Process mineralogy characteristics of a very fine disseminated refractory gold deposit

Abstract

The grade, recovery rate, or leaching rate of gold concentrate obtained by the flotation process or cyanide leaching process of gold ore is low, which is typical refractory gold ore. In order to fully understand the properties of the gold ore and optimize the gold recovery process and indicators, the process mineralogy of the ore was systematically studied by means of chemical multi-element analysis, optical microscope, scanning electron microscope (SEM), X-ray energy spectrometer, automatic mineral parameter analysis system (BPMA), and other test methods. The results show that the average grade of valuable element gold in the ore is 2.98g/t, and the contents of harmful elements mercury and carbon are 0.50% and 0.32% respectively; The main gold ore is natural gold, with a small amount of silver gold and tellurium gold; The main metal minerals are pyrite, pyrrhotite, magnetite, hematite, etc; The main gangue minerals include quartz, feldspar, kaolinite, mica, calcite, etc. Under the condition that the grinding fineness is -0.074mm, accounting for 90%, the distribution rates of single gold and bare gold in the ore are 3.15% and 57.66% respectively, and the distribution rates of gold with pyrite and quartz crystals are 5.77%, and the total distribution rates of the three are 66.58%, that is, the maximum theoretical flotation recovery rate of gold under the grinding fineness, but the particle size and fineness of gold minerals are both 5 μ Below m, the particle size of some gold ores is less than 0.5 μ m. It exists in the form of fine particles, micro gold, or ultra-micro gold, and it is difficult to recover gold by the flotation process, so it is recommended to adopt the whole slime cyanidation leaching process.