Scotgold Resources Ltd lowered its 2021 guidance for gold production, citing “teething problems” over handling issues and low recruitment due to pandemic restrictions imposed since 25 December.
The company said that problems had occurred in three key areas of crusher circuit chokes, flotation circuit pumps and filter press controls at its Cononish gold and silver mine.
The crushing circuit had been designed to handle the full Phase 2 production rate of 15tph. Scotgold added that Cononish ore frequently broke into thin flat ‘slabs’ and at various points in the circuit, where there were ‘pinch point’, the slabs were prone to bridging and creating blockages.
The company is modifying the identified pinch points to permanently resolve these problems.
Five positive displacement (PD) pumps were installed to move various products between the two banks of flotation cells which comprise the flotation circuit.
Some of the pumps were undersized, resulting in significant spillage, and also suffered from extremely high wear rates with the Cononish mine material.
A vertical spindle pump, previously used on the bulk processing trial plant, is more appropriate Scotgold is now sourcing and replacing the remaining PD pumps.
The filter press circuits (tailings and concentrate) which have complex automated cycles, suffered from numerous control system problems during commissioning. These have now largely been resolved and more minor materials flow issues are being addressed.
Scotgold, whose headquarters are in Nedlands, Australia, announced its first gold pour on 30 November 2020. bit.ly/3j6O2Th
Last Friday (29 January) it said that tonnage throughput for January was “negligible” due to multiple materials handling issues between circuits. Those issues have now been resolved and remaining problems are expected to be dealt with by the end of February 2021.
“All major processing components have operated at or above design capacity, and the plant is therefore still expected to reach the full designed production rate of 3,000t per month.
“As a result of the lost production during this ramp up period, the company is reducing its production guidance for 2021 from 9,910oz Au as announced in December 2020, to between
8,700oz Au and 7,800oz Au from between 31,500t and 28,400t ore processed.”
EXPLORATION WORK
The gold exploration and production company is also exploring at the Cononish and Grampian projects with the aim of increasing the mineral resources around the mine and making new discoveries.
Scotgold’s interests across its option areas over the Dalradian Belt have focused on extending the soil sampling grid over Cononish and the Beinn Udlaidh and Inverchorachan prospects, which lie within the Glen Orchy Central and Inverliever East option areas respectively.
The company has been applying the Ionic Leach1 method both to stream sediment and soil sampling programmes across the Scotgold’s company’s option areas, and reprocessing geophysical data collected during 2018 and 2019.
A total of 625 samples have so far been collected from 10 of the 13 option areas. Sampling continues as well as follow up mapping in areas identified as anomalous (gold values in excess of the 90th percentile, >1.8 ppb).
“Scotgold remains in a strong position to continue our commercial growth trajectory after achieving first gold on 30 November 2020,” said chief executive Richard Gray.
“Despite the frustrating but resolvable materials handling issues that arose this month, our confidence in the ultimate performance of the mine continues to grow.
“The lessons learnt, as well as opportunities identified, during this Phase 1 ramp up will be used to optimise our plans for the Phase 2 expansion in 2022.”