Laboratory SIP Responses for Artificial Sulfide Minerals

Recently, spectral induced polarization (SIP) has been applied to metallic deposits containing sulfide minerals to estimate the mineralized zone in South Korea. Understanding the resulting phase differences that depend on the volume content and sizes of particles of these sulfide minerals is key to interpreting the distribution and quality of mineralized zones using SIP survey results. For this study, we constructed a SIP measurement system consisting of an impedance analyser, a sample holder, and electrodes. The experiment was conducted by using three sulfide minerals of different volume contents and grain sizes, viz. chalcopyrite, pyrite, and galena. The sulfide grain sizes were varied in five steps, and the their varying volume contents were divided into eight grades. From the SIP measurements, the maximum phase increased with increasing sulfide mineral content, but the phase and critical frequency, or frequency at the phase maximum, were slightly different depending on the mineral analysed. Using a 20% sulfide fraction by volume with particles 1.0–2.0 mm in diameter, the phase magnitudes of the chalcopyrite, pyrite, and galena were obtained as 220, 255, and 257 mrad, respectively, and their respective critical frequencies were 100 Hz, 210 Hz, and 50 Hz.