DilZt ANNUAL REPORT 
Magnesite bricks have been tried, but owing to their high price, 
great brittleness and high heat conducting power have not been suc- 
cessful. : | 
Beauxite bricks or additions of beauxite to clay have also been 
disappointing as far as the writer has been able to learn. 
Cement clinker linings, consisting of crushed and screened cement 
clinker and a little sand, have been quite successful, according to the 
reports of two cement mills. These linings are put in like concrete, and 
if they should prove satisfactory in every respect would afford an easy 
solution of a troublesome problem. Further data, however, are neces- 
sary before a final opinion can be given. 
Kiln Improvements.— [he rotary kiln is experiencing constant changes 
in various respects, of which a few will be quoted. Edison proposes the 
use of two jets of coal dust (see figure 57). Michaelis, Jr., obtained 
a patent on projections arranged around the kiln wall which are to retard 
the movement of the material downward, but which in the opinion of 
the writer are liable to give a great deal of trouble in operation. An- 
other inventor proposes the uses of a water jacketed kiln lining in the 
hottest zone analogous to the-blast furnace lining. Lessing provides 
the kiln with a ribbed lining through which small jets of air are forced 
under pressure, and a good many other modifications might be cited. 
Shaft Kiln,—The vertical shaft kiln used so extensively in Europe 
has no place under American conditions owing to its greater cost of 
operation due to the extra labor required, the cost of briquetting and 
the irregularity in output and quality of clinker. Its intrinsic fuel 
consumption is, of course, considerably less than that of the rotary kiln, 
being about 61 pounds of coal per barrel under favorable conditions. If 
used at all the system adopted should include the dry pressing of the raw 
cement bricks and burning the kiln with forced draft so as to increase 
the capacity. Figure 58 represents the Dietzsch shaft kiln operated 
continuously. 
Fusing Portland Cement.—Occasionally the idea of doing away 
with all intermediate and fine raw grinding machines by fusing the 
cement to a liquid mass and grinding the resulting cooled slag crops up. 
This certainly is a fascinating idea and appeals to the theoretically in- 
clined mind quite strongly. Yo make Portland cement by charging 
limestone and clay into a blast furnace and running out the liquid slag 
certainly seems a simple process. Jex in 1900 suggested that the lime 
in the Portland cement composition be lowered, as fused cement would 
require less lime than vitrified cement. Thus he suggests among others 
a cement of the following composition: 
