Pilot-Plant Production of Titanosilicate Sorbents

Pilot-plant testing of a laboratory technology for producing alkaline titanosilicate sorbent from the current titanium-containing technogenic waste from the enrichment of the Khibiny apatite–nepheline ore shows that this technology can be modeled on an enlarged (pilot-plant) scale. The parameters of the main technological operations in systems of various salt compositions are checked and optimized. For example, in the ammonium sulfate systems, a two-phase precipitate is formed, which consists of phases similar to the minerals zorite and ivanyukite at their weight ratio of about 1 : 0.8–1.0. A one-phase precipitate in the form of ivanukite crystals is formed in the sulfate system. A study of the technical and sorption properties characterized in the tests of sorbents finds that the absorption of the Cs⁺ cation is due to the substitution for the Na⁺ cation in the interframework space of the crystal. The Sr²⁺ cation is also substituted for Na⁺ and is additionally deposited on the sorbent particles due to the alkaline reaction of its surface. The sorption capacities of powder and granules for Sr²⁺ are, on average, 170 and 160 mg g^–1, respectively; and for Cs+, 275 and 245 mg g^–1, respectively. Tests will be continued as pilot batches of the sorbent with stable structure and properties are produced for testing in specialized organizations.