Two-section innocent treatment technology for cyanogens-containing tailing pulp

Abstract

The invention discloses a two-section innocent treatment technology for cyanogens-containing tailing pulp. The technology comprises a pulp concentration step and an oxidization step, wherein in the pulp concentration step, thickening equipment is used for improving the concentration of the pulp to 50-55 percent; thickened supernate is returned to a site selection technology; high-concentration pulp enters the next treatment procedure; a thickening theory is that solid-liquid separation is performed through gravity sedimentation; in the oxidization step, oxidization is divided into two stages by an OOT oxidization method; in the first stage, sulfuric acid is added to control the pH of the pulp to be 9 to 10, and most releasable cyanides, thiocyanate ions and reductive substances can be removed through oxidization, so that the concentration of the releasable cyanides is smaller than 30 mg / L, and the concentration of the thiocyanate ions is smaller than 10 mg / L; in the second stage, the sulfuric acid is added to adjust the pH of the pulp to be 7 to 8; active carbon is fed in the second oxidization stage to enhance the oxidization effect; due to the adsorption effect of the carbon, gold in part of the tailing pulp can be recycled.

Description

technical field [0001] Gold mines generally use sodium cyanide to leaching gold. The cyanide-containing tailings slurry produced by it is harmful to the natural environment during the stacking process, and it needs to be treated harmlessly. The present invention will solve the standard discharge and safety Stacking problem. Background technique [0002] 1. Current status and development trend of harmless treatment technology of cyanide-containing tailings pulp [0003] In recent years, the harmless treatment of cyanide-containing tailings slurry has been gradually paid attention to. There are two types of treatment methods. One is to carry out comprehensive treatment of tailings slurry by pressure filtration, dry stacking of filter residue, and filtrate, and reuse or discharge after treatment; One is the direct treatment of tailings slurry. The method is basically to destroy cyanide. The methods include the Inco method, the alkaline chlorination method, and the ozone oxidat...

AI Technical Summary

Problems solved by technology

[0004] 2. Advantages and disadvantages of cyanide-containing tailings pulp treatment technology

[0016] ① If the pH value is too low during the reaction process, HCN and SO will escape 2 , and the residual cyanide is high; when the pH value is too high, the residual cyanide is also high, so the control of the reaction pH value is strictly required; when there is ferricyanide in the cyanide pulp and wastewater, it is difficult to oxidize to reach the standard

[0019] ④ May need to add catalyst copper salt - precious non-ferrous metals are consumed

[0020] ⑤ High power consumption, generally 3 to 5 times that of the chlorine oxidation method

[0023] ⑧When the wastewater contains arsenic, the removal rate of arsenic decreases due to sulfur dioxide reducing the arsenic to a low price, and the arsenic in the wastewater may exceed the standard

[0033] ① If the equipment is not well sealed during wastewater treatment, CNCl will escape into the air and pollute the operating environment

[0036] ④The concentration of chlorine ions in the drainage is high, which makes the surface water and soil salinized, and the water conservancy facilities corrode

[0037] ⑤ When the concentration of chloride ions is high, a large amount of calcium and magnesium will be dissolved. After the waste water leaks from the tailings pond, it will pollute the groundwater and greatly increase the concentration of calcium, magnesium and chlorine in the groundwater, which will seriously affect the function of the water. In severe cases, it cannot be drunk , cannot irrigate farmland

[0038] ⑥ The transportation and use of chlorine-based oxidants, especially liquid chlorine, has certain risks. Human and animal poisoning, farmland and fish pond damage accidents caused by chlorine leakage occur from time to time in other industries

[0039] ⑦In recent years, the price of chlorine products has risen, and the treatment cost is high

[0049] ① Poor adaptability, the ozone method is only suitable for treating clarified liquid with a CN- content of less than 30mg / L, and most of the gold cyanide plant wastewater is ore pulp, and the CN- content is above 80mg / L, so this method can only be used as a secondary level processing method

[0050] ②The investment is large, and the price of the ozone generator, air dust removal and moisture removal equipment is relatively high

[0051] ③Large power consumption, producing 1kg of ozone consumes 15-20kwh of electricity, while a 50t / d all-slime cyanide plant requires more than 100kg of ozone per day, which is equivalent to increasing the capacity by 100kw

Compared with the current wastewater treatment capacity of 15kw, the electricity consumption is too large. Due to the large investment in electricity and the high price of electricity, the treatment cost is bound to be high, and it is difficult to compete with sulfur dioxide-air oxidation and chlorine oxidation.

[0052] ④The oxidation process is non-selective, when reducing substances in wastewater such as SCN - , SO 3 2- Ozone depletion is greater when equal

⑤ The equipment of the ozone generator is complex, difficult to maintain, and requires high requirements for the operator

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