The effects of calcium fluoride (CaF2) additions on the densification and mechanical properties of hydroxyapatite–zirconia composites (HA–ZrO2) were investigated. When small amount of CaF2 was added, the density of the composites was markedly enhanced. The reactions of HA with CaF2, which led to the formation of fluorapatite (FA), were attributed to the observed improvements in densification. W...

this study aims to investigate and optimize the effects of the main parameters including the particle size, gravity and magnetic separation combination, high gradient magnetic separation, magnetic field intensity, shaking table slope, washing water flow, and electrostatic separation upon the rare earth element (ree) recoveries from iron mine waste. the electron microprobe showed that high amoun...

microgastropod fauna from the upper devonian cephalopod bed and overlying lower tournaisian strata of the original reference section of the shishtu formation have been examined. twenty genera and one unknown genus have been identified. the original aragonite shells have been replaced either by pyrite or fluorapatite

different samples have been prepared from different products in chadormalu iron ore concentrator plant: low intensity magnetite separators concentrate (magnetite concentrate), reverse flotation tail (final hematite concentrate), flotation concentrate (apatite concentrate), final tail (l.i.m.s. tail + reverse flotation concentrate+ apatite flotation tail). the samples were used for rare earth el...

we have performed density functional theory investigations on the adsorption properties of ammonia molecule on the undoped and n-doped tio2 anatase nanoparticles. we have geometrically optimized the constructed undoped and n-doped nanoparticles in order to fully understand the adsorption behaviors of ammonia molecule. for tio2 anatase nanoparticles, the binding site is preferentially located on...

The process of biomineralization apatite in nature has been studied by scientists from various fields science for more than a century. Unlike the volcanogenic, hydrothermal, and other types igneous apatites, genesis which is entirely clear, formation phosphate ores marine sedimentary origin still debatable. Since concentrations water bodies are too low spontaneous precipitation solid phosphates...