Treatment method for improving leaching rate of arsenic and carbon-containing complex refractory gold ore

Abstract

The invention discloses a treatment method for improving the leaching rate of arsenic and carbon-containing complex refractory gold ore, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: firstly, grinding raw ore until-0.15 mm accounts for 80-95%, filtering and drying to obtain a material a; the material a is placed in a muffle furnace to be roasted, the temperature ranges from 600 DEG C to 1200 DEG C, the time ranges from 1.5 h to 2.5 h, and a material b is obtained; grinding the material b until the material b with the particle size of 0.074 mm accounts for 90-100% to obtain a material c; a leaching aid is added into the material c according to the dosage of 500-2000 g / t, stirring and pre-oxidation are conducted for 2.5-3.5 h, and a material d is obtained; a pH regulator is added into the material d, the pH value of the ore pulp is regulated to 11-13, a leaching agent is added according to the dosage of 5000-10000 g / t, stirring and leaching are conducted for 24-48 h, and a material e is obtained; the material e is filtered and washed, and filtrate and filter residues are obtained respectively. The treatment method is simple in technological process, easy to operate, capable of saving energy, environmentally friendly and good in applicability, and compared with traditional stirring hydrogenation leaching, the treatment method can improve the leaching rate of gold by 5%-10%, the leaching rate can be increased, and the leaching time can be shortened.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy, and particularly relates to a treatment method for improving the leaching rate of complex refractory gold ores containing arsenic and carbon. Background Art

[0002] Gold has a very wide range of uses. In addition to being used as a financial reserve, currency, and for processing jewelry, gold is also widely used in many fields such as aerospace, chemical engineering, electrical and electronics, and medical devices. As global gold ore resources are continuously exploited and utilized, high-grade and easily beneficiated gold ore resources are becoming increasingly depleted, and refractory gold ores with huge reserves are gradually becoming an important raw material in the gold production industry. According to statistics, more than 60% of the gold reserves in the world are hosted in refractory gold ores.

[0003] The cyanidation leaching process is the main method for extracting gold from ores or concentrates. Currently, more than half of the gold mines in the world use the cyanidation method for gold extraction, but there are also bottleneck problems such as low gold leaching rate, high toxicity, and unsatisfactory direct leaching effects on refractory gold ores containing arsenic, sulfur, copper, and carbon. The reasons for the difficulty in leaching refractory gold ores are as follows: Firstly, the gold-bearing minerals and gold particles are relatively fine and are encapsulated in sulfide minerals such as pyrite (FeS2) and arsenopyrite (FeAsS); secondly, the content of harmful arsenic or organic carbon is relatively high and is inseparable from gold.

[0004] Based on this, it is very necessary to develop a reasonable and feasible treatment method for improving the leaching rate of complex refractory gold ores containing arsenic and carbon. Summary of the Invention

[0005] The purpose of the present invention is to provide a treatment method for improving the leaching rate of complex refractory gold ores containing arsenic and carbon.

[0006] The purpose of the present invention is achieved as follows: The treatment method for improving the leaching rate of complex refractory gold ores containing arsenic and carbon includes the following steps: Grinding: Grinding the raw ore to -0.15 mm accounting for 80 - 95%, then filtering and drying to obtain material a; Roasting: Placing material a in a muffle furnace for roasting at a temperature of 600 - 1200 °C for a time of 1.5 - 2.5 h to obtain material b; Regrinding: Grinding material b to -0.074 mm accounting for 90 - 100% to obtain material c; Pre-oxidation: Adding a leaching aid to material c at a dosage of 500 - 2000 g / t, and stirring for pre-oxidation for 2.5 - 3.5 h to obtain material d; Leaching: Adding a pH regulator to material d to adjust the pH value of the pulp to 11 - 13, adding a leaching agent at a dosage of 5000 - 10000 g / t, and stirring for leaching for 24 - 48 h to obtain material e; Filtration and washing: Filter and wash the material e to obtain filtrate and filter residue respectively.

[0007] Compared with the prior art, the technical solution of the present invention has the following advantages: Through oxidative roasting - pre - oxidation with leaching aid - stirring leaching, the present invention recovers arsenic - and carbon - containing refractory gold ores. The process flow is simple, easy to operate, energy - saving, environmentally friendly, and has good applicability. Compared with traditional stirring hydrogenation leaching, this treatment method can increase the gold leaching rate by 5 - 10%, accelerate the leaching rate, and reduce the leaching time. Description of the Drawings

[0008] Figure 1 It is a process flow schematic diagram of the treatment method described in the present invention. Detailed Embodiments

[0009] The following further describes the present invention, but does not limit the present invention in any way. Any transformation or replacement based on the teachings of the present invention falls within the protection scope of the present invention.

