Date of Award


Document Type


Degree Name

Master of Chemical Engineering (MChE)


Chemical Engineering

First Advisor

A. M. Cooley


During the past several years the United States Bureau of Mines and the University of North Dakota have conducted extensive investigation aimed toward the up-grading of lignite coal. These investigations include steam drying, carbonation, briquetting, and gasification of North Dakota lignite. Research work by both the Bureau of Mines and the University of North Dakota is continuing and expanding at the present time. During the past year the construction and operation of a lignite research laboratory on the University campus has been authorized by the United States government. The operation of this laboratory by the United States Bureau of Mines should aid lignite in taking its place among the important fuels and chemical raw materials of the near future.

The work being discussed in this paper is a part of this continuing research program. This work has been sponsored by the North Dakota Research Foundation with the cooperation of the Chemical Engineering Department of the University of North Dakota.

The purpose of the present work is the application of a rather unique method of pulverization to the size reduction of lignite coal. It is a well known fact that during the size reduction of a material by conventional methods the work required increases greatly as the size of the product is increased. Another factor leading to the difficult size reduction of raw lignite coals is its high moisture content of approximately 35 percent. This high moisture content is sufficient to form a paste of the lignite when fine pulverization is attempted. It was hoped that the apparatus under investigation for the present paper would provide an economical method of pulverizing lignite--either wet or dried--to the very fine sizes necessary for many commercial applications of solid fuels.