syama
The Syama Gold Project is located in the south of Mali, West Africa approximately 30kms from the Côte d’Ivoire border and 300km southeast of the capital Bamako.
Resolute has an 80% interest in the project through its equity in Sociêtê des Mines de Syama S.A. (SOMISY). The Malian Government holds a 20% interest in SOMISY, 15% of which is free carried.
Ore for the Syama Operations was sourced from the Syama open pit. Due to the refractory nature of the ore it is treated using conventional four stage crushing, ball-milling, sulphide floatation and dewatering, roasting, calcine leaching and elution at the rate of 2.4Mtpa.
Operations
The 2009 financial year saw the commencement of oxide treatment, the completion of construction and the commencement of operational commissioning of the sulphide circuit. During this period, the operation produced 24,762 ounces, with all costs being capitalised.
The initial trials of treating oxide material through the completed sections of the circuit, which commenced in October, were eventually abandoned during February due to a range of difficulties in treating this material. Once this decision was made, all efforts were focused on commissioning the flotation circuit to commence stockpiling concentrate in preparation for the completion of the roasting circuit. Treatment of sulphide ore commenced through the flotation circuit in mid March with the recoveries and concentrate specifications within expected ranges.
The roaster commenced initial heat-up in April and after overcoming some initial operational factors began autothermal operations. The roaster performance has been steadily improved as operator’s have gained operational experience. Performance of the remainder of the processing plant has been affected by a large number of failures in smaller components, mainly pumps and fans.
Good progress has been made in the development of the pit, with the east wall failure rectification almost complete by year end, as well as improvements to the contractor’s performance and system development.
Total material moved for the year was 5.05 million BCM, with the focus on waste removal to facilitate ore production. The contract miner’s performance improved steadily over the year and at year’s end, total movement figures were in line with budgeted levels.
For the period the processing plant treated 716,768 tonnes at an average head grade of 1.71g/t Au. Recovery averaged 63%. The low recovery is a result of the issues relating to the oxide treatment and related preg-robbing, as well as the commissioning issues, particularly with the earlier inconsistent operation of the roaster. The roaster needs to operate in a steady, controlled manner to ensure roasting is complete and the maximum carbon is burnt off.
Outlook
Although the early phase of commissioning has been frustrated by many interruptions, small component failures and difficulty in achieving timely delivery of spares, it has shown that the overall process will achieve expected results. A major delivery of spares is due for delivery in August and a major maintenance programme is planned to coincide with a mill re-line in September. Following this programme, all of the identified components will have been overhauled and brought to their required installation specifications. The operation will also have additional spares available for future maintenance and the required critical (insurance) spares will have been identified and the procurement process started for their delivery. This will allow the processing plant to run consistently and allow the focus to switch to optimization, both in throughput and recovery.
A drilling programme in the pit is planned to commence in the first quarter of 2010. This will allow for better definition of the distribution of sulphides in the ore and hence result in better scheduling of the ore delivered to the ROM pad which will in turn allow for optimal operation of the roaster. The improvement in contractor performance focus will remain in place to further reduce unit costs, as well as to give better flexibility in ore deliveries to the ROM pad to further improve feed blending.
All of the above improvements will allow the operation to ramp up to the 250,000 ounce production per annum target in an orderly manner.
