510 F. H. Hatch — The Iron Ore Supplies of the World. 



France. The ore — geologically a bedded oolitic ironstone of Jurassic 

 age — is a carbonate, partly oxidized to brown ore, containing from 

 27 to 36 per cent iron, as mined, with an average of 10 per cent 

 moisture. The ores are in part siliceous, in part calcareous, and good 

 smelting charges can be obtained by mixing these two varieties in 

 suitable proportions. A valuable feature is the high-phosphorus 

 content, permitting the manufacture of a basic pig containing from 

 17 to 1"9 per cent phosphorus, and suitable for the basic Bessemer 

 or Thomas process. In the greater portion of the field only one bed 

 (the " grey bed ") is worked ; but its thickness varies from 6 to 20 feet 

 and the reserves are very large, being generally put down at about 

 5,000 million tons. 



Besides the minette ores, France possesses in Normandy, Anjou, 

 and Brittany, oolitic bedded ores of Ordovician age. These occur 

 in a number of detached synclines either as carbonate or hseiuatite. 

 The ores (calcined in the case of the carbonate) average from 45 to 

 48 per cent iron, 10 to 20 per cent silica, and 0'4 to 0'8 per cent 

 phosphorus. They are smelted to basic iron at the Mondeville 

 works, near Caen, for the Normandy deposits, and at the Trignac 

 works, near St. Nazaire, for the Brittany and Anjou deposits. The 

 reserves are estimated to be about 200 million tons. 



With the cession of Alsace-Lorraine, Germany lost its biggest 

 orefield, but it retains a number of smaller producing districts, the 

 reserves of which amount to some 1,300 million tons. 



United States. 



Lake Superior produces four-fifths of the iron-ore output of the 

 United States. (In 1918 it was 86 per cent of a total of 70 luillion 

 tons.) The ore is derived from a series of ranges in Minnesota, 

 Wisconsin, and Michigan, respectively known as the Mesabi, the 

 Marquette, the Menominee, the Gogebic, the Vermilion, and the 

 Cuyuna, the order given being that of the importance of the annual 

 production. At first all the ore was obtained from open- workings 

 by steam-shovel and other forms of mechanical excavator, and was 

 shipped without further treatment. Mining is, however, becoming 

 more and more necessary, and in places water-concentration, and 

 even calcining, are being introduced in order to raise the iron 

 content and diminish the silica and sulphur. The ore is in the main 

 a haematite, but in part is hydrated. Magnetite is only found in the 

 Marquette range and in small proportion. The average iron content of 

 the ore mined is diminishing, having fallen from 56'2 per cent in 1902 

 to 52 per cent in 1912. The phosphorus content, too, is increasing, 

 the percentage of Bessemer ore having fallen from 64'9 in 1902 to 

 42-9 in 1912. 



From the iron ranges the ore is railed to the shipping ports of 

 Duluth, Ashland, Marquette, and other ports at the western end of 

 Lake Superior, and from there shipped by water to be smelted in 

 Chicago, on the shore of Lake Michigan, or at Cleveland and Buffalo 



