A combined treatment method for sodium fluorosilicate production and magnesium removal from phosphate rock

Abstract

The invention relates to the technical field of phosphorite quality improvement, particularly a sodium fluosilicate production-phosphorite demagging combined treatment method. Sodium sulfate and wastewater generated in the wet-process phosphoric acid sodium fluosilicate coproduction process are utilized and returned to the phosphorite demagging treatment technique so as to utilize the residual sulfuric acid and fluosilicic acid and remove the magnesium element in the phosphorite, thereby enhancing the phosphorite grade. In the treatment process, since the content of sulfuric acid in the wastewater in the fluosilicic acid coproduction process is lower and the fluosilicic acid content is lower, the raw materials added into the reaction kettle for phosphorite treatment have low corrosiveness to the equipment, thereby lowering the cost for the phosphorite grade enhancement treatment. The sulfur element and fluorine element in the sodium fluosilicate sewage can not be abundantly discharged into the environment, thereby providing a new way for sodium fluosilicate sewage treatment, relieving the sodium fluosilicate wastewater treatment load and lowering the environmental pollution.

Description

technical field [0001] The invention relates to the technical field of phosphate rock quality improvement, in particular to a combined treatment method for producing sodium fluorosilicate and demagnesizing phosphate rock. Background technique [0002] At present, my country's phosphate rock resources are in the status quo of "more but not rich, more in the south and less in the north, difficult to choose and distinguish", and have been listed by the Ministry of Land and Resources as one of the 20 kinds of mineral resources that cannot meet the needs of national production. With the increase of phosphorus chemical industry's demand for phosphate rock resources and the continuous consumption of rich ore, how to rationally and effectively utilize low- and medium-grade phosphate rock, especially the rational utilization of high-magnesium phosphate rock has become a difficult problem for my country's phosphorus chemical industry at this stage. [0003] The utilization of phosphate...

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Problems solved by technology

[0006] However, the above technology needs to use sulfurous acid, sulfuric acid and fluosilicic acid for proportioning, and the concentration of sulfurous acid is ≥ 5%, the concentration of sulfuric acid is 1-20%, and the concentration of fluosilicic acid is ≥ 7%. The obtained mixed acid is highly corrosive, and the loss of phosphorus pentoxide in phosphate rock is large, and the requirements for the equipment for magnesium removal treatment of phosphate rock are relatively high, and the energy consumption and cost are relatively high during the treatment process.

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