6 WASHING, COKING, AND CUPOLA TESTS. 
important result of the washing tests is shown in the percentage of 
ash and sulphur actually removed. The reduction of these impuri- 
ties by washing, of course, increases the percentages of fixed carbon 
and volatile matter over the amounts present in raw coal. These 
facts, the number of washings, and the methods of washing, are 
recorded, thus furnishing valuable data as a guide to the treat- 
ment necessary to render each coal tested most suitable for coking. 
Altogether there were 101 regular washing tests and 12 special tests. 
The results of these tests show an increase in moisture of 10 to 30 
per cent, a reduction in ash in the 1905 tests of 15 to 50 per cent and 
in the 1906 tests of 20 to 60 per cent, and a reduction in sulphur in 
the 1905 tests of 10 to 40 percent and in the 1906 tests of 10 to 50 
per cent. A few examples of the total amount of reduction may be 
mentioned. A raw coal containing 5.05 per cent of sulphur con- 
tained after washing 2.47 per cent, a total removal of 55 per cent. 
Proportionate reductions in sulphur were made in coals containing 
lesser amounts. The ash in a raw coal containing 42.56 per cent 
was reduced by washing to 29.67 per cent, a total removal of 65 per 
cent. In a similar manner ash in a raw coal containing 15.72 per 
cent was reduced to 10.16 per cent, a total removal of 41 per cent; 
and in a coal containing 9.81 per cent to 5.38 per cent, a total removal 
of 59 per cent. It is evident that coals which are in the raw state 
utterly unfit for steaming purposes can be made fairly good steaming 
coals by washing, and that coals unsuited for coking can be made 
available in the same way. 
It is proposed to conduct during the next fiscal year washing tests 
with much improved apparatus at the fuel-testing plant recently 
established at Denver, Colo., where experiments in washing and coking 
will be made on the coals mined in the Rocky Mountain region, with 
a view to determining what can be done to make them available for 
the production of metallurgical coke. 
The coking tests were made in ovens of the regular beehive pattern, 
two of standard size 7 feet high, and one of standard diameter 6 feet 
4 inches high. Samples of coke were taken from five different parts 
of the oven in practically the same location for each test, so as to- give 
a standard method of comparison for each coke. The present report 
covers 192 tests, made on 100 coals, the samples having been col- 
lected from 17 States and 1 Territory. One hundred of these tests 
were made on raw coal, 82 on washed coal, and 10 under miscellane- 
ous conditions. In some of these tests it was found that the addition 
of pitch produced coke from coal which when tested raw gave either 
no coke or coke of an inferior quality. In other tests the addition of 
pitch did not improve the quality of the coke. The tabulated results 
of the coking tests should be studied in the light of the description of 
the resulting coke which accompanies the tables. The physical tests 
