Guyana Goldfields Inc reports that the phase one mill expansion which was designed to increase the hard rock throughput rate from 5,600 t to 6,600 t/d has been completed on-time and slightly under budget with initial benefits to recovery already being observed within current operations.

The expansion consisted of debottlenecking the back end of the circuit and included the addition of three leach tanks, a pre-leach thickener, carbon management systems and the expansion of the elution circuit. Due to additional retention time within the leaching circuit, the phase one mill expansion is already demonstrating increased recoveries by approximately 1% to an estimated average recovery of 92.5%. The original timeline for completion was by the end of the first quarter of 2018 for a capital cost of $21 million.

The second phase of the mill expansion is expected to allow the processing of 7,500 t/d of hard rock ore and a further increase in recovery of 1% to 2% with the utilization of a pre-crushing circuit and ball mill from a previously purchased 1,000 t/d modular processing plant. Results from a series of bulk test work on expanding the pre-crushing capacity have been highly encouraging demonstrating an approximate 3% improvement in grind, as well as, an approximate 2% overall improvement in gold recovery. This expansion is expected to be completed by the end of the fourth quarter of 2018 at a capital cost of $6 million as the majority of this capital has already been expended. The company has awarded JDS Mining with the engineering and procurement for the second phase of the mill expansion.