A method of crystallizing concentrated copper electrolysis waste liquid to produce crude nickel sulfate

Abstract

The invention discloses a method for producing crude nickel sulfate by crystallizing concentrated copper electrolytic waste liquid. The method comprises the following extraction process: the copper electrolytic waste liquid to be concentrated and a water absorbent are put in two containers respectively; the contact area between water vapor and the liquid surface is increased with a proper method;spaces above the two containers are sealed and communicated with each other; air in the space above the liquid surface is pumped away by a vacuum system; the temperature of the copper electrolytic waste liquid is appropriately increased through heating, so that vapor pressure is increased, and water forms vapor at a higher speed; the water absorbent absorbs the vapor in the space at a higher speed; solid nickel sulfate is crystallized out when the copper electrolytic waste liquid is concentrated to a certain degree. The whole production process can be subjected to closed operation, and is freeof acid mist and environmentally friendly; energy consumption is controllable, and production cost is low.

Description

technical field [0001] The invention discloses a method for producing crude nickel sulfate through crystallization of concentrated copper electrolysis waste liquid, which relates to a method for concentrating an aqueous solution. Background technique [0002] At present, the methods of purifying and removing nickel in copper electrolyte mainly use crystallization method, extraction method and ion exchange method. Most domestic manufacturers use crystallization methods to produce crude nickel sulfate, mainly electrothermal evaporation method, freeze crystallization method, steam indirect heating concentration, direct fire concentration method, immersion combustion evaporator to produce crude nickel sulfate, etc. The electrothermal evaporation method has the advantages of high degree of automation and high nickel removal efficiency, but its application is limited due to high power consumption, low capacity, high environmental protection investment and operating costs. The fre...

AI Technical Summary

Problems solved by technology

The electrothermal evaporation method has the advantages of high automation and high nickel removal efficiency, but it has high power consumption, low capacity, high environmental protection investment and operating costs, and its application is limited.

The freeze crystallization method has not been widely used due to factors such as requiring a lot of equipment, occupying a large area, and low nickel removal efficiency.

The direct fire concentration method has the advantages of simple equipment and high nickel direct recovery rate, and was once widely used in small copper smelters. Large and other shortcomings

Steam indirect heating and concentration uses steam indirect heating to evaporate the solution. Due to the high acid content of the solution and serious corrosion, the requirements for vacuum evaporation materials are high. The enamel reaction kettle is used, which has the characteristics of high temperature resistance and high acid, but its heat transfer efficiency is low. Low crystallization rate, low direct nickel recovery rate, slow evaporation rate, more suitable for factories with small processing capacity

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