Abstract: In order to provide a basis for the development and utilization of an oxidized copper mine in Tibet,the mineral composition and content,structure and texture,main mineral dissemination characteristics and dissemination size were systematically studied by means of chemical analysis,scanning electron microscopy (SEM) and mineral automatic quantitative analysis system (MLA). The results indicated that:① the copper content of the ore is 1. 01%,and the copper mainly occurs in malachite,azurite,chrysocolla,chalcopyrite,chalcocite and limonite. The copper content of limonite is high,which is mostly a mixture of limonite and malachite and often contains different amounts of chalcocite residual crystals. ② The structure of the ore mainly includes metasomatic structure,metasomatic residual structure, inclusion structure, interstitial structure and granular structure,which are mainly massive,disseminated,veined,banded and crust-like structures. ③ The copper in the ore mainly exists in the form of copper oxide minerals,in which the free and bound states account for more than 96% of the total copper content,mainly in the form of malachite and azurite. ④ The disseminated particle size of copper oxide minerals in the ore is mainly 0. 64 ~ 0. 02 mm,and that of copper sulfide minerals is mainly 0. 32 ~ 0. 02 mm. ⑤ When the grinding fineness is -0. 074 mm accounting for 61%,the dissociation degree of copper sulfide minerals and copper oxide minerals reaches 93%. Therefore,it is considered that the suitable grinding fineness of ore is -0. 074 mm accounting for 61%. 

Key words: process mineralogy,structure and texture,dissemination characteristics,dissemination size,grinding fineness, dissociation degree