he BULLETIN 572, U. S. DEPARTMENT OF AGRICULTURE. 
Thus, R. J. Wysor* has shown in an investigation on the escape of 
potash from blast furnaces that the specially designed tower spray 
washers used for purifying the gas from the blast furnace are only 
moderately efficient in freeing the gas from the finest dust particles, 
and that much of the water-soluble alkalies remains in the gas 
current after leaving the washers. This result is explained on the 
ground that the particles of fume are in such an exceedingly fine 
state of division that they escape contact with the relatively large 
drops of water: 
Experiments to show the effect of variations in burning on the 
volatilization of potash have been made recently at the plant of 
the Security Cement and Lime Co. It was found that as the burn- 
ing conditions were varied from normal to such a temperature as 
to give overburned clinker, the percentage volatilization of the 
potash increased from 31.6 per cent to 42.6 per cent.? 
A similar result was obtained also in this laboratory in the analysis 
of seven cement samples furnished us by the Tidewater Portland 
Cement Co. The samples were collected successively as the burning 
was raised from a temperature giving a very soft clinker to that 
sufficient to make a very hard clinker. Corresponding samples of 
raw mix were collected at the same time, giving a composite sample 
which analyzed 0.71 per cent potash. The results obtained in the 
analysis of the cement samples are shown in Table III. 
TasBLe Ill.—Effect of variable burning on the liberation of potash in cement kilns. 
ue evans é ns a el 
Potash in of tota : otash in of tota 
Sample. | clinker. potash i Satie: clinker. potash 
| volatilized. volatilized. 
en hs | | 
Per cent. | Per cent. Per cent. Per cent. 
INO! tas APF ae 3 obs 0.69 40.0 WVNorhs Sea ey 0.51 55. 
i fe ar Dees pel ae .70 | 39.1 No Oss eee 44 | 61.7 
Ng Sos = oat ee. -58 49.5 NOM Disa eye, . 48 58.4 
LOE PE eee he ee . 4 50. 7 | 
i | | 
a Very soft. - b Very hard. 
These results show that the potash volatilized increases with the 
temperature of burning, but the increase apparently is not sufficient 
to attribute the great variation in the potash volatilized in different 
plants entirely to differences in the temperature of burning. 
That it is possible also to bring about by chemical means an in- 
crease in the amount of potash volatilized has been demonstrated 
recently at the plant of the Security Cement and Lime Co. This 
is effected by adding ordinary salt both to the raw mix and to the 
coal used for fuel, and in such quantity that the total added amounts 
1 Bul. Am. Inst. Mining Engineers, 121, 1 (1917). 2 Anderson and Nestell. Loc. cit. 
