Pyrrhotite of gold-bearing ores: composition, point defects, magnetic properties, gold distribution

On a basis of comprehensive analysis of the crystal structure, chemical and phase composition pyrrhotites from ores and near-ore rocks, an analytical expression for calculating the concentration of defects in crystals and to assess the stoichiometry of the minerals was received. The calculation of the concentration of point defects in the crystal structure pyrrhotites from ores of different degrees gold-bearing, from host rocks with different chemical composition and estimation the relationship between gold content in pyrrhotite-bearing ore, near-ore slates and chemical composition, stoichiometry of the mineral, concentration in it of defects and vacancies was spent. Concentration of point defects was calculated separately for trace elements (Co, Ni, Cu, Zn, etc.) forming defects of inclusion (introduction) and cationic vacancies in the crystal structure. As a result, mathematical modeling based on the parameters of the X-ray spectra, chemical composition, the dependence of the concentration of point defects and their ordering in the crystal structure of the content of gold in ores and near-ore rocks was established. The maximum gold content in ore is reflected in the chemical composition and structural parameters of stoichiometric pyrrhotite and namely in these pyrrhotite of vacancy are completely ordered in even (odd) basic planes of crystal structure. The chemical formula to represent the composition of nonstoichiometric minerals contained in the crystal structure of atoms, different from atoms of mineral-matrix was offered. It is established that the maximum magnetic induction of pyrrhotite and gold concentrations in pyrrhotite-bearing ores have a slight shift relative to each other. The variant of interpretation of position pyrrhotite-bearing gold bodies in magnetic fi elds was offered.