The Bolivian President Evo Morales has invited proposals from firms to help develop a new US$75 million tin and zinc processing plant for the country’s Colquiri tin and zinc mine. The government plans to award the contract on 20 June with an aim to complete construction of the plant within two years.
ITRI understands that the new 2,000 tpd plant will be used to treat tin and zinc ore from the mine while the existing ore dressing plant will be optimised for treating tailings from day-to-day operations and from the tailings ponds, where tin content is estimated at some 0.5% Sn. The existing plant is currently processing some 1,200 tpd of tin and zinc ore, with a maximum capacity of 1,300 tpd. The Ministry of Mining has suggested that the expansion will allow an increase in production to just less than 7,500 tonnes of tin and 40,000 tonnes of zinc each year. For comparison, total production from Colquiri in 2015 totalled 4,229 tonnes of tin and 15,700 tonnes of zinc.
The necessary financing has already been obtained, with the US financial firm Nalex having agreed a US $ 75 million loan for the construction of the plant with the Ministry of Mines and the Colquiri leadership in October 2015. The agreement includes a 3 to 10 year grace period and an interest rate of 2.9%.
Empresa Minera Colquiri made profits of just over US $ 5 million in 2015, despite the fall in tin and zinc prices during the year, compared to a combined total of US$ 43.6 million in the previous three years. US$ 40 million of this has been reinvested into construction of a new underground vehicle access ramp, equipment, ventilation and exploration. Economic mineralisation at the mine is understood to be plentiful, with mine officials stating that unpublished tin reserves complying with JORC standards are capable of sustaining current production levels for a minimum of 16 years.