This document specifies a reduced molybdophosphate photometric method for the determination of the total phosphorus mass fraction of hard coal, lignites and coke. Two methods for taking the phosphorus into solution are specified, namely extraction from the coal or coke ash with acid or by repeated oxidation of the coal or coke, by acid, to remove carbonaceous matter.
BSI recommends this version of standard for organisations operating in or with the UK. The ISO edition is available here if required.