China has detected an additional 200 tonnes of gold in Laizhou, Shandong Province, making the cumulative gold reserves of the Xiling gold mine 580 tonnes, the largest single gold deposit nationwide.

The economic value of the gold reserve is estimated at 200 billion yuan.

"The size of the deposit is the largest in China, and a rare figure globally," said Chi Hongji, the head of Xiling gold mine's exploration group.

The main ore body of the Xiling gold mine is 1,996 meters long, 2,057 meters wide with a maximum thickness of 62.35 meters, which provides 4.26 grams per tonnes on average. It is estimated to produce 10,000 tonnes of gold ore per day for over 30 years.

"We drilled more than 180 holes over 300,000 meters. One of the drill holes is 4,006.17 meters deep, a precedent for small-diameter drilling in our country," said Feng Tao, deputy general manager of Shandong Gold Group Co., Ltd., the owner of Xiling gold mine.