The story of iron making in India reaches back into the recesses of the past to times when communities evolved their own techniques of mining, smelting and production. Today, these communities have discarded their traditional knowledge and skills, adapting instead to new occupations.
The discovery and use of iron began around the middle of the second millennium BCE, independently, in at least three regions – Karnataka in the south, U.P-Rajasthan in the north and West Bengal-Bihar in the north-east. This led to a second urbanization in India and finally to the Mahajanpadas, various kingdoms, in India. During the early phases of the Iron Age, locally available iron ore was exploited and an infant form of smelting was used.
Initially, iron was used for making household objects and decorative items but then, as the requirement for implements made from this metal and various other uses of it spread, reaching out to inaccessible rural settlements, refinement became necessary. Certain categories of iron implements constantly needed improvements. And so, while attempting to improve the quality of iron, ancient Indian blacksmiths, through trial and error, produced steel – an alloy of iron and carbon which is stronger and harder than iron. In addition, these people discovered and perfected heat treatment techniques. Because of this, steeling of iron became possible and heat treated steel was used for a variety of products, including agricultural tools.
In the course of time, Indian iron smelters and blacksmiths made such rapid progress in ferrous metallurgy that they could forge large iron structures like iron beams such as those of the Konark temples and massive pillars like the famous one in Delhi. This tradition of iron making continued even in the British period. The quality of steel was so good that in 1875 more than fifty thousand tonnes of steel ingots were exported to the United Kingdom for the construction of the world famous London Bridge. Pre-industrial iron smelting and forging flourished as a cottage industry in the Indian subcontinent until the beginning of the 19th Century and, in fact, is still alive in some remote areas.
The iron ore deposits in India were available right from the surface and so little mining was required. Techniques of smelting, of course, varied substantially from region to region. The size and shape of the furnace differed, as did the types of tuyeres and bellows, the slag disposal techniques and refining methods. However, the basic principle remained the same.
Each tribe had its own distinct method of working and furnace design. There were, in fact, three types of furnaces – Kamar Joda, Chingle Becha and Jiragora, which were popular among Indian blacksmiths. Agarias communities, in Chottanagpur Plateau and in parts of Orissa, were considered to be the well known iron smelters of their times. These people used to carry the ore in specially made baskets, which were locally called dadu or tukna. Mining here was practiced as a group activity, some engaged in digging of ore, others in hand picking and cleaning the ore pieces and packing them into the dadu or tukna. Digging was carried to a depth of six to eleven feet.
The practice of ore dressing in different parts of the sub-continent was more or less the same, irrespective of the type of ore. This began at the mining area itself. The ore was picked by hand and then broken into smaller fragments with a flat hammer. The crushed material was accumulated and winnowed against a strong wind. In parts of south India, the ore was further enriched through density separation by washing of finer particles of quartz in the river. The Agarias roasted the ore in an ordinary fire of wood and bark. These communities used the Jiragora type furnaces for smelting iron ore. In this design, the shaft tapered towards the top and had three openings. One opening was at the top and the others at the bottom. The opening at the top was used for feeding ore and charcoal. Often, a bamboo platform, resting on poles and plastered with clay was erected at the level of the furnace. The smaller and longer openings at the bottom were used for supplying the blast and retrieving the bloom and slag respectively.
As time moved on, this technical heritage diminished. Iron producing communities who were once masters of metallurgy are now trying to adapt themselves to new jobs, discarding their own heritage, inadvertently contributing to the passing of traditional technology and the erosion of a bygone way of life…the inevitable result of change.
Author: P. P. Deshpande Photographs: Vibha Tripathi Source: Heritage India Magazine Volume 3, Issue 3 (2010)