[0010] The treatment method for improving the leaching rate of arsenic - and carbon - containing refractory gold ores described in the present invention includes the following steps: Grinding: Grind the raw ore to 80 - 95% passing through - 0.15mm, then filter and dry to obtain material a; Roasting: Place material a in a muffle furnace for roasting at a temperature of 600 - 1200°C for 1.5 - 2.5h to obtain material b; Re - grinding: Grind material b to 90 - 100% passing through - 0.074mm to obtain material c; Pre - oxidation: Add leaching aid to material c at a dosage of 500 - 2000g / t, and stir for pre - oxidation for 2.5 - 3.5h to obtain material d; Leaching: Add a pH regulator to material d to adjust the pH value of the pulp to 11 - 13, add a leaching agent at a dosage of 5000 - 10000g / t, and stir for leaching for 24 - 48h to obtain material e; Filtration and washing: Filter and wash the material e to obtain filtrate and filter residue respectively.

[0011] The roasting time is preferably 2h.

[0012] The pulp concentration of material c is 30 - 50%.

[0013] The leaching aid is composed of component A and component B. By mass, component A: component B = 0.2 - 10:1; where component A is at least one of sodium peroxide, potassium peroxide, calcium peroxide, boron peroxide, barium peroxide, hydrogen peroxide; component B is at least one of sodium chlorate, calcium hypochlorite, sodium hypochlorite, lead nitrate.

[0014] The preferred ratio and composition of the leaching aid by mass parts are as follows: Component A: Component B = 2 - 3:1; wherein Component A is any one of barium peroxide, sodium peroxide, and hydrogen peroxide; Component B is any one of sodium chlorate, calcium hypochlorite, and lead nitrate.

[0015] Furthermore, when the dosage of the leaching aid is 500 - 1000 g / t, Component A: Component B = 3:1, Component A is hydrogen peroxide, and Component B is lead nitrate; when the dosage of the leaching aid is 1000 - 2000 g / t, Component A: Component B = 2:1, Component A is barium peroxide, and Component B is calcium hypochlorite.

[0016] The preferred stirring pre-oxidation time is 3 h.

[0017] The pH regulator is lime, and after adding it, stir for 3 - 5 min.

[0018] The preferred dosage of the leaching agent is 5000 - 7000 g / t.

[0019] The leaching agent is Jinchan gold extraction agent.

[0020] Example 1

[0021] For a gold mine in Laos, the gold content in the raw ore is 3.20 g / t, the arsenic content of harmful elements is 0.20%, the CaO content is 42%, the SiO2 content is 3.89%, the carbon content is 4.2%, and the arsenic-containing sulfide minerals in the ore are mainly realgar, scorodite, and arsenopyrite.

[0022] The above ore is processed by the following steps: Grinding: Grind the raw ore to 80% passing - 0.15 mm, then filter and dry to obtain material a; Roasting: Load material a into a ceramic bowl and place it in the middle position of the muffle furnace hearth for roasting at a temperature of 1100 °C for 2 h to obtain material b; Re-grinding: Grind material b to 95% passing - 0.074 mm to obtain material c; Pre-oxidation: Pour material c into a stirring leaching tank with a pulp concentration of 40%, add the leaching aid at a dosage of 500 g / t. Component A of the leaching aid is barium peroxide, and Component B is calcium hypochlorite, where A:B = 2:1, and stir for pre-oxidation for 3 h to obtain material d; Leaching: Add lime to material d at a dosage of 3000 g / t, stir for 5 min to adjust the pH value of the pulp to 12, add the Jinchan gold extraction agent at a dosage of 5000 g / t, and stir for leaching for 24 h to obtain material e; Filtration and washing: Filter and wash material e to obtain the filtrate and filter residue respectively.

[0023] The ore was treated with the above steps and stirred for 24 hours, and the gold leaching rate was 88%.

[0024] Comparative Example: After grinding, the original ore had a particle size of -0.074 mm, accounting for 95%. Without pretreatment, the leaching rate of gold was only 82% after direct stirring and leaching for 36 hours. This shows that the treatment method of the present invention can improve the leaching rate of gold ore and accelerate the leaching rate.

[0025] Example 2

[0026] In a gold mine in Guizhou, the gold content of the raw ore is 5.05g / t, the harmful element arsenic content is 0.15%, the CaO content is 28.21%, the SiO2 content is 9.13%, and the carbon content is 5.1%. The arsenic sulfide minerals in the ore are mainly realgar, orpiment, and arsenopyrite.

[0027] The above ore samples were processed by the following steps: Grinding: Grind the raw ore to -0.15mm, accounting for 90%, and then filter and dry to obtain material a; Calcination: Put material a into a ceramic bowl and place it in the middle of a muffle furnace for calcination at 1000°C for 3 hours to obtain material b; Regrinding: Grind material b to -0.074mm, accounting for 98%, to obtain material c; Pre-oxidation: Pour material c into a stirred leaching tank with a pulp concentration of 45%. Add a leaching agent at a dosage of 1000g / t. The leaching agent components A are hydrogen peroxide and B are lead nitrate. The ratio of A:B is 3:1. Stir and pre-oxidize for 3 hours to obtain material d. Leaching: add lime at a rate of 3000 g / t to material d, stir for 5 min, adjust the pH value of the slurry to 12, add Jinchan gold extraction agent at a rate of 6000 g / t, stir and leach for 24 h to obtain material e; Filtration and washing: Filter and wash the material e to obtain the filtrate and filter residue respectively.

