Certified reference material for coal in accordance with the PN-EN ISO 17034:2017-03 standard and ISO GUIDE 35:2017

Due to an absence of domestic certified reference materials for coal on the Polish market, an attempt was made to manufacture a new and innovative product tailored to its needs. The chosen candidate material was hard coal acquired from Poland’s coal mines. A single reference material unit consisted of 50g of an analytical hard coal sample with a grain size below 0.2 mm. A manufacturing method was developed enabling production of matrix reference materials addressing the needs of the domestic solid fuel market, and was directed at research laboratories carrying out analyses of solid fuels for the energy and coking sectors. The adapted manufacturing scheme of a certified reference material for coal was presented with a description of the chosen critical steps of the process and discussion of the obtained results in terms of homogeneity, stability, characterisation of the reference material as well as assigned values to particular properties and their uncertainty budget. The results obtained during homogeneity, short-term and long-term stability assessments as well as reference material characterisation confirmed the feasibility of the investigated certified coal reference material manufacturing process. The obtained levels of relative expanded uncertainties of the measurements confirmed the feasibility of the manufactured certified reference material for establishing and maintaining metrological traceability of measurement results. The presented research establishes a base for planning out production of additional reference materials as well as providing the know-how for designing manufacturing schemes for reference materials for solid fuels, or waste related materials like fly ash, or furnace waste.