The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorpti...The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorption rate was relatively high before 30 minutes, and then dropped. The saturated adsorption capacity (a) of Pb2+ and kinetic parameters (b, α , D and k) increased with increasing initial concentrations of Pb2+. These parameters (except a) decreased while Na+ was present in the solution. Furthermore, the smaller the rocks were in grain size, the bigger these kinetic parameters would be, though the parameter a was almost constant.展开更多
Strontium speciation transferring in strontium residue and mixing strontium ore are investigated with extracting experiment, X-ray powder diffraction(XRD), X-ray fluorescence spectrometer(XRF) and Atomic Absorption Sp...Strontium speciation transferring in strontium residue and mixing strontium ore are investigated with extracting experiment, X-ray powder diffraction(XRD), X-ray fluorescence spectrometer(XRF) and Atomic Absorption Spectroscopy(AAS). The results show that there are strontium carbonate, strontium sulfate, strontium sulfide, and a little amount of strontium silicate and strontium ferrite in strontium residue. Impurities in strontium residue mainly contain carbonate and oxide of calcium, iron, magnesium and aluminum etc. The amount of strontium sulfide in strontium residue is larger than that in strontium ore. And a little strontium silicate and strontium ferrite are found in strontium ore. It is concluded that acid soluble method is used firstly in the process of producing strontium carbonate from mixing strontium ore. In addition, mechanical smash method and surface active treatment to strontium samples are beneficial to the ratio-leaching increase of strontium. The research achievement helps to save energy and decrease pollutants emission in strontium processing industry.展开更多
Strontium ferrite was prepared from Strontium Waste Residue (SWR) as a material. Strontium chloride was obtained by leaching SWR with ammonia chloride, and then SrCl2 was converted to SrCO3. Strontium ferrite (SrFe12O...Strontium ferrite was prepared from Strontium Waste Residue (SWR) as a material. Strontium chloride was obtained by leaching SWR with ammonia chloride, and then SrCl2 was converted to SrCO3. Strontium ferrite (SrFe12O19) was formed by roasting the mixture of SrCO3 and FeCl3 in a proper proportion. The structure and magnetic susceptibility of strontium ferrite were investi-gated. The results showed that strontium conversion ratio increased with decreasing SWR grain diameter. The largest ratio was pre-sented when n(NH4Cl/Sr) was 3.6. What is more, the conversion process coincided with the kinetic characteristics of fractal reaction. The magnetic susceptibility of strontium ferrite decreased