Evaluation of identification methods for chrysocolla - A Cu-smectite-like hydrous silicate: Implications for heap-leaching extraction of copper

Chrysocolla has been characterized by XRD, FTIR, DTA-TG, TEM and EPMA in or der to clarify properties of this phase and to identify a suitable routine identification method. Chrysocolla is X-ray amorphous, although in some cas es slightly sensitive to EG-treatment. IR spectra indicate a trioctahedral layer-silicate structure, resembling in many features that of trioctahedral smectites. HRTEM images do not show a phyllosilicate-like: repetitive laye ring in accordance with XRD results. The SiO2/CuO ratio is considered respo nsible for the degree of crystal ordering achieved. SiO2/CuO ratio near 1 r esults in an amorphous phase, while SiO2/CuO near 1.3 generates more smecti te-like characteristics. For routine analyses in mining operations, DTA-TG is considered feasible, once basic mineralization types are known at a site .