Method for producing calcium hydrophosphate and sodium nitrate by decomposing phosphorus ore with nitric acid

Abstract

The invention discloses a method for generating calcium hydrogen phosphate and sodium nitrate through nitric acid decomposing phosphate ore. The technique is that the nitric acid is used for decomposing the phosphate ore, mirabilite is used for removing calcium, and limestone powder and lime milk are used for neutralizing and preparing feed calcium hydrogen phosphate as well as co-producing the sodium nitrate, so the technique comprises 6 production processes: the nitric acid is used for decomposing phosphate ore powder, the sodium nitrate is added to remove fluoride, and the mirabilite is added to obtain dihydrate gypsum through double decomposition; besides, the limestone and lime milk are used for respectively preparing fertilizer grade and feed grade calcium hydrogen phosphate through neutralization precipitation, and then soda is used for removing impurities such as calcium, magnesium, etc., through neutralization and purification, crystal is distilled to prepare the sodium nitrate. The technique method provided by the invention can not only prepare the feed calcium hydrogen phosphate product and the sodium nitrate product, but also have byproducts such as high-quality dihydrate gypsum, the fertilizer grade calcium hydrogen phosphate and sodium fluosilicate; meanwhile, the invention does not consume sulfur resources, discharge little waste and can be treated easily; furthermore, the invention develops a technique line to prepare various chemical products for areas lacking the sulfur resources by using phosphate ore resources, and has good economic and environmental protection benefits.

Description

technical field [0001] The present invention relates to phosphorus oxysalt, also relates to the sodium nitrate prepared by double decomposition of calcium nitrate, specifically, belongs to the method for producing calcium hydrogen phosphate and sodium nitrate by decomposing phosphate rock with nitric acid. Background technique [0002] It is a well-known technology to decompose phosphate rock with nitric acid and produce nitrophosphate fertilizer by freezing method or mixed acid method. Ma Buzhen introduced the production status of nitrophosphate fertilizer in the article "Production Status and Development of Nitrophosphate Fertilizer" ("Henan Chemical Industry" 2001, No. 6, pp. 5-7), and analyzed the process characteristics of freezing method and mixed acid method; Wang Qingcheng et al. "Study on Preparation of Sodium Nitrate by Glauber's Salt Metathesis Method" ("Mineral Resources Utilization" No. 5, 1997, pp. 19-21) introduced the process conditions for preparing sodium n...

AI Technical Summary

Problems solved by technology

Feed calcium hydrogen phosphate is currently mostly produced by wet-process phosphoric acid, but the wet-process phosphoric acid used is basically obtained by treating phosphate rock with sulfuric acid, which needs to consume sulfur resources; for areas lacking sulfur resources, this process may not

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