[0028] The ore was treated with the above steps and stirred for 24 hours, and the gold leaching rate was 92%.

[0029] Comparative Example: After grinding, the original ore had a particle size of -0.074 mm, accounting for 98%. Without pretreatment, the leaching was carried out for 36 hours, and the gold leaching rate was only 84%. This shows that the treatment method of the present invention can improve the leaching rate of gold ore and accelerate the leaching rate.

[0030] Example 3

[0031] A gold mine in Guizhou, with the same composition as in Example 2.

[0032] The above ore samples were processed by the following steps: Grinding: Grind the raw ore to 95% passing -0.15mm, then filter and dry to obtain material a; Roasting: Load material a into a ceramic bowl and place it in the middle of the muffle furnace hearth for roasting at 800°C for 2.5h to obtain material b; Regrinding: Grind material b to 90% passing -0.074mm to obtain material c; Pre-oxidation: Pour material c into a stirring leaching tank with a pulp concentration of 35%, add a leaching aid at a dosage of 1500g / t. The components of the leaching aid are A: sodium peroxide and B: sodium chlorate, with A:B = 3:1, and stir for pre-oxidation for 2.5h to obtain material d; Leaching: Add lime to material d at a dosage of 3000g / t, stir for 3min, adjust the pH value of the pulp to 13, add a Jinchan gold extraction agent at a dosage of 7000g / t, and stir for leaching for 36h to obtain material e; Filtration and washing: Filter and wash material e to obtain filtrate and filter residue respectively.

[0033] Treat the ore with the above steps, stir for leaching for 36h, and the gold leaching rate is 95%.

[0034] Comparative example: After grinding the raw ore, 90% passes -0.074mm. Without pretreatment, directly stir and leach for 48h, and the gold leaching rate is only 85%. It shows that the treatment method described in the present invention can improve the gold leaching rate and accelerate the leaching rate.

Claims

1. A treatment method for improving the leaching rate of complex refractory gold ores containing arsenic and carbon, characterized in that, It includes the following steps: Grinding: Grind the raw ore to 80 - 95% passing through -0.15mm, then filter and dry to obtain material a; Roasting: Place material a in a muffle furnace for roasting at a temperature of 600 - 1200°C for 1.5 - 2.5h to obtain material b; Regrinding: Grind material b to 90 - 100% passing through -0.074mm to obtain material c; Pre - oxidation: Add a leaching aid to material c at a dosage of 500 - 2000g / t, stir and pre - oxidize for 2.5 - 3.5h to obtain material d; Leaching: Add a pH regulator to material d to adjust the pH value of the pulp to 11 - 13, add a leaching agent at a dosage of 5000 - 10000g / t, stir and leach for 24 - 48h to obtain material e; Filtration and washing: Filter and wash material e to obtain a filtrate and a filter residue respectively.

2. The processing method according to claim 1, characterized in that, The roasting time is 2h.

3. The processing method according to claim 1, wherein The pulp concentration of material c is 30 - 50%.

4. The processing method according to claim 1, characterized in that The leaching aid is composed of component A and component B. By mass, component A: component B = 0.2 - 10:1; where component A is at least one of sodium peroxide, potassium peroxide, calcium peroxide, boron peroxide, barium peroxide, hydrogen peroxide; component B is at least one of sodium chlorate, calcium hypochlorite, sodium hypochlorite, lead nitrate.

5. The processing method according to claim 4, characterized in that The leaching aid is composed of component A and component B. By mass, component A: component B = 2 - 3:1; where component A is any one of barium peroxide, sodium peroxide, hydrogen peroxide; component B is any one of sodium chlorate, calcium hypochlorite, lead nitrate.

6. The processing method according to any one of claims 4 or 5, characterized in that, When the dosage of the leaching aid is 500 - 1000g / t, component A: component B = 3:1, component A is hydrogen peroxide, and component B is lead nitrate; when the dosage of the leaching aid is 1000 - 2000g / t, component A: component B = 2:1, component A is barium peroxide, and component B is calcium hypochlorite.

7. The processing method according to claim 1, characterized in that, The stirring and pre - oxidation time is 3h.

8. The processing method according to claim 1, wherein The pH regulator is lime.

9. The processing method according to claim 1, wherein The dosage of the leaching agent is 5000 - 7000g / t.

10. The processing method according to any one of claims 1 or 9, characterized in that The leaching agent is Jinchan gold extraction agent.

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