Red Mud as an Additional Source of Titanium Raw Materials

<p>In this study the extraction of titanium from bauxite residue (red mud) with 2 step acid leaching was proposed. In the first step red mud was leached with diluted hydrochloric acid under stirring to remove the soluble Ca, Na, Al, Si and K at 25 ⁰C and pH=3 for 1 hour. The content of iron and titanium in the solid residue increased to 57.7% and 6.4%, respectively. The factors influencing sulfuric acid leaching of the solid residue in the second stage were examined by factorial design. The optimal iron and titanium extraction efficiency was obtained after leaching at 50 oC and L:S ration 20:1 for 90 min when 80 g/L sulfuric acid was used. The titanium oxide content in the concentrate obtained under the optimum conditions amounted to 46.7%. The maximum recovery of titanium in the sulfuric acid solution has not exceeded 6%.</p>

First crystal-structure determination of chromites from an acapulcoite and ordinary chondrites

We report the first crystal-structure determinations of chromites from an acapulcoite and from ordinary chondrites. Cell edges range from 8.3212 (3) to 8.3501 (1) Å, while the oxygen positional parameters are in the range 0.2624 (3) to 0.26298 (9). Their compositions show they are very close to the chromite end-member FeCr2O4 with limited Al and Mg content. Titanium oxide content exceeds 1 wt.%, whereas the amount of Fe3+ is negligible. Extraterrestrial chromite is distinguished readily from terrestrial analogues on the basis of the cell edge and oxygen positional parameter. These distinctions will facilitate ongoing attempts to reconstruct the palaeoflux of meteorites to Earth from resistant extraterrestrial spinel grains recovered from ancient sediments.

Preparation of Alumina Microfiltration Membrane with Different Titanium Oxide Content

Alumina microfiltration membrane was prepared with solid particle sintering method by changing the content of TiO2. The membrane flux, rejection to PEG10000 and rupture strength were tested. The results showed that: when the firing temperature is 1400°C, PVA is 2%, TiO2 is 1%, alumina microfiltration membrane flux reached 1.93m3/m2·h, PEG10000 retention rate is 13.5%, and the flexural strength is 74.38MPa.