RESUMO
The Kroll process has been employed for titanium extraction since the 1950s. It is a labour and energy intensive multi-step semi-batch process. The post-extraction processes for making the raw titanium into alloys and products are also excessive, including multiple remelting steps. Invented in the late 1990s, the Fray-Farthing-Chen (FFC) Cambridge process extracts titanium from solid oxides at lower energy consumption via electrochemical reduction in molten salts. Its ability to produce alloys and powders, while retaining the cathode shape also promises energy and material efficient manufacturing. Focusing on titanium and its alloys, this article reviews the recent development of the FFC-Cambridge process in two aspects, (1) resource and process sustainability and (2) advanced post-extraction processing.
RESUMO
The extracellular biosurfactant product secreted by a marine bacterium was concentrated and purified directly from the fermentation broth in a single step by ultrafiltration (UF) employing YM 30 kDa (UF-I) and Omega 10 kDa (UF-II) polyethersulfone membranes. The optimum operating pressure required for both membranes, UF-I and UF-II, were found to be 30 and 35 psi, respectively. The biosurfactant from the fermentation broth was recovered in higher amounts using UF-II (89%) than using UF-I (73%). An analysis of the critical micelle concentrations (CMC) of the recovered lipopeptides showed a lower CMC value of 15 mg L⻹ for the UF-II product, indicating higher degree of purity (83%) when compared to that of the UF-I product (78%). The ultrafiltered products were characterized using Fourier transformed infrared spectroscopy and matrix-assisted laser desorption ionization time of flight mass spectral analysis, which demonstrated the presence of two families of lipopeptides.
