Iron Ore
Almost every one knows that there are extensive copper deposits along the Lake Superior shore of what is now northern Michigan. In the 17th century word of these was several times taken to Europe where in old publications was mentioned a huge ingot of copper from which the Indians chopped pieces with their hatchets. At that early date maps of the region were drawn which are wonderfully accurate, and, from time to time over a period of a century and a half, adventurers attempted to gain wealth in this favored region.
Map Showing Distribution of Iron Ores of America
However, despite the definite knowledge of considerable mineral wealth there and rumored claims of much more, Michigan at the time of her admission to the Union in 1836 bitterly opposed having what is now the northern peninsula included within her territory in lieu of a ten mile wide strip of northern Indiana and Ohio, and it has been said that she nearly went to war to resist it. Even after the discovery of the iron ore deposits, no one realized the full importance of the minerals of this region.
Showing Typical Mesaba Ore Bed Which, after Earth Covering is Removed, Becomes an Open Pit Mine
During the many years of campaigning for Federal help in the building of a canal at Sault Sainte Marie, the fisheries, valued at $1,000,000 a year, were given as the leading reason why a canal should be built, and it was no less a personage than Henry Clay, who, in opposing appropriation for this purpose, referred to the project and the district as “beyond the remotest settlement, if not in the moon.”
Now, within eighty years of that time, the annual tonnage of shipping passing through the Sault Sainte Marie canal is as great as the combined tonnage from the ports of New York, London, Liverpool, Antwerp, and Hamburg, and, as against the $1,000,000 value of the fisheries, the value at the mines of the ore alone shipped from this region amounts to about $100,000,000 yearly.
Shenango Open Pit Mine, Chisholm, Minn.
Interior of a Hard or Lump Ore Mine
As the copper deposits are mostly along the shore of the lake and the great iron ore beds occur seven or more miles inland, the latter were not discovered until Sept. 19, 1844, when William A. Burt, a Deputy United States Surveyor, noticed that the needle of a solar compass of which he was the inventor became unreliable. In looking about to discover the magnetic source which must be the cause of the variation, members of his party discovered ore just beneath the sod near what is now Negaunee, Michigan. Inventor-like, Burt’s only concern was to devise some preventive for future interference by stray magnetic currents. He simply noted in his book that there was here a deposit of iron ore and neither he nor any of his party profited or apparently attempted to profit from the discovery.
Showing Ore Body and Shaft Method of Mining
The Indians seem to have had no previous knowledge of these ore deposits.
The first shipments of ore naturally were samples taken from what afterward came to be known as the Jackson mine and trials of them in blacksmiths’ forges were made at Jackson, Michigan (from which town went the first seriously-minded pioneer, Philo M. Everett), and at Cucush Prairie. They were soon afterward tried in a blast furnace at Sharon, Pa.
The first plan was to build forges and manufacture iron near the mines. So there was established on Carp River a forge to which the ore was hauled in winter when the ground was frozen. It turned out, however, that while very good bar iron was manufactured here, it could not be delivered in Pittsburg at a cost less than $200 a ton. As the market rate for iron then was but $80 a ton the plan was not financially successful.
Lighting the Fuses in a Shaft Mine
Attention was turned to the shipping of ore to furnaces better located as regards coke supply and market. It was possible to make this a profitable undertaking only through cheap ore handling and transportation. So, to-day, the ore which is better adapted than the other raw materials for handling by labor-saving devices and transporting without deterioration, is taken to the coke and limestone, and to the market for the product. While the weight of coke used is but half that of the ore smelted, its greater bulk, loss by breakage when handled in quantities, and deterioration upon exposure preclude its manipulation in the way which would be necessary to get it to the ore.
View of Hull-Rust Mine, near Hibbing, Minn.
The marvelous development of this territory into the greatest ore producer of the world, including the hauling of the first small shipment on mule back, the building of the plank and then the “strap” railroad with grades so steep that the small trucks often ran over and killed the mules, the building of the steam railroad, the successive building and enlarging of canal locks at Sault Sainte Marie connecting for use of ever larger and larger ore boats the waters of Lake Superior and Lake Michigan, and the growth of ore boat fleets to such size that during the shipping season scarcely ever is one boat out of sight of another over the entire 800 mile journey from Duluth to the furnaces along Lake Michigan and Lake Erie, is within the memory of men still living. Marquette was the shipping point during the earlier days and the history of this and adjacent regions during the latter half of last century vies in pioneering flavor with the tales of our early western frontiers, and with the more recent Yukon mining camps.
The Routes by Which Lake Superior Ores Go to the Furnaces
The first two mines, the Jackson and the Marquette, have come to be particularly well known historically. The development of these and other ranges in northern Michigan and Minnesota, particularly the Menominee, Gogebic, Vermillion, etc., and, since 1890, the Mesaba and Cuyuna, have brought about revolutions in ore digging, handling and transportation, which followed each other with extreme rapidity. The ore carrying boats, for instance, may almost be said to have jumped from a length of three hundred to six hundred feet, and the Sault Sainte Marie canal locks were several times almost immediately outgrown, though rebuilt again and again, each time so much larger than before that they were deemed impossible to be outgrown.
