Canadian mining company, Mercator Minerals declared that it has updated the production guidance for its Mineral Park mine located in Arizona.
The mine is anticipated to generate 89 million copper equivalent pounds through 2012. This value is in line with the previous production guidance released by Mercator Minerals in January 2012, which projected a production of 90 to 100 million copper equivalent pounds.
In the Q1 of 2012, harder ore had decreased mill throughput rates, which in turn resulted in reduced copper production. According to Mercator Minerals, this effect of harder ore on mill throughput rates has now been addressed. The revised production guidance is based on 50,000 tpd throughput levels with up to 40% hard ore blend of total mill feed. Based on the timing of operation with different hard ore ratios in the mill feed, this threshold has been established.
At the transition zone, a reduced percentage of supergene copper mineralization of higher grade was encountered, resulting in low grade copper from this material. Molybdenum grades remained unaffected.
Under the 2012 mine plan, about 20% of the material to be processed included transition zone ores. Mercator Minerals believes that by mining the transition zone, copper tonnage and grade contact will link with the block model, as the copper grades in hypogene mineralization located inside and beneath the transition zone is less inconsistent. On the whole, the transition zone denotes a minor percentage of the life-of-mine mineral reserves and the total mineral resource for the Mineral Park mine.
At present, Mercator Minerals is assessing how mining will impact other regions of the deposit that feature a section of comparable transitional material.