Modern Mining August 2018

MINING News

Weatherly tackles its water problems at Tschudi Weatherly International has outlined a recovery plan for its Tschudi copper mine in northern Namibia, following a signifi- cant water ingress on 11 May 2018. conducted an assessment of water risk and developed a recovery strategy for the mine. The recovery strategy is based on a 12-week delivery and includes:

driven pumps and installation of 1 800 m of high-pressure HDPE pipelines. A canal and settling dam are now fully commissioned to handle the water dis- charge, with the canal capable of handling more than 6 000 m 3 /h. Distribution from the settling dam is maximised with cur- rent installed infrastructure at 2 000 m 3 /h to direct water to various discharge points via a storm water pond, with the balance of the water overflowing the settling dam back into the aquifer. Significant progress has been made to design, cost and implement a significant upgrade of the dewatering infrastruc- ture. The system will be upgraded to increase abstraction and discharge rate to a nominal 3 000 m 3 /h via a predominantly electric grid-power system. According to Weatherly, the systemwill be developed in three phases at an estimated capital cost of N$44 million. This will include an addi- tional grid power substation to increase power supply to the mine. 

The recovery strategy and expenditure plan, which will require a capital invest- ment of N$14,3 million, has been approved and work is underway to increase pump- ing capacity to lower and stabilise the water levels in all pits and allow mining operations to regain access to ore. “We are confident that with the neces- sary financial assistance we will be able to implement the recovery plan and restore normalised production levels at Tschudi by December 2018,” comments John Sisay, Chief Executive Officer of Weatherly Mining Namibia. “We are appreciative of the support and understanding from the Ministry of Mines & Energy, the Namibian Government at large and all other stake- holders during this challenging time.” Specialist water expert Bob Kinnell from Strategic Water Management in Australia

 water abstraction , related to all equip- ment and infrastructure required to reduce water levels in the pits and to pump it into the canal that runs along the footwall of the pit;  water discharge , dealing with mov- ing the water away from the open-pit mining area and discharging it at re-injection areas which have been approved by the Department of Water Affairs; and  implementation of various supporting actions to improve water management post recovery. The recovery phase is now well under- way with end-June target water levels achieved. Abstraction capacity has been increased from 1 400 m 3 /h to 3 000 m 3 /h through the rental of additional diesel-

August 2018  MODERN MINING  13