The form of occurrence of the extracted metal is of great importance for the choice of the technological scheme of ore processing. It is important for the technologist to know in what form of mineral formations the metal is found, what is the chemical and physical connection between it and the mineral components of the ore. Direct mineralogical and mineragraphic analysis often proves powerless to solve this problem, especially in cases where the content of the extracted metals is expressed in several grams per ton of processed ore and when the form of occurrence of the elements is unusual. This situation was especially clearly revealed in the study of the form of occurrence of platinum metals in copper-nickel ores. For our ores, this problem was first solved by the Nickel Group of the Leningrad Mining Institute as a result of broadly set studies using methods of chemical and mineragraphic analysis of ore samples and maximally unified and enriched fractions with the studied components, obtained by precision methods of gravitational, electromagnetic and flotation enrichment. Only in this way was it possible to establish the composition, mutual connection of platinum and nickel and copper minerals and to make a correct forecast of the behavior of these minerals during enrichment. For the first time, such platinum minerals as cooperite, braggite, stibio-palladinite and sperrylite were diagnosed in our ores, their chemical characteristics were given and the extremely important fact of fine dispersion of the greater part of palladium in nickel and iron sulfides was established. The results of these works were summarized in a special monograph and laid the foundation for the scheme of technological processes of our copper-nickel industry.
