The accumulation of spent vanadium catalysts from sulfuric acid production poses a serious environmental problem on a global scale. Existing hydrometallurgical methods focus on vanadium extraction, often leaving a solid siliceous residue without qualified application. In this study, a resource-saving technology for the full-cycle synthesis of a granulated catalyst was developed using the solid leaching residue of SVC as a secondary carrier and bentonite as a structural promoter. Sulphuric acid leaching (۱۵% H۲SO۴, ۸۵ °C, ۴ h, and solid-to-liquid ratio ۱:۴), filtration, washing, and thermal activation were carried out, with a complete material balance established for the key components (V, S, and K). The V۲O۵ recovery was ۸۵.۰%. The secondary carrier was synthesized by extrusion molding using washed siliceous residue (SBET ≈ ۱۵ m۲/g) and bentonite (۱۵ wt.%). Statistical significance was assessed using Student’s two-sample t-test for independent samples with n=۵ and p=۰.۹۵; the normality of the distribution was tested using the Shapiro-Wilk test, and the effect size (Cohen’s d) was calculated. It was found that the addition of ۱۵% (by mass) of activated bentonite to the secondary siliceous residue yields carrier granules with a strength of ۶۲ ± ۴ N/granule, which corresponds to ~۲.۲ MPa at a granule diameter of ۶ mm (۶.۲ MPa was erroneously mentioned) and a developed macroporous structure (Vtotal = ۰.۳۶ ± ۰.۰۲ cm۳/g), ensuring efficient mass transfer. The waste-based synthesized catalyst (۸% V۲O۵) demonstrated an activity of ۹۳.۹±۰.۶% at ۴۸۵ °C, which is statistically indistinguishable from the performance of the industrial SVD standard (p > ۰.۰۵). A closed-loop technology is proposed, allowing up to ۸۵ wt.% of hazardous waste to be returned to the production cycle. A preliminary assessment of economic efficiency indicates a potential reduction in raw material costs of ۲۵-۳۵%, provided that production is scaled up to industrial volumes (>۱۰۰ tons per year). Resource tests demonstrated stable catalytic activity over ۶۰ h of continuous operation at ۴۸۵ °C. This duration confirms the absence of rapid degradation of the active phase; however, long-term testing (۱,۰۰۰+ h) is required to assess industrial durability.
