181-186<span style="font-size:14.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">The kinetics of dry versus wet grinding of several feed size fractions of
lignite in a laboratory size porcelain mill are reported here using feed
fractions prepared to -600+425, -425+300 and -300+212μm mono-sizes. The
kinetics process is first-order up to 8 min for dry grinding while it is
first-order up to 16 min for wet grinding. However, the specific rates of
breakages decrease as feed sizes decrease for both dry and wet grinding. Rates
of breakage (Si) of wet grinding are found to be consistently
higher than those of the dry values. The dry <span style="mso-bidi-font-style:
italic">Bi,j rates are also γ=1.58, =0.58 and β=7.11,
as the wet values obtained to be γ=1.45, =0.63 and β=6.45. The breakage
parameters, therefore, indicate that wet grinding in a porcelain ball mill is
more efficient to get finer product sizes. The simulated product size
distributions of both dry and wet grinding are in good agreement with the
experimental product size distributions using a standard ball mill simulation
program.</span