Stabilization of iron ore tailings with cement and bentonite: a case study on Golgohar mine

The abundance of mining activities continuously increases mine wastes/tailings that require storage/disposal. It is well understood that the accumulation of tailings around mines, and consequently, their spreading in the environment could cause serious ecological hazards. Reuse and recycling of mine tailing materials, in construction and earthwork applications (such as non-structural building elements, roads), offset possible environmental pollutions and safeguard natural resources. This study investigates experimentally the cement/bentonite stabilization of iron ore tailings from the Golgohar iron ore mine, which is the largest producer of raw (un-smelted) iron products in Iran. A comprehensive series of compaction and uniaxial compression tests was performed on mixtures of cement/bentonite and tailings. Test results reveal that the introduction of cement/bentonite to iron ore tailings requires higher water content for optimum compaction and results in lower dry density. The addition of bentonite increases the unconfined compressive strength (UCS) very little, whereas there is a great strength enhancement for tailing-cement mixtures, particularly after a period of moist curing. The cement-stabilized iron ore tailings may be incorporated in road constructions as they easily fulfill strength requirements of base and subbase course layers, while the bentonite-treated tailings are applicable as cover materials in layered disposal of tailings.