Solutions for the Handling of Bulk Solids in the Supply Chain
Today raw material transport over great distances is a standard procedure in the minerals and metals industries. Industrial minerals are now shipped across the globe in vast volumes demanding efficient logistics to minimise both the cost of transportation and the carbon footprint. Especially under these circumstances, ingenious solutions for the handling of material during storage and transshipping can help save the pivotal dollar.
(ed. WoMaMarcel - 25/6/2015)
Unloading Flat Bottom Wagons
Where hopper bottom wagons are not available then flat bottom wagons may be employed but a Wagon Tippler will be required if the discharge is to be automated. Typical designs from Schade include the O-frame, C-frame and pivot-frame designs all supplied with various designs of indexer to automate the movement of the wagon and wagon rake eliminating the need to hold a shunter or switcher for the duration of the rake discharge.
Of course the wagon tippler may be supplied with the associated plate feeder or, where excavation depth may be limited, the Samson feeder offers significant advantages.
From the road truck or railcar discharge the raw material or fuel may be conveyed into the storage hall and stacked by travelling stacker or from overhead tripper system all of which are offered by Schade along with the automation package for unattended operation.
Stacking, Blending & Reclaiming
Typical longitudinal storage solutions with travelling and luffing boom stacker plus a cantilevered boom style reclaimer recovering dissimilar materials from discrete storage bays or when handling the same material the circular storage offers a compact alternative with also the option of layered loading and blending using the Bridge Reclaimer system.
Circular storage and blending bed by Schade fpr BHP Blackwater mine in Australia.
The boom type chain scraper reclaimer concept draws material from the inclined stockpile face and discharges to a collecting conveyor running parallel to the stockpile. The recovered material may be conveyed to silo storage or bunkers where it may be blended and delivered in controlled proportions to perhaps a milling system before processing.
For larger installations typically in such as Australia and South Africa central preparation plants draw raw materials from often a number of satellite mining operations for blending, washing and loading to trains for transfer to the port. Clearly the central prep-plant has an enormous advantage in that only one railroad is required clearly saving significant cost and enabling most efficient use of the rail network. However, material must be hauled from the mine sites to the prep-plant using a fleet of large dump trucks or more often road trains with multiple side tipping trailers. The intake of material from these road trains is a challenge since the trucks must be rapidly discharged and returned to the mine requiring high performance intake capacity and high holding capacity. Again the Samson Surface Feeder with D6 conveyor chains and rollers extends the required receiving area and offers a high holding capacity without the need for deep excavations and underground hoppers. Surface mounting is less polluting and offers easy access for maintenance and housekeeping.
In the complex market that exists today many minerals of vastly different handling characteristics must be transported from the mine site to processors, often on different continents, with often many logistics steps along the way.
And in addition to extracted minerals we also have to consider the movement of industrial by-products from such as power plant (Synthetic Gypsum) and steel works (Slag) which have become important assets in the global fight to reduce greenhouse gas emissions.