Traditional blast furnaces in Dabieshan

Dabieshan 大别山 is a mountainous region around the point where the provinces of Henan, Hubei, and Anhui meet. The traditional iron industry survived here longer than in most parts of China.

Blast furnace in Xinyang, Henan, photographed ca. 1917 by E. T. Nyström. Reproduced from Tegengren (1923–24, vol. 2, plate 34, left).

Blast furnace in Xinyang, Henan, photographed ca. 1917 by E. T. Nyström. Reproduced from Tegengren (1923–24, vol. 2, plate 34, right).

Blast furnace in Jinzhai 金寨, Anhui, ca. 1958. Reproduced from All China makes iron and steel, 1959.

 Sketch of the Huang Jiguang 黄继光 blast furnace in Macheng 麻城, Hubei, as used in the Great Leap Forward period, and associated requisites, reproduced from ‘Jing geng xizuo’ 1958: 22.

Vertical section of the Huang Jiguang blast furnace in Macheng, Hubei, as used in the Great Leap Forward period, redrawn from ‘Jing geng xizuo’ 1958: 22. Dimensions are given in ‘market inches’ (shicun 市寸, 3.3 cm).

Description by the Swedish engineer Erik T. Nyström (新常富)

The blast-furnaces have an exterior shape reminding of a half barrel put on top of a whole one, the whole height being only about 2.5 m and the width about l m. The furnace is built of [fireclay] and strengthened with longitudinal and latitudinal iron hoops. There is one opening at the back for the tuyère and one tap-hole in front for iron and slag.

The blower consists of a hollow tree trunk, 2.5 m long and of 0.25 m inner diameter, with a piston operated by a long wooden rod. lt is connected with the tuyère by pipes of fircclay, 6 cm inside diameter and 0.5 m long.

The blast-furnace is at first charged with charcoal which is set on fire, whereupon the blast is started and then ore concentrates gradually added. One furnace is capable of turning out about 1000 catties (0.6 tonne) in 24 hours.

The molten raw iron running from the furnace is allowed to spread out in shallow moulds, thus forming thin sheets about 50 ×12 × 1 cm.

The raw iron sells at the furnace at from 40 to 50 cash per catty, or $50 to $60 per ton.

(Quoted, Tegengren 1924: English: 335; Chinese translation, 中 230–231)

Description by the geologist Guo Yujing 郭玉璟, 1932

The blast furnace, or ‘sand-smelting furnace’, has the following dimensions:

It is divided into an upper and a lower section. The outside is hooped with iron bands, four each on the upper and lower sections. These are joined together by several straight iron rods.

The area around the taphole is the most subject to melting. In Xinyang 信阳, sandstone from Jiayu 嘉鱼 County, Hubei, is used [for the taphole stones]; in Shangcheng 商城, diatomaceous earth from Qishui 蕲水 [modern Xishui 浠水], Hubei, is used. The two materials are equally refractory.

Materials for furnace construction

Loess and sand are used, together with unburnt charcoal from furnace slag, washed and powdered. This is called ‘charcoal powder’. The loess is mixed with sand and charcoal powder and plastered evenly on the inside of the furnace. The proportion of loess to white sand is ca. 100 to 34. When this has dried, charcoal powder is plastered over the whole; then the furnace is ready. At the bottom, where the temperature is highest, old taphole stones (diatomaceous earth) and a small amount of salt are added to the charcoal, loess, and sand.

Tuyères

The material is the same as above. This is formed into a long tube, 61 cm long, with outer diameter 10 cm, inner diameter 5 cm, weight ca. 20 kg. One furnace uses four tuyères every 24 hours. The most important detail in the installation of the tuyère is its angle: the blast should be directed precisely toward the taphole. Otherwise the temperature will be insufficient.

The windbox

A wooden windbox is used for the blast. It is 213 cm long, with inner diameter 30 cm, outer diameter 41 cm. Valves are installed inside. The shaft is 366 cm long. It is worked by two persons.

Blowing-in

First the furnace is filled with charcoal. This is burned until the furnace bottom is extremely hot. Then another layer of whole charcoal is added, followed by a layer of crushed charcoal, to a thickness of 61 cm. Then a small amount of ironsand is added, thickness ca. 2.5 cm.

The blast is operated until the top of the furnace burden sinks down; then charcoal and crushed charcoal, thickness 13 cm, and ironsand, thickness 2.5 cm, are added continuously in a cycle. After the third addition of ironsand, molten iron appears. Charcoal and ironsand are added one more time, and then the molten iron is tipped out. At the same time a hooked measuring rod is inserted into the tuyère. If the tuyère has been shortened by melting it is pushed further in, so that it is flush with the inner wall. In one day and night the inputs are:

And the output is

The molten iron is tipped into a large iron ladle which is lined with a mixture of salt and loess and further with charcoal powder. The iron is poured into a sand form, 51 cm long and 13 cm wide.

The furnace lining . . . is subject to corrosion. It should be repaired every two or three days.

The smelting slag does not flow freely; it contains small pieces of charcoal and bean-shaped iron aggregates. These are crushed, washed, and returned to the furnace.

Translated from Zhang Youxian & Guo Yujin 1932: 1: 239–241.

Another, much more detailed, description

is in Tufa liantie 土法煉鐵 1958. This and several other descriptions, from 1916 and 1958, are translated in my Dabieshan (Wagner 1985).

References

All China makes iron and steel. 1959. Beijing: Foreign Languages Press.

‘“Jing geng xizuo” gao chan duo shou: “Huang Jiguang lu” de jishu jingyan “精耕細作”高產多收—“黃繼光爐”的技術經驗’. 1958. Yejin bao 冶金报 1958.45: 20–22, 34.

Tegengren, F. R. 1923–24. The iron ores and iron industry of China: Including a summary of the iron situation of the circum-Pacific region. 2 vols. (Memoirs of the Geological Survey of China, series A, no. 2). Peking: Geological Survey of China, Ministry of Agriculture and Commerce. Part I 1921–23, part II 1923–24. English text and abridged Chinese translation by Xie Jiarong 謝家榮. Chinese title: Zhongguo tiekuang zhi 中國鐵鑛誌, by Ding Gelan 丁格蘭 (Dizhi zhuanbao, A.2 地質專報甲種第二號).

Tufa liantie 土法煉鐵. 1958. Zhengzhou.

Wagner, Donald B. 1985. Dabieshan: Traditional Chinese iron-production techniques practised in southern Henan in the twentieth century. (Scandinavian Institute of Asian Studies monograph series, no. 52). London & Malmö: Curzon Press.

Zhang Youxian 張友賢 & Guo Yujing 郭玉璟. 1932. ‘Henan tie kuang 河南鐵礦’. Henan sheng dizhi diaochasuo huikan 河南省地質調查所彙刊 1: 221–243.

Last edited by DBW 25 February 2023
Stylistic changes 1 June 2024