Improvements in the Manufacture of Chromium and its Alloys.
Year: 1887

page_text: Date of Application, 28th Oct., 1887
Complete Specification Left, 21st July, 1888
Complete Specification Accepted, 5th Oct., 1888
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Chromium and its Alloys.
I, LORENTZ ALBERT GROTH of No. 5 Crosby Hall Chambers, London, E.C. Civil
Engineer, as a communication from abroad by Victor Rouff and Ernest Rouff, in the
City of Paris, Gentlemen do hereby declare the nature of this invention to be as
follows:-
The object of this Invention is the manufacture of chromiuin and its alloys by
simultaneous employment of alcalious chromates or carthy alkaline and silica.
When we
use alcalious chromates we intimately mix one of these neutral
chromates with flint and charcoal, we place them in a reducing apparatus, such as a
crucible, and we heat them to a red heat.
At this temperature the flint reacts on the neutral chromate, to form an alkaline
silicate and free chromic acid, which in presence of charcoal is reduced to metallic
chromium giving oxide of carbon. This chromium is spongy and it is impregnated
with alkaline silicate, containing a slight excess of carbon, which ensures a complete
reduction.
The alkaline silicate, being soluble in water, is eliminated by washing the spongy
chromium, and we obtain chromium containing the impurities of the materials
employed, charcoal and silicium combined, silicate not dissolved, and the excess of
charcoal for the complete reaction.
If to the mixture of neutral alkaline chromate, of flint and of charcoal we have
added oxides of iron, copper, manganese, or minerals analagous to those substances,
we shall obtain in a single operation sponges, which constitute pure alloys of
chromium.
The
We obtaine by the same process chromo-silicium and chromo-scheelium.
spongy chromium which we obtain may be alloyed by melting with non volatile
metals.

page_text: We can replace the flint in the reaction by acid silicates or by boracic acid or acid
borates, in which case according to the nature of the silicate or borate selected the
final silicate or borate will be more or less soluble.
We can likewise employ acid chromates, which decompose in neutral chromates
and oxide of chrome by producing a deflagration. The reaction with these chromates
is the same except that the oxide of chrome requires a higher temperature for its
reduction.
When we employ alcalious chromates, the reaction requires a higher temperature
and the alcalious silicates, which we obtain at the end of the operation, being
insoluble, we separate them from the chrome by melting the sponge to eliminate
them.
Dated 1:04
1007

page_text: 1
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Chromium and its Alloys.
I LORENTZ ALBERT GROTH of No. 3 Tokenhouse Buildings London E.C. Civil
Engineer as a communication from abroad by Victor Rouff and Ernest Rouff in the
city of Paris, gentlemen 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 :-
The object of this invention is the manufacture of Chromium and its alloys by
simultaneous employment of alcaline chromates and silica.
When we use for example chromate of soda an intimate mixture is made of
equivalent quantities of neutral chromate of soda of silica and of carbon.
This mixture is placed in a reducing apparatus such as a crucible and heated to a
red heat.
This
At this temperature the reaction of the elements is produced, the silica combines
with the soda to form silicate of soda and the free chromic acid, in the presence of
carbon, is decomposed into oxide of carbon and yields metallic Chromium.
Chromium is spongy and it is impregnated silicate of soda containing a slight excess
of carbon which ensures a complete reduction.
The silicate of soda being soluble in water is eliminated by washing the spongy
Chromium and we obtain chromium containing the impurities of the materials
employed, carbon and silicium combined, silicate not dissolved and the excess of
carbon for the complete reaction.
If to the mixture of alkaline neutral, chromate of silica, and of carbon, we have
added oxides of iron, copper, manganese, or minerals analagous to these substances,
we obtain in a single operation sponges which pure alloys of chromium.
We obtain by the same way chromo-silicium and chromo-scheelium. The spongy
chromium which we obtain may be alloyed by melting with non volatile metals.
We can replace the silica in the reaction by acid silicates or by boracic acid or
acid borates in which case according to the nature of the silicate or borate selected
the final silicate or borate will be more or less soluble.
We can likewise employ acid-chromates which decompose into neutral chromates
and oxide of chromium by producing a deflagration. The reaction with these
chromates is the same except that the oxide of chromium requires a higher tempera-
ture for its reduction.
When we employ alcaline chromates the reaction requires a higher temperature
and the alcaline silicates which we obtain at the end of the operation being insoluble
we separate then from chromium by melting the sponge to eliminate them. It is
evident that the proportion of materials varies necessarily with the nature of the
chromate used and its richness in chromium. Further when alloys are in question
all depends upon the metallic combination, which it is desired to obtain. The process
of manufacture remains the same, whatever may be the quantities of chromate, of
silica, of carbon used.

page_text: an example:
9,720 kiles.
6
21 lbs. 7 ozs. 6 dwts. of chromate of potash
'
13
4
"
22
"
"
2,800
=
6
3
of silica (or more)
of charcoal
37
"
"
and a chrome is obtained combined with silicium in certain proportion and containing
a little charcoal. It is understood that the proportion of silica and of charcoal varies
with the quantity of silicium and of charcoal which is desired to combine with the
metallic chrome.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare, that what we
claim is
The manufacture of chromium and its alloys principally in manner herein
described.