratio of water to material is 4-5:1.

[0018] The preferred leaching temperature is 65~70℃.

[0019] The preferred leaching time is 2 hours.

[0020] The stirring speed is 400~700 r / min, preferably 500 r / min.

[0021] The iron removal process can be performed using potassium ferric sulfate.

[0022] The purification process can employ a two- or three-stage zinc powder replacement method.

[0023] The electrodeposition can be performed using the zinc sulfate solution electrolytic deposition method.

[0024] The leaching residue is washed with water until the pH value is between 6 and 7.

[0025] Example 1

[0026] Grinding: Take 500g of oxygen-sulfur mixed zinc concentrate and grind it using a dry ball mill at a speed of 300 rpm for 1 hour to make the mineral powder particle size <500 mesh.

[0027] Maturation: Mix the mineral powder with 400g of concentrated sulfuric acid and mature at 200℃ for 2 hours.

[0028] Leaching: 2L of water was added to the matured material, and leaching was carried out with stirring at 500 r / min at a leaching temperature of 65℃ for 2 hours. After solid-liquid separation, leachate and leaching residue were obtained. Based on sampling and analysis, the leaching rate of the mixed zinc concentrate was calculated to be 92.30%.

[0029] Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0030] Example 2

[0031] Grinding: Take 500g of oxygen-sulfur mixed zinc concentrate and grind it using a dry ball mill at a speed of 350 rpm for 1 hour to make the mineral powder particle size <500 mesh.

[0032] Maturation: Mix the mineral powder with 450g of concentrated sulfuric acid and mature at a temperature of 250℃ for 2 hours.

[0033] Leaching: 2.5L of water was added to the matured material, and leaching was carried out with stirring at 500 r / min at a leaching temperature of 70℃ for 2 hours. After solid-liquid separation, leachate and leaching residue were obtained. Based on sampling and analysis, the leaching rate of the mixed zinc concentrate was calculated to be 94.75%.

[0034] Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0035] Example 3

[0036] Grinding: Take 500g of oxygen-sulfur mixed zinc concentrate and grind it using a dry ball mill at a speed of 400 rpm for 0.5h to make the mineral powder particle size <500 mesh.

[0037] Maturation: Mix the mineral powder with 600g of concentrated sulfuric acid and mature at 100℃ for 1.5h.

[0038] Leaching: 3.5 L of water was added to the matured material, and leaching was carried out with stirring at 400 r / min at a leaching temperature of 50℃ for 1 h. After solid-liquid separation, leachate and leaching residue were obtained. Sampling analysis showed that the leaching rate of the mixed zinc concentrate was 94.12%.

[0039] Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0040] Example 4

[0041] Grinding: Take 500g of oxygen-sulfur mixed zinc concentrate and grind it using a dry ball mill at a speed of 400 rpm for 0.5h to make the mineral powder particle size <500 mesh.

[0042] Maturation: Mix the mineral powder with 200g of concentrated sulfuric acid and mature at 300℃ for 4 hours.

[0043] Leaching: 3L of water was added to the matured material, and leaching was carried out with stirring at 700 r / min at a leaching temperature of 80℃ for 4 hours. After solid-liquid separation, leachate and leaching residue were obtained. Sampling analysis showed that the leaching rate of the mixed zinc concentrate was 93.45%.

[0044] Zinc recovery: The leaching solution is subjected to iron removal and purification, and then electrowinning is performed to obtain zinc products.

[0045] Example 5

[0046] —Comparative Example 500g of oxygen-sulfur mixed zinc concentrate was directly leached with 450g of sulfuric acid and 2.5L of water without grinding or aging. The leaching was carried out with stirring at 500 r / min, at a leaching temperature of 70℃, for 2 hours. After solid-liquid separation, leachate and leaching residue were obtained. Sampling analysis showed that the leaching rate of the mixed zinc concentrate was 68.73%.

Claims

1. A process for hydrometallurgical zinc production from an oxygen-sulphur mixed zinc concentrate, c h a r a c t e r i s e d in that, The method comprises the following steps: Grinding: grinding the oxygen-sulfur mixed zinc concentrate to make the particle size of the ore powder less than 500 mesh; Curing: mixing the ore powder with concentrated sulfuric acid, the liquid-solid mass ratio of the concentrated sulfuric acid to the ore powder being 0.4-1.2:1, the curing temperature being 100-300 DEG C, and the curing time being 1.5-4 h; Leaching: stirring and leaching the cured material, the liquid-solid mass ratio of water to the material being 4-7:1, the leaching temperature being 50-80 DEG C, and the leaching time being 1-4 h, to obtain leaching liquid and leaching residue after solid-liquid separation; Recovering zinc: removing iron and purifying the leaching liquid to obtain zinc product after electrodeposition.

2. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The grinding is dry ball grinding.

3. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 2, characterized in that, The rotation speed of the dry ball grinding is 300-400 rpm, and the time is 0.5-1 h.

4. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The liquid-solid mass ratio of the concentrated sulfuric acid to the ore powder is 0.8-0.9:

1.

5. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The curing temperature is 200-250 DEG C.

6. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The curing time is 2 h.

7. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The liquid-solid mass ratio of water to the material is 4-5:

1.

8. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The leaching temperature is 65-70 DEG C.

9. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The leaching time is 2 h.

10. The process for hydrometallurgical zinc production from an oxysulfidic zinc concentrate according to claim 1, characterized in that, The stirring speed is 400-700 r / min.

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