Process selection for phosphate flotation

Phosphate processing technology depends on the type of phosphate minerals and associated gangue. To meet the requirements of the fertilizer industry, the P2O5 content of phosphate minerals should be enriched to about 30%.

Flotation has been used in industry as the main technology for phosphate purification for more than half a century. More than 60% of the world's industrial phosphate is produced by flotation.

The flotation process not only improves the grade of P2O5, but also reduces the particle size to more than 90% of the content of 100 mesh.

The current technologies used for sedimentary phosphate flotation are generally divided into three categories: (i) direct-reverse flotation; (ii) single reverse flotation and (iii) double reverse flotation. Direct-reverse flotation is more widely used and has been proven to be suitable for most phosphate minerals in my country.

In this process, siliceous minerals are discharged by direct flotation, while calcareous minerals are discharged by reverse flotation.

Phosphate minerals mainly include siliceous phosphate minerals, calcareous phosphate minerals and calcareous-siliceous phosphate minerals. Different types of phosphate ores should be separated by specific flotation processes according to the characteristics of the mineral composition.

Siliceous phosphate ores can be separated by anion direct flotation and cation reverse flotation, while calcium phosphate ores are preferably separated by single anion reverse flotation.

Calcium-siliceous phosphate ores usually use a two-step flotation process, namely direct reverse flotation or double reverse flotation, to remove silica and carbonate gangue minerals in steps.