CN-121992217-A - Method for leaching nickel concentrate by using wet chlorine

Abstract

The invention discloses a method for leaching nickel concentrate by using wet chlorine, belonging to the field of hydrometallurgy. Solves the problems of high use cost of liquid chlorine, risk of chlorine overflow in the vaporization heating process, low effective utilization rate of the vaporized chlorine and raw materials, and the like. The method comprises the steps of mixing nickel concentrate and copper-removing tailings according to the mixing process, flushing slag with new water, enabling slurry to automatically flow into a slurry tank for slurry, returning the slurry into a reaction kettle for stirring after slurry, preparing liquid alkali in a two-stage absorption tower to serve as absorption liquid, starting a tail gas absorption fan and a tail gas absorption pipeline valve of the reaction kettle, introducing steam and wet chlorine into the reaction kettle for reaction with the slurry, returning the reacted slurry into a filter press for solid-liquid separation, and obtaining leaching liquid and leaching slag. The common liquid chlorine is replaced by wet chlorine generated in the industrial production process, so that the problems of high use cost of the liquid chlorine, risk of chlorine overflow in the vaporization heating process, low effective utilization rate of the vaporized chlorine and raw materials and the like are solved.

Inventors

• LIU JIALE
• YUE ZHIZHOU
• LI XIAOPENG
• XIANG YUANCHUN
• YANG XIAOXIA
• ZHU YONGZE
• LU XIAOFANG
• Chang Kaishan
• Gao Haiyin
• ZHOU LINHUA
• CHEN RUISHAN
• HU YONGJI

Assignees

• 金川集团镍钴股份有限公司
• 兰州金川新材料科技股份有限公司

Dates

Publication Date

20260508

Application Date

20260212

Claims (5)

1. 1. A method for leaching nickel concentrate using wet chlorine, comprising the steps of: Mixing nickel concentrate and copper-removing tailings, namely copper-nickel slag, adding the mixed materials into a slag flushing tank, flushing slag by using new water or leached slag washing water, and starting stirring to perform pulping after the slurry automatically flows into a pulping tank; step two, after slurrying, returning the slurrying liquid into a reaction kettle for stirring, preparing liquid alkali in a two-stage absorption tower as absorption liquid, and starting a tail gas absorption fan and a tail gas absorption pipeline valve of the reaction kettle; Introducing steam, wet chlorine and slurry into the reaction kettle to leach nickel concentrate to obtain leached liquid, absorbing residual chlorine by alkali, and then absorbing waste gas to discharge the generated waste water; And fourthly, returning the leached liquid to a filter press for solid-liquid separation to obtain filtrate and filter residues, washing the filter residues by hot water, returning washing water to slurrying for recycling, continuously extracting metal elements such as nickel, copper and the like by taking the washed filter residues as a pyrogenic raw material, and carrying out subsequent treatment by taking the filtrate as a raw material of electric nickel.
2. 2. The method for leaching nickel concentrate by using wet chlorine according to claim 1, wherein the mass ratio of the nickel concentrate to the decoppered tailings in the first step is 5-8:1, and the liquid-solid mass ratio of the nickel concentrate to fresh water or leached slag washing water after mixing is 5-8:1.
3. 3. The method for leaching nickel concentrate by using wet chlorine according to claim 1 or 2, wherein in the second step, a liquid alkali absorption liquid is prepared, the volume ratio of water to liquid alkali is 1:2-5, and the pH is >11.
4. 4. The method for leaching nickel concentrate by using wet chlorine as claimed in claim 4, wherein in the third step, the wet chlorine is introduced after the temperature is higher than 60 ℃, the reaction temperature is 60-100 ℃, the introducing pressure of the wet chlorine is higher than 0.005MPa, the specified value of the terminal potential is higher than 370mv, and the heat preservation time is 30 minutes.
5. 5. The method for leaching nickel concentrate by using wet chlorine according to claim 5, wherein Ni=80-200 g/L, cu =10-50 g/L, pH =0.5 in the leaching solution obtained in the fourth step, and Ni <20%, cu <15%, S <60% and moisture <60% in the leaching residue obtained.

