History of WPCR
The White Pine Copper Refinery (WPCR) was constructed in 1982 at a cost of $82 million and was part of a former fully integrated copper producing operation that included a mine, mill, smelter, refinery and power plant. The mine, mill and smelter closed in 1995 after 40 years of operation. The refinery continued in operation as a toll facility until purchased by Hudson Bay Mining and Smelting (HBM&S), Ltd in January, 2006. Refinery operations were curtailed in August of 2010 due to HBM&S closing its copper smelter in Canada. The Refinery was purchased by Traxys Power Group in June of 2011. PM Power Group (PMPG) purchased the refinery in August of 2014 from Traxys. A preliminary study was completed in 2010 to convert the refinery from electro-refining to electro-winning.
Original design capacity of the refinery was 60,000 short tons of copper cathode per year. Through technology improvements and expansion, rated capacity was increased to 80,000 short tons per year.
The refinery was ISO certified for Quality 9001, Environmental 14001, and OHSAS Heath Safety Management 18001.
WPCR previously utilized 9 electrowinning cells (liberators) which are used to maintain copper tenor in tankhouse electrolyte and provide de-copperized solution for nickel plant operations. Liberators were located in the west end of the tankhouse cell area adjoining commercial half section A1. Cleaned anode scrap is used as a cathode which was shipped back to Flin Flon for re-melting into anodes. Insoluble lead anodes provides current transfer. Due to the irregular dimensions of anode scrap, current efficiency in liberators is quite low ranging from 60% to 70%. Annual plated production from liberator cells is 2,500,000 lbs, none of which could be sold due to quality issues. Shipping of non-saleable copper back to Flin Flon copper smelter not only increased transportation costs but also increased operating inventory load.
Due to the installation of 720 EMEW electro-winning cells to control copper tenor in electrolyte and provide de-copperized electrolyte for nickel plant operation, the existing liberator cells were removed and the capacity to add 10 additional commercial cells was completed, allowing an additional 5,500,000 lbs. of copper cathode annually. Saleable cathode from the new EMEW process is 3,000,000 lbs. as well.
EMEW process was developed by Electrometals Technology Limited in Ashmore, Australia. Electrometals is an Australian publicly traded company.
Bench scale testing was conducted at White Pine during 2006, using electrolyte from different tankhouse streams. Results of bench testing indicated that most of the cathode analysis did meet B-115 specifications and warranted proceeding with a two-cell pilot plant testing program. Original pilot testing started in October 2006 and continued for 6 months with White Pine personnel operating the plant. Pilot plant testing was required to determine sizing of the EMEW plant and to establish that cathode quality specifications could be met on a full scale. After operating the pilot plant for 6 months, it was determined that the full-scale plant size would have to be increased by 25% to maintain proper copper tenor in tankhouse electrolyte. Results of the pilot plant testing were quite good, with most of the product meeting B-115 specifications.
During pilot plant testing, WPCR personnel visited a 270 cell EMEW plant in operation at a Phelps Dodge plant in El Paso, Texas. Copper was being plated from a pickling bleed stream from the rod plant line. Cathode produced was then re-melted into rod. Previously this bleed stream was disposed of without recovering the copper metal.
The EMEW plant was installed between 2007 and 2008 with a total installed cost of $5,846,697. The EMEW plant ran to its design capacity for 2 years and within that time period paid for itself multiple times over. WPCR was eventually shut down in 2010 due to shutting down of the smelter in Manitoba due to environmental concerns.
Description of Proposed Operations
The EMEW facility at WPCR remains intact and capable of producing 3,000,000 lbs. of copper cathode from an appropriate raw material source. Lab testing has proven that there are multiple potential raw material supplies that are worth performing pilot testing again to prove economics of production from a standalone EMEW facility.
Constant improvements in copper demand, as well as increased regulation regarding environmental controls of landfilled materials, have created multiple options for raw materials for copper cathode production in the EMEW plant.