RI 3382 Grindability Of Alabama Coals ? Introduction

The material published in this report is part of a special study of some of the chemical and physical properties of Alabama coals. The complete study included friability and grindability determinations, high and low temperature assay distillation tests, and ash fusion-temperature determinations. Proximate and ultimate analyses and. calorific values of the coal samples also were obtained. This paper is concerned only with grindabilities, although proximate analyses have been included to give a better picture of the problem as a whole. The growing interest in grindabilities of coals is a result of the increase in use of pulverized fuel in REscent years. The tenative ball-mill grindability method D409-35T4/was used in making all the determinations. The method of sampling and the technic of the testing procedure is described in Considerable detail in this report because the procedure was established quite recently. The ball-Mill grindability index is a measure of the ease with which coal may be ground, which may be an important factor in estimating pulverizing costs. Up to the present time few data on the grindability of Alabama coals have been published. The data in this paper show that the Warrior and Cahaba fields exhibit a wide range of grindability in their coals. The mines tested are well distributed throughout the productive areas of these fields, and it is possible to make rough estimates of the grindabilities of coals not listed in this report from the data given for mines situated in the same vicinity. ACKNOWLEDGMENTS This study was conducted at the Southern Experiment Station of the Bureau of Mines in cooperation with the University of Alabama. The Alabama liming Institute was of great assistance in furthering the investigation, and the work was undertaken largely as a result of its request that the Bureau of Mines should make certain studies of Alabama coals. Grateful acknowledgments