· The changfa method originated from the name of a Chinesemade (changfa) diesel powered rock crusher that is used for crushing excavated auriferous deposits. The unit is mostly fabried and welded or assembled locally in Ghana by Chinese entrepreneurs. The method typically involves excavating ore deposits manually with simple tools such as pickaxes, shovels or spades. .
Obuasi Gold Mine, Ghana. The gold operation at Obuasi, 200km northwest of Accra in Ghana, was the major asset of Ashanti Goldfields Company (AGC), established in London in 1897. Producer of. Gold. Loion. Southcentral Ghana. Reserve base. proven ore proven and probable (201706) Annual production. 243,000oz 391,000oz Au (201405) Expand Share Article. The Obuasi gold mine .