Rio Tinto Group, one of the world's largest mining companies, reported a 628 million ton upgrade in copper resources at its Kennecott Utah Copper Bingham Canyon Mine.
The newly found resources constituted the increase by 0.48 %, totaling copper estimate to 637 million tons.
Now the company is engaged in developing methods for open-pit mining.
Kennecott's Bingham Canyon Mine has produced more copper than any mine in history - about 18.1 million tons. It has been in operation for more than 100 years. The discovery will allow the mine to significantly extend its life.