Rio Tinto aluminium ore and minerals estimate changes
Mining giant Rio Tinto has announced changes in estimates of Ore Reserves and Mineral Resources at Pacific Aluminium operations at Weipa and Gove.
Gladstone's Queensland Alumina Limited, Rio Tinto Yarwun and Boyne Smelters Limited are all involved in processing ore and alumina from both the northern Queensland and Northern Territory mines.
The changes, announced to the Australian Stock Exchange on Wednesday, will be included in Rio Tinto's 2020 Annual Report to be released by February 22.
"The Rio Tinto Aluminium RTA Pacific Operations Ore Reserve estimate has decreased by 305 Mt, from 1,530 Mt to 1,224 Mt," the company said in the statement to the ASX.
"The reduction in Ore Reserve estimate is associated with a routine review of price assumptions over the life of the mine.
"There has been no material change to the economic cut-off methodology or process.
"The application of the updated pricing assumptions has removed lower quality material from the Ore Reserve estimate.
"There has been no material change to the other reserve modifying factors, including: governmental, tenure, environmental, cultural heritage, social, community or operational."
Meanwhile, RTA Pacific Operations Mineral Resources exclusive of Ore Reserves estimates have increased.
"Mineral Resources exclusive of Ore Reserves has increased by 128 Mt, from 1,949 Mt to 2,077 Mt," the statement to the ASX said.
"This includes 1,330 Mt of Inferred Resource at North of Weipa, which remains
unchanged from 2019.
"The increase was mainly due to changes in the forecast pricing assumptions used in the reserving process."
The estimates are reported in accordance with the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, 2012 and the ASX Listing Rules.