Low-cost magnesium aluminate spinel ceramics were successfully synthesized from the minerals of magnesite(M) and bauxite(B) via one-step sintering method. The effect ratio bauxite to magnesite on phase evolution, microstructure, as well mechanical properties was thoroughly investigated. structural analysis indicated that Mg2+ or Al3+ ions dissolved in lattice formed Mg-rich/Al-rich MgAl2O4 (MA)...

The occurrence of very-high-grade bauxite ores karst-type deposits resulting from Fe-leaching is particular importance, because they are widespread in the Mediterranean metallogenetic province and result natural beneficiation ore quality. present study focuses on mineral transformations variations major trace elements, including platinum-group elements (PGE) chemistry along a profile Parnassos-...

In the present study, prediction of Alumina recovery efficiency (A.R.E), the amount of produced red mud (A.P.R), red mud settling rate (R.S.R) and bound-soda losses (B.S.L) in Bayer process red mud has been carried out for the first time in the field. These predictions are based on Lime to bauxite ratio and chemical analyses of bauxite and lime as Bayer process feed materials. Radial basis func...

Aluminium, with more than 50 Mt annual production in 2016, is an essential material in modern engineering designs of lightweight structures. To obtain aluminium ingots from bauxite, three main processes are involved: the Bayer process to produce alumina from bauxite; the anode manufacturing process to produce electrodes, and the smelting process using the Hall-Héroult technology. The Hall-Hérou...

Western Australia is unique in its botanical diversity. There are over 7000 species of native vascular plants of which over 3000 are endemic (Keighery 1992). Phytophthora cinnamomi has a major impact on this diverse flora and directly effects over 2000 species from a diverse range of plant families (Wills 1993). Its indirect effects in terms of botanical impact through the loss of vertebrate an...

We study two reservation deposit policies for a service rm to increase its revenue through higher capacity utilization. First, under the no deposit policy, the rm requires no reservation deposit and imposes no no show penalty. Anticipating potential no shows, a rm may overbook; hence, there is no guarantee that the reserved service will be provided under the no deposit policy. On the contrary, ...

Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importanc...