Iron production
Iron production converts iron ore into pig iron through a process known as smelting at a furnace. Early in the history of iron production in the US, most furnaces used charcoal as fuel, so charcoal production and iron production were often closely linked. Ironworks are some of the first and most enduring examples of industry in the United States, and remnants of them survive particularly well in rural parts of the country. [1]
History
In the eighteenth and nineteenth centuries, small-scale metalworking operations produced everyday objects like many forms of kitchenware, toys, building materials, and tools. [2]
Iron Communities
Self-sufficient communities, called iron plantations, were built around these furnaces. Many workers were needed to run an iron plantation, including colliers, miners, woodcutters, molders, founders, patternmakers and their helpers. Hopewell Furnace, in Pennsylvania, employed roughly 200-250 people in the nineteenth century. Workers at iron plantations would often bring their families along with them, so the community at Hopewell Furnace would have consisted of about 600 people. [3] The lands of iron plantations would include housing, gristmills and sawmills, farming land, and vast amounts of woodland, as well as barns, company stores, springhouses, blacksmiths, schools, churches, carpenter's shops, forges, casting houses, charcoal storage, and many other buildings. [4]
Fuel
Prior to the 1830s, every furnace in the US burned charcoal as fuel. Around the 1860s, coal and coke began to replace charcoal in some areas, but overall iron production increased so much that the use of charcoal still continued to rise up to 1890, and the last charcoal-powered furnace in the US was in blast until 1945. [5]
Operation
Efficiency was known to be inconsistent between furnaces in different places and at different times. Factors affecting this include differences in furnace construction and operation, as well as varying compositions of iron ore and qualities of charcoal used. [6] Ironworks had to be near water and sources of raw materials such as charcoal, limestone, and iron ore. [7] Colonial ironworks used a variety of techniques to produce iron.
Bloomery
A bloomery was a small operation that heated iron ore to refine and shape it, producing wrought iron. Bloomeries needed simple equipment like a hearth, a bellows, and a tool for manipulating the iron. Bloomeries were common in colonial America, and operated between the seventeenth and twentieth centuries. Disadvantages of bloomeries include limited production, wasted heat, and an inability to completely separate the iron from slag.[8]
Blast Furnace
Notes
References
- Straka, T. J. (2014). Historic Charcoal Production in the US and Forest Depletion: Development of
Production Parameters. Advances in Historical Studies, 3, 104-114. http://dx.doi.org/10.4236/ahs.2014.32010
- McVarish, Douglas C. 2008. American Industrial Archaeology: A Field Guide. Walnut Creek, Calif.: Left Coast Press, Inc.