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f_ <br /> Modifications to the approved Mine Plan <br /> Modification to Mill Circuit <br /> CC&V is proposing the installation of a new conveyor belt below the high pH filter press conveyor belt <br /> within the HGM and a semi-enclosed concentrate storage building. The concentrate storage building is <br /> designed to store approximately 3,000 cubic yards of concentrate and includes a truck load out facility. <br /> The concentrate stockpile building will be located immediately adjacent to the HGM with concentrate <br /> removed in a batch process at a rate of approximately 3,000 tons per month(approximately one quarter of <br /> full production). <br /> During concentrate production, the entire leach circuit will be isolated and whilst the circuit will continue <br /> to circulate material no new material will be added. The existing regrind cyclone feed pump will be used <br /> to bypass the regrind cyclone, and fine grinding circuit and to pump flotation concentrate to the existing <br /> regrind discharge pump box. From the regrind discharge pump box, concentrate will be pumped in to the <br /> existing concentrate thickener using the existing regrind discharge pump. The leach circuit would then be <br /> bypassed by pumping concentrate directly from the concentrate thickener to the high pH filter feed tank <br /> using the existing concentrate thickener underflow pumps. The existing high pH filter presses will be used <br /> to dry the concentrate. Process flow diagrams detail the changes to the process have been included with <br /> the engineering design drawings within Attachment 1. <br /> The changes proposed will also allow the existing high pH filter press conveyor to be made reversible. <br /> The high pH filter press conveyor belt will run in the opposite direction thus depositing the concentrate <br /> onto a new conveyor which will move the concentrate out of the HGM into the new concentrate stockpile <br /> building, thus replenishing the stockpile. The flotation tailings will transfer on to the filtration collection <br /> feed conveyor belt system, whereby the material will be transferred out of the building for mixing with <br /> leach ore as per current practices. <br /> Once the stockpile reaches capacity the high pH filter press conveyor will be switched back to the normal <br /> direction, the float concentrate will be mixed with the float tailings stream and will be stockpiled near the <br /> Load out Bin (LOB). The 3,000 cubic yard concentrate stockpile is estimated to last approximately 30 <br /> days; once nearly depleted the high pH filter press conveyor will be reversed and campaigned until the <br /> concentrate stockpile is replenished. Prior to the campaign the high pH filter press feed tank and high pH <br /> filter presses will be rinsed to prevent cross-contamination. Whilst the concentrate will be removed prior <br /> to the addition of cyanide, the filtered concentrate will be checked to ensure no cross-contamination has <br /> occurred. <br /> There are no increases in existing or new chemicals/hazardous materials resulting from this change. A <br /> modified Toxicity Characteristic Leaching Procedure (TCLP)' has been undertaken on the concentrate <br /> (same testing procedure, larger testing quantity than what is required for the EPA TCLP testing method), <br /> confirming the concentrate contains no cyanide; the results of the test have been attached to TR-89 <br /> (Attachment 2)along with the Safety Data Sheet(SDS)for the concentrate(Attachment 3). <br /> Construction of Concentrate Storage Building <br /> The concentrate storage building will be constructed due south of the HGM, leaving an 8 foot breeze way <br /> between the two buildings. The building will be 64 feet by 70 feet in size to accommodate the safe <br /> operation of a front end loader for truck loadouts. The attached general arrangement drawings detail the <br /> design and location of the structure(Attachment 1). <br /> To accommodate the HGM changes and the addition of the new conveyor belt system, the paddle mixer <br /> and agglomerator will be removed and replaced with a single conveyor belt. The Conveyor belt will <br /> transfer tailings to the existing conveyor system which stockpiles the tails near the LOB. The tailings will <br /> Toxicity characteristic leaching procedure(TCLP)is a soil sample extraction method for chemical analysis employed as an <br /> analytical method to simulate leaching through a landfill. <br />