REDUCTION OF PHOSPHORUS CONTENT OF CERTAIN HIGH PHOSPHORUS MANGANESE ORES OF INDIA BY ROASTING WITH SODIUM CHLORIDE FOLLOWED BY LEACHING IN ACID MEDIUM I: STATISTICAL DESIGN OF ROASTING EXPERIMENTS

摘要

The high phosphorus manganese ores of eastern coastal region of India require drastic chemical treatment to reduce their phosphorus contents because of its very complex nature of occurrence in these ores. The method consists in roasting the ore with 2-6 percent sodium chloride (by weight of ore) at 750 deg- 800 deg C followed by leaching in dilute nitric or hydrochloric acid. Both roasting and leaching operations are important in this process involving a number of variables or factors which influence the phosphorus content in the final product. In such cases statistical analysis of the data provides a better picture of the influence of different variables or the combination of variables. An attempt has been made in this paper to use statistical methods not only to assess the significance of different variables hut also to ascertain the optimum conditions of roasting.