Remediation of oil‐contaminated sand by coal agglomeration using ball milling

Abstract

The mechanical shear force provided by a less energy intensive device (usually operating at 20–200 rpm), a ball mill, was used to perform coal agglomeration and its effects on remediation of a model fuel oil‐contaminated sand were evaluated. Important process parameters such as the amount of coal added, milling time, milling speed and the size of milling elements are discussed. The results suggested that highly hydrophobic oil–coal agglomerates, formed by adding suitable amounts of coal into the oil‐contaminated sand, could be mechanically liberated from cleaned sand during ball milling and recovered as a surface coating on the steel balls. Over 90% removal of oil from oil‐contaminated sand was achieved with 6 wt% of coal addition and an optimum ball milling time of 20 min and speed of 200 rpm. This novel process has considerable potential for cleaning oil‐contaminated sands.

Keywords:

• coal agglomeration
• oil‐contaminated sand
• remediation
• ball milling