Used as analytical reagents, pesticides, and resin finishing catalysts in textile printing and dyeing industry. As a gas flux to provide an inert atmosphere. Used as a flux for aluminum or copper welding, as a catalyst in the manufacture of sand resin adhesives for magnesium and magnesium alloys and other easily oxidized metal casting and precision casting. It should be stored in a cool, ventilated and dry warehouse. The packaging should be kept tightly closed to prevent damage to the packaging. Protect from rain and sunlight during transportation. Can be used as flame retardant and chemical reagents. It is obtained by fluorination of boric acid with 40% HF and neutralization with ammonia.
Methanesulfonyl chloride plant introduced the fluoroboric acid ammonia gas neutralization method. Hydrofluoric acid and boric acid were fluorinated in a fluorination kettle at 60°C for more than 2 hours to prepare a fluoroboric acid solution, which was sent to the ammoniation kettle to pass ammonia for neutralization , Use a flow meter to control the ventilation. A large amount of heat is released during the reaction, and an ice bath is set outside the kettle for cooling. Frequently measure the ammoniation temperature and adjust the ventilation rate. When the pH reaches 3 to 4, stop the ammonia flow. After cooling down, the product that has crystallized out is separated, the remaining liquid is evaporated and concentrated, cooled and crystallized, centrifuged, and dried below 80°C to obtain a finished product of ammonia fluoroborate.
BHF4+NH3→NH4BF4
What role does fluoboric acid play in the electroplating industry
It is mainly used in tin plating or tin-lead plating system. It is a complex compound. The free fluoroboric acid in the plating solution has little effect on the composition of the plating. Its function is to ensure the normal dissolution of tin and lead in the anode. It can inhibit the hydrolysis of divalent tin and improve the stability of the plating solution. Sn(BF4)2+H2O=Sn(OH)BF4↓+HBF4
It can be seen from the equation that free fluoroboric acid can prevent the hydrolysis reaction of divalent tin. At the same time, its existence improves the conductivity of the solution, which is beneficial to improve the dispersion ability of the plating solution. However, excessive fluoroboric acid will accelerate the dissolution of the anode, causing the concentration of the main salt to rise, and on the contrary reduce the dispersion ability of the plating solution, and even stepped plating. Therefore, the concentration should be controlled within the range.