Chromium contamination in ferronickel slag: A soil column leaching test study

Ferronickel slag is solid byproducts from ferronickel smelter. It has been used in construction fields as compaction material in road construction and concrete construction. This study aims to characterize the ferronickel slag physical, chemical and leaching potential, identify the soil properties in the study area, and the chromium content in the leachate by conducting leaching test through soil columns in the laboratory. Methods used in this study were X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). Soil samples were taken from three locations, i.e. settlement area, plantation area, and harbor area and the ferronickel slag samples from the stockpile nearby the ferronickel plant in Pomalaa District, Southeast Sulawesi, Indonesia. The results show that the leaching test produces leachate water with very high chromium content (4 – 13 mg/l) from harbor area soil, compared to soil from settlement area and plantation area which exceeded the quality standards set by the Government Regulation No. 82/2001 about water quality management and water pollution control in Indonesia (0.005 – 1 mg/l).