Improvements in the Art of Producing Calcium Carbide.
Year: 1898

page_text: Date of Application, 1st Jan., 1898-Accepted, 19th Feb., 1898
COMPLETE SPECIFICATION.
Improvements in the Art of Producing Calcium Carbide.
I, JULIUS LEEDE, Engineer, of No. 915 Chicago Avenue, Minneapolis, in the
County of Hennepin and State of alinnesota, one of the United States of America,
do hereby declare the nature of this invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the follow-
ing statement:—
My invention relates to improvements in the art of producing calcium carbide.
The object of my invention is the production of calcium carbide by a simple,
effective and cheap process.
Heretofore this substance has been obtained, in commercial quantities, by treat-
ing a mixture of pulverized carbon and lime in an electrical furnace, and by
treating carbon and lime saturated with liquid hydro-carbon in such furnace.
I have discovered that the mixture of lime and heavy hydro-carbons, such as
pitch, bitumen, natural or artificial asphaltum, and like substances, which fuse at
moderate heat, treated in a retort to drive off the light hydro-carbons, gives a
product approximating, and having a slight odor of, calcium carbide, and which
is believed by me to be an incipient chemical combination of carbon and calcium.
During the distilling or retorting process some oxygen from the lime is thought to
combine with carbon and pass off as an oxide of carbon. The compound resulting
from this retorting process is hard and coke-like in texture, and has conductivity
approximating that of pure carbon.
When this substance is intensely heated by an electric furnace or otherwise, (a
much lower temperature being sufficient than is required by the usual mixture of
coke and lime), a complete chemical combination of the carbon and calcium,
reduced from the line, takes place, and the resultant product is a crystallized
calcium carbide, free from ash and other solid impurities, which are always present
in coke or like solid carbons of commerce.
In practice, I take lime, preferably quicklime, in a pulverulent condition, and
incorporate with it coal tar pitch, in about equal quantities by weight, and then
heat the mixture in an ordinary retort furnace and thereby distil or drive off the
volatile constituents and obtain a hard coked product.
The duration of the retorting process extends from fifteen to thirty minutes,
according to varying conditions, the same being continued until the volatile
products are eliminated.
The product of the retorting process is, by preference, pulverized, and then
intensely heated by electricity or otherwise, and a final product of crystallized
calcium carbide obtained in the condition above stated.
A convenient way of mixing the lime and pitch is to first fuse the pitch in a
retort crucible, and then incorporate with it the lime by means of stirrers.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
-
The improvement in the art of producing calcium carbide, which consists in

page_text: mixing heavy hydro-carbons and lime, retorting the mixture to drive off the
volatile constituents, and produce a hard coke-like product, then subjecting the
compound thus obtained to extremely high heat, substantially as described.
Dated this 1st day of January 1898.
BOULT & WADE,
Agents for the Applicant.