Management of Spent Refractories from Nigerian Cement Plants: Environmental Compliance and Recycling Options

This study examines the management of spent refractory linings arising from kiln and furnace maintenance at Nigerian cement plants, assessing current disposal practices, environmental compliance status, and technically feasible recycling options. Nigeria's cement industry operates over thirty kiln lines nationally, each requiring periodic refractory relining that generates hundreds of tonnes of spent material annually. The study employs a structured survey methodology administered to environmental and production managers at eight cement plants located in Ogun, Niger, Edo, Benue, and Borno States, supplemented by laboratory characterisation of spent refractory samples from three plants and review of regulatory compliance documentation. Spent material is characterised by XRF, XRD, and TCLP leachate testing for heavy metals. The survey assesses waste generation volumes, disposal routes used, awareness of DPR and NESREA regulations, and openness to circular economy initiatives. Findings reveal that landfill disposal without TCLP testing is the dominant practice, with one plant discharging directly onto unlined ground adjacent to the kiln. Laboratory characterisation confirms low heavy metal leachability, classifying the waste as non-hazardous under USEPA criteria, supporting the case for beneficial reuse. Technically viable recycling options identified include use as aggregate in concrete road bases and as raw material feed in ceramic tile production. The study recommends a formal spent refractory management protocol for Nigerian cement plants. Keywords: spent refractories, cement plant, waste management, recycling, environmental compliance.