Masters Theses


Yaqing Li


"The necessity to develop a viable alternative to oil means that the development of coal-water fuels (CWF) has become increasingly important. However, the existing methods of comminution to prepare ultrafine particles for CWF are very inefficient. Consequently, a number of novel methods of comminution have been investigated in order to increase the efficiency of the process.

In this research, a new method of comminution using a high-pressure waterjet has been tested to produce ultrafine particle sizes necessary for efficient CWF process. To establish the fundamental performance of the waterjet mill, the influence of the operational pressure, standoff distance, feed size, mode (dry/wet) of feed material, and ash content of feed material were evaluated. The comminution products were characterized in terms of particle size, surface area change, particle size distribution (PSD), and morphological properties.

The experimental results show that this new comminution method offers a promising means for achieving the size reduction required for use in CWF. It was also found that the waterjet-mediated comminution of coal was strongly affected by all these operating parameters. Higher operational pressure led to finer products that were more spherical shaped, while the energy efficiency of the mill strongly depended on the initial feed size and standoff distance. Since there is currently no accurate mode assessing the size of the comminution products, a volume-based fractal model was deduced to characterize the particle size distribution of the comminution products through a single and exact parameter"--Abstract, page iii.


Galecki, Greg

Committee Member(s)

Sezai, Sen
Tien, Jerry C.
Awuah-Offei, Kwame, 1975-


Mining Engineering

Degree Name

M.S. in Mining Engineering


Missouri University of Science and Technology

Publication Date

Fall 2012


xv, 109 pages

Note about bibliography

Includes bibliographical references.


© 2012 Yaqing Li, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Coal preparation
Size reduction of materials
Water jets

Thesis Number

T 10122

Print OCLC #


Electronic OCLC #