Mining industry professionals, regulators and government representatives met with experts from the Australian Nuclear Science and Technology Organisation on 5 June to tackle the problems associated with naturally occurring radioactivity in minerals.
In welcoming participants to the workshop, the Director of ANSTOs Materials Division, Dr Adam Jostsons, stated that naturally occurring radioactivity can occur in many ore bodies and its presence can have a significant influence on mine development and processing technologies as well as on product marketing and environmental management.
ANSTO has recognised the need for local industry to address these issues in supporting a research project on the removal of radioactivity from mineral products to ensure that Australian mineral industries remain competitive in the future.
"Industries affected by radioactivity include those for heavy minerals (such as ilmenite, rutile, zircon, tantalite, garnets), gold and copper, phosphate ores, and rare earths and industrial minerals, as well as the iron, coal, petroleum and natural gas industries," he said. "Because we are a major supplier of mineral products, this is of major concern to Australia."
A senior metallurgist at ANSTO, Doug Collier, said that the principal sources of radioactivity in ores are uranium-238 and thorium-232, which are often found in mineral products. Thorium is commonly found in rare earth products. Lead-210 and pollonium-210 can be a problem in copper, iron and other hydro- and pyrometallurgical circuits, while radium-226 is commonly found in gypsum from phosphate ore processing, oil and gas drilling wastes, in tin and thermally processed gold ores and in slags.
"The solids, products and wastes need to be categorised in relation to the concentration of contained radioactivity, the total quantity of contained radioactivity and the particular radionuclides present," Mr Collier said.
Mr Collier said that radioactivity can be removed using chemical processes, but that in some cases, the radioactivity is best left in its mineral matrix. A senior health physicist at ANSTO, Frank Harris, told delegates that technologically enhanced natural radioactive nuclides in products or intermediates can create occupational and public hazards if not managed well.
"Perceptions of radiation may be harder to deal with than the actual radiological hazard. Information is the single biggest weapon against misconceptions, and this is generally very effective in the workplace, where safety considerations are formally addressed."
The keynote speaker at the workshop was Dr Victor Hugo, Marketing Development Manager from Iluka Resources. Other ANSTO staff to make presentations included a senior radiochemist, Ms Sue Brown; a leader in the Operational Health Physics Group, Ms Alison Parkes; a senior professional officer, Mr Ned Blagojevic; a member of the Radiochemistry Group, Mr Christopher Bowles; and Group Leader of Environmental Pathways, Dr John Harries. Mr Stuart Prosser of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) made a presentation about the role of the federal regulator.