Loading Ore at an Open Pit Mine
Showing Other Typical Ore Bodies, Shaft Mined
Practically all of the ore beds, with the exception of the Mesaba, yield hard or lump ores and most of them are shaft mines in which mining has to be done underground and the ore blasted down. Blast furnaces had never used any but lump ores when along came discovery of the immense soft ore deposits lying just beneath the surface of the ground over a region one-hundred miles long in what is known as the Mesaba district of Minnesota. These soft ores were so accessible and so rich that they drew the attention of the iron makers of the whole country. But, alas! While perfectly good in every other respect, they were merely dry powder and not adapted to blast furnace methods. There were great discussion, excitement, and ridicule among or at those who invested in these soft ore mines. Eventually, of course, blast furnace men worked out feasible methods of converting soft or what are termed “Mesaba Range” ores into iron in the blast furnace. Those brave spirits, who in the face of ridicule dared to invest in and develop Mesaba properties, have long been reaping their financial reward which still shows no sign of diminishing, as “Mesaba Range” mines are “the” mines of to-day.
A Close View of the Hoover & Mason Unloaders
While it may be done, it has not been found desirable to make up the entire “burden” or furnace charge of soft ores alone as long as lump or hard ores are obtainable to mix with them, but often more than half is soft ore.
Starting an Open Pit Mine. The Earth Covering is Being Removed
While ores from the shaft mines, called “Old Range” ores, are won by going down into the earth sometimes as far as 3,000 feet, drilling holes in the rock, blasting down the ore, and loading it into buggies which are hoisted to the surface, “Mesaba Range” ores are made available by simply “stripping” off the thin earth covering, then caving or loading with steam shovels the soft ore into railway cars. Some of the illustrations presented show the ore trains and shovels, and the manner in which the open pits are worked in terraces.
One naturally wonders how it is possible to mine and carry these ores to the shipping ports of Duluth, Superior, Two Harbors, Marquette, Ashland, Escanaba, etc., put them aboard ore carrying boats, transport them by steam power to Milwaukee, Chicago, Gary, Detroit, Cleveland, Pittsburg, Buffalo, and the many other iron centers and convert them into iron and steel at a profit. This, of course, is only possible because of the inventive genius of man. For every operation ingenious machinery has been constructed which has brought the cost of such operations to its lowest terms.
Unloading Cars of Coal or Ore is a Simple Matter with the Modern Car Dumper
Ore Cars are Unloaded by Gravity at Docks. The Chutes Then Convey the Ore from the Ore Pockets into the Boat’s Hold
By modern methods the cars carrying the ore from the mines are run up trestle-work into positions above the ore bins high over the docks. The mammoth ore carrying boats are merely steel shells with quarters for crew and machinery at bow and stern, and hatches built with exact twelve foot centers between. They are tied alongside the dock, long steel chutes, also spaced twelve feet apart, are lowered along most of the length of the boat and the ore slides into the vessel’s hold evenly all along as it has to do, else the buoyancy of lighter parts of the boat might break the frail shell. The entire load of 10,000 tons of ore is ordinarily taken aboard in less than one hour. Pulling out immediately the vessel traverses Lake Superior, the Sault Sainte Marie canal, Lake Michigan or Lakes Huron and Erie as the case may be, and ties up at the dock at destination. Years ago it would have been unloaded by men with buckets or wheel-barrows, requiring some days at best. Now, however, the hatches are uncovered and several ore unloaders with huge clam shell buckets taking as high as fifteen tons of ore at a “bite” descend like vultures upon it. Within four or five hours the boat is again empty with no manual labor having been done upon the ore from the mine to the furnace pile with the exception of a little heaping up of the ore in the corners of the boat’s hold, which the ore unloaders could not reach.
Hoover & Mason Unloaders at the Illinois Steel Co., South Chicago, Ill.
A young man named Alexander E. Brown could not bear, in the old days, to see the ore so awkwardly unloaded, and in 1880 started the procession of ore unloading devices. There are now several successful ore unloaders of which the Brown hoist, the Hoover & Mason, and the Hulett are probably the best known. With the Hulett unloader the operator has to be an aviator, as his position is directly above the grab bucket. He descends into the hold with the bucket, comes up with it and is with it in its entire journey from the boat’s hold to the dump and back again. It must be dizzy business.
The Hulett Unloader. Note the Operator’s Head in White Spot Just Above the Grab
Time is too precious to hold the boat at the dock long enough that each bucketful, large as it is, can go directly to its final bin. It is dropped just back of the unloading machine from which it is again picked up by other buckets which carry it back toward the furnaces and deposit it in cement ore troughs awaiting further journey to the ore house, from which it goes to the furnaces. The empty ore boat immediately coals with whole car loads of the fuel dumped into chutes leading to her bunkers by the car dumper and proceeds on her way back to the mines for another cargo of ore. The round trip, including loading and unloading, requires but seven days.
