For blended coking coals, application of probability analysis to vitrinite reflectance data can be used to evaluate mixing-technology and to monitor blend consistency, for improved plant efficiencies. Our proprietary software has been accurately determining proportions of coal blend components at several North American coke oven batteries for over a decade.
Our Quality Control page has more information on our blend proportion analysis technique.

There is also one of our early publications available :Fingerprinting Coking Coals and Blends.