Winner: Xstrata Copper
Project: ESP Dust Recovery Plant
Location: Mt Isa, Queensland
This novel project addresses issues associated with the copper smelter byproduct – electrostatic precipitator (ESP) dust which is formed as a byproduct of the copper smelting process.
It is collected from the smelter gas stream in an electrostatic precipitator, where process water is added and the dust is either processed through the newly commissioned ESP Acid Leach Plant or it is diverted to stockpile.
ESP dust is an environmental hazard; it presents a serious hygiene risk to humans, creates a dusting issue and takes up valuable real-estate on the mining lease when stockpiled.
A large stockpile of ESP dust has been accumulated over approximately 16 years of smelter operation. Aside from the hazards, a considerable opportunity exists as the ESP dust contains valuable copper and gold.
Brett Harries (R) and Peter Woodall, both from Xstrata Copper, Mount Isa Mines, take home the Zenith winner’s trophy in the Metal Products Manufacturing category.
Brett Harries, Smelter Business development manager with Xstrata Copper, said the operation faced many challenges. “The issue with the project was the material is actually a by-product from the smelting process. It has a lot of minor elements in it which are harmful for the environment,” he told PACE.
“Over the years of operation we accumulated about 130,000t of this material. We had to deal with two things: overcoming the environmental aspect, the liability there, so we could comply with our own sustainable development standards, as well as unlocking the significant opportunity associated with the copper and other base metals that were locked up in that material.”
“There was the need to develop a very unique technology to reclaim the material and transport it to a newly designed plant. And there was another specific control around controlling the pH of the dust once it’s in solution to a very tight band, where it will allow the recovery of the value-add material, but at the same time, allow us to separate out the harmful minor elements, stabilise them, and then stored,” explained Harries.
It is forecast that all arising and stockpiled dustwill be consumed by the middle of 2011 after the commissioning of a second Agitruck. As a result, an additional 20kt of copper and 18koz of gold that otherwise would have been written off, will be recovered.
The judges said this innovative project delivers a win-win for the environment and a commercial return for an otherwise waste byproduct.
Check out all the Finalists in the Metal Products Manufacturing category.