A Good View of the Hatch System of Modern Ore Boats and Four Hulett Unloaders at Work
As in many other lines of commercial endeavor of to-day, speed and large tonnage have been the aim and it would seem that in ore handling and conveying devices the limit has about been reached. The big steam shovels, gravity docks, ore tanks or boats, and unloading and coaling devices, with the low cost of water transportation have made our modern iron and steel preëminence possible. To show the importance to us of this water transportation, we might mention that the rate for carrying ore from Lake Superior ore ports to the Lake Erie furnaces has been as low as $.0007 per ton per mile while the transportation cost by way of a well operated railway at that particular time was more than $.005 per ton per mile—more than seven times as much.
The Rehandling Bridge with Stock Ore Pile and Blast Furnace at Rear
Though for some years past more than three-quarters of all of the iron ore used in the United States has come from seven or eight mines in the northern peninsula of Michigan and the adjacent part of Minnesota, it must not be understood that the Lake Superior mines are the only ore deposits in this country. Figures show that such an inference is far from the truth. It is true, however, that they have made the United States what it is, the leading iron producer of the world. There are still immense quantities to be mined on the Lake Superior ranges. Their heavy production of cheaply handled high grade ore has, of course, held back development of other districts, which also have great natural resources. The Birmingham, Ala., region for instance, is a great ore and iron producer, right now producing the third largest tonnage of any district in the country. Some time in the not far off future, Alabama with her great deposits of iron ore, coal, and other natural resources is going to announce herself in no small voice. New York, Pennsylvania, Tennessee, and Virginia rank next after Minnesota, Michigan, and Alabama as ore producers, and several other states of the Union are not paupers in resources of iron ore.
Hulett Grab Buckets in the Hold of an Ore Boat
We should not get so enthusiastic over our ore supply and iron production as to think that other countries are devoid of such material. Almost every civilized country has ore enough that it does pretty well. With many the trouble is that the ore has objectionable constituents or that supply of cheap fuel is not available. Germany has large deposits of iron ore, but until the invention of the basic Bessemer process about 1870 she was handicapped because of the high phosphorus content of her ore. The basic processes, both Bessemer and open-hearth, allow of the removal of this phosphorus during the conversion into steel, and they therefore brought Germany to the front as an iron producer.
The excellence of Sweden’s iron and steel has long been known the world over. Sweden produces approximately one per cent of the world’s total production of iron and steel, but her ore has been of such high grade that iron made from it has maintained its position as a standard for use in the manufacture of highest grade crucible steels. The very finest steels for cutlery and tools, and even the softer grades of steel of northwestern Europe, have been made from Swedish iron as a base.
Iron ore, of course, is classified by geologists and chemists into varieties with such names as hematite, magnetite, siderite, etc., which here little concern us.
To be worked at a profit, the iron content of the ore must be high with the smallest possible amounts of undesirable impurities, particularly phosphorus, sulphur, and silica. There are, however, certain impurities which are not undesirable, for instance, lime, which will act as a flux and neutralize the effect of some of the undesirable impurities. For these reasons the prices for iron ore are based on the iron content and modified by the relative amounts of undesirable and desirable impurities. Phosphorus is almost a domineering factor and at present approximately fifty cents a ton more is paid for Bessemer ore (that containing less than .050 per cent phosphorus) than for non-Bessemer ore. As might be expected the best ores have been the first used and the grade is constantly falling. Instead of the 66 per cent iron ores of some years ago those coming nowadays contain not much more than 59 per cent of iron and the Bessemer ores described above are getting scarcer, so that for some years practically all of the furnaces have been mixing with them as much higher phosphorus ore as could be used without pushing the phosphorus content of the mixture over the allowable limit.
We often hear people surmising what is to become of us when all of the iron ore of this planet has been used. There is no harm in taking stock of resources and in this case it does us much good. It happens that each time the count is taken of iron ore available and that which under future and better methods of working can be utilized, we find ourselves immensely better off than the previous report had made out and we have less cause to worry about the future. The last inventory was taken by the extremely ambitious International Geological Congress held at Stockholm, Sweden, in 1910. It shows that the world yet has enough rich ore to make 10,192,000,000 tons of iron, and, a further supply of ore for 53,136,000,000 tons of iron, which could be used if necessary.
So we will get along for a while yet.
CHAPTER III
THE OTHER RAW MATERIALS
Old Charcoal Kilns, near Negaunee, Mich.
Since the beginnings of iron manufacture, charcoal has been a favorite fuel. Though during the past two centuries coke has grown to be the standard, with anthracite and some few bituminous coals finding use in certain favored localities, charcoal may be considered the fuel which developed the iron industry, at least until recent years.