The Humboldt County Building Department has granted provisional authority for the Ashdown Mill to begin operations in advance of administrative processing and issuance of the Occupancy Permit. The permit is expected within the next few weeks. The provisional authority granted allows the mill staff, under the direction of Earl Harrison, to ramp up to full-scale testing and trials of the crushing, grinding, and flotation circuits using run-of-mine material. While every component of the mill has previously been run and tested separately, the focus now shifts to the integration of all systems, and the fine-tuning of the equipment. Concentrates will be generated as a product of these trials, which will provide the baseline information necessary to dial-in the chemistry and metallurgy necessary to produce a final product that meets commercial specifications. The final product will be 50% Mo or higher, and individual metal “contaminants” such as copper, lead, and zinc will be suppressed to specified levels.
Initial tests of the preliminary concentrates generated through only the unit cells and rougher cells (and not the cleaner cells) have been assayed and show highly efficient recoveries of molybdenite (see above). The systems have been modeled for simplicity of operation and total flexibility, allowing the slurry, called pulp, to be directed through the mill in one of a combination of routes. This will facilitate quality control once the mill and mine are up to full capacity.
Under the 1000-ton bulk sample permit, the mine has been further developed to allow for removal of mineralized material in the North Zone.
This material (see above) will be stockpiled on the ore pad adjacent to the mill, which currently holds several hundred tons of run-of-mine rock. The fine ore bin is filled, awaiting the start-up of the mill later this week. Underground crews continue to drift parallel to the old decline, heading south toward the South Zone high-grade. The plan is to drift through granitic diorite rock and then reenter the old decline and continue ahead to the mineralized zones. Following water removal from the old workings in the South Zone and once draw points and raises are in place, a steady supply of the 1000-ton sample material will ramp up, with the mill operating at a schedule designed to keep pace with mine output. Concentrates can be dried, bagged and sold during this period, which is the top priority of management. Full and standardized production will continue to be enhanced, requiring additional men, working faces and mine development, which are planned for this fall along with finalization of the Plan of Operations Permit.
The transition from building the mine and mill to operating it on a full-scale commercial basis has been in process for the past four weeks and is anticipated to take several more months. However, production and sale of concentrates can occur on an ever-increasing basis, as the Occupancy Permit is issued and bonding is posted and adjudicated. |
