Blackwater PEA Describes Major Mine for New Gold

A preliminary economic assessment of New Gold’s Blackwater gold project, shown here in aerial view, forecasts a
$1.8-billion expenditure for development of a 500,000+ oz/y open-pit mine and mill. (Photo courtesy of New Gold Inc.)
New Gold Inc. has received a preliminary economic assessment (PEA) from AMEC Americas for its Blackwater gold project, located 160 km southwest of Prince George, British Columbia, and 450 km north of the company’s New Afton mine (E&MJ, September 2012, p. 52). The PEA considers a 60,000-mt/d, open-pit mining operation that would produce an average of 507,000 oz/y of gold and 2,039,000 oz/y of silver over an initial mine life of 15 years. Production is targeted to start in 2017. Development capital costs are esti-mated at $1.8 billion, including a $346 million contingency.

The Blackwater mineral resource esti-mate is based on a block model estimate that incorporates more than 147,282 indi-vidual assays from 168,709 m of diamond drill core in 449 drill holes. Average drill-hole spacing of approximately 50 m is suf-ficient to support mineral resource estima-tion up to the indicated category.

Mining operations will be carried out with an initial equipment fleet of two 311-mm electric blast-hole drills, two 56-m3 electric cable shovels, one 18-m 3front-end loader, and 16 290-mt trucks. A 10-m bench height was selected for mining.

The 60,000-mt/d processing plant will utilize conventional crushing, grinding, leaching, and carbon-in-pulp (CIP) to produce a gold-silver doré. A gravity circuit consisting of centrifugal concentrators will treat a portion of the primary cyclone underflow to recover coarse metallic gold. The gravity concentrate will be directed to an intensive cyanidation reactor for extrac-tion of gold and silver. Ground material will be directed to a leach feed thickener, then to a leaching and CIP extraction circuit.

Extracted gold and silver will be released from carbon in the stripping columns and recovered by electrowinning before being smelted into a gold-silver doré product. Stripped carbon will be treated in a regeneration kiln.

The Blackwater project is located approximately 112 km southwest of Vanderhoof, British Columbia, and is close to existing infrastructure. Access to low-cost hydroelectric power is available and will require the construction of a 133-km transmission line.

Based on the success of its 2012 sum-mer exploration campaign, New Gold increased its 2012 Blackwater exploration drilling target to more than 250,000 m from the previous target of 210,000 m. Since the mid-May PEA mineral resource cut-off, the company has drilled an addi-tional 100,363 m in 377 holes. As of late September, there were 13 drills active at the Blackwater site.

“The completion of the Blackwater PEA and upcoming filing of our project descrip-tion will allow us to formally begin the per-mitting process for Blackwater,” New Gold President and CEO Robert Gallagher said. “With the benefit of our permitting and development track record and strong stake-holder relationships at New Afton and in the Blackwater area, we look forward to advancing Blackwater with similar success.”

As featured in Womp 2012 Vol 10 -