Comparative analysis of quality of coal slurries from the current production and dumped in settling ponds

Electroenergetic industry in Poland is currently burning and predicts in the future incineration of certain amounts of coal slurries. Those slurries may come both,from current production, as well as they may be acquired from settling ponds, in which they were dumped when, there were no economic premises or technical possibilities of their current usage. Coal slurries being located in earth settlers are waste from the legal point of view, however slurries coming from current production are the energetic fuel. It doesn't depend on their quality parameters. Currently new energy boilers are designed adapted to burning slurries coming from current production or from ponds. For this reason it is important to know the quantity and the quality of energy slurries. The paper presents the results of comparative analysis of quality parameters of coal slurries dumped in settling ponds and the slurries from the current production that were delivered to three power plants. The analysis was carried out basing on the quality parameters of slurries according to the Polish standard (hard coal for energy production purposes) and basing on the quality of fuel demanded for burning in a newly designed fluidal boiler. The analysis shows that the majority of slurries, both from the current production and being the result of settling pond exploitation, may be used as a fuel. It is necessary to remember, that ranges of parameters (Q/A) given in the standard, do not determine usefulness (or its lack) of slurries for burning process in certain installation; standards are being applied voluntarily, they are fulfilling the information part about the quality of the product, they are helpful when entering into agreements for supplies and for negotiating the price of supplies, as well as in enforcing the quality declared by the deliverer (e.g. in case of secondary settlement of accounts).