Ho-pi

At Ho-pi (Hopi) in northern Honan two modern shafts were under construction in 1957-8; but the coal from Ho-pi is expected to be of rather poor quality and so will be mixed with rich coal from P'ing-ting-shan (Pingtingshan) in central Honan for coke making.

1963, “The Coal Industry in Mainland China Since 1949”, in The Geographical Journal, volume 129, number 3, →ISSN, →JSTOR, →OCLC, page 333

At Ho-pi (Hopi) in northern Honan two modern shafts were under construction in 1957—58: but the coal from Ho-pi is expected to be of rather poor quality and so will be mixed with rich coal from P’ing-ting-shan (Pingtingshan) in central Honan for coke making.

1974, D. J. Dwyer, editor, China Now: an Introductory Survey with Readings, Longman, →ISBN, →LCCN, →OCLC, →OL, page 236

In time, this evolved into the room and pillar (or pillar and stope) method that came to be used widely, especially in Chinese coal mines. We have good evidence for the use of this technique in the remains of a Sung/Yuan (c. +13th century) coal mine at Ho-pi 鶴壁 in Honan (some 25 km southwest of An-yang).

1999, Joseph Needham, Peter J. Golas, Science and Civilisation in China, volume 5, Cambridge University Press, →OCLC, page 299