Century Mine Advances Toward Production
During its 16 years of operation, Century was one of the largest zinc mines in the world, producing and processing an average of 475,000 metric tons per year (mt/y) of zinc concentrate and 50,000 mt/y of lead concentrates at Lawn Hill. The product was transferred in slurry form via a 304-kilometer-(km) underground pipeline to Century’s Port facility at Karumba.
When processing operations ceased at Century in early 2016, New Century Resources spotted an opportunity to monetize the remaining mineral assets. These include more than 2.2 million mt of JORC compliant zinc metal equivalent resources located within tailings, and more than 1 million mt of JORC compliant zinc and lead resources in the Silver King, South Block and East Fault Block base metal deposits. In addition, Century hosts several substantial phosphate deposits which were never developed.
During July, hydraulic mining crews arrived on site and began preparing for mining activities. A slurry winning pontoon and infrastructure were installed in the tailings receival sump. A water winning pontoon was launched onto the evaporation dam. Electrical installation and dry commissioning were nearing completion.
Processing plant refurbishment had been completed and full testing with water had been initiated. All circuits were loaded with reagents. The final tailings pipeline to the historical open-pit were installed and commissioned. All plant employees were onsite and making the transition from day shift only to 24/7 operation.
New Century said it remains on track for first production in August. A set of 2018 concentrate shipping schedules have been established with offtake partners. The company hopes to eventually become one of the world’s top 10 zinc producers.
A comprehensive plan of work is also in place to progressively take the mine site, the pipeline and the port facility to full closure over a long-term period through to 2050. Restarting operations at Century, initially via tailings reprocessing, allows much of the scheduled rehabilitation to be achieved through new cash-flow-generating site activities. After the tailings are reprocessed, the material will be pumped into the existing open pit, which allows for final encapsulation and eliminates the need for capping of the tailings dam on surface.
It also significantly reduces the overall footprint of the disturbance for the Century mining operations, which should allow for a progressive reduction in the total financial assurance surety required for the site.