A group of archaeologists recently unearthed a 2,000-year-old blast furnace for iron

smelting in central China's Henan province, known as part of the birthplace of the ancient Chinese civilization.

The archaeologists believe that the blast furnace was first built during the Han Dynasty (206 B.C. to A.D. 220) and it had never stopped operation during the last two centuries of the Han Dynasty.

The oval blast furnace was found in an ironworks ruin in Lushan County of Henan Province.

"It is the largest, best preserved and most advanced ancient blast furnace that has ever been discovered in the world," said Liu Yuncai, engineer-in-chief of the Beijing Capital Steel Company and a well-known metallurgist in China.

"It has separate notches for slags and refined irons and thus can largely improve its efficiency," Liu said.

He noted that the blast furnace also has a well-designed stuffing-platform and a special facility to make use of the river motion power to save labor.