Historical silicomanganese sludge deposits represent a potential secondary source of manganese, although its recovery is complicated by the heterogeneous chemical and mineralogical characteristics of the material. This study investigated the chemical, mineralogical and particle size characteristics of silicomanganese sludge and comparatively evaluated physical and hydrometallurgical approaches for manganese recovery. Thirty-five samples collected from the investigated deposit were characterised, and a representative composite sample was used for particle size classification, magnetic separation, density separation and hydrometallurgical experiments. Manganese was distributed throughout the entire particle size range, with limited enrichment in the finer fractions. Magnetic and density separation provided only partial pre-concentration, with overall manganese recoveries of approximately 27.4% and 24.4%, respectively. Hydrometallurgical treatment was investigated using HCl-water and aqua regia-water leaching systems, followed by sequential alkaline precipitation with KOH. Fe- and Al-bearing species were removed at controlled pH before recovery of the manganese-rich precipitate at pH 9–10. Under the most favourable conditions, the recovered products contained approximately 99–100% MnO equivalent, as determined by XRF, while the principal residual impurities were generally below 0.1%. Both leaching systems produced highly purified manganese-rich products, while the HCl-water route achieved comparable results without the use of aqua regia. The results demonstrate that physical separation provides only limited manganese pre-concentration, whereas acid leaching followed by selective purification and precipitation represents a promising route for the recovery of high-purity manganese-rich products from historical silicomanganese sludge.