The Dwight- Lloyd McWane Ironmaking Process (D-LM) is the first commercial process of its particular type and one of the few commercial processes involving prereduction of iron ore in existence today. This presentation reviews some promising ironmaking processes which involve iron ore prereduction, with special attention being given the D-LM process. Although the D-LM process is continuous from iron ore to high quality molten cast iron, the research and discussion herein is limited to principal variables involved in the production of high quality carbonized pellets in the prereduction phase of the operation. The variables of process temperature and pellet carbon content are studied and related to the chemical property of prereduction of oxides, the physical property of pellet crush strength, and the electrical property of pellet resistance. Through the use of a bench-scale test devised herein, it is found that maximum prereduction of iron oxides is obtained at approximately 20 percent pellet carbon and a carbonizing temperature of 2000ºF., carbonized pellet crush strength increases drastically as pellet carbon increases above 25 percent and reaches a maximum at 1800ºF. carbonizing temperature, and electrical resistance of pellets decreases rapidly as both pellet carbon and carbonizing temperature increase. With the use of these relationships it is proposed that the bench-scale prereduction apparatus utilized in research be used as a quality control device in the prereduction step of the D-LM ironmaking process --Abstract, pages ii-iii
