Coal Preparation » General
This Handbook sets out recommended practices for using coal grain analysis (CGA) data to interpret coal quality for a variety of applications, and to understand the use of CGA for quantitative assessment of dust samples. It encompasses typical quantitative and qualitative information in the form of practical advice and guidance.
Coal product is a particulate matter. Mining, handling, preparation, transport and utilisation are all impacted by how the particles behave. Each particle is unique in the same way that snowflakes are each unique. Most aspects of coal quality, coal preparation and coal utilisation are better understood when they are considered at the particulate level.
CGA is normally undertaken on a representative sample that has been ground to 1 mm topsize. A obvious question is “What value is an analysis at 1 mm topsize when we typically process and sell the coal at 50 mm topsize?” The answer lies in the fact that the coal is produced to meet a market demand. The predominance of the market demand is for pulverised fuel including power station boiler and blast furnace injection (at 0.1 mm topsize) and coke oven feed (typically at 4 mm topsize). Thus by analysing and interpreting coal at 1 mm topsize in the first instance, the data are directly relatable to the particle size scale of utilisation in the market. Application of CGA to larger topsize is also addressed in this Handbook.