Formation of titanium phosphate composites during phosphoric acid decomposition of natural sphene

摘要: Decomposition of mineral sphene, CaTiOSiO{sub 4}, by H{sub 3}PO{sub 4} is investigated in detail. During the dissolution process, simultaneous calcium leaching and formation titanium phosphate (TiP) take place. The main product decomposition a solid phosphate-silica composite. XRD, solid-sate NMR, IR, TGA, SEM BET data were used to identify characterize composite as mixture crystalline Ti(HPO{sub 4}){sub 2}.H{sub 2}O silica. When 80% phosphoric acid degree higher than 98% completely transferred into liquid phase. Formation proceeds via meta-stable phases, Ti(H{sub 2}PO{sub 4})(PO{sub 4}).2H{sub 4}). sorption affinities TiP composites examined relation caesium strontium ions. A decrease concentration leads with greater properties. maximum capacity observed when 60% sphene decomposition. work demonstrates valuable option within 2}O-SiO{sub 2} synthesis scheme, use flows for isolation CaHPO{sub 4}.2H{sub fertilizer. - Graphical abstract: new scheme formore » preparation ion-exchangers upon one-stage process natural presented. Syntheses {alpha}-TiP-silica proceed phases. determines porosity final products their affinities.« less