Morupule Colliery is an underground coal mine located in Palapye, Botswana. It is the country’s only operating mine and has been in production since 1973. The mine is 100%-owned by Debswana Diamond Company and operated by the company’s coal mining division Morupule Colliery.
The coal produced is supplied to Botswana Power Corporation’s (BPC) Morupule A thermal power station. The mine is estimated to contain 70 billion tonnes of proven and probable reserves.
In June 2012, the Morupule Colliery Limited (MCL) 1 expansion project was commissioned. The project was launched in October 2010 at a cost of BWP1.7bn ($218m). It was undertaken to supply coal to the new 600MW Morupule B power station built next to the Morupule A plant.
The mine’s capacity has increased from 1 million ton per annum (mtpa) to 3.2mtpa following the expansion.
Thermal power station and Morupule Colliery expansion project
The daily power demand in Botswana is 550MW, of which 100MW is supplied by the Morupule A plant. The remaining power is supplied by Eskom of South Africa and the Southern African Power Pool.
Due to an increase in domestic demand, South Africa plans to end its power supply to Botswana in 2012. As a result, Botswana needed to explore alternative energy sources. Construction of a second thermal power station was considered as the best option to meet the demand for power.
The Botswana government directed BPC to construct the new power station. BPC in turn has requested the expansion of the Morupule mine to meet coal demand for 23 years. The mining project will enable Botswana to become self-reliant for its electricity needs. A bankable feasibility study for the project was completed in September 2009.
Works carried out under the expansion project included the upgrade of existing conveyors, construction of an additional coal storage facility, and reconstruction of the existing crushing and screening plants. A second conveyor stream feeding the Morupule B station was also built.
In addition, a 750m concrete reservoir, new office buildings, pump station, workshops, control room, fire station, sewage plant and laboratory were constructed.
Mining and processing of coal at Morupule
Morupule is made of the Karoo Supergroup and the Palapye Group sandstones. It contains medium to low grade sub-bituminous coal.
Coal is extracted from the 8m thick Morupule seam and the No.2 seam through conventional room and pillar mining methods. These operations are carried out at a depth of 85m and accessed through a single shaft. Continuous drill and blast methods were originally used after continuous miner operation commenced in 2004.
The number of continuous miners operating at the mine went up from one to four following the expansion. The extracted ore undergoes primary crushing to reduce its size to 300mm and a secondary crushing which further reduces the size to less than 32mm.
The mine is equipped with a 1mt capacity coal washing plant, which has been operational since January 2008. The plant removes coal particles that are less than 15mm. It uses a Dense Media Separation (DMS) process to separate high calorific value (CV) coal from low calorific value coal.
The coal is fed to the plant which includes a slow rotating drum. High CV coal floats on the top and low CV coal settles at the bottom. Coal from secondary crushing and the washing plant is blended and fed into the conveyor system to feed the power station.
Financing for the Morupule colliery expansion project
The expansion project is being funded by a BWP1.2bn ($154m) bank loan provided by Stanbic Bank in Botswana, First National Bank of Botswana and Barclays Bank of Botswana. A further BWP506m ($65m) was raised from shareholders.
Contractors involved with the coal mine expansion in Botswana
Fluor Daniel was awarded the engineering, procurement, construction and management contract for the colliery’s expansion.
SSI Engineers & Environmental Consultants and ADP Projects were involved in the pre-feasibility phase, feasibility and detailed design of the project.
Future developments of the Morupule coal mine
Debswana is planning to further expand the mine in two phases, MCL 2 and MCL 3. The expansion projects will enable optimum utilisation of resources and allow Botswana to export energy to neighbouring countries.
Debswana is the world’s leading producer of gem diamonds, contributing about 30% of world output by value from four mines.
MCL 2 will enable the mine to supply coal for phase two of the Morupule B power station. It will focus on the development of the underground Morupule main seam to produce 8.5mtpa. An investment of $700m is expected to be made in the project.
MCL 3 will be an open cut development with a capacity of 5mtpa. It will exploit 9m of the Morupule main seam and 6m of the No.2 seam.