The technology used in silicon calcium (or calcium-silicon) Elemental phosphorus ore, which is an organic substance of a combination of "carbonate flotation" and "silicate flotation" two techniques, i.e. with the "two-step flotation The process "excludes carbonate and silicate impurities in phosphate rock, respectively. According to the nature of the ore processed, it is determined whether to adopt the "positive one", "anti-one" or "double" technology. High- magnesium primary ore like the Haikou Phosphorite Mine in Yunnan adopts “anti-one-positive” flotation; the Guifeifu-through-rock phosphate mine can use “positive-reverse flotation”; the US “high-magnesium-phosphorus mine” uses “double reverse flotation”. The most reasonable. The process characteristics are adaptable to changes in ore properties and can achieve normal temperature flotation.
The use of this technique to select phosphate rock generally yields satisfactory results, concentrate P ₂ O ₅ . The grade can reach more than 30%, the MgO content can be reduced to below 1%, and the P ₂ O ₅ recovery rate is generally above 80%. The use of "double-reverse" flotation technology in the high-magnesium phosphate ore dressing in Florida, USA, has been called by the US as "the best result ever seen in the world."