Improvements in Process of Manufacturing Metallic Carbides.
Year: 1899

page_text: Date of Application, 8th Aug., 1899-Accepted, 30th Sept., 1899
COMPLETE SPECIFICATION.
Improvements in Process of Manufacturing Metallic Carbides.
I, HERMAN LEWIS HARTENSTEIN, of No. 6322, Ellis Avenue, Chicago, State of
Illinois, United States of America, Manufacturer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
Certain new and useful improvements in process of manufacturing metallic
carbides, of which the following is a specification.
This invention relates to improvements in the process of manufacturing metallic
carbides, and has for its object to provide a process whereby such carbides may
be produced from blast furnace slag, which is under ordinary conditions con-
sidered a waste product.
In the British Letters Patent No. 224 of January 4, 1898, there is set forth
a process and apparatus, whereby metallic carbides may be produced from blast
furnace slag. This slag frequently varies in its composition and is sometimes
deficient in the calcium requisite for the production of a satisfactory result.
I propose to remedy this deficiency by adding to the slag, preferably when this
latter is in a molten condition as it is drawn from the furnace, lime-stone of
carbonate of lime in a crushed or pulverized condition, and carbon in a finely
divided state, and then subject the mixture to the action of an electric current,
whereby it is fused, and the compound metallic carbide described in the Letters
Patent No. 224 of 1898 is produced.
In practice I prefer to employ for the purpose of treating the mixture of slag,
limestone and carbon, the process set forth in the Letters Patent No. 224 of 1898,
wherein the slag is treated while still in a molten condition as it is drawn from
the furnace, and for the purpose of carrying out said process I prefer to employ
the apparatus set forth in the Patent No. 224/98, also hereinbefore referred to,
but I wish it understood that I consider my invention as including the treatment
of the materials named for the production of metallic carbides by any known
process of electro-metallurgical smelting, as, for instance, by the submitting
of the slag, limestone and carbon in proper proportions to the action of the
ordinary electrical furnace. This latter method, however, of carrying out my
invention is ordinarily not to be preferred on account of the expense involved
in the handling of the slag.
In carrying out my invention in its preferred form, I introduce the slag in
the molten condition in which it is drawn from the furnace into the converter
chamber of the apparatus already referred to, and add thereto the necessary
proportion of limestone. This addition is preferably effected with the limestone
in a finely powdered condition, and I deem it best to introduce this finely
powdered limestone along with the finely powdered carbonaceous material by
forcing it into the molten slag along with a reducing gas. The mixture is then
agitated and electrically treated in the manner described in the prior Letters
Patent hereinbefore referred to, the resultant product being a compound metallic
carbide such as is set forth in the said Letters Patent No. 224/98.
While I have referred to carbonate of lime as the matter to be added, and prefer

page_text: the same by reason of its superior cheapress and accessibility, it is obvious that
the limestone may be burned before adding it to the slag, and that other materials
containing calcium may be substituted therefor.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The hereinbefore described improvement in the manufacture of metallic
carbides, which consists in adding to blast furnace slag limestone and a car-
bonaceous material, and subjecting the admixture to the action of an electric
current, substantially as described.
2. The hereinbefore described process of manufacturing metallic carbides,
which consists in bringing blast furnace slag to a molten condition, adding
thereto limestone and a carbonaceous material, and subjecting the molten mass
to the action of an electric current, substantially as described.
3. The hereinbefore described process of manufacturing metallic carbides,
which consists in adding to molten blast furnace slag as it comes from the furnace,
limestone and a carbonaceous material, and then subjecting the molten mass
to the action of an electric current, substantially as described.
4. The hereinbefore described improvement in the manufacture of metallic
carbides, which consists in diffusing through molten slag as it comes from the
furnace, suitable proportions of carbonaceous material and limestone in a finely
divided state, and then subjecting the mixture to the action of an electric
current, substantially as described.
Dated this 8th day of August 1899.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and 25, Cross Street, Manchester,
Agents.