Improvements in the Treatment of Metallic Carbides.
Year: 1898

page_text: Date of Application, 23rd Aug., 1898-Accepted, 12th Nov., 1898
Improvements in the Treatment of Metallic Carbides.
A communication from abroad by THE INTERNATIONAL PATENT Co., of 46, Von
Buren Street, Chicago, Ill., United States of America.
I, WILLIAM LLOYD WISE, of No. 46, Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Chartered Patent Agent, 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 following statement:-
On contact with water, calcium or like metallic carbide promptly re-acts and
forms acetylene gas. The re-action is immediate and vigorously persists-with
marked production of heat-until the supply of carbide or of water is quito
exhausted. To control the greedy chemical play and thus to prevent excessive
evolution of the gas beyond immediate needs is the chief aim in devising the
various portable lamps and the fixed generators of larger sort which have now
become familiar for the utilization of acetylene.
By the present invention, the metallic e.g., calcium carbide is itself modified for
more certain and regular production of the gas. Under such conditions, the pre-
pared carbide not only serves to neutralize the structural defects inherent in many
of the existing devices and which often make them unsafe, but in notable instances
beside, will enable a simpler type of device to be used with entire economy and
security.
Heretofore, it has been proposed to render calcium carbide water-repellant.
The lump carbide, generally in cartridge form, was dipped into a fused bath of
glucose, rosin, paraffine or the like, and thus took on a protective coat. During
evolution of the acetylene, the heat of re-action sufficed to melt the coat or if the
coat were left as a shell, the water would none-the-less eat rapidly into the exposed
end of the charge and prematurely consume it away.
Calcium carbide was also soaked in petroleum or else a petroleum layer was
At each immersion,
floated upon the bath in which the charge was immersed.
the carbide first encountered the petroleum and repeatedly absorbed it. The mass
became more inert with each successive dipping.
As distinguished from these prior efforts, the invention designs to produce a
charge, measurably and uniformly water-repellant by utilizing an ingredient
associated always with the carbide proper, namely, free lime.
Commercial calcium carbide contains a minor per cent. of lime which passes
with it from the electric furnace, unaffected. By crushing the carbide to powder,
the free lime becomes disseminated throughout. On running the powder through
sieves of various mesh, the carbide is classified into several grades of material;
the coarser of these grades will be acted upon more quickly in the water bath,
as presently appears.
The scheme of classification just stated enables the operator to select charges
having a greater or less vield, in a given time, as need may require. Or if the
grade of the carbide powder be the same, an increase in the size of the prepared

page_text: charge will prolong the period of gas evolution. Whether the carbide powder
be of the same or of different degrees of fineness, the distinctive treatment next
to follow is equally applicable.
7
A bath of tallow, linseed or other oil, stearin, olein, oleic acid or any equivalent
material capable of ready saponification with lime is briskly heated in a kettle
or some convenient appliance, generally over an open fire. The heat renders the
bath limpid and expels the moisture; when nearly boiling, the carbide powder
is stirred into the bath. and thoroughly commingled therewith. The quantity of
powder taken may suffice to reduce the mass to the consistency of a soft dough.
Stirring continues and under influence of the heat, the lime in the carbide
powder is quickened and 'unites rapidly with the oil particles to form a gummy
cement. Persistent heating renders the batch thicker and thicker, until finally
it tends to roll into a lump. Just before this stage is reached, the prepared mass
is taken off and pressed at once, while still hot, into moulds, or forms of various
size, ready to receive it. The balls, cartridges. or briquettes quickly set and are
ready for immediate use.
The saponified lime serves as an agglutinant for the carbide. A small quantity
of free lime may be supplied as a separate addition if the original carbide powder
be deficient therein or a more rapid or greater hardening is desired.
Thrown into water, the carbide compound made as just detailed re-acts there-
with but gives off its acetylene very gradually and maintains a practically con-
stant flame, e.g., in a portable lamp, especially if care has been taken to classify
the carbide powder and to adjust the amount of free lime addition, as experience
will determine, in keeping with the hourly capacity of the burners to be supplied
with the gas. Water eats but slowly into the carbide composition, the disengaged
gas or the heat of re-action (perhaps both agencies) constantly causing the, lime
cement to detach and flake off in small portions and thus to expose fresh particles
of carbide for attack.
When oleic acid (.e., ordinary "red-oil" of the soap and candle maker) is
selected for the bath, it is practically free from glycerine; its saponification is
more rapid and the finished carbide compound thence resulting develops less foam
on immersion in water.
The "foaming" of the carbide is to be attributed perhaps to the presence of
glycerine, and is more marked where neutral fats or oils constitute the original
bath. To correct this evil it is generally customary to add a small proportion
or wax and of rosin, which ingredients also aid in insuring the even consumption
of the finished compound.
In practice, good results may be obtained if the several materials are taken by
weight in about the following proportions, viz. :
Oleic acid ("red-oil”
10501

page_text: like conditions of treatment to produce the hydro-fuge agglutinant. Or, a small
addition of free lime can be supplied, as an extra ingredient, to saponify the oil.
By utilizing the free base in manner contemplated, it becomes feasible to
pulverize and classify the carbide, passing it through sieves of various fineness
e.g., 20-100 mesh so as to grade the product and yet protect the resultant solidified
compound against rapid evolution of acetylene, because of the presence of the
water-repellant de-hydrated cement which unites the particles and in measure
coats them.
Obviously, variations can be made according to the mechanic's skill without
departure from the essentials of the advance.
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: 1
1. Solidified pulverulent metallic carbide having a de-hydrated, saponified,
hydro-fuge agglutinant, substantially as described.
2. Solidified pulverulent metallic carbide in which the de-hydrated, saponified
minor portion of its associated free base constitutes the hydro-fuge agglutinant,
substantially as described.
3. Solidified pulverulent calcium carbide having the de-hydrated, saponified
portion of its associated free lime for a hydro-fuge agglutinant, substantially as
described.
4. Solidified pulverulent calcium carbide having the de-hydrated, saponified
portion of its associated free lime for a hydro-fuge agglutinant in union with
wax and rosin or either of them, substantially as described.
5. The method of preparing hydro-fuge metallic carbide compositions which
consists in admixing an oily material with the pulverized carbide and free lime,
agitating the mass under heat sufficient to de-hydrate and saponify the oil and
when the mass becomes adherent allowing the same to cool, substantially as
described.
6. The method of preparing hydro-fuge metallic carbide compositions which
consists in admixing oil with the pulverized carbide and its associated free base,
stirring the mass under heat sufficient to de-hydrate and saponify the oil, and to
render the batch gummy, and thereupon compressing the finished product until
it solidifies and sets on cooling, substantially as described.
1000
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.