The San Francisco call., 1908-05-10
WASHING OF COAL
INCREASES VALUE
Government Tests Show Vast
Improvement in Many
Fuel Supplies
Sulphur and Ash Removed and
Coking Quality Added to |
Poor Material

WASHINGTON, May Goals which
are in the raw state utterly unfit for
steaming purposes can be made into
fairly good steaming Goals by washing.
and Goals quite unsuited for coking can
be made available for such use by the
same simple oper-@on. The facts in
relation to these Goals brought out by
tests carried on at the fuel testing
plant of the United States geological
survey at Forest Park, st. Louis, are
announced in a bulletin (No. 1850 just
] issued by the survey.
The tests of washing and coking
Goals and of the behavior of the result
ing coke in cupola practice reported in
the bulletin, were made during the fis-
cal years 1905 and 1905. and were car
ried on in connection with investiga-
tions Of the steaming and gas produc-
/ ing qualities of the same Goals by bril-
auetting. Preliminary tests of many of
the Goals as received from the mines
showed them to be too high in ash, in
sulphur. or in phosphorus to make sat
| isfactory metaIlurgical coke without
prior treatment, and some Goals pos
sessed better eoking qualities than
others.
| 1t was found that the washing of
some Goals so reduced the percentage
of ash and sulphur as to make avail
able for the production of coke a coal
which would otherwise have no value
for this purpose. The reduction of the
impurities by washing. of course, in
creases the percentages of fixed carbon
and volatile matter over the amounts
present in the raw COAL
Altogether 101 regular washing tests
and IL special tests were made. The
results of these tests show an increase
in moisture of 10 to 80 per cent, re-
duction in ash of 20 to 60 per cent, and
reduction in sulphur of 10 to so per
cent For example, a raw coal con-
tanning sos per cent of sulphur COM
tained after washing 2.47 per cent,
removal OF So per cent. The ash in
raw coal containing 42.56 per cent was
reduced by washing to 1861 per cent,
total removal of SO per cent; that in a
raw coal containing 15.72Nper cent was
reduced to 1915 per cent. a total re-
moval of IL per cent and that in
coal containing 9.S1 per cent TO 5-3S
per cent. a removal of SO per cent
The cost of washing coal in Germany
is said TO range from less than cents
to 10 or IL cents per ton; in the United
States from to 1S cents per ton. The
coking tests were made in ovens of
regular beehive pattern, and the report
covers 1872 tests made on 100 Goals, the
samples having been collected from
II states and one territory. OF these
washed coal and 10 under miscellaneous
conditions. In some of the tests it
was found that the addition of pitch
produced coke from coal. which, when
tested raw, gave either no coke or
coke Of inferior quality. In other tests
the addition Of pitch did not improve
the quality.
After the dismantling of the plant
at Forest Park in the spring OF 1907
a new fuel testing plant with much
improved apparatus was established at
Dencer. AT this plant experiments in
washing and coking will be made on
Goals mined in the Rocky mountain
region with view to determine what
can be done to make them available
for the production of metallurgical
coke.
The cupola tests on the coke, which
are reported by DR.. Richard Moldenke,
were carried on along lines described
in professional paper No. 4S OF the sur
vey. The bulletin comprises the results
Of 10 tests, and the data concerning
record of melt, taken in connection with
the indications of the sources of the
Goals and the analyses of the corre-
spending coke, the rate of melting per
hour and the amount of iron recovered
Equally interesting is the table giving
the chemical effect on iron from cupola
tests of cokes made from Goals mined
in various states.
The washing tests are reported by c..
r. Delamater; the coking tests by A.
w. Belden, and the report is prefaced
with an Introduction by Prof Joseph A.
Holmes, in charge of the technologic
branch of the survey.