System for increasing yield of wet-process fluorine phosphate

Abstract

The invention discloses a system for increasing the yield of wet-process fluorine phosphate. The system comprises a stirring barrel, concentrated phosphoric acid and a defluorinating agent enter the stirring barrel through a pipeline reactor to be uniformly mixed, and a discharge port of the stirring barrel is communicated with a second-section concentrated phosphoric acid inlet of a sieve plate defluorinating tower; air passes through an air heater and then is communicated with a hot air inlet in the lower portion of the sieve plate defluorination tower, saturated steam is communicated with a steam inlet in the lower portion of the sieve plate defluorination tower, a fluorine tail gas outlet in the upper side of the sieve plate defluorination tower is communicated with an entrainment separator, and the entrainment separator is communicated with a fluorine absorption washing tower. A wet-process phosphoric acid outlet in the lower part of the sieve plate defluorination tower is communicated with a finished product acid storage tank; according to the system disclosed by the invention, the yield of fluorine in the existing process for producing ammonium phosphate by wet-process phosphoric acid can be increased by 20% or above, the amount of P2O5 fluosilicic acid per ton is 60kg or above, the fluorine content of the product ammonium phosphate is remarkably reduced, and the system has obvious economic benefits, resource benefits and environmental benefits.

Description

technical field [0001] The invention relates to the technical field of wet-process phosphoric acid production, in particular to a system capable of increasing the fluorine yield of wet-process phosphoric acid. Background technique [0002] After more than 60 years of development, China's phosphorus chemical industry has gone through a development path from imported products to export products, realized the historical leap from a major importer to a major manufacturer, and became a major producer of phosphate fertilizers in the world. As of the end of 2019, my country's phosphate fertilizer total Production capacity is P 2 o 5 22.4 million tons, with an output of 16.102 million tons, an achievement that has attracted worldwide attention. There are many types of phosphate fertilizers, and ammonium phosphate is the main product. In 2019, the output of ammonium phosphate was 13.593 million tons, accounting for 84.4% of the total phosphate fertilizer output. Ammonium phosphate ...

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Problems solved by technology

But feed phosphoric acid defluorination technology has relevant reports, CN104176719 A has reported a kind of tower-type air-lifting feed phosphoric acid defluorination method, feed-grade low-fluorine phosphoric acid is heated to 90~105 ℃ and introduced into defluorination empty tower from the upper part, and the bottom of the tower is passed Inject air to complete defluorination. This technology has low defluorination efficiency. It is used for low-fluorine phosphoric acid, and it is an empty tower with short residence time. The defluorination efficiency is increased by circulation, and the cost is high; CN112174104 A reports a kind of wet-process phosphoric acid. High-temperature stripping defluorination method and device, after mixing the defluorination agent and de-weighted and clarified concentrated phosphoric acid evenly, heating to 70~90°C, and then keeping the phosphoric acid in the liquid storage tank at the lower part of the defluorination tower passing through the coil tube or tubular defluorination tower. boiling state

This patent suffers from high energy consumption, serious corrosion of coiled tubes or tubular tubes under high temperature conditions, short residence time of phosphoric acid, and low defluorination efficiency

CN110467167 A discloses a wet phosphoric acid defluorination method coupled with precipitation pre-defluorination and stripping defluorination. The phosphoric acid after precipitation defluorination passes through multi-stage defluorination towers, and the air temperature is 20-30°C. Low, after entering the defluorination tower, the temperature of phosphoric acid will become lower, which is not conducive to the removal of fluorine, and the defluorination process is long and the cost is high

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