Rock Phosphate

Brief Overview

Rock phosphate, or phosphorite, is a solid substance that has a high phosphorous content. Some phosphate rocks are used to make calcium phosphate nutritional supplements for animals. However, the role of phosphate rock in the production of phosphate fertilizers for agriculture is highly vital.  A large percentage of the common fertilizers have an “N-P-K” rating.  The P stands for the phosphorous component in fertilizers. Phosphorus is required to help plants capture the sun’s energy and begin the photosynthesis process.

Rock phosphate may occur as high-grade ore (> 30% P₂O₅), medium-grade ore (20%–30% P₂O₅), and low-grade ore (15%–20% P₂O₅). The very high-grade ore blends with medium-grade ore for direct sale. The high-grade ore is mined, crushed, and sold to various fertilizer plants. The low-grade ore is beneficiated by reverse/inverse flotation techniques.

Manufacturing Process

Phosphate ore is mined and converted into rock phosphate. The conversion of phosphate ore is a process which includes washing, flotation and calcining. Froth flotation is used to concentrate the mined ore to rock phosphate. The mined ore is crushed and washed, creating a slurry, this ore slurry is then treated with fatty acids to cause calcium phosphate to become hydrophobic.

Applications of Rock Phosphate:

• It is known to be the primary raw material for phosphate fertilizers
• It is used to manufacture phosphoric acid
• It is used as an ingredient in animal-feed supplements
• It is used as a food additive ingredient
• It is used in the manufacture of cosmetics, pharmaceuticals and detergents
• It serves as an anti-corrosion agent
• It can be incorporated in ceramics
• It can be used in the production of insecticides and fungicides
• It can aid in water treatment and metallurgy