Abstract
The accurate determination of the opaque minerals present in an ore is very often of prime importance to the mill-man if he would work out the problem of separation intelligently. It is sufficiently obvious that a chemical analysis or an assay will only give him data as to the elements present and will leave him more or less in the dark as to the minerals represented in the ore. Since it has been found that certain sulfides are more amenable to flotation methods than others, the value of accurate mineralogical determination of the ores would appear to be particularly necessary in this form of milling. However, it should also be quite evident that any milling problem would be benefited at its inception by a careful study of the mineral content of the ore, the approximate quantitative proportions of the minerals present, and their mutual inter-relationships.
