iron-slag-samples
Preparing iron slag samples for studying its microstructures Image courtesy: Tiatemjen Tzudir

Scientists from Nagaland University and the Indian Institute of Technology, Guwahati (IIT-G) have studied the history and evolution of smelting in Wui village of Tuensang district of Nagaland, agencies stated quoting a report by Rayies Altaf of the India Science Wire.

The village is well-known for its traditional art of iron-smelting and iron tool production since pre-colonial times.

In the medieval times, spears forged from Wui were highly valued. Iron smelting was once the primary source of livelihood for Wui people. Smelting of Wui community was of exceptional quality and kings from even far off places such as Myanmar would get their weaponry specially made from Wui. However, iron smelting is a dying art and people of Wui are struggling to preserve their traditional knowledge.

The researchers studied various chemical properties and compositions, quality and quantity of mineral iron content and other oxides to grasp the use of early iron technology in Nagaland.

It emerged that iron ore used for smelting in early days was primarily mined from this region. Thus it was, perhaps, a major source of iron-ore in Nagaland.

The researchers excavated two trenches at two different localities of the village. This was done on the assumption that the people from this area may have been engaged in iron-smelting for generations and, therefore, there was a high probability for extracting slag refuse from the deep layers of the trenches, which may prove vital for understanding early metallurgical practice.

The first trench revealed a four metre thick cultural deposit, revealing six layers. The excavation yielded cork-mark potteries, animal bones, glass beads, slag and good quality charcoal. The second trench too revealed a thick habitation deposit. Evidence from this trench included plain and cork-mark potteries, perforated roof tiles of slates, glass beads and charcoal. Charcoal from both trenches was carbon dated and their age ranged from 800-753 BCE to 980-1053 AD.

An analysis of microstructure iron slag and ore samples was done using X-ray diffraction. Hardness test was also done to understand microstructures in terms of its strength and hardness. Electrical furnace test was done on the iron ore sample to examine the chemical variations. All these tests provided detailed account of the presence of different mineral compositions.

Tiatemjen Tzudir, one of the co-authors of the study was quoted as saying that this research is part of an ongoing study and that they are looking for further evidence for smelting and iron smithing for better understanding of technological and social processes involved in pre-modern iron production in Wui and other sites in Nagaland.

The research team included Tiatemjen Tzudir and Tiatoshi Jamir from Nagaland University and Sukanya Sharma from IIT-G. The study results have been published in journal Current Science.