Resolute Mining brings Syama sulphide roaster back to capacity
Resolute Mining told the market on Friday that the sulphide roaster at its Syama Gold Mine in Mali has been successfully brought back online, and was operating at nameplate capacity.
The London-listed firm said the Syama roaster was a “key component” of the sulphide processing circuit, and was taken offline in early October due to the detection of a crack in the main external shell.
Repairs to the roaster were completed in early December, within the scheduled timeline and the allocated budget, and without any recordable safety incidents.
The Syama roaster repair consisted of a complete replating over the crack on the main roaster body by cutting and welding new 10mm plate steel.
An additional crack in the primary cyclone and two minor cracks on the main roaster body were also replated as part of the repair programme, in addition to a range of refurbishments and maintenance to the sulphide circuit infrastructure.
Controlled reheating of the roaster to dry and cure recently installed refractory lining and to bring the unit up to normal operating temperature began on 11 December.
First ore was introduced to the grinding mills on 13 December, and a stock of concentrate was accumulated while the roaster was gradually reheated to operating temperature.
On 19 December, concentrate was introduced to the roaster.
In addition to the restart of roaster operations, a new secondary cone crusher was commissioned on 14 December.
Extensive refurbishments and enhancements to the sulphide grinding, flotation and calcine regrind circuits had also been commissioned, starting on 11 December.
The roaster and all aspects of the Syama sulphide circuit were said to be performing as expected.
Resolute said the improvements made to the sulphide processing circuit were aimed at ensuring target recoveries and throughput were achieved in 2020 and beyond.
Underground mining at Syama continued without interruption during the roaster repair programme.
Resolute's said its fully-autonomous haulage fleet was now commissioned and operational.
More than 400,000 tonnes of high-grade underground ore was now available on the run-of-mine pad.
The available stockpile of underground ore ensured that sulphide processing operations would be unconstrained by ore availability during 2020, and provided greater confidence in achieving targeted throughput.
Resolute said the “comprehensive” roaster repair programme, and the contemporaneous refurbishments and maintenance completed to the entire Syama sulphide circuit, had allowed it to reschedule the next planned roaster shutdown.
The next major biennial roaster maintenance shutdown was previously scheduled for May 2020, but had now been deferred until January 2021.
“The roaster repairs and associated unscheduled sulphide circuit maintenance has been a complex project which has been successfully completed efficiently and safely,” said managing director and chief executive officer John Welborn.
“I congratulate our project, technical and operating teams at Syama for their success in this herculean task and for the exceptional response in delivering a solution to our requirements.
“The Syama sulphide circuit is now fully operational and ready to demonstrate our ambitions at Syama by delivering strong stable recoveries from consistent ore feed from the Syama Underground Mine.”
Welborn said the “significant” ore stockpiles it now had available would allow the company to focus on cost efficiencies with its autonomous underground mine systems, rather than requiring a focus on maximising mined and hauled tonnages.
“During 2020, we intend to investigate opportunities to expand both the underground mine production capacity, and the processing capacity of the sulphide circuit, beyond the current nameplate of 2.4 million tonnes per annum.
“The crack to the roaster, and the required unscheduled sulphide circuit downtime, has resulted in a material loss in production from the Syama sulphide circuit in the December 2019 quarter.
“However, we have worked hard to offset this lost production from other production sources and complete the repairs as quickly as possible.”
As a result, Welborn said the material loss in sulphide production was likely to have only a minor impact on overall group production and targeted 2019 financial year production guidance at 400,000 ounces of gold.
“The lost production in 2019 is more than offset by the additional production we now expect to gain in 2020 by the deferral of the next major roaster shutdown to early 2021.”
At 1512 GMT, shares in Resolute Mining were up 2.32% at 58.83p.