Nanotechnology V 1505Synthesis and Characterization of Single-Crystalline Alkali Titanate Nanowires.-Na2Ti6O13 and KTi8O16.5 nanowires are synthesized by reaction of TiO2 nanoparticles with a mixture of molten BaC2O4 and NaCl or KCl (without BaC2O4) in the presence of a nonionic surfactant (NP-9, sonication, 800-825°C, 3 h). The samples are characterized by SEM and TEM. The nanowires have diameters around 100 nm and lengths of up to a few tens of microns. The preparation method may also be extended to the fabrication of other ternary oxide nanostructures. -(XU, C.-Y.; ZHANG, Q.; ZHANG, H.; ZHEN, L.; TANG, J.; QIN*, L.-C.; J.

For a low grade dolomite type fluorite ore in the Hebei province, it was observed that the depressant CK102, a mixture of sulfuric acid, sodium silicate and aluminum sulfate, can effectively inhibit the gangue mineral dolomite in the flotation of fluorite. However, the inhibition mechanism of the depressant is still unclear. In this paper, the flotation separation performance and underlying mechanism of CK102 inhibiting dolomite were investigated through mineral flotation tests, adsorption measurements, infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). The flotation results showed that the inhibition effect of CK102 on dolomite flotation was much more remarkable than that of fluorite flotation under optimum conditions. Adsorption measurements revealed that there was competitive adsorption between the depressant and collector and that the adsorption of the depressant CK102 prevented the collector modified sodium oleate from adsorbing onto the surface of minerals. The FT-IR and XPS results showed that the co-oxygen cross-linked component of the depressant CK102 chemisorbed on the surface of dolomite; the CaSiO3 precipitation was generated from the reaction of CK102 with Ca 2+ groups on the surface of the dolomite; Al2MgO8Si2 precipitation was also generated from Mg 2+ reacting with the sodium silicate and aluminum sulfate of CK102. The above adsorptions and reactions enhanced the hydrophilicity of the dolomite surface and the dolomite was effectively depressed.