Description

Method for leaching nickel concentrate by using wet chlorine Technical Field The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for leaching nickel concentrate by using wet chlorine. Background In industrial application, the chlorine leaching method is a method for starting to use liquid chlorine to gasify and leach chlorine in the leaching process of nickel concentrate by utilizing the strong oxidation characteristic of chlorine in solution and taking copper or iron valence ions as oxidation-catalysts and realizing hydrometallurgical processes of nickel concentrate and alloy materials at high temperature and normal pressure, and the method has been developed into a mature setting process basically until now, but the liquid chlorine has the problems of high use cost, risk of chlorine overflow in the gasification heating process, low effective utilization rate of gasified chlorine and raw materials, and the like, and most of factories use an alkali absorption method to treat wet chlorine produced by a chlorination system, and the liquid alkali absorption chlorine technology directly causes the production cost of electrodeposited cobalt, high environmental protection risk and chlorine resource waste in the problems. Disclosure of Invention The invention aims to provide a method for leaching nickel concentrate by utilizing wet chlorine, which aims to solve the problems that in the background technology, the use cost of liquid chlorine is high, the overflow of chlorine is easy to cause in the use process, and the effective rate of the reaction of the vaporized chlorine and raw materials is low. In order to achieve the above object, the technical scheme of the present invention is as follows: A method for leaching nickel concentrate using wet chlorine, comprising the steps of: Mixing nickel concentrate and copper-removing tailings, namely copper-nickel slag, adding the mixed materials into a slag flushing tank, flushing slag by using new water or leached slag washing water, and starting stirring to perform pulping after the slurry automatically flows into a pulping tank; step two, after slurrying, returning the slurrying liquid into a reaction kettle for stirring, preparing liquid alkali in a two-stage absorption tower as absorption liquid, and starting a tail gas absorption fan and a tail gas absorption pipeline valve of the reaction kettle; Introducing steam, wet chlorine and slurry into the reaction kettle to leach nickel concentrate to obtain leached liquid, absorbing residual chlorine by alkali, and then absorbing waste gas to discharge the generated waste water; And fourthly, returning the leached liquid to a filter press for solid-liquid separation to obtain filtrate and filter residues, washing the filter residues by hot water, returning washing water to slurrying for recycling, continuously extracting metal elements such as nickel, copper and the like by taking the washed filter residues as a pyrogenic raw material, and carrying out subsequent treatment by taking the filtrate as a raw material of electric nickel. Further, in the first step, the mass ratio of the nickel concentrate to the decoppered tailings is 5-8:1, and the liquid-solid mass ratio of the nickel concentrate to the fresh water or the leached slag washing water after mixing is 5-8:1. Further, in the step two, preparing liquid alkali absorption liquid, wherein the volume ratio of water to liquid alkali is 1:2-5, and the pH is >11. Further, in the third step, after the temperature is more than 60 ℃, the wet chlorine is introduced, the reaction temperature is 60-100 ℃, the wet chlorine introducing pressure is more than 0.005MPa, the terminal potential specified value is more than 370mv, and the heat preservation time is 30 minutes. Further, ni=80-200 g/L, cu =10-50 g/L, pH =0.5 in the leaching solution obtained in the step four, and Ni <20%, cu <15%, S <60% and moisture <60% in the leaching slag. The method has the advantages that a uniform slurry system is formed by mixing and slurrying nickel concentrate and copper-removed tailings, ideal material basis is provided for subsequent reaction, fresh water consumption and waste water emission are reduced, a two-stage alkali liquor absorption system is pre-configured and a tail gas treatment device is started before slurried feed liquid enters a reaction kettle, a safety protection barrier is constructed, so that tail gas can be immediately absorbed in the subsequent chlorine use process to prevent overflow risks, industrial byproduct wet chlorine and steam are directly introduced to carry out leaching reaction, the potential hazard of chlorine leakage in the traditional liquid chlorine vaporization link is avoided, the utilization rate of the wet chlorine is improved to more than 85% by accurately controlling reaction conditions, meanwhile, residual chlorine is efficiently treated by an alkali absorption system preset in the step two, the consu