Characterisation of Limestone Deposits for Cement Production in Sokoto State

Limestone deposits in Sokoto State, North West Nigeria, constitute the primary raw material base for the cement industry in the region, yet comprehensive quality characterisation studies remain limited relative to the scale of identified occurrences. This study characterises the chemical, mineralogical, and physical properties of limestone samples from a selected deposit in Sokoto State, evaluating their suitability as feedstock for Portland cement production. Bulk samples and channel samples were collected from quarry exposures and natural outcrops at regular intervals along two profiles. X-ray fluorescence analysis determined the major oxide composition, with particular attention to calcium oxide, silicon dioxide, aluminium oxide, iron oxide, and magnesium oxide contents, which control cement clinker quality. X-ray diffraction identified mineralogical phases including calcite, dolomite, quartz, and clay minerals. Calcite purity and calcium carbonate equivalent were computed from the analytical results. Physical tests including point load strength, Los Angeles abrasion, and bulk density were conducted to evaluate processability. The lime saturation factor, silica modulus, and alumina-iron ratio were calculated to assess the raw mix suitability for wet and dry process kilns. Findings are benchmarked against Sokoto Cement Company's published quality specifications for incoming limestone. This study provides undergraduate students with a complete raw materials evaluation workflow applicable to industrial minerals assessment. Keywords: limestone, cement production, geochemistry, Sokoto State, raw materials.