China Nonferrous Metallurgy

Conventional hydrolysis via the sulfate process produces metatitanic acid exhibiting broad particle size distribution， low specific surface area， and inadequate purity， which severely limits its applicability in high-end fields such as battery materials and catalysis. This study innovatively developed a dispersant-regulated one-step hydrolysis process for preparing metatitanic acid from industrial titanyl sulfate solution. Using a single-factor variable method， we systematically investigated the effects of parameters such as dispersant polyacrylamide（PAM） dosage， stirring speed， and hydrolysis time on metatitanic acid properties. The co-evolution mechanism of particle size distribution and specific surface area of metatitanic acid was explained by experimental results and characterization results， and the following main conclusions were obtained. The optimum hydrolysis process conditions were as follows： PAM dosage 0. 9%， stirring rate 420 r/min， hydrolysis time 2. 65 h. Under these conditions， the average specific surface area of metatitanic acid was 262 m² /g， the average purity of calcined TiO₂ was 99. 58%， and the average particle size range was 2. 65-2. 95 μm， which was better than the food grade standard （GB 1886. 341—2021） and nano grade standard （GB/T 19591—2023）. The prepared metatitanic acid has an anatase TiO₂ structure and has colloidal properties. The metatitanic acid contains a large amount of water molecules， hydroxyl groups and sulfate radicals. It is easy to form coarse metatitanic acid aggregates by Ostwald ripening and agglomeration. The porous structure between the aggregates increases the specific surface area of metatitanic acid. The hydrolysis mechanism reveals that the dispersant reduces surface tension through a longchain adsorption layer， inhibits dense particle packing， accelerates nucleation rates， and promotes the formation of fine， porous metatitanic acid. This process is simple， green， and efficient， providing a new pathway for the industrial preparation of battery-grade high-specific-surface-area metatitanic acid and advancing the high-quality development of high-performance titanium dioxide.