IRON AND STEEL. Iron, in chemis try, ferrum, is a metallic tetrad ele ment, symbol Fe. at. wt. 56, sp. gr. of pure iron 7.8. Iron occurs nearly pure or alloyed with nickel in meteorites, but is generally found in combination with oxygen and as a carbonate. It is widely diffused in rocks, and often forms the chief coloring matter of clays and sands. It also occurs combined with sulphur. The chief ores used for the manufacture of iron are magnetite, hwmatite, brown oxide, spathic ore and clay ironstone. The ore is first calcined, to expel the water and carbonic acid and most of the sulphur, and to convert the oxides to peroxide, which prevents the waste of iron in the form of slag. The calcined ore is then smelted, with the addition of coke and limestone; the limestone unites with the silica present and forms a fusi ble slag, while the oxide of iron is re duced by the action of the carbon mon oxide. The iron thus obtained is called cast or pig iron, and is very impure. Pure iron is prepared by placing four parts of fine iron wire, cut in pieces, and high temperature. Iron is a soft, tough, tenacious, malleable, ductile, white metal, not acted upon by dry air; but it rusts in moist air containing carbonic acid, form ing a hydrate of the sesquioxide.
Iron is mentioned in the Bible as early as Gen. iv: 22. On the sepulchers of the Eg-yptian Thebes, butchers are depicted as sharpening their knives on a round bar of metal which, from being blue, is assumed to be iron. Iron ore is said to have been discovered in Mount Ida about 1406 B. c. The Romans early knew it. Iron mines came into operation in Britain 54 B. C. The exportation of iron was prohibited by the British gov ernment in 1354, and in 1483 the impor tation of such manufactured iron goods as could be made at home was forbidden. In 1783 Cort obtained a patent for roll ing, and in 1784 for puddling iron. The hot blast was discovered by Dalton in 1827, and the Bessemer process for con verting crude iron into manufactured iron and steel in 1856.
Native iron is found in masses or smaller portions in meteorites. It is
nearly pure, still it contains 1 to 20 per cent. of nickel with traces of cobalt, man ganese, tin, copper, chromium, phospho rus, etc. Specimens of ore so pure as to admit of direct forging into horseshoes have been mined at Shepherd's Mountain, in the Iron Mountain district of Missouri.
The following table shows the iron ore shipped from the mines of the United States in 1918 and 1919, by States: one part of black oxide of iron in a Hes sian crucible, and covering it with a mix ture of white sand, lime, and potassium carbonate in the proportions used for glass-making; a cover is then closely ap plied and the crucible exposed to a very The total stocks of iron ore for 1919 were estimated at 12,986,000 long tons.
The production of iron in most foreign countries was seriously curtailed during the war, and in some countries it was en tirely cut off. In 1918 the following countries produced the chief supply, out side of the United States: Cuba, 653,829 metric tons; Newfoundland, 769,821 metric tons; France, 1,671,851 metric tons; United Kingdom, /5,285,083 metric tons; Algeria, 782,047 metric tons.
The imports of iron ore Into the United States in 1919 amounted to 476, 461 long tons, valued at $2,385,689. The exports amounted to 996,569 long tons, valued at $4,308,746. The total produc tion of pig iron in 1919 was about 30, 646,000 long tons, valued at $809,246,000. There were exported 321,261 long tons of pig iron, valued at $12,313,183.
There were in Dec. 31, 1919, 262 blast furnaces in operation. There were at the end of 1919 22 open hearth furnaces in the course of construction.
The steel produced in the United States in 1918 amounted to 44,462,432 long tons. Of this 9,376,235 tons were Bessemer steel, 34,459,391 tons were open hearth steel, 115,112 tons were crucible steel, and 511,693 tons were other steel. Steel production in °the+ countries in 1918 was as follows: United Kingdom, 9,744,891 metric tons; Germany, 14,875, 753 metric tons; France, 1,809,771 met ric tons; and Canada, 1,717,318 metric tons.