Empress Catherine II Saint Petersburg Mining University, Saint Petersburg, Russia

M. A. Pashkevich, Doctor of Engineering Sciences, Professor, Head of the Department of Geoecology, mpash@spmi.ru
V. A. Matveeva, Candidate of Engineering Sciences, Associate Professor, Director of the Scientific Center "Assessment of Technogenic Transformation of Ecosystems", Matveeva_VA2@pers.spmi.ru
M. E. Evdokimova, Postgraduate Student, Department of Geoecology, s235011@stud.spmi.ru

The recycling of non-ferrous ore processing waste with the production of marketable products is an important aspect in achieving sustainable development of production facilities in the mineral and raw materials complex. According to the Russian Federal Service for Hydrometeorology and Environmental Monitoring (Rosprirodnadzor) report on activities in 2024, Russia generated 8.5 billion tons of industrial waste containing, on the one hand, high concentrations of pollutants, and on the other hand, valuable components that can be utilized in various sectors of industry and agriculture. This paper addresses the problems of recycling titanium ore processing waste – titanium sludge. The main approaches for their processing include the use of sludge as fillers for construction materials (cement, brick) and as feedstock for the production of titanium dioxide-based pigments; however, these methods are often limited by low extraction efficiency of target components. Therefore, it is proposed to utilize the waste as feedstock for coagulant production. The objective of this research was to select optimal leaching parameters for titanium sludge to obtain titanium-based coagulant. A review of scientific and technical literature devoted to the utilization problem of titanium-containing waste was conducted. The chemical and phase compositions of the waste were determined using X-ray fluorescence and X-ray diffraction (XRD) methods. Reagents for acid leaching of titanium sludge were experimentally selected, and the influence of process time and temperature on titanium extraction efficiency was revealed. The research established the maximum degree of titanium dissolution into solution, amounting to 40.7%, obtained by leaching the sludge with aqua regia solution at a solid-to-liquid ratio of 1:3.5 for a contact time of 1 hour at room temperature (20 °C).

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