| Company | New Gold Inc. |
| Date | February 28, 2014 |
Executive Summary
The Mesquite Mine is an operating heap leach gold operation located in California. The processing facilities were designed to process 8,800 gallons per minute (gpm) of pregnant gold solution, producing up to 140,000 ounces of gold annually from a combination of 98 million tons of oxide ore grading 0.016 opt and 30 million tons of non-oxide ore. At the time of the site visit, the solution flow rate was approximately 13,000 gpm. The total life-of-mine tonnage will be approximately 128 million tons at an average grade of 0.018 opt gold.
Originally, the ore was crushed; however, since the operation restart in 2007, run-of-mine (ROM) ore is leached. ROM ore with lime added for pH control is trucked to the heap leach pad and stacked to a height of 20 ft, with ultimate pad height increased from 200 ft to 300 ft. Gold recovery uses a carbon-in-columns (CIC) circuit with six-ton carbon columns, followed by pressure AARL desorption, electrowinning, and thermal carbon regeneration.
Operations Profile
- Status: Operating
- Mine Type: Heap Leach (ROM)
- Throughput: 8,800 gpm (designed); 13,000 gpm (actual at site visit)
- Annual Production: Up to 140,000 oz Au
- Total LOM Tonnage: ~128 million tons
- Average Grade: 0.018 opt Au
- Ore Types: Oxide (98M tons @ 0.016 opt), Non-oxide (30M tons)
- Pad Height: 20 ft stacking; 300 ft ultimate
Processing Methods
- Leaching: Heap leach with dilute sodium cyanide, drip emitters
- Carbon Adsorption: Carbon-in-Columns (CIC), six-ton columns
- Desorption: Pressure AARL strip circuit
- Electrowinning: Used for gold recovery from strip solution
- Carbon Regeneration: Thermal reactivation kiln
- Acid Wash: Acetic acid wash (being added for mercury removal)
Reagents
- Sodium cyanide
- Hydrochloric acid
- Lime
- Caustic soda
- Antiscalant
Certifications
- International Cyanide Management Code certified (October 2011)
Reports
Website: https://www.equinoxgold.com/our-mines/mesquite-gold-mine/
Report Date: February 28, 2014
Region: California
Ore type:
