|
|
Article: Beneficiation of apatite rock phosphates by calcination: effects on chemical properties and fertiliser effectiveness.
- Article from:
- Australian Journal of Soil Research
- Article date:
- March 1, 2001
- Author:
CopyrightCOPYRIGHT 2001 CSIRO Publishing. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
Introduction
Most rock phosphates (RPs) are apatite-bearing rocks that contain enough phosphorus (P) to be utilised for the manufacture of fertilisers, elemental P, and/or phosphoric acid (Gary et al. 1974). Some RPs are calcined during beneficiation to remove impurities, to increase P concentration, or to make Fe- and Al-phosphate impurities more available to plants (Milnes 1976). These RPs may also be used as direct application fertilisers but the effect of calcination on the agronomic effectiveness is likely to be adverse (Khasawneh et al. 1980). However, this effect is not well defined for the various RPs.
The effect of calcination on the properties ...