Name and Location
Rainy River gold/silver project, Ontario, Canada.

Client
New Gold Inc.

Project Description
The Rainy River gold deposit contains measured and indicated mineral resources suitable for direct processing, from mine to mill, of 106-million tonnes at 1.54 g/t gold and 2.88 g/t silver, representing 5.2-million ounces of gold and 9.8-million ounces of silver. In addition, the openpit measured and indicated mineral resources suitable for stockpiling and future processing, totalling 71-million tonnes at 0.43 g/t gold and 2.09 g/t silver, representing one-million ounces of gold and 4.8-million ounces of silver.

A feasibility study has chosen openpit mining as the primary method to mine the Rainy River deposit, owing to the proximity of mineralisation to the surface. Deeper, higher-grade portions of the deposit will be mined from underground. The openpit mining production schedule incorporates an elevated cutoff grade strategy during the first nine years of mining to increase the mill feed grade. Material below the elevated cutoff grade will be stockpiled for processing during the later years of the project life.

In addition, the start of production from the openpit will signify the development of the underground mine, with initial production from underground expected in 2018. The targeted mill throughput of 21 000 t/d will initially be sourced exclusively from the openpit and, once in full production, the underground mine will contribute 1 500 t/d of ore, with the balance of the 19 500 t/d coming from the openpit.

At full capacity, openpit mining operations will be undertaken with an equipment fleet comprising three 216 mm blast-hole drills, one 29 m³ and two 26 m³ hydraulic shovels, one 18 m3 wheel loader and twenty-two 220 t haul trucks. A 10 m bench height has been selected for mining.

The openpit mine will provide process plant feed, starting at a nominal rate of 21 000 t/d, or 7.7-million tonnes a year, declining to 19 500 t/d, or 7.1-million tonnes a year, once the underground mine reaches its full production.

Total mining of ore, waste and overburden will peak at 69-million tonnes a year. The operational stripping ratio, excluding waste and overburden stripping during the development phase, is 3.5:1.0.

The underground mine will be accessed through a 4 km decline from a surface portal located to the east of the openpit. The underground design supports the ultimate extraction of 1 500 t/d of ore by longitudinal longhole open stoping. The underground mineralisation occurs in subvertical horizons varying in width from about 3 m to 20 m, with the weighted average width across the various zones being about 8 m. The various areas of underground mineralisation provide for flexibility in the production schedule to recover higher-grade material earlier in the mine life. Longitudinal longhole open stoping in each zone will proceed in a retreating pattern from the strike extent of ore to a common access point on all levels. Mining is scheduled to proceed upwards from the lowest level of the zone, or from an adopted sill elevation, with backfill providing the working platform for each successive lift. On average, stopes 8 m wide, 20 m long and 20 m high have been used for mine planning. At full capacity, ore handling from underground workings to surface will be accomplished through a fleet of four 7 m³ loaders and six 45 t haul trucks.

The 21 000 t/d process plant will use conventional crushing, grinding, leaching, carbon-in-pulp (CIP) and gold recovery technology to produce gold/silver doré. The overall design uses a simple and conventional flowsheet.
Run-of-mine material will be crushed to 165 mm in the gyratory crusher and subsequently conveyed and ground in the semiautogenous (SAG) mill in closed circuit with a scalping screen and a pebble crusher. Undersize from the scalping screen will be combined with the ball mill discharge and pumped to a cyclone cluster. The underflow from the cyclone cluster will feed the ball mill. A portion of the ball mill discharge will be treated by a gravity circuit. The cyclone overflow will be thickened in a preleach thickener and pumped to the cyanide leaching circuit, which is designed for about 30 hours of retention time. The discharge from the leach circuit will flow gravitationally to a CIP circuit where the leached gold will be adsorbed onto carbon. Loaded carbon will be sent to the carbon stripping circuit where the gold and silver will be recovered as sludge in electrowinning cells and then filtered, dried and smelted into doré bars.

The tailings from the CIP circuit will be sent to the cyanide destruction circuit and then discharged into the tailings storage facility.

Key process equipment will consist of:
• a 1 371 x 1 950 mm gyratory crusher;
• a SAG/ball mill/crusher grinding circuit, comprising
• one 11 x 6.1-m-diameter 15 MW SAG mill,
• one 7.9 x 12.3-m-diameter 15 MW ball mill,
• one 448 kW pebble crusher, and
• one 45-m-diameter preleach thickener;
• Whole ore leaching and CIP circuit comprising:
• eight 18-m-diameter leach tanks,
• seven 360-m³-capacity CIP tanks, and
• one 45-m-diameter predetox thickener.

Value
The total estimated development capital cost for the project is $885-million, inclusive of a $70-million contingency.

Duration
Commissioning is targeted for late 2016, with the first year of full production expected in 2017.

Latest Developments
The environmental assessment report has been finalised.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
New Gold media and communications, Julie Taylor, tel +1 416 324 6015, fax +1 416 324-9494 or
email julie.taylor@newgold.com.