Open AccessElectrostatic beneficiation of coal. Quarterly technical progress report, October 1, 1996--December 31, 1996
Author(s) -
M.K. Mazumder,
D. A. Lindquist,
K.B. Tennal
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/524156
Subject(s) - beneficiation , separator (oil production) , particle size , grinding , particle size distribution , coal , particle (ecology) , surface charge , analytical chemistry (journal) , materials science , mineralogy , chemistry , work function , metallurgy , metal , thermodynamics , chromatography , physics , geology , oceanography , organic chemistry
From previous study, we know that oxidation of the coal surface will decrease the efficiency of electrostatic beneficiation by increasing the negative charge of the carbon particles. The polarity and magnitude of charge acquired by the nonconducting particles varied depending on the state of ``oxidation`` of the surfaces and the work function relative to the metal surface. The formation of oxide layer on the coal particles are rather rapid, therefore, the grinding and charging processes are needed to be carried out in a nitrogen or argon atmosphere. It is clear that impaction efficiency between coal particle and charger will decrease with decreasing particle size and particle velocity. So, it is necessary to charge small particles in a different process. We plan to size classify the coal particles into three size fractions: (1)fine (<40{mu}m). (2) medium (40{approximately}100{mu}m). (3) coarse (100{approximately}200{mu}m). Static mixer and a new designed charger (powder pump connected with a circular tubing) are used in the experiment. And we planned to measure the charge to mass ratio distributions as a function of the particle size distribution on the separator plates. This report discusses the following: determination of the charge to mass ratio distributions as a function of particle size distribution; and method to measure the mass, charge and size of the particle