(Yicai) July 1 -- Zijin Mining Group’s stock price rose after the authorities in China confirmed that one of the firm’s mines is now the country’s biggest for copper after its reserves were found to be 76 percent larger than initially determined.

The shares of China’s largest copper producer [SHA: 601899] closed 2.7 percent higher at CNY18.04 (USD2.50) each today. The wider Shanghai market rose 0.9 percent.

The reserves of Julong Copper Mine, in which Zijin has a 50.1 percent stake, are nearly 5.8 million tons bigger than thought, equal to 14 percent of China’s total as of late 2022, Zijin Mining said after the market closed on June 28, citing a natural resource ministry review. Located in the Xizang Autonomous Region, the mine’s reserves will increase to 25.9 million tons from 14.7 million.

The company’s Tongshan Copper Mine in Heilongjiang province will also increase its reserves to 3.8 million tons, an increase of 3.7 million tons, the Fujian province-based firm added.

Zijin Mining has started expanding the Julong project, which is situated on a plateau at an altitude of 5,200 meters, to raise the mine’s annual copper output to a point between 300,000 and 350,000 tons from last year's 154,400 tons.

The second phase will start trial production in the first quarter of 2026, and it will also boost the output of molybdenum and silver. The third phase, which is still under planning, should further increase the mine’s annual copper proaction to 600,000 tons, making it the world’s biggest.

Zijin Mining also expects to expand the Tongshan project this year to add an annual 12,000 tons of copper production, as well as hike the capacity of associated minerals molybdenum, gold, and silver, the firm said.

The company produced 1.01 million tons of copper last year, making it the only Asian miner to exceed the 1 million ton mark, according to its annual report. China's total output was 1.6 million tons, according to data from the China Nonferrous Metals Industry Association.

Editor: Emmi Laine