MINERAL PORTS AND STOCKPILES
Stocked and loaded
With commodity prices hitting a solid patch of form , the development and expansion of bulk loading facilities are once again being considered . Dan Gleeson investigates some of the technology and equipment that may feature on such projects
Mining companies are , once again , thinking big when it comes to project development . Outside of the precious metals sector , bulk and
base metal producers are considering scale , efficiency and , in some cases , automation .
This all has a bearing on the mineral stockpiles being built and the port operations loading and unloading the cargoes of product that come with these developments .
Conveying a message
To create an optimised stockpile on mine sites or by ports , the material needs to be conveyed and
discharged in an efficient and productive manner .
Several companies in the field have released new overland conveyor options to satisfy this demand , with processing flowsheet major Metso Outotec one such firm .
Late last year , the company introduced a full range of overland conveyors for “ economic and energyefficient bulk material transportation ”.
Designed for transporting bulk materials in long distance mining applications , the overland conveyor solutions can be used at both open-pit and underground operations and , according to the company , offer the lowest total cost of ownership .
Lars Duemmel , Vice President , Bulk Material Handling Systems at Metso Outotec , said : “ The robust design of our overland conveyors allows for capacities of up to 20,000 t / h , including over 5 km on a single flight for a seamless process . What is also important is that you can achieve power savings of up to 30 % with the patented Energy Saving Idlers ® ( ESI ).”
ESI , according to Metso Outotec , significantly reduces the overall rolling resistance on conveyor belts , leading to savings in the electrical power costs to operate the conveyor . This energy-efficient technology provides significant cost savings for
operating belt conveyors and , in the case of long overland conveyors , savings on capital equipment costs as well , the company says . In addition , there is reduced operating expenses over the extended life of conveyor components .
Duemmel added : “ Thanks to our extensive process engineering capability and proven installations around the world , we are able to support our customers with complete end-to-end conveyor solutions .
“ This includes concept studies and definitions for all types of terrains and route types with horizontal and vertical curves . Our expertise also covers postinstallation services and maintenance , including a full range of accessories , belts and components .”
Convey , stack , stockpile
Opened in 2005 as a surface mine , Knight Hawk Coal ’ s Prairie Eagle mine , in the Illinois Basin of USA , has been expanded over time to include two underground mines , Knight Hawk ’ s main coal preparation plant and multiple truck load-out facilities . Now one of the most efficient underground mining plants in the country , according to BEUMER Group , it produces around 5 Mt / y of coal , of which more than 80 % is processed and delivered to the Prairie Eagle preparation plant .
Germany-based BEUMER Group was engaged by mine management to come up with a more sustainable operating solution that reduced the mine ’ s reliance on truck transportation , according to Andrea Prevedello , System Technology Global Sales Director , BEUMER Group , Germany .
“ We provided an overland conveyor that transports the coal from the mine to the main processing plant ,” he said . “ Our conveyor helps the company to considerably reduce its ecological footprint . With this technology , Knight Hawk can significantly reduce its long-term environmental impact compared to using truck transportation .”
Depending on the customer , stockpile dimensions and design can vary . Two layouts are generally available : circular and longitudinal , BEUMER Group says
BEUMER ’ s solution at the mine features a singleflight curved conveying system that eliminates the cost of tower steel and greatly reduces the quantity of components and necessary spare parts , according to the company . It reduces the dust , noise , maintenance and operating costs associated with the transfer points , BEUMER said .
The company not only supplied the conveying solution to Knight Hawk ; it also supported the mining group in building a stockpile for hard coal .
“ The requirements for storing coal are obviously very different from other materials ,” Prevedello explained . Some of the requirements change if the stockpile is covered and if explosion-proof equipment is needed . Hard coal is also very susceptible to spontaneous combustion , which is why the height of the stockpile must , in certain cases , be limited .
Depending on the customer , stockpile dimensions and design can vary . Two layouts are generally available : circular and longitudinal , BEUMER says .
“ Their dimensioning and design depend on the purpose of the stockpile ,” Prevedello said . Space availability and possible future expansions are also critical factors to consider .
The application must also be considered : does , like Knight Hawk , the customer want to store the bulk material temporarily , then continuously feed it for further processing ?
“ Then longitudinal stockpiles are your best choice ,” Prevedello said . These structures can also be extended , if necessary , according to BEUMER . The irregular flow of bulk material arrives at the stockpile and can then be continuously introduced to the process . Circular stockpiles are frequently used for other bulk materials , eg limestone and clay .
56 International Mining | MARCH 2021