Gold occurrence of Jiaojia gold mine in Shandong province
(School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
Abstract: The microscopy and scanning electronic microscopy (SEM) were used to study the gold occurrence of Jiaojia gold mine, Shandong province. The results show that the gold-bearing minerals are composed of pyrite, chalcopyrite, gangue, sphalerite and galena. 77.12% of gold minerals are the sulphides and 22.88% are the gangues. The gold occurrence is composed of 60.28% fissure gold, 21.63% inclusion gold and 18.09% crystal fractured gold. The morphology of gold mineral is composed of sphere, triangle, rectangle, strip and erose. The Jiaojia gold mineral owns large grain size range from 3−5 μm to 100 μm. 1.5% of gold grains is more than 0.104 mm, 5.26% is 0.074−0.104 mm, 23.31% is 0.043−0.074 mm, 3.76% is 0.043−0.037 mm and 64.29% is less than 0.037 mm. The occurrence of gold mineral is composed of native gold, electrum, native silver, iron-bearing native silver, goldcuprid and acanthite. Electrum is the most important mineral, accounting for 71.56%. The average quality is 641.26‰ for gold and silver mineral.
Key words: gold mine; gold occurrence; gold-bearing mineral; gold mineral