Once Grand, Now Forgotten: What Do We Know About the Superhigh-Organic-Sulphur Raša Coal?

Abstract

The Istrian coal mines, located in the eastern part of the Istrian Peninsula (Northern Adriatic Sea, Croatia) had by far the most important and economically the most valuable deposits of the anthracite coal reserves in Croatia since the 18th century until the year 1999, when their excavation and use in the coal-fired power plant Plomin ceased. The coal is found within the Palaeocene Kozina limestone beds. Four coal basins, Karojba, Sveti Martin, Pićan, and the Labin basin, hosted seven coal mines, e.g. Tupljak, Potpićan, Kozljak, Štrmac, Raša, Ripenda, and Krapan. The coal has been generally known under the name of Raša coal. It is exceptional in world terms due to its high content of organic sulphur, which can be up to 14%. Herewithin, this paper reviews Croatian scientific publications devoted to various aspects of Raša coal, along with the most important publications on either similar coals or relevant subjects worldwide. A brief introduction deals with the role of coal in electricity production, and the history of coal mining in Istria. The following chapter summarises current knowledge of the coal sulphur geochemistry, with several examples of high-sulphur coals from India and China. It is followed by the geological, geochemical, and physical characterisation of Raša coal. Since perturbations to ecosystems caused by coal combustion have been documented in numerous papers from a number of countries, Croatian studies carried out to determine the impact of Raša coal combustion on the local environment are also presented.

Geochemistry of Croatian superhigh-organic-sulphur Raša coal, imported low-S coal and bottom ash: their Se and trace metal fingerprints in seawater, clover, foliage and mushroom specimens

“…Herewith, element measurements of biological, aquatic, airborne, and soil samples commonly give an insight into the effects of human activities such as fossil fuel combustion and mining on the environment (Adriano et al, 1980;Dreher and Finkelman, 1992;Kierczak et al, 2008;Dowarah et al, 2009;Csavina et al, 2012;Silva et al, 2012;Flues et al, 2013;Gomez-Gonzalez et al, 2014Oliveira et al, 2014;Saikia et al, 2015). Since the Labin City area has represented the major Croatian coal mining, metal industry, and coal-fired electricity centre for more than two centuries (Medunić et al, 2016a), the local aquatic as well as terrestrial environments could have been presumably exposed to mine and/or ash wastes, and airborne particles from former as well as recent stacks' emissions by multiple pathways. Therefore, surface fresh and seawater samples together with three plant communities (clover, mushroom, and foliage) were analysed for their sulphate and elemental composition.…”

“…Recently, Medunić et al (2016a) reviewed historical, geological, geochemical and environmental aspects of the Raša coal mines located on the eastern part (Figure 1) of the Istrian Peninsula (Labin City area, North Adriatic, Croatia). They had been by far the most important and economically the most valuable deposits of the lignite (a high volatile B bituminous rank) coal reserves in Croatia since the 18th century till 1999, when their excavation and use in the local Plomin coal-fired power plant (PPP) ceased.…”

Use of Bacteria and Synthetic Zeolites in Remediation of Soil and Water Polluted with Superhigh-Organic-Sulfur Raša Coal (Raša Bay, North Adriatic, Croatia)

“…Figure 2 presents the results of desulfurization conducted on SHOS Raša coal. It shows that maximum removal of its sulfur, which was almost entirely in organic form [5,26], was up to 5% at best, i.e., not significant. However, it shows a general trend of decreased S concentrations in coal with time.…”

“…Evidently, Raša soil is polluted with all analyzed PTEs and S compared to unpolluted soil collected far from the study area [4,5,20,28]. Briefly, S, Se, V, and U were elements indicative for Raša coal weathering, both from underground deposits and surface coal waste piles abandoned across the study area [1,5,26]. Strontium is typical for marine and karst environments, while Cr, Cu, Pb, and Zn commonly result from metal processing industries [20].…”

Comparative Review of Croatian and Indian Air Pollution Studies With Emphasis on Pollutants Derived by Coal Combustion

“…The Plomin city area (Fig. 1b) is an interesting site from an environmental point of view as it has been a major source of the Croatian energy production for more than 100 years (Medunić et al, 2016b). As the domestic Raša coal was characterised by remarkably high values of sulphur, up to 13−14% (Hamrla, 1959;Valković et al, 1984a, b), a few medical studies (carried out by Croatian gynaecologist L. Mohorović) established the correlation between ground SO 2 levels and health problems of pregnant women and small children (Mohorović, 2003(Mohorović, , 2004.…”