Process for producing high-purity ammonium dimolybdate through ion exchange method

Abstract

The invention discloses a process for producing high-purity ammonium dimolybdate through an ion exchange method. The process comprises the following steps: I, preparing a sodium molybdate solution, (I) dissolving and (II) filtering and secondary leaching; II, performing ion exchange: (I) adsorbing and (II) resolving; and III, crystallizing and drying. The process adopts the ion exchange method toprepare ammonium molybdate, has the environment-friendly advantages, realizes recycling use, in process, of ammonia nitrogen, and meets process requirements of clean production; moreover, the processis simple and short, the impurity removal effect is good, the process controlled degree is high, and the product quality is stable; needed auxiliary material varieties are fewer, ion exchange resin can be repeatedly used, and material movement is less; automatic control is easily performed, labor productivity is favorably improved and labor intensity is favorably reduced, the working environment is friendly, and social benefits are better; and the raw material adaption is strong, and a metal recovery rate is high, and low-grade calcined products and various other molybdenum-containing raw materials can be treated.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, in particular to a process for producing high-purity ammonium dimolybdate by an ion exchange method. Background technique [0002] The raw material for conventional ammonium molybdate production is molybdenite, and the production process is: molybdenite—roasting—industrial molybdenum oxide—pickling—ammonia leaching—crude ammonium molybdate solution—magnesium chloride impurity removal— - Ammonium sulfide removal of impurities - Refined ammonium molybdate solution - Nitric acid precipitation - Ammonium tetramolybdate - Ammonia dissolution - Evaporation crystallization - Ammonium dimolybdate. The process flow chart of the production of ammonium molybdate by the classic method is as follows figure 1 shown. [0003] The method for the production of ammonium molybdate by the classic method is a widely used method in China at present. It is characterized by simple equipment, small investment...

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Problems solved by technology

[0003] The method for the production of ammonium molybdate by the classic method is a widely used method in China at present. It is characterized by simple equipment, small investment and small processing capacity, but the method has the following disadvantages: (1) The leaching rate of industrial molybdenum oxide is not high during ammonia leaching , the molybdenum in the slag is not easy to recover in this process, resulting in low recovery rate and high cost; (2) the impurity removal effect is poor, and the chemical properties of the product are difficult to meet the national standard requirements; (3) the raw material has poor adaptability and can only be used with high quality (4) The working environment is poor and the equipment is easily corroded; (5) It is difficult to implement automatic control; (6) Environmental protection emissions (such as waste water, waste gas and waste residue, etc.) are difficult to meet the national requirements. During the production process, ammonia leaching consumes a large amount of ammonia, acid precipitation consumes a large amount of nitric acid, and produces a large amount of high-concentration ammonia nitrogen compounds, causing the discharge of ammonia nitrogen to seriously exceed the standard. It is necessary to spend a lot of money to solve the treatment of ammonia nitrogen waste, which is brought by the classic process production. the greatest evil

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