4 CONTENTS. 
Page. 
Methods of manufacture of Portland cement 
Preparation of the mixture for the kiln 
Percentage of water in raw materials 44 
Methods and costs of drying 
Grinding and mixing 
Dry methods ^ 
Slag-limestone mixtures 4 ^ 
General methods 
Composition of the slag 
Granulation of slag 49 
Drying the slag 49 
Grinding the slag 
Composition of the limestone 49 
Advantages of using slag-limestone mixtures ... 50 
Wet methods ™ 
Burning the mixture - 
Summary of burning pr< >cess 
Theoretical fuel requirements - 
Losses of heat 
Actual fuel requirements and output 
Effect of composition on burning 
Character of kiln fuel 
Drying coal 
Pulverizing coal 
Total cost of coal preparation 
Clinker grinding 
Addition of gypsum 
56 
56 
57 
57 
57 
5Sj 
58 
Part II. Portland-cement Resources of the United States. 
Introduction 
Alabama ; 
Portland-cement materials, by Eugene A. Smith ■ 
Northern Alabama 
General geology 
Limestones 
Chickamauga limestone 
Mississippian ( ' ' Lower Carboniferous ' ' ) limestones to- 
days and shales - - - 
Ordo vician ( ' ' Lower Silurian ' ' ) and Cambrian shales b 
Mississippian ( ' ' Lower Carboniferous ' ' ) shales 6 
Pennsylvanian ( ' ' Coal Measures ' ' ) shales 6 
Cretaceous clays 
Analyses 
Central and southern Alabama 
Selma chalk or "Rotten limestone" 
St. Stephens or Vicksburg limestone 
Analyses 
Portland-cement industry 
Bibliography 
Arizona . 
Portland-cement materials 
Bibliography - 
