Method for recovering reagent level anhydrous sodium sulfate from raffinate obtained in process of extracting nickel from nickel sulfate solution

Abstract

The invention provides a method for recovering reagent level anhydrous sodium sulfate from raffinate obtained in a process of extracting nickel from a nickel sulfate solution by adopting bi(2-ethylhexyl)phosphate (P204) as an extracting agent. The method comprises the following steps of: firstly adding a certain amount of hydrogen peroxide in raffinate for gently heating and insulating, and adding active carbon for absorbing and filtering to remove a small amount of organic matters; then adding excessive sodium sulphide in filtrate to remove heavy metal ions such as nickel and the like, adding sodium persulfate to remove excessive sulphur ions and chloride ions in a system, adding excessive calcium hydroxide in the filtrate to remove phosphate radical ions, and removing excessive calcium hydroxide by using sodium carbonate; and finally, after regulating the pH value of the filtrate by using concentrated sulfuric acid to 5-6, concentrating and crystallizing, centrifuging while heating, and drying to obtain the reagent level anhydrous sodium sulfate. The method for recovering the reagent level anhydrous sodium sulfate is simple in operation and is mild in process conditions, and can be used for effectively removing various kinds of impurities in the raffinate with a comprehensive recovering rate of above 90 percent; and the obtained reagent level anhydrous sodium sulfate accords with the analytically pure standards of chemical reagents through testing. According to the invention, through processing and comprehensively utilizing the raffinate, the reagent level anhydrous sodium sulfate is recovered, and the purposes of saving energy, reducing emission, reducing environmental pollution and lowering production cost are achieved.

Description

technical field [0001] The present invention relates to a kind of production method of anhydrous sodium sulfate, relate in particular to a kind of method of reclaiming reagent grade anhydrous sodium sulfate from the raffinate of nickel sulfate solution extraction nickel, more specifically relate to a kind of Hexyl) phosphoric acid (referred to as P204) as an extractant to recover reagent-grade anhydrous sodium sulfate from the raffinate of nickel sulfate solution. Background technique [0002] Anhydrous sodium sulfate, commonly known as Yuanmingfen, anhydrous Glauber's salt, is one of the bulk products of the inorganic salt industry. Anhydrous sodium sulfate is in the form of white uniform fine particles or powder, and is mainly used as a filler for synthetic detergents, a cooking agent in the paper industry, and a laxative in the pharmaceutical industry; the main production methods of anhydrous sodium sulfate are: vacuum evaporation, calcium Glauber's salt method, conversi...

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Problems solved by technology

Anhydrous sodium sulfate is in the form of white uniform fine particles or powder, and is mainly used as a filler for synthetic detergents, a cooking agent in the paper industry, and a laxative in the pharmaceutical industry; the main production methods of anhydrous sodium sulfate are: vacuum evaporation, calcium Glauber's salt method, conversion method and rayon by-product method, some of these methods have complex process, high cost, difficult to remove some impurities, poor product color, low recovery rate, so looking for a new, simple and low-cost non-toxic Sodium sulfate water preparation method has become the focus of technical development in this field

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