Jun 13 2016
Trevali Mining Corporation ("Trevali" or the "Company") (TSX: TV; BVL: TV; OTCQX: TREVF; Frankfurt: 4TI) provides a mine and mill commissioning update for its Caribou Zinc Mine in the Bathurst Mining Camp of northern New Brunswick. A detailed description and discussion is provided below and progress highlights are as follows:
Caribou Mill - key commissioning & preliminary production statistics (figures rounded)
| |
Q1-2016 |
April 2016 |
May 2016 |
June 2016 (MTD**) |
| Tonnes Mined |
191,005 |
58,564 |
57,103 |
10,560 |
| Tonnes Milled |
200,670 |
60,032 |
53,038*** |
13,350 |
| Average Mill Tonnes-per-day* (TPD) |
2,675 |
2,636 |
2,874*** |
2,907 |
| Average Head Grades % |
|
|
|
|
| Zinc |
5.9% |
6.1% |
5.7% |
6.4% |
| Lead |
2.6% |
3.0% |
2.6% |
3.2% |
| Silver - Oz (ounces)/ton |
2.0 oz/t |
2.7 oz/t |
2.3 oz/t |
2.8 oz/t |
| Average Recoveries % |
|
|
|
|
| Zinc |
71% |
74% |
78% |
79% |
| Lead |
58% |
57% |
58% |
55% |
| Silver (in Lead concentrate) |
38% |
32% |
31% |
33% |
| Concentrate Produced DMT (dry metric tonnes): |
|
|
|
|
| Zinc |
17,732 |
5,832 |
5,041 |
1,470 |
| Lead |
7,586 |
2,634 |
1,968 |
583 |
| Concentrate Grades % |
|
|
|
|
| Zinc |
47.8% |
46.4% |
47.2% |
46.2% |
| Silver - Oz (ounces)/ton |
4.0 oz/t |
5.3 oz/t |
5.1 oz/t |
4.8 oz/t |
| Lead |
39.3% |
39.6% |
40.2% |
40.5% |
| Silver - Oz (ounces)/ton |
20.3 oz/t |
19.5 oz/t |
19.9 oz/t |
21.0 oz/t |
* Exclusive of downtime for scheduled mill servicing and maintenance cycle days.
** June MTD as of June 7, 2016.
*** In late-May an electrical storm affected northern New Brunswick including the Caribou site. Unfortunately this resulted in an unplanned mill shut-down following a series of lightning strikes with both the SAG and Ball Mill motors shutting-down following power surges. Prior to re-starting site operations our electrical contractor completed detailed examination of both motors over the following days which resulted in loss of throughput during this period. The mill is currently processing at approximately 2,900 tpd in June month-to-date.
Caribou Zinc Circuit Summary
During May-2016 and June-2016 Month-to-Date ("MTD") the Caribou metallurgical team made very significant improvements on increasing zinc recoveries towards entitlement ranges as outlined in the Caribou PEA report (see Technical Report on Preliminary Economic Assessment for the Caribou Massive Sulphide Zinc-Lead-Silver Project, Bathurst, New Brunswick, Canada prepared by SRK Consulting (Canada) Inc., on the Company's website or on SEDAR).
The Company continues to focus on highlighted areas for metallurgical improvement with modifications to be implemented during ongoing scheduled maintenance periods (please see News Release TV-NR-16-11, May 11, 2016 for details). Modifications completed during May, and which are ongoing include:
- Primary grind: Continues to consistently trend lower year-to-date at increasingly higher throughputs. In January the primary grind averaged 41 µm versus 36 µm in May. Work is ongoing and the mill team is currently optimizing the ball charge (smaller media) in Ball Mill #1.
- Zinc recoveries continue to trend higher as the metallurgical team continues to improve the plant process water quality (essentially manage the calcium content).
- IsaMill redundancy work is complete.
Ongoing scheduled optimization initiatives include:
- Increase in the number of sample stations for the on-stream sample analyzer.
- SAG mill modifications, primarily installation of newly designed lifters and shell liners will commence in June and continue during scheduled shut downs throughout the summer period.
- Cyclone control optimization to further increase circuit stability -- June.
- Pumping infrastructure including capacity and electrical upgrades are in progress. Standby pumps are also being rebuilt. The upgrades are designed to result in improved performance when handling the finely ground process feed.
Caribou Mining
With the zinc circuit essentially de-risked, site is focusing on underground operations. The technical services team continues to de-bottleneck underground operations. Progress during the month includes the successful implementation of a production drill/blast QA/QC program. Site continues to liaise closely with our service provider in this regard and Trevali's Peruvian blasting consultant, who is now on site, to provide additional support. Fleet availability is also anticipated to improve with the arrival of a new underground scoop in early June.
Stope drawpoint extraction rates continue to exceed PEA planned rates, by up to 4 times more productive, through innovative design. Utilization of new planning tools and modeling has provided additional truck capacity at the drawpoint.
The Company remains committed to its plan to ramp mine production to 2,500-2,700 tpd by the end of Q2.
Qualified Person and Quality Control/Quality Assurance
EurGeol Dr. Mark D. Cruise, Trevali's President and CEO, Paul Keller, P.Eng, Trevali's Chief Operating Officer are qualified persons as defined by NI 43-101, have supervised the preparation of the scientific and technical information that forms the basis for this news release. Dr. Cruise is not independent of the Company as he is an officer, director and shareholder. Mr. Keller is not independent of the Company as he is an officer and shareholder.