METHODS FOR CHARACTERIZATION OF MINING WASTE:EUROPEAN PROFILE

Document on Best A vailable Techniques of Tailings and W aste-Rocks in Mining Activities, prepared by the IPPC Office in Seville (July 2004). It aims on establishing an unified and coordinated approach to the applied techniques for mining waste characterisation and the referred sampling and analytical standards in different EU countries and will serve as a background document for the European Standardisation Office. SAFEMANMIN Brief overview of the used meth ods At present, the method s used for characterization of mining wastes in different EU countries depend on the peculiarities of the studied wastes and the results expected. Generally, sampling of the studied material (solid or liquid) is done according to world or particular country standards. Further studies of the material are accomp lished using wide v ariety of techniques, from wet chemical, physical, mineralogical to specific geotechnical testings. Methods for characterization Sampling(According to EU, Non-EU, standards ISO, EPA, WHO, ASTM) Type of mining waste solid liquid Mine waters, processed waters W aste materials in dumps, heaps and tailing impoundments, contaminated soil Reffered standards:ISO (International Organization for Standartization); BS (British Standard); BSS (Bulgarian State Standard); ASTM (American Society for Testing and Materials); EN (European Standard); CEN (Comit é Eur opean de Normalisation); IM (Internal Method); US EP A (United States Environmental Protection Agency), WHO (W orld Health Organization). Complete list of standards are included in the report. In situ filtration and acidification (using relevant supra pure acids) and preservation in sterile bottles; measuring pH, Eh, TDS, EC, etc. Total ionic comp osition, po llutants (m etals, semimet als, other inorganic substances - H S, SO , F, PO , Cl, CN ; 2 4 3 radioactive - R a, Th, U; organic - m ono- and p olycycled hyd rocarbon s, microorganisms, etc. IC P-A ES, IC P-M S, AA S, chem ical analyses, microbiological tests. Sampling according to relevant standards for soil, rocks or other materials; point, linear, bulk samples Physical properties, chemical and mineral composition, trace elements, pollutants, microorganisms, etc. Geotechnical testing (made at opening and closing deposits): - Index testing, moisture content, specific gravity; - Atterberg limits (for clays), grain size distribution; - Compaction test (for particles <20mm); - Dry density and mass; Desiccation test; Permeability testing; - Strength testing; Consolidation testing - triaxial and oedometer testing, rowe cell; Settlement testing - drained/undrained settling test, settling velocities, mudline testing (settled density of tailing samples); Geotechnical modelling testwork (combined air-drying, consolidation, strength testing; Specialist testing (wind tunnel, dewatering, filter leaf); Gravity thickening and centrifuge testing; V iscosity. Soils for civil engineering Chemical analyses: - Total sulphur content and acid producing sulphides and sulphates (using a combustion furnace); - Total carbon and neutralizing carbonate (using a combustion furnace); determination of metals (non-destructive and destructive methods): - Instrumental neutron activation analysis (INAA); W avelength /Energy dispersive X-ray fluorescence spectrometry (WD/EDXRF), XRF; - Acid digestion (using various acids depending on the element examined); - Sintering and fusion (applied mainly for determination of Si); - Flame/Grafite furnace/Hydride generator atomic absorption spectroscopy (major/minor/As, Sb, Se); - Inductively coupled plasma atomic emission/mass spectroscopy (ICP-AES, ICP-MS); Sequential extraction (for soil analysis mainly); - Acid base accounting tests (for determination of acid generation potential of sulphidic wastes and contaminated soil); - Kinetic tests (Humidity cells) - for prediction of geochemical behaviour of tailings and waste rock); Column test; Lysimeter and Cesium tests; - Paste pH and metal leaching tests (using deionised water as medium); - Flow around and flow-through test (determination of leachability from various materials; Mineralogical analyses: - X-ray diffraction analysis (XRD); XRF; - Scanning electron microscopy (SEM, ESEM), Electr on probe microanalysis (EPMA); Reflected/Transmitted light microscopy. Characterization of additives (alkaline, pozzolanic, organic materials; clays) - determination of moisture content, grain size distribution, swell index, metal and non-metal oxides, heavy metals, N, P, C, cation exchange capacity (for zeolites), metals leachability, etc. Ecotoxicity tests and Microbiological tests (Salmonella, Streptococchi, Spore di Clostridi) ICP-MS XRF AAS SEM Conclusions Although each of the EU countries has a specific environmental protection problems to solve and mining waste disposal and facilities management, general conclusions concerning the mining waste characterization techniques could be outlined. These techniques will be listed in the project report and they will provide the necessary background for establishing of a Decision Support Tool for Minimizing the Impact of the Mining Industry on the Environment.