The remote Balama graphite operation, owned by ASX-listed Syrah Resources will be powered by a generator plant that is being constructed by South Africa-based Zest Energy, part of the Zest WEG Group.
According to Alastair Gerrard, Zest Energy MD, the plant will start producing electricity during the first quarter of 2017, generating an initial capacity of 12.5 MW with an installation of seven 2 200 kW diesel generators.
“The isolated location of the Balama mine – over 250 km west of Pemba in northern Mozambique – means that while the operation does have access to power from the national grid, it will need to be supplemented to ensure adequate supply for full plant demand,” Gerrard says.
“We need to ensure 100% availability and have consequently designed the plant with substantial standby capacity to allow for maintenance and repairs without affecting supply.”
He says the plant, the largest footprint project tackled by Zest Energy yet, will initially run with seven 2 200 kW generators of which six will be running and one will be on standby. It will later be expanded to include eleven generators, of which two will be standby units.
Equipment for the extensive scope of supply has been sourced from various companies within the Zest WEG Group, locally and worldwide. The containerised power generators include WEG alternators with automatic voltage regulation systems, as well as motorised louvres, generator auxiliary systems and fuel and lube tanks. To cool the engines, a horizontal-type radiator system, rated for 50°C ambient temperature, was manufactured in South Africa. Each radiator includes 10 WEG 3 kW fan motors positioned in two cooling banks of five fans each.
“One of the challenges of the mine environment is the presence of graphite dust, which is highly conductive and must not be allowed to enter the power generation units,” Gerrard says. “For this reason, a filter system was designed that could accommodate the high volumes of moving air required to cool the engines, while also requiring as little maintenance as possible.”
Once again, a local solution was designed in the form of a custom-engineered, self-cleaning cartridge type ventilation and pressurisation fan unit, comprising four WEG 7.5 kW fan motors.
To feed diesel to the generators, Zest Energy will install a 30 000 litre intermediate fuel tank to draw from the customer’s bulk fuel storage system with a duplex fuel filtration and circulation system.
A local fuel connection point within the plant area will also be installed as a contingency, should bulk fuel supply not be available. To comply with environmental regulations, a bunded fuel and oil area will be constructed with an oil-water separation system.
“We will also provide various systems for plant auxiliary power requirements and for plant earthing and lightning protection, as well as cabling, terminations, racking and supports to all plant electrical equipment,” Gerrard says.
“Through our member companies in the Zest WEG Group, we are able to give our customer a single point of contact for the range of services we are providing, while project managing and quality controlling every aspect of the power plant.”