Montana oil and mining journal. [volume] (Great Falls, Mont.) 1931-1953, 1941-04-05

I to produce hlgh chrome COutSH
alloy of over 500 chromium. (l
may be possible for some Montana
chemist to make a process where
by the coal is substituted by carbon
produced by Montana gas wells
and in that way making Montana
self-sufficient in the production OF
/ ferrochrome materials If not the
/ ferrochrome itself.)
The ferrochromium alloy after
/ this heat treatment contains a tot
al of from 60 to 20 percent chrom-
/ ium, from one to eight percent car
1 bon, stated amount of silica and
the remainder iron. Ores used in
the manufacture of this product
have ranged from As to SO per-
cent chronic oxide and less than
five percent silica. The Canadian
company that has the lease on the
Benbok property is able to pro-
duce a high chromium content fer
rochromium from the lower grade
However they hold the patent rights
on this process and 1t is not used
by any companies within the United
States to date.
Alloy Uses
The ferrOchromium is alleged
with many other elements to pro-
duce better and individual alloys
for specific uses. Alleging metals
are manganese, tungsten, vanadium,
nickle, carbon and silicon. These al
Toys are bracketed into three clas-
sifications: low, medium, and
high-content chromium alloys.
The low-chromium content al
Toys are arranged over a far great
er field than any of the others in
the variety of uses. Where hard
ness strength and toughness is nee
essary, from one to five percent
chromium is used. Armor-plate.
gears, small tools, crusher jaws.
balls for ball-mills and some cut
cry are typical Of this type now
used. Recently it has been proven
that structural steel, cables. and
bridse steel can be produced from
this low-chromium steel and save
the expense of paint maintenance
Oscillation of this metal is halted
after small amount of oxidation
has taken place on the surface
This action is more positive than
any obtained by surface coverings.
inns IS especially beneficial in the
case OF hull plates of ships since
sea water is inactive with chrom-
ium.
The addition Of nickle gires adj
ded strength and toughness with
out the loss Of hardness. High speed
cutting tools that can maintain
their hardness at a cherry-red heat
are made by the addition of chrom-
ium to tungsten in the approximate
ratio of one chrome to three tung-
stem. Chrome-yanadium alloys are
the toughest, most fatigue-resist-
ing alloys used in the making of
Tools, axles, crankshafts, etc.
Stainless Steel
Inc medium chrome-steels are
classed generally as the stainless
steel variety which is the most
FAMILIAR to the public of any of the
ailoys. The percent here ranges from
II TO Is percent chromium. This
amount of chromium renders the
steel Inactive when in contact with
acids or Oxiding agents found in
everyday uses about the homes Ad-
dltional carbon or nickle are used
also in this steel.
Hlgh-chromium alloys are used
Where resistance to oxidation at
nigh temperatures is needed as in
roasting and annealing furnaces.
Inc non-ferrous group of chrome
Alloys are made with such allowing !
metals as cobalt, tungsten, vana- |
dlum, molybdenum and nickle. va
rlous combinations and percentages
OI these metals are used in the nj |
ra-wear-resisting parts of excava-
-lnS and drilling machinery and
also is used by welders to build I'D
worn parts of the machinery. Pre-
'ision and surgical instruments are
MADE from this group of high-con-
alloys.
refractory Uses.
Inc second main division in the
Uses of chromite is in refractory
uses. In this industry chromite
bricks and cement are used to line
ne refractory furnaces and parts
u furnaces that are suited for this
Ilnd of Innings.
Because of the high melting
'oint of these brick (2.OOOo CT
IND their resistance to gases. they
IRE being used Increasingly in fur
races and kilns where there is con-
act between the Innings and acids
md gases. Lower grade ores are
lsed in this part of consumption.
However the high iron content is
again Objectionable because of the
Owered point Of fusibility.
The third group of uses is chem
cal. The highest grades of chrom-
tie are used here. Ores containing
80 % or more of chromite oxide and
10 sulphur are generally desired |
or this part of the industry. This
're is reduced to some form of
chromium salts or compounds from
which paint pigments are made and
is done. Paint pig
nents are the earliest uses of
chrome dating back as far as the
development of the Reed Mine Ia
VI ID L., !