The invention discloses a method for preparing high-purity
quartz sand through
reverse flotation, which comprises the following steps: S1, ore pretreatment: pretreating raw ore to obtain
quartz sand; the
quartz sand obtained in the first step is placed in a flotation tank, the
mass concentration of ore pulp is adjusted to be 30%-60%, an adjusting agent is added into the ore pulp, the pH value of the ore pulp is adjusted to be 2-4, then an inhibitor is added, stirring is conducted for 3-5 min, a collecting agent continues to be added, stirring is conducted for 10-20 min, finally a
foaming agent is added, air is introduced,
reverse flotation is conducted, stirring, foam scraping and washing are conducted, and quartz sand concentrate is obtained; the inhibitor is
modified starch with the particle size being smaller than 500 nm and the substitution degree being 0.1-1.0, the dosage is 50-250 g / t, and carboxyl and
aldehyde groups are introduced into the
modified starch; quartz sand concentrate obtained after flotation is subjected to secondary acid leaching and high-temperature chlorination to obtain high-purity quartz sand,
modified starch serves as an inhibitor, meanwhile, hydroxyl (-OH) in
starch molecules and the surface of quartz form
hydrogen bonds, the surface of the quartz is covered, adsorption of a collecting agent to the quartz is hindered, and quartz loss is reduced.