ISHPEMING — When the iron mines in the Eastern part of the U.S. were stripped of their high-yield ores, Thomas Edison began to tinker with ways to improve the iron content of low-grade ores. He invented a magnetic ore separator using electromagnetics. Iron ore prices were high during the 1880s and so finding a way to separate the iron from waste rock seemed to be a way to make a profit.

The mines in the eastern U.S. were in competition with the high-grade ore coming out of the Lake Superior region. It seems ironic, in a way, that one of Edison’s machines was installed at a mine on the Iron Range.

“At Humboldt, where there is an attempt being made by Mr. Mallory, of Chicago, to concentrate the lean ores of that place by the Edison system, the works are in operation but are not yet running satisfactorily. It is said that a product running over 60% in metallic iron is being secured but it is desired to get it still cleaner, about 65 per cent.” (Iron Ore, March 30, 1889)

Mr. E.G. St. Clair, of Ishpeming, is engaged in studying out a successful plant for the treatment of lean iron ores. He lately made a trip to New York city where he visited Edison ‘the wizard’ in the interest of his plans, receiving valuable instruction. He thinks the Edison electric machine will separate the ore from the rock without any trouble, and this, used in connection with other appliances he has been studying, ought to save enough ore to make a paying business for a mill.

He has a plan of the proposed plant at his office in this city and is experimenting in a quiet way on different kinds of ore. The ore is not handled after it is put in the ore pocket, being carried by endless belts, etc., from one machine to another. Mr. St. Clair has secured the old Magnetic mine, eight miles distant from Republic, where there is a practically inexhaustible quantity of magnetic ore, associated with rock.” (Iron Ore, March 30, 1889)

“The mining men of this region patiently await the result of the trial of the Venstrom magnetic ore concentrator at Michigamme. The Edison machine whish has been put in operation at the Humboldt, is not yet perfected to the satisfaction of the inventor.” (Iron Ore, July 13, 1889)

In December 1890, disaster struck the concentrating plant.

“The concentrating works of the Edison company, located at Humboldt, were consumed by fire on Wednesday evening. The loss is estimated at about $20,000, upon which there was insurance covering about one-third of the amount. The works were ‘just being placed in shape,’ so that the burning of the entire plant is to be regretted. Just what will be done as to rebuilding, we have not learned. It had been given out that Edison was soon to have visited the place and was to have lent his energies to the perfecting of different features of the mill. A box car and a small dwelling house were also consumed.” (Iron Ore, December 6, 1890)

“The burning of the Edison concentrating works at Humboldt is much regretted by those interested in the enterprise for the reason that the company was experimenting with an entirely new process of concentration, one new to the work, and never before tried at any place. The discovery was due to the enterprise of Mr. W.P. Schwartz, who has had charge of the plant for some time. After determining upon the new plan, he fitted up one of the new machines, this necessitating a complete change from the old, and had it at work but a short time when the fire destroyed the works. He had opportunity to demonstrate the fact that that the new method of treatment would secure twice the amount of ore obtained by the old, and that the product was also better.” (Iron Ore, December 13, 1890)

“Thomas Edison, the wizard of Elmo Park, was in this section a few days since, and paid a visit to the scene of his concentrating works wreck. Besides he visited other properties in that vicinity. He is still employed in perfecting a machine for the perfect and rapid separation of ore from rock, and thinks he has achieved considerable in this direction. At Ogden his new plant has just started up. This is said to have a capacity of 2,000 tons of concentrated ore per day, although no such amount has been treated by it in that time.

Mr. Edison is a very modest appearing man and would pass along the street before thousands of people not one of whom would look upon him as a wonderful inventor were he not personally known to them.

Just what will be done with reference to the works at Humboldt has not yet been decided upon.” (Iron Ore, June 13, 1891)

The economic climate of the 1890s was vastly different than that of the 1880s and high prices were no longer being paid for iron ore.

“There has been nothing done, so far as we can learn, by the Lake Superior companies in the way of making contracts for ore deliveries this year. At the time a year ago, several sales had been consummated. The season for contracts grows later with each succeeding year.” (Iron Ore, January 7, 1893)

“Mr. Edison now comes with another machine, and is going to make a practical trial of its virtues at the old Spurr mine, near Michigamme. We believe he has already made a test of it in the east, and is putting up his plant at the Spurr with the idea of locating it there permanently, with the object in view of earning a profit out of the lean ores of that locality.

While the gentleman world famous for his wonderful inventions may supply the electric current successfully to street cards and telephones, and make it possible for these enterprises to earn dividends for their shareholders, we see no chance for him to do this in the concentration of the ores at the Spurr. When iron ore was selling at from $6 to $7 per ton there was an inducement offered for the treatment of the badly mixed ores of this district, but today there is no possible chance for such a mill to earn a dollar.” (Iron Ore, January 7, 1893)

There is no indication that Edison ever built the plant at the Spurr. While the concentrating machines were regarded as a failure, the electromagnetic separation of magnetic iron ore from the waste rock is part of the pelletization process now in use.