assessment of the possibility of using leucoxene-quartz concentrate as raw material for production of aluminium and magnesium titanates

Leucoxene-quartz concentrate is a large-tonnage by-product of development of the timan oil-titanium field (oil-saturated sandstones) which is not commercially used at present. high content of titanium compounds (to 50 % by weight) and lack of industrial, cost-effective, and safe technologies for its processing determine a high relevance of the work. conventional processing technologies allow increasing the concentration of tio2, but they are only a preparation for complex and hazardous selective chlorination. the process of pyrometallurgical conversion of leucoxene-quartz concentrate into aluminium and magnesium titanates was investigated. it was ascertained that the temperature of solid-phase reaction in al2o3-tio2-sio2 system necessary for the synthesis of aluminium titanate (al2tio5) is 1,558 °с, and for mgo-tio2-sio2 system – 1,372 °с. scaling up the process made it possible to synthesize a significant number of samples of titanate-containing products, the phase composition of which was studied by x-ray phase analysis. two main phases were identified in the products: 30 % aluminium/magnesium titanate and 40 % silicon dioxide. in products of pyrometallurgical processing in the presence of aluminium, phases of pseudobrookite (3.5 %) and titanite (0.5 %) were also found. it was ascertained that in magnesium-containing system the formation of three magnesium titanates is possible: mgtio3 – 25, mg2tio4 – 35, mgti2o5 – 40 %. experiments on sulphuric acid leaching of samples demonstrated a higher degree of titanium compounds extraction during sulphuric acid processing. an integrated conceptual scheme for processing leucoxene-quartz concentrate to produce a wide range of potential products (coagulants, catalysts, materials for ceramic industry) was proposed.