Any contractor working in the mining industry knows that environmental and worker safety issues are just as important as project uptime and product turnover.
So, when the VDM Group teamed-up with design consultancy Norman Disney & Young (NDY) in 2010 to build a transportation system for a fledgling iron ore project at Port Hedland, Western Australia, the duo was well-versed in the importance of 'dust suppression'.
The 'Utah Point Berth Project' - which is now a fully-functioning, multi-user berth in the Pilbara - was commissioned for use by second tier miners, allowing them to share infrastructure costs.
The project team was required to deliver a conveyor system capable of carrying 7500 tonnes of iron ore per hour, 24-hours-a-day - which equates to 18 million tonnes per annum - from 13 stockpiles of product with a combined capacity of 910 000 tonnes.
Paramount to the conveyor set-up was a purpose-built dust suppression system to minimise dust particles emitted in to the air when the iron ore, magnetite and chromite was transported from the stockpiling facility for export.
"The wharf was designed for small cape vessels with 120,000 tonnes capacity each. Only one ship can be loaded at a time, however the wharf has a state-of-the-art mooring system which has the ability to dock and release ships in minutes. It also has the capacity to hold ships in place during the 7.5m tide," VDM Utah project manager, Jean-Claude Sulon, told Ferret.
According to NDY Utah principal engineer, Rob Murdoch, the multi-tier project involved: the design of an automated stockpile and dump point dust suppression system; the water supply for conveyor transfer stations; conveyor wash boxes; mobile reclaim hoppers; stackers; and the shiploader dust suppression system.
"The dust suppression system utilises a series of water cannons and sprinklers throughout the materials handling process that maintains dust extinction moisture levels and prevents windborne dust from affecting nearby towns," Murdoch told Ferret.
"The completed system is fully-automated via remote weather sensors, proximity sensors and solenoid actuated valves. The control was integrated into the site control system."
According to Sulon, the 'dust issue' needed to be 'designed out' of the system to meet the customer's requirements.
"When material is transferred from one element to another dust is a natural outcome, so at every point, from in-load at delivery of product into the hoppers into stockpile, to out load where product was deposited by WA600 front end-loaders into mobile hoppers onto conveyor belts and through several transfer points, and eventually onto a shipload and into the vessel, dust suppression was used," he said.
"The stockpiles were also under suppression and an automated system which monitored the weather; wind, temp and evaporation, would then automatically spray the stockpiles in a self-determined routine."
In addition, all excess dust suppression water was captured via an integrated drainage system and recycled, he said.
"The excess water was pumped back to primary settling pond, which in-turn fed a secondary and tertiary pond, and then into holding tanks, thus conserving water."
NDY also integrated the pipework for the fire hydrant and dust suppression system pipework, eliminating the need for separate pipework and storage tanks.
"Due to the scale of the site, this reduction of pipework had a significant impact upon capital expenditure for the project," Murdoch explained.
"We believe that these two systems have not previously been combined in a similar application."