Technology and device for producing defluorinated phosphoric acid

Abstract

A technology for producing defluorinated phosphoric acid is characterized in that fluorine-containing phosphoric acid produced from wet-process phosphoric acid is divided into two parts, one part is used as a returned acid, and the other part is used as crude phosphoric acid; an injection pump A, a reaction kettle, an injection pump B, a gas-liquid separator and an absorption tower are sequentially connected through pipelines to form a circulating closed pipeline system which is in a micro-negative pressure state; the injection pump A and the injection pump B enable a gas in the system to circularly flow at a high speed, and the injection pump A sucks and mixes the returned acid and sulfuric acid, then sucks a reaction liquid and sulfuric acid in the reaction kettle, mixes the reaction liquid and sulfuric acid with gas flow and sprays the obtained mixture onto the liquid level of the reaction kettle; vacuum generated by the injection pump B makes the crude phosphoric acid and low-fluorine hot steam emitted from the reaction kettle be sucked and mixed and then enter the gas-liquid separator, a liquid led out from the gas-liquid separator is refined product defluorinated phosphoric acid, the gas is sent to the bottom of the absorption tower, and a defluorination tail gas led out from the top of the absorption tower enters the injection pump A and circularly flows; and a washing liquid is sprayed from the top of the absorption tower, and fluosilicic acid liquid is led out from the bottom of the absorption tower. The invention further discloses a device for producing defluorinated phosphoric acid.

Description

technical field [0001] The invention belongs to the field of fluorine resource utilization, and in particular relates to a defluorinated phosphoric acid production process and device. Background technique [0002] Fluorine is an element with extremely high reactivity, known as the "urchin in chemistry". However, once fluorine is combined with other elements, it will become a compound with "high safety performance" that is heat-resistant and difficult to be eroded by drugs and solvents. The chemical properties of the compound are stable, and fluorine has strong non-metallic properties. Fluorine only appears in the form of minerals, and the main fluorine-containing minerals in industry are fluorite and fluoroapatite. The chemical formula of fluorite is (CaF2), which has various colors and is widely distributed all over the world. It is the main source of fluorine; the mining of fluorite ore is the largest source of fluorine in the world. Due to long-term mining, the reserves ...

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Problems solved by technology

The utilization rate of fluorine in the above-mentioned current process is only 0.4%, and about 2% of the fluorine resource enters phosphoric acid and phosphogypsum

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