HIGH PROFILE
Jansen ’ s super-sized borers
Paul Moore reviews the electric , automated and supersized borer miner-based Sandvik mining systems that will be used at BHP ’ s advancing Jansen potash operation
Potash mining is booming , a combination of fertiliser demand globally in conjunction with world events affecting supply from Russia and Belarus . And , as with other types of mining , a major focus for operators , existing and new , is reducing GHG emissions , while at the same time increasing efficiencies . BHP from the outset wanted to make its new Jansen potash mine in Saskatchewan as automated and as emissions free as possible . A low water footprint and low emissions were embedded in the mine design and mining method from the beginning .
In Stage 1 , the mine is expected to produce approximately 4.35 Mt / y of potash . Jansen Stage 2 would then add around an additional 4 Mt / y . Across all four stages at Jansen , BHP has a long term roadmap to between 16 and 17 Mt of annual production . For now , global events have brought first planned production from Stage 1 forward – the company is now looking at late 2026 first production instead of 2027 .
On the technology side , at the recent Bank of America Smartmine conference in June 2022 , BHP Chief Technical Officer , Laura Tyler said : “ Jansen will be the most advanced and sustainable potash mine ever built . As a new operation , we do not have to retrofit technology and we can install at design . It will be difficult , if not impossible , for existing potash miners to retrofit and recreate the operational advantages that we are seeking to capture over the next couple of years . For example , during design we wanted to provide a proven alternative to the conventional active borer technology , so we partnered with Sandvik to look at the options … we will introduce a high degree of automation , integrated design and eventually a remote operation centre like we see at WAIO , BMA and Escondida to drive the borers of the future . We will be connected to it from surface , potentially even from Saskatoon .”
Jansen is expected to emit ~ 50 % less CO 2e per tonne of product versus the “ average performer ” in Saskatchewan potash mines . Underground mining and support fleet will be more than 80 % electric , but BHP will pursue 100 % electrification as well as aiming at all carbon neutral electricity through commercial partnerships . It will also look to implement technologies like carbon capture and storage to mitigate natural gas emissions in the processing plant .
Tyler added : “ Stage 1 will have just four mining systems , capable of producing the equivalent of 10 to 14 typical systems , able to monitor the ground ahead and adjust its mining height to match the orebody . This is a sustainable advantage , with around 60 % less fleet creating around a 10 % operating cost saving as well as fewer active mine faces , so therefore increasing stability , and a smaller environmental footprint . Jansen , we believe , will set a new benchmark for equipment and decision automation in the potash industry . We will have three times the number of process sensors and 10 times the number of machine health monitoring sensors compared to the next largest producer in Saskatchewan .”
This , married together with the latest processing technology , means BHP expects to achieve an industry-leading recovery rate of around 92 %, and Jansen Stage 1 will have approximately 50 % less carbon emissions per tonne than the average in the basin and approximately 60 % less fresh water consumed on the same basis . The high recovery rates will be enabled by separate fine and coarse flotation with on-stream analysis and crystallisation which recovers fine potash from waste streams .
Mining will be some 900 m underground , excavating the top of the Prairie Evaporite Formation . The actual mining height will be variable between 3.7 m and 4.4 m , with an average cutting height of 3.8 m . Borer miners and accompanying Extendable Belt Systems ( EBS ) make up the selected mining system for continuous mining in production rooms . A network of conveyor belts transport the ore from the working face to the
The Sandvik MF460 has been developed in close co-operation with BHP
shaft area for hoisting at the service shaft . Production mining is supported by a fleet of continuous miners , battery haulers , LHDs , maintenance vehicles , and personnel carriers . So BHP is bringing together the new ultra large borer miner design with an advanced conveyor system as well as BEV rubber tyred equipment .
The ultra large borer miner – the cable-powered Sandvik MF460 – will be teamed with a Sandvik PO140 EBS . This integrated system is notable for being much larger than other mining machines in the Saskatchewan Potash basin . Four of these systems , developed in close cooperation with Sandvik , will each be capable of about 2.7 Mt for a total potential production capacity of 10.8 Mt / y . The MF460 led system means less workers , so a lower labour cost per tonne , but also a lower overall equipment cost per tonne of potash produced which it believes will give an operating cost advantage over other Saskatchewan potash majors like Nutrien and Mosaic .
The MF460 will cut a width of 6 m per cut ( and as stated a height of up to 4.4 m ). One cut and a return cut will be up to 1.8 km in length , leaving a room of 12 m wide . The full face mining machine has a cutting head that can vary in height and will have ground penetrating radar , to minimise dilution while managing ground conditions . The MF460 machine integrated with the EBS has been in development by Sandvik and BHP for more than a decade to de-risk this new approach , including a full-scale underground trial in a salt mine in Heilbronn , Germany that has been running for several years . In addition to the borer miner led mining system , Sandvik is also supplying a fleet of battery electric LHDs which will be integral to the support of Jansen ’ s underground operations . BHP has ordered 10 underground battery electric loaders along with one electric tethered loader . IM
44 International Mining | SEPTEMBER 2022