Contents of ores and host state of gold in Quanxing gold deposit in Gansu

The Quanxing gold deposit is a meta-clastic rock type deposit,chemical compositions of the ores are relatively simple,mainly consisting of SiO_2(~73.60%),Al_2O_3(~10.40%).The useful elements of the ores mainly contain gold(averaging 3.45×10~(-6)),and silver,and the harmful elements are lower contents of organic carbon,arsenic and sulphur.The main metal minerals include limonite, hematite and jarosite,and the gangue minerals are dominated by quartz,feldspar,sericite and clay minerals.The ores show idiomorphic or hypidiomorphic granular structure and disseminated texture.Gold in ores usually exists as natural gold with the grain size less than 0.005mm,mainly trapped within gold-host minerals(dominated by limonite and pyrite) and partly distributed in their cracks.