382 



REIBLING AND REYES. 



Samples of well-burned and underburned stationary kiln clinker fresh 

 from the kilns, were also collected and then subjected to the examination 

 recorded in Table III. 



Table III. — Effects of different temperatures of burning on raw-material (station- 

 ary kiln process with limestone and clay). 



Brand 

 of ce- 

 ment. 



Kind of clinker. 



Fineness 

 through — 



Microscopic test (duplicate 

 specimens). 



Soundness 



(5-hour 

 steam test). 



200 

 mesh. 



100 

 mesh. 



. 



Well-burned clink- 



93.6 



100 



An almost immediate forma- 



Slightly disinte- 





er. 







tion of plumes and feathery 

 rosettes. No needles until 

 after 10 minutes, when a few 

 formed. 



grated. 







Underburned 



89.4 



100 



Mass of radiating clusters and 



Slightly disinte- 





clinker. 







single needles and plumes. 



grated. 







Selected, thorough- 

 ly fused clinker 



83.8 



99.6 



No crystals in 1 hour . 



Perfectly sound. 













which showed no 













white specks 













when fractured. 











L 



Well-burned clink- 



93.6 



100 



An almost immediate formation 



Not disintegrat- 





er. 







of plumes. 



ed but scales 

 on bottom sur- 













face, and off of 

 the plate. 



L 



Underburned 



90.8 



100 



A mass of radiating clusters and 



Completely dis- 





clinker. 







single needles and plumes. 



in tegra ted 

 and badly 

 swollen. 



L 



Selected, thorough- 

 ly fused clinker 



100 



100 



No crystals in 1 hour 



Perfectly sound. 















showing homoge- 













neous composi- 













tion and no white 













specks. 











The data recorded in Tables II and III show that in the manufacture 

 of Portland cement, as the temperature is increased the nonsintered 

 calcium oxide gradually is converted into the sintered material, having 

 different physical properties. This naturally. is what might be expected; 

 but this conversion may occur at temperatures far below those necessary 

 for the proper burning of Portland cement clinker. Therefore, under- 

 burned cement may contain both sintered and nonsintered lime, but the 



