The reason why hydrofluoric acid is needed for flotation of quartz sand is that hydrofluoric acid can form fluoride with the oxides on the quartz surface, thus changing the chemical properties of the quartz surface, making it easier to interact with collectors and foaming agents, and improving the flotation efficiency.
Specifically, there is usually a layer of oxides on the surface of quartz sand, such as silica, alumina, etc. These oxides will make the quartz surface have a certain negative charge, thus reducing the flotation efficiency. Hydrofluoric acid can react with these oxides to generate fluoride ions, which make the quartz surface positively charged, making it easier to interact with negatively charged collectors and improving flotation efficiency.
In addition, hydrofluoric acid can also remove iron, aluminum and other impurities on the surface of quartz sand, and improve the purity of flotation quartz sand.
It should be noted that hydrofluoric acid has strong corrosiveness, and safety measures should be taken during operation to avoid harm to personnel and equipment.
