The accumulation of iron-rich tailings, a solid waste from the titanium industry, poses significant environmental pollution risks. To address this and convert the tailings into valuable resources, this study employed an acid leaching-purification-oxidation-calcination process. This process utilized the iron content in the tailings to produce iron oxide red, which is then used as an iron source to synthesize iron-chromium spinel for application in black ceramics. This paper investigated the effects of initial Fe²⁺ concentration, reactant molar ratio, and oxidizing temperature on the formation of iron oxide yellow crystal seeds. Building on this, the study explored how different calcination temperatures influence the properties of iron oxide red, its conversion into iron-chromium spinel, and its impact on the coloration of black ceramics. The results show that under the conditions of 0.4 mol/L Fe²⁺ concentration, a reactant molar ratio of 2.2∶1, and an oxidation temperature of 35 ℃, the iron oxide yellow crystal seeds obtained from acid-leached purified ferrous chloride solution are calcined at 750 ℃. This produced red iron oxide has a purity of 98.875%, an average particle size of 2.973 μm, and a high degree of crystallinity in a rod-like shape. Using this red iron oxide as a precursor, the iron-chromium spinel formed by sintering at 1 280 ℃ exhibits the best blackening effect in black ceramic color plates, with a L^* value of 37.35, differing by only 0.57 from the standard sample.