Silica-calcia low-grade collophanite positive and inverse floatation process

The invention relates to a silica-calcia low-grade collophanite positive and inverse floatation process, which comprises the steps: 1 silica-calcia low-grade collophanite ores are broken up and grinded to enable phosphate minerals and gangue mineral monomers to dissociate, then are added with water to mix size, enter positive and inverse floatation, get rid of impurities in ores, and improve grade of phosphorite. Compared with the prior art, the silica-calcia low-grade collophanite positive and inverse floatation process has the advantages that the content of only one kind of gangue minerals can be reduced by adopting direct floatation and single inverse floatation, can reduce the contents of silicate minerals, carbonate minerals and iron and aluminum silicate minerals, can obtain low magnesium low power half oxide low silicon phosphate concentrate by adopting the silica-calcia low-grade collophanite positive and inverse floatation process, successfully achieves mineral processing enrichment of collophane calcium collophanite, and can improve use rate of phosphorus resource. The silica-calcia low-grade collophanite positive and inverse floatation process overcomes the defects that an existing floatation process can not be applied for mineral processing of silica-calcia collophanite which is high in content of high power half oxides.