Options for Washability Analysis of Coal—A Literature Review

Abstract

The existing Australian Standard for float and sink analysis of coal is likely to be phased out over the next five years because of its reliance on toxic organic liquids. Thus, the Australian coal industry needs to urgently find a suitable alternative, allowing enough time to establish a new approach with a new standard. It is possible that the industry in other countries will follow this lead. Several studies have been conducted in the past, all indicating advantages and disadvantages. The purpose of this review document is to examine the options available for washability analysis within a single document. The conclusion reached by the review document is that the main options for a new washability analysis involve water-based systems. These approaches contrast gas pycnometry that requires no liquid media. It is also concluded that satisfactory alternatives to the current standard on washability analysis exist; however, certain compromises will be required as all have certain disadvantages, either technical or economical.