What is Iron Ore and Why was it mined?
Here is an interesting summary of iron ore production in Maryland…..
Iron is a silvery-white, solid metal that commonly appears as a brown and sometimes nearly black oxide of iron. Its chemical symbol Fe, is derived from ferrum, the Latin word for iron. By volume, iron is the most abundant element, making up 34.6% of the earth.
To refine iron ore it is necessary to separate the physical and chemical impurities in the ore. Iron oxide is the main component of iron ore. By burning charcoal fuel, carbon monoxide gas is formed from the charcoal and iron oxide, which can react further to form carbon dioxide. When the carbon dioxide is released, iron (with some remaining impurities) is the result. Various processes were used to create iron: a simple forge, a bloomery forge or a blast furnace. Traditionally, four tons of ore can produce one ton of iron. The ore is dug out of a pit and then transported to a forge, where impurities are extracted, leaving the raw iron.
Because fire created from wood alone is not hot enough to melt the iron from the ore, charcoal was used as a fuel. Charcoal is partly burned wood produced by a smoldering process over a period of two weeks. Wood is stacked in a mound and covered, usually with turf to control the air supply and ensure that the wood does not catch fire. The chestnut trees were excellent sources of charcoal. Most of the region’s charcoal was created by “colliers” who moved about the country making use of resources where available.
Iron processing employs a simple forge that would resemble a backyard barbecue of today. The iron was heated and hammered by a smith to remove most of the impurities. Repeated heating and hammering resulted in a workable product. This method was time consuming and labor intensive. Mined ore was initially processed in a bloomery forge. As technology advanced, a blast furnace was developed. This advance in technology eliminated the need for alternate heating with hammering to pound out impurities, making this a more efficient method of production.
The final product was known as “Pig Iron”. This iron was heated and then formed by hammering, rolling or casting into items such as weapons, pots, nails. etc.
Why was there such a demand for iron?
The Great Northern War (1700-1721) between Sweden and Russia created a critical need for iron ore throughout Europe. England, a major importer of highly regarded Swedish iron was forced to look at its American colonies for its iron needs. As iron exports from Sweden slowed, the beginning of the English colonial iron industry can be traced to the creation of iron works on the Rappahannock River in Virginia in 1713. Iron quickly became a principal component of the early colonial economy. The iron industry was the basis for the wealth of the nation’s early leadership and the foundation of the new United States. George Washington’s family involvement in local iron mining provided some of the wealth to pursue other significant and profitable ventures.
In 1723 John England arrived in America and began operating the Principio Furnace in Cecil County, MD. The Principio venture was a very successful operation due in part to a corporate structure resembling one of a modern-day company. Among its board of directors were members of George Washington’s family. Also in 1723, Samuel James and investors built Abingdon Furnace with financial support from some of the leading iron masters in Pennsylvania. Lack of an economical supply of flux caused the operation to fail and the works were sold at sheriff’s sale in 1735. Others continued to mine ore, but, by the turn of the 20th century, the last of the proprietors ceased operations.
The iron forges in NC experienced similar fates.
Post-Civil War industrialism drastically changed the iron industry in the South. Ownership of ironworks operations before the Civil War centered on a singly owned plantation style management structure. After the war, many individual and family owned operations attempted to improve management and marketing by consolidating and incorporating. Advances made by charcoal fueled iron makers could not be met by iron operators in the South. North Carolina manufacturers could not build larger furnaces or a greater number of furnaces to match the production of the iron makers in the areas where there were abundant, high-grade coal resources.