Feature story link: https://www.australianmining.c…

How Denmark is helping drive sustainability in Australian mining

FLSmidth

Danish original equipment manufacturer (OEM) FLSmidth has been supporting the sector for decades and has become a market leader for its pit-to-plant solutions spanning everything from crushing and milling, pumping, flotation and separation through to tailings management and beyond.

With a customer base brimming with the world’s leading mining companies across commodities such as iron ore, gold, copper, nickel and lithium, FLSmidth aims to achieve ​“sustainable productivity through innovation”, a vision embodied by the OEM’s MissionZero strategy. 

MissionZero is centred around driving a paradigm shift of zero emissions, water waste, and energy waste in mining by 2030 not only for FLSmidth’s own operations, but also for its customers. 

This ambition becomes possible when multiple technologies are combined. An example of this is FLSmidth’s MissionZero Mine. 

“To achieve zero emissions, it’s not simply about electrifying the mine operation; it’s also about changing the flowsheet using different technology, to reduce the energy and water needed for production,” FLSmidth APAC mining president Tamer Eid told Australian Mining.

FLSmidth found that if a mining company replaced a traditional wet milling SABC (SAG mill/​ball mill/​pebble crusher) circuit, standard flotation cells and a cyclone sand tailings dam with the MissionZero Mine, the operation would realise a 30 – 45 per cent reduction in overall energy consumption, along with an 80 per cent reduction in water consumption. 

The operation would also realise increased metals recovery.

“If we put in different technology together such as coarse flotation, REFLUX flotation, our market leading high-pressure grinding rolls (HPGRs) and dry stack tailings, you can actually change the flowsheet to reduce your energy and water demands significantly,” Eid said.

Comminution (making a big rock into a small rock) is estimated to use in the vicinity of 2 – 3 per cent of the world’s total energy.

“So when you have different technology that can change the game of comminution and reduce that energy consumption, that is significant,” Eid said.

FLSmidth’s OK Mill can use dry grinding instead of a water-based method, saving on water and energy usage by 10 – 20 per cent kWh/​t (kilowatt-hour per tonne) in the process.

HPGRs also use a dry grinding process and are therefore a more sustainable alternative than SAG mills and ball mills. 

Miners will not only save energy with HPGRs, but they also achieve emissions reduction indirectly from the elimination of the steel grinding media needed inside SAG and ball mills. 

Coarse flotation also reduces energy consumption. 

“Coarse flotation enables miners to beneficiate with larger particle sizes, meaning they can grind less to liberate the ore, using up to 45 per cent less energy per kWh/​t,” Eid said.

“With coarse flotation alone, you reduce the amount of energy needed and therefore the amount of energy generation required to deliver the same throughput, and it can be applied to existing circuits.” 

There are also opportunities in tailings management.

“Instead of having a tailings pond, you can have dry stack tailings, where tailings are stacked on top of one another,” Eid said.

“That means you can recover up to 95 per cent of valuable water, utilise it back in the process, and you don’t have big tailings dams and high-water usage. 

“Especially in the drier places of the world, such as some of the mines in the north-west and Pilbara region of Western Australia, water is at a premium. For some new mines, companies need to have different dewatering and tailings arrangements to enable these mines to be viable.”

Eid said while each of these technologies is effective independently, they produce even greater results when combined.

“We work closely with customers to help integrate these different technologies – using our end-to-end flowsheet capability. This delivers extra value and supports not only changing the NPV (net present value) of the mine itself, but also fulfilling their corporate social responsibility goals,” he said.

This feature appeared in the October issue of Australian Mining.