Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Wide range of feed materials recognised as applicable for plasma processing

In the project research tasks various feed materials have been used. The fly ashes obtained from the Nofer Institute of Occupational Medicine in Lodz and the fly ashes and carbon filter deposits from the Belchatow power plant have been tested. The composition and quantity of the additives such as the sludge wastes from the chemical industrial plant producing sodium chromate (post-chromium sludge) and the sewage sludge from a municipal wastewater treatment plant from Lodz have been also determined.

The tested ashes were consisted of inorganic compounds, mostly SiO2 and Al2O3. The medical ash was grey with dark-grey and black elements and it contained needles and glass pieces. The ash from Belchatow power plant was loose and powdery, but not homogenous and its colour was grey-brown. The ashes were separated into specific fractions.

The post-chromium sludge, used in the project, contained mainly CaO, Fe2O3, MgO, SiO2 as well as chromium at various oxidation states (III and VI). The total chromium content in the sludge was 16,34 % of dry mass. This sludge was of a loose homogenous mixture of brown-grey-black colour. In the case of the municipal wastewater sludge simple three oxides (P2O5, CaO and MgO) were the main inorganic compounds. This sludge was exceptional because of the organic matter dominated in it. This sludge was a loose, heterogeneous mixture with pieces of organic matter of a grey-black colour. The sludge was also separated into specific fractions. All these feed materials were recognized as applicable for plasma processing.

Even if all the tested feeds had different compositions they were still applicable for thermal plasma vitrification due to a large content of glass generating oxides. The vitrificates were chemically stable (leachability tests) and they had a homogenous structure and a high mechanical resistance.

Reported by

Technical University of Lodz (TUL)
Stefanowskiego 4/10
90-924 Lodz
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