Method for reducing iron and aluminum ions in wet phosphoric acid

Abstract

The invention discloses a method for reducing iron and aluminum ions in wet phosphoric acid. The method comprises the following steps of: oxidizing wet phosphoric acid with hydrogen peroxide; and adding potassium oxalate and sodium carbonate to the oxidized wet phosphoric acid for carrying out chemical reaction treatment so as to partially removing iron and aluminum ions from the wet phosphoric acid. The method has the advantages of stable effect and simple and convenient operation for removing the iron and aluminum ions from the wet phosphoric acid, and a generated precipitate is not needed to be filtered and can be directly used as an additive for producing a compound fertilizer and added to products without influencing the quality of the compound fertilizer; meanwhile, materials used in the precipitate method has low cost, and can be obtained easily, therefore, the method has stronger competitive force and stronger advantages in industrialized production; and the iron and aluminum ions in the wet phosphoric acid purified by the method are better purified, wherein the purifying rate of iron ions can reach 20-70 percent, and the purifying rate of aluminum ions can reach 5-30 percent.

Description

Technical field [0001] The invention relates to a method for reducing iron and aluminum ions in wet-process phosphoric acid. Background technique [0002] Wet-process phosphoric acid is an intermediate product for the production of ammonium phosphate, heavy superphosphate and a variety of phosphate products. It is an indispensable raw material for metallurgy, petroleum, chemical, electronics, medicine, food and other industries. After preliminary treatment, the wet-process phosphoric acid produced by the factory contains more iron, magnesium, aluminum ions and other impurity ions, which affects the subsequent reaction. Therefore, the current research on the purification method of wet-process phosphoric acid has received extensive attention. Industrial purification methods mainly include crystallization, ion exchange, solvent precipitation, organic solvent extraction, concentration purification, electrodialysis, etc. But they all have certain shortcomings, such as: organic solve...

AI Technical Summary

Problems solved by technology

But all have certain shortcoming, for example: the cost of organic solvent extraction method is higher, and process is complicated; In solvent precipitation method, the separation of phosphoric acid and solvent needs to be distilled, and energy consumption is big (except when back-extracting with alkali), and solvent recovery There is a certain loss, and the removal rate of impurities is not high; the amount of resin used in the ion exchange resin method is large, and it needs to be regenerated; the crystallization method cannot obtain high-purity phosphoric acid in one crystallization, and multiple crystallizations must be carried out. Pure mother liquor is separated, so it is necessary to study the utilization of impure mother liquor, etc.