Method for preparing fluoboric acid

Abstract

The invention discloses a method for preparing fluoboric acid. The method comprises the following steps of: pretreating boracic acid, namely adding industrial boric acid into water, heating, dissolving, filtering until the solution is clarified, concentrating the filtrate until solids are separate out, cooling, crystallizing and centrifuging to obtain refined boric acid; dissolving the boric acid in water to prepare a solution, putting the boric acid solution into a plastic container, performing an ice-water bath, slowly introducing hydrogen fluoride into the boric acid solution, and guaranteeing that the reaction temperature does not exceed 40 DEG C in the reaction process so as to obtain the fluoboric acid, wherein the fluoboric acid reacts with the hydrogen fluoride in a theoretical molar ratio. The invention has the advantages that: the hydrogen fluoride is not produced in the whole reaction process, and the fluoboric acid at different concentrations can be prepared according to actual needs, so that the concentration of the fluoboric acid can be up to 50 percent.

Description

technical field [0001] The invention relates to a preparation method of a compound, in particular to a preparation method of fluoboric acid. Background technique [0002] Fluoboric acid is an important raw material for preparing fluoborate, especially for cleaning aluminum and alloys before electroplating, electropolishing pure aluminum, removing flux from low-activity metal substrates, and re-cleaning electroplated parts. It is an important component of electroplating solutions. Components of aluminum and steel phosphate passivation anticorrosion agents, the most suitable lead-dissolving electrolyte for lead storage batteries, enhancing crude oil penetration ability in oilfield exploitation, making diazonium salt stabilizers and raw materials for various fluoroborates, alkylation and polymerization catalyst. The traditional preparation process of fluoroboric acid is to react hydrofluoric acid and boric acid according to the theoretical ratio, but a large amount of heat wil...

AI Technical Summary

Problems solved by technology

The traditional preparation process of fluoboric acid is to react hydrofluoric acid and boric acid according to the theoretical ratio, but a large amount of heat will be generated during the reaction process, so the reaction temperature is not easy to control, and hydrofluoric acid is easy to decompose, which will cause damage to the atmosphere. Contaminated hydrogen fluoride gas is produced, the reaction is incomplete, and the concentration of fluoroboric acid is lower than 30%