Supervisors info:
Ευστράτιος Κελεπερτζής, Αναπληρωτής Καθηγητής, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ,
Ζαχαρένια Κυπριτίδου, (Ε.ΔΙ.Π.), Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Summary:
The Lavrio area, with a long mining history, is known for the exploitation of
deposits containing mainly lead, zinc and other metals. This thesis examines three
different types of mining waste from the Lavrio area a) slags from the calamine
ore smelting, b) mineral waste from the hydromechanical beneficiation of
sulphide ore and c) sulphide flotation tailings. The aim of the study is to investigate
the pseudo-total and geochemically active metal concentrations in the three
mining wastes, compare the results and evaluate their environmental risk. The
elements considered are Pb, Zn, Cd, Cu, Mn and Fe. A total of 8 samples were
processed where: a) the pseudo-total content (US.EPA 3050B method) and b) the
geochemically active fraction was determined by weak HNO3 0.43M infection. The
quantitative analysis of trace elements was carried out by Flame Atomic
Absorption Spectroscopy (FAAS). In addition, mineralogical analysis was carried
out by XRD technique on each type of waste to identify and study the minerals
contained in them. The sample with the highest concentrations, both total and
extractable, is slag. In particular, the metal extraction rates for slags are Mn
(100%) > Fe (94%) > Pb (88%) > Zn (50%) > Cu (40%) > Cd (35%). The wastes
present different mineralogy, slags for example contain minerals such as
pyrolusite-fayalite-magnetite. In contrast, the sterile materials show minerals
such as greenockite and hemimorphite, while in the sulphide flotation tailings
pyroxene and yarosite. A geochemical correlation between Cd and Zn is observed
through their high concentrations and extraction rates. This correlation is also
confirmed mineralogically by the presence of smisthonite and sphalerite. At the
same time, the sulphide flotation tailings showed the lowest concentrations but
high extraction rates for Mn and Zn. Compared to the samples of a previous
geochemical research, the examined wastes show significantly higher enrichment
in Pb, Zn, Cd and Cu. Although the concentrations of metals in the slag samples are
quite high, they do not pose an environmental risk compared to the waste from
hydro-mechanical beneficiation. Finally, the present work can be a starting point
for further studies on the mining waste of Lavrio.
Keywords:
Μεταλλευτικά απόβλητα, Λαύριο, σκωρίες, δυνητικά τοξικά στοιχεία
