VANCOUVER, BRITISH COLUMBIA--(Marketwire - March 22, 2013) - American Bonanza Gold Corp. (News - Market indicators)(OTCQX:ABGFF) ("Bonanza" or "Company") is pleased to announce progress at the 100% owned Copperstone gold mine in Arizona during February.
The mine has made significant progress since January, when it experienced the short-term impact of an influenza outbreak, as it continues to ramp up to the design rate of 450 tons of ore per day. February highlights included:
- Ore grade - increase of 42% resulting in an increase of ounces shipped
- Development mining progress - increase of 32% on January's figures
- Gold ounces shipped - up by 68% from January's figures
- C Zone and D Zone - breakthrough area now connected allowing for better material haulage & ventilation
- Senior team hires - New Mine Manager and new Chief Geologist starting in mid-March
| Production Summary (see below for detailed breakdown of figures) |
| |
| Development Mining |
Oct |
Nov |
Dec |
Jan |
Feb |
| Zones |
3 |
5 |
5 |
<4 |
7 |
| Development mined |
153 t/d |
337 t/d |
302 t/d |
146 t/d |
253 t/d |
| Ore Mining |
|
|
|
|
|
| Total rock mined |
291 t/d |
605 t/d |
612 t/d |
463 t/d |
562 t/d |
| Ore mined |
139 t/d |
269 t/d |
310 t/d |
317 t/d |
308 t/d |
| Rounds per day mined |
>2.5 |
5 |
5 |
5 |
4.3 |
| Ore Processing |
|
|
|
|
|
| Ore processed |
360 t/d |
351 t/d |
334 t/d |
322 t/d |
315 t/d |
| Mill recovery |
72% |
72% |
68% |
82% |
86% |
| Concentrates |
|
|
|
|
|
| Gravity concentrate |
42 Oz/t |
25 Oz/t |
48 Oz/t |
15 Oz/ t |
47 Oz/t |
| Flotation concentrate |
17 Oz/t |
13 Oz/t |
69 Oz/t |
23 Oz/t |
30 Oz/t |
| Gold shipped |
902 Oz |
650 Oz |
1,118 Oz |
520 Oz |
878 Oz |
Development Mining
During February, development mining accelerated to 458 feet of development, and extraction of 253 tons per day, representing a 32% increase on January's figures. This is a result of increased available manpower after the short-term influenza outbreak that affected over 50% of the personnel at the mine in January. Development also increased as the mine focus was on catching up development mining that fell behind in January.
Ore Mining
Ore mined in February was down slightly on January's figures due to the focus on catching up on development time lost in January. The mine performance continued at an average of 4.3 rounds of mining progress per day. The mine was able to take longer rounds due to dry conditions and better ventilation.
The mine also focused on dilution control with access to more stopes of better grade material to mine towards the end of the month. This increase in ore grade from 0.059 to 0.101 resulted in an increase in gold shipped of 878 ounces. The mine continues to focus on increasing the number of active headings to 11 to maximize grade control and maintain a steadier feed grade to the mill.
The C and D Zones were connected during February which allows the mine to improve truck haulage and improve ventilation. The breakthrough connected the C and D zones and acted as a loop, which allowed for a significant amount of hard ventilation piping and extra fan usage to be eliminated.
Ore Processing
Mill recovery during February averaged 86% showing that processing rates are continually improving toward the design rate of 90%.
Ore tonnage processed through the plant was slightly down at 315 t/d compared to January's figures of 322 t/d as the team minimized processing low grade stockpile material through the mill, and due to the continued development to build a stockpile of ore for grade management.
Concentrates
878 ounces of gold were shipped during February showing a considerable improvement on January's figures as the mine and processing plant recover from the impact of the manpower shortage in January. Concentrate grades for the gravity circuit averaged 47 ounces of gold per ton, and the flotation concentrate grades averaged 30 ounces of gold per ton. The gravity circuit continues to outperform expectations. A small Knelson concentrator is being set-up to on the tailings line to see if further gold can be collected from tails by gravity methods. The tails Knelson went on-line March 9th.
Senior Team Hires
American Bonanza Gold Corp. is delighted to announce the appointments of Andy Patton as the new Mine Manager of the Copperstone Mine, and Lawrence Buss as the new Chief Geologist:
- Mr. Patton brings a considerable wealth of experience to the project having worked for 23 years in mine administration, strategic planning and production management for organizations including American Barrick, Canadian Salt and De Beers.
- Mr. Buss brings significant geological experience to the project having worked for 32 years in geology, production, evaluation, and exploration for gold mining companies such as Appollo Gold, Goldcorp, and North American. Mr. Buss also brings significant modeling and block interpretation skills to Bonanza.
Mr. Brian Kirwin, President & CEO, commented: "The Copperstone Mine team continues to make good progress towards design rate, and during February, they worked to overcome the issues we faced in January due to manpower shortages. We also welcome Andy Patton and Lawrence Buss to the team and also their contribution in helping to bring the mine up to planned design rate in the near future."
Mine and mill performance for the full month of March will be announced during mid-April.
About American Bonanza Gold Corp.: Bonanza is operating the newly constructed Copperstone gold mine in Arizona. For more information please visit Bonanza's website at www.americanbonanza.com.
This release was reviewed by Douglas Wood, P.G., Vice President, Exploration of Bonanza, a non-independent Qualified Person within the meaning of NI 43-101.
AMERICAN BONANZA GOLD CORP.
Brian Kirwin, President & Chief Executive Officer
We seek safe harbour.
