Process for producing zinc sulphate monohydrate from waste acid and waste zinc dross

Abstract

A process for producing zinc sulphate monohydrate (feed grade) from waste acid and waste zinc dross includes the steps of (a) sulfuric acid leaching, (b) deironing, (c) purification for copper and cadmium removal, (d) dechloridation, (e) defluorination, (f) indium and cadmium extraction and (g) evaporative crystallization. The feed-grade zinc sulphate monohydrate is produced from the waste acid, waste zinc dross and the like, comprehensive utilization of waste is achieved, and the production cost of raw materials is reduced, so that resources are saved. Therefore the waste of massive zinc enterprises in China is recycled to produce economic benefits, the waste is changed into the valuable, a disadvantage is turned into an advantage, secondary utilization of the waste is achieved, comprehensive recycling of waste acid and waste dross resources is achieved, solid and liquid are separated, and the concentration crystallization and drying technology, the energy saving technology and the like are improved. The work of energy conservation, water conservation, comprehensive utilization, environment protection and the like is completed, the social benefits are remarkable, and remarkable environmental protection benefits and economic benefits are achieved.

Description

technical field [0001] The invention relates to a process for producing zinc sulfate monohydrate by utilizing waste acid and waste zinc slag. Background technique [0002] Compared with foreign countries, my country's zinc sulfate industry has a certain gap, which is mainly reflected in: [0003] a) The scale of the enterprise is small, the production organization is scattered, the concentration of the industry is low, and the overall strength of the enterprise is generally weak. [0004] b) Low-grade products, many primary products, unreasonable product structure, and high production costs. [0005] c) Zinc materials have turned from advantages to disadvantages, and the initial products will be more restricted by resources and the environment. [0006] d) The overall level of technology and equipment is low, and advanced technology and production control methods are not used much. [0007] e) my country's zinc sulfate industry has poor technology development and technolo...

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Problems solved by technology

[0007] e) my country's zinc sulfate industrial technology development and technological innovation capabilities are poor, and general enterprises do not have enough funds and manpower to invest in scientific research

[0008] f) Some enterprises have problems such as poor technical and economic indicators, poor product quality stability, and poor environmental conditions

[0009] my country is a big producer and consumer of waste acid and waste residue, but the problem of disposal of waste acid and waste residue has not been well resolved

At the same time, waste sulfuric acid will also react with sulfurous acid and sulfide in rocks and soil, releasing harmful substances such as sulfur dioxide and hydr

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