Abstract:The rapid development of the new energy industry continues to promote the development of the nickel metallurgy industry, and the proportion of resources such as laterite nickel ore is an increasingly large proportion of nickel production raw materials. High-pressure acid leaching (HPAL) is an efficient hydrometallurgical technique that integrates with producing battery materials such as nickel sulfate, the main technology for processing laterite nickel ore domestically and internationally. The autoclave is the core equipment in the HPAL process. However, the inner surface is prone to scaling during the laterite nickel ore leaching process. This serious issue affects production continuity, limits operational efficiency, and poses potential safety risks. The scaling mechanism of the autoclave was investigated through the analysis of industrial scaling samples and scaling experiments, and control strategies for scaling was proposed and experimentally validated. The influence of key factors, such as slurry density, acid-to-ore ratio, and stirring speed, on scaling growth was systematically explored. Furthermore, the effectiveness of sodium dodecylbenzene sulfonate (SDBS) as a surfactant in inhibiting scale formation was studied. The results indicate that the main cause of the scale layer is the rapid nucleation and growth of low solubility products such as hydronium alunite ((H3O)Al3(SO4)2(OH)6) and hematite (Fe2O3) on the inner surface of the autoclave. Under optimized experimental conditions, adding SDBS can significantly reduces the scale growth rate, with the scale deposition decreasing from 47.47 grams to 2 grams. This study provides fundamental data for understanding the scaling mechanism in the HPAL process also validates the feasibility of using SDBS as a scale inhibitor for laterite nickel ore leaching, and systematically improves the efficiency of high-pressure acid leaching for laterite nickel ore.