CK.] 
WASHING TESTS. 
65 
oisture and ash, and the refuse 1,968 pounds. The washed coal, 
terefore, must have been the difference, or 6,045 pounds. 
The results given above show great improvement. The slack was 
:tremely dirty, as the analysis shows. Washing reduced the ash 
om 28.39 per cent in the raw coal to 7.59 per cent in the washed 
>al. The sulphur was likewise reduced from 4.30 to 2.89 per cent, 
n the whole the reduction in the impurities is highly satisfactory, 
it the amount of coal lost in the operation (1,968 pounds) is too great 
r economical work. It is possible that better results might have 
jen obtained if the tests had been continued, but enough has been 
>ne to show that great improvement may be made in the quality of 
e slack coal in this field by washing. 
The improvement in washing this slack was still further tested by 
sam tests made on the raw coal and also on the washed product. 
Steam tests showing effect of washing Missouri No. 3 coal. 
Equiva- 
Dry coal 
lent evap- 
Dry coal, 
Dry coal, 
Total 
coal con- 
sumed. 
Horse- 
burned 
oration 
per indi- 
per elec- 
Coal tested. 
power de- 
per sq. ft. 
from and 
cated 
trical 
veloped 
of grate 
at 2123 F., 
horse- 
horse- 
by boiler. 
surface, 
per pound 
power 
hour. 
power 
hour. 
per hour. 
of dry 
coal. 
Pounds. 
Pounds. 
Pounds. 
Pounds. 
Pounds. 
lvv slack 
10, 828 
11,044 
149.5 
189.7 
21.85 
21.72 
5.82 
7.43 
4.86 
3.81 
6.00 
ashed slack 
4.70 
A washing test was also made of about 6J tons of this coal for cok- 
g purposes. No trial was made of the raw coal in the oven, so it is 
^possible to make a direct comparison of the coke, but the chemical 
alyses give some idea of the improvement produced. 
Analyses showing effect of washing Missouri No. 
1 coal. 
Raw coal. 
Washed coal 
for coking. 
h 
28. 39 
4.30 
7.24 
lphur 
2. 74 
GENERAL TESTS. 
In addition to the above-mentioned special tests, a groat many 
arges of coal for the coke ovens were washed, and generally with 
rly satisfactory results, considering the small amount of coal in 
*h charge. 
Bull. 261—05 5 
