This on-line Fingerprint Library allows you to explore and understand the principal petrographic differences among world coking coals. Each coal is unique – and so is its’ Fingerprint.<\/p>\n
For over a decade, we have recorded Fingerprints – Reflectance Profiles – of coals from all over the world, but because most of them are not our property and are protected by client-confidentiality, we cannot use them. Instead we have prepared a collection of modeled coals that are virtually identical to the coal Fingerprints of the naturally-occurring coking coals.<\/p>\n
To illustrate Fingerprint variation, and how this impacts quality of metallurgical cokes, we have chosen the ASTM coke-strength Stability Index, or Coke Strength prediction, as the base graph (Figure 1). Other parameters could equally have been used – for example the prediction of Plastic Layer Thickness, measured in the Sapozhnikov test, and featured in Chinese & Russian coal classifications! The graph is shown below in terms of coal Rank and coal Type. Move the mouse over the graph, and a corresponding mathematically-modelled coal Fingerprint for that particular Maximum Vitrinite Reflectance & Total Inert content is displayed, in the transposed terms – Random reflectance & Vitrinite percent – the parameters of the ISO Coal Classification. The unique five digit identifier code is derived from the percent Vitrinite, and Random reflectance (x100), for the coal shown in the profile.<\/p>\n
These diagrams illustrate that Provincialism plays a big part in dictating the quality of a coal (Fig. 2, below). For example, coal 50123, from Australia, and 67142, from Canada, both have the same Volatile Matter content of about 23% DAF, yet their Romax and Vitrinite content are quite different. Because VM is not an independent variable, alone, it is a relatively insensitive measure of Rank , so care must be taken when comparing coals, especially from different parts of the world, as in the ASTM Classification of Coal by Rank.<\/p>\n
The Library is best viewed at 1024×768 resolution, but if you are running a greater resolution, you may wish to resize your browser so that the Fingerprint graph does not overlay the Coke Strength graph<\/p>\n