DECOMPOSITION BY PRESSURE IN INORGANIC ANALYSIS

A suitable apparatus for pressure decomposition of refractory inorganic materials with acids is described. The materials are heated under pressure in a steel autoclave lined with a PTFE crucible in a thermostatted oven fitted so that the autoclaves can be rotated. The decomposition process is hastened not only by pressure but also by continuous agitation. The decomposition of corundum was studied in detail. The proposed decomposition method was successfully applied to the analysis of titanium and tin dioxides, ferrites, boron nitride and several resistant rocks and minerals. Different acid mixtures are recommended for different materials; a pure silicon dioxide solution was easily prepared by pressure dissolution with potassium hydroxide. The methods are very suitable for routine use. © 1969.