Fluorine-free extraction method of insoluble potassium ore

The invention provides a fluoride-free extraction method of insoluble potassium ore, and relates to the technical field of ore extraction. The method comprises a potassium feldspar ore crushing process, an ore grinding process, a magnetic separation process and a flotation process. According to the method, the potassium feldspar is floated through a collecting agent composed of sodium hexametaphosphate, sodium oleate and lauryl amine under the fluoride-free weak acid condition through sulfuric acid, the surface hydrophobicity of the potassium feldspar is improved, the potassium feldspar floats upwards and is separated out, the acidity is weak, and the corrosivity and cost of sulfuric acid are lower than those of hydrofluoric acid, so that according to the extraction method provided by the invention, the corrosion to equipment and the influence on human bodies and the environment can be reduced, the production cost is reduced, meanwhile, the high-quality potassium feldspar concentrate, the mica concentrate and