The open-pit method mining operation in Gosowong has been completed, and currently Gosowong Gold Mine is actively conducting mining activities on its two underground production areas; Kencana, and Toguraci, by combining the mining methods of Cut & Fill, and Stoping.
Kencana Underground Mine
The Kencana underground mine has been operational since June 2005. The mine uses a combination of Overhand and Underhand Cut & Fill underground mining methods. The average material movement achieved by Kencana mine today, is about 1,600 tons per day.
Although it has been in production for more than 15 years, Kencana mine is still actively producing and is one of the backbones of the Gosowong Gold Mine project. More than 260 crew members consisting of UG Operation, Engineering, Plant and Crusher teams work together to process production at this mine. Currently, more than 90% of the management, supervisor and field personnel running Kencana’s day-to-day operation, are men and women of the North Maluku regions.
Toguraci Underground Mine
The Toguraci underground mine started operating in May 2011, using the Underhand Cut & Fill and Long-hole Stoping mining methods. Currently the average amount of total material movement achieved in the Toguraci underground mine, is about 1,500 tons per day.
Toguraci has its unique characteristic not found in underground mines at other locations. That is the existence of geothermal hot springs in the mine, which can reach temperatures up to 80 degrees Celsius. This of course, presents its own challenges for the production activities carried out by the crew of the Toguraci underground mine, which currently numbers more than 290 people.
The strategy carried out to eliminate the impacts of the hot water presence in order for the mining activities can run smoothly and safely, is to use an active dewatering system, which is equipped with 20 bore hole units. In addition, Toguraci has been equipped with a chiller facility that serves to drain cold air to compensate the high temperatures in the production area caused by the flows of hot water.
Ore from the Mines
The mineral ore produced by the underground mines is sent to the Ore Treatment facility that has a processing capacity of up to 800,000 dry metric tons per year. Through the process at this facility, the end-product in the form of Dore Bullion is produced and then shipped to off-site refining facilities to be refined before being marketed to meet the world’s gold needs.
Since taking over PT Nusa Halmahera Minerals (NHM), Indotan is committed to increase the productive age of Gosowong Gold Mine to be much longer. Large amounts of investment have been allocated to finance aggressive exploration programs, as well as revitalization with new equipment for a better mining productivity which is more effective and efficient. The development of short, medium and long-term strategies, has also been structured to manage new reserves that have been successfully discovered.
