The contribution of pollutants to variability of tailings composition was evaluated using Principal Component Analysis (PCA).
Low loadings of Au and Ag in the other three PCs show that precious metals have no significant influence in describing variability of tailings composition.
Although, Ag has a similar toxicity with that of Cr, it was not considered in the calculus of contamination indices because the statistical analysis revealed that precious metals have low influence in describing the variability of tailings composition.
Interpretation of results using multivariate statistics allowed to distinguish between the natural and anthropogenic origin of metals and their grouping in 4 principal components that describe the tailings elemental composition and water leachable fraction of contaminants iv.
Figure 4 Dendrogram showing the clustering of tailings based on leachate composition.
Figure 3 Dendrogram showing the clustering of tailings based on elemental composition and ABA parameters.
Chromium and Ni with low influence (5%) on the variability of elemental composition of tailings are included in PC4 ascribed to traces of biogenic elements.
The mineralogical and elemental (Al, Fe, Ca, K, Mg, Na, Mn, Ba, Zn, Pb, Cu, Ni, Cr, As, Cd, Co, Sr, Ti, V, W, Ag, Au, S) composition of tailings were determined and the ARD generation potential was assessed using Net Neutralization Potential (NNP).
These emissions are linked to the bitumen extraction and tailings treatment processes, tailings properties (composition, age, residence time), and environmental factors (wind, temperature, rain, and ice cover).
Considering the firing temperature and tailings addition amount, the properties, phase compositions and microstructure of final fired samples were studied.
The grading curve of the tailings silty sand indicates that the grain composition is relatively homogeneous.
