Mineralogical changes during beneficiation of phosphate ore by calcination and washing were studied by factor analysis with oblique rotation, and by using factors of factors (obtained with a factor-factor correlation matrix as input). Several minerals and reactions are indicated, including the possibility of distinguishing between different contributions to the CO2 variance. From the point of view of using the results as a guide for multiregression analysis and building a linear model for the process, the most important results are as follows. The parameters of the product grade (P2O5 and chloride) are influenced by factors measured by x-ray fluorescence (Al2O3, SiO2 SO3 and MgO). Factors measured by thermogravimetry (water of hydration, portlandite and carbonate) have only a small influence. Most of the variance for halite is determined by elements derived from clay, whereas most of the variance for CO2 is correlated with MgO. Magnesium replacing calcium in the francolite indicates the CO2 level and thus the decrease in P2O5 content. The MgO content in the francolite can be used to indicate the maximum P2O5 content in the product.
|Number of pages||9|
|Journal||Analytica Chimica Acta|
|State||Published - 1 Sep 1981|
ASJC Scopus subject areas
- Analytical Chemistry
- Environmental Chemistry