Study On Metallogenic Geological Characteristics And Ore Process Mineralogy Of ML553 Gold Deposit In Tanzania

The ML553 gold mine project in Tanzania is a Chinese goverment-owned mining enterprise that actively responds to the “One Belt,One Road” initiative and strengthens international capacity cooperation.In recent years,a medium-sized greenstone belt type gold deposit resource was discovered in an African country through geological exploration with an amount of gold ore of more than 10.8 tons.For the present,the characteristics of “high sulfur-high arsenic” are rare in China,and the relevant investigation of the ore-forming of such geological characteristics is not sufficient.Even there are some studies on the mineralogy of this type of ore;it is difficult to provide some guiding for mining.Through detailed research on the ore-forming geological conditions,geochemical characteristics and ore-controlling factors of the deposit,this paper studies and analyzes the process of mineralogy characteristics of the ore,guides the development of mining planning,and provides basic data support for the selection of ore processing technology.The main achievements in this paper are:1.The ML553 gold deposit is a tectonic-altered rock type gold deposit associated with the Archean greenstone belt.The Nyanzian Group greenstone provided primitive gold elements for mineralization.The strong magmatism of the later orogenic period granite provided rich ore-forming fluids and thermal driving forces for mineralization.The main gold ore bodies,e.g M1-I,M1-II,are strictly controlled by the near-East torsional shear-structured shear zone.2.The primary halo geochemical analysis indicates that there is a significant positive correlation between gold and arsenic in the ML553 mining area.The superposition of the leading edge elements and the near-mineral elements or tail elements in the lower part of the main ore body suggests that there is still a good prospecting potential in the deep part.3.Most of the gold minerals in the ore are natural gold.The metal minerals in the ore are mainly pyrite and arsenopyrite;the non-metallic minerals are mainly iron dolomite,quartz and muscovite(including sericite).4.The distribution of gold minerals can be divided into inclusion gold,intergranular gold and fissure gold.65.51% of gold mineral fine particles are encapsulated in pyrite,arsenopyrite and gangue minerals.5.The dissociation characteristics of sulfide aggregates under different grinding fineness are discussed.It is considered that the gold mine is not suitable for direct cyanidation leaching.It is recommended to use total sulfide flotation-gold concentrate oxidation pretreatment-hydrometallurgy,namely Gold extraction process.