Production process of semiwater-diaquo phosphoric acid

Abstract

Of the production process of semiwater-diaquo phosphoric acid, the technological keys include the calcium separating rate in the first reaction tank in the semiwater reaction part being controlled in50-60 %; the two-place addition of sulfuric acid in the semiwater reaction part including the partial addition to acid mixer for mixing with phosphoric acid and other partial addition to dilute phosphoric acid tank for controlling the concentration of sulfate radical in 8-10 %; pumping partial dilute phosphoric acid added with sulfuric acid into the first reaction tank while the other part being fed to acid mixer and the second reaction tank; and one increased vacuum flash distilling slurry cooler in the diaquo reaction part. The present invention has wide phosphate are adaptability.

Description

technical field [0001] The invention relates to a production method of wet-process phosphoric acid, in particular to a production method of hemihydrate-dihydrate phosphoric acid. Background technique [0002] In the 1970s, the development and research of hemihydrate-dihydrate recrystallization high-concentration wet-process phosphoric acid technology was carried out in the world, and there were many technological processes formed, but only the British company Fressons was finally industrialized. SK. Hetero (Norsk-Hydro) process and Japan's Nissan company improved C method process. It is worth noting that the phosphate rock mainly used in the production of Norsk Hetero process technology is Moroccan phosphate rock; the phosphate rock mainly used in the production of Nissan's improved C method is Florida phosphate rock in the United States. (1. Wu Peizhi "Wet Process Phosphoric Acid", Chemical Industry Press, 1987, Chapter 12, P246-291; 2. The Construc...

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Problems solved by technology

Although Yunnan Red Phosphorus Chemical Co., Ltd. used the Jiangchuan Phosphate Mine in Yunnan Province to conduct a small-scale evaluation test before introducing the patented technology of Nuoske Hetero, and carried out an annual production of 60,000 tons of P according to the results of the small-scale evaluation test. 2 o 5 The design of the device, but in the actual production, due to the purchase of raw material phosphate rock in many places in Yunnan, the quality of phosphate rock has changed to a certain extent, so that the production process of Norsk Hetero's hemihydrate-dihydrate phosphoric acid imported from abroad and The process conditions are not suitable for the production of phosphate rock in Yunnan, China, and the production capacity of the equipment is greatly limited. Enterprises urgently need to research and develop more reasonable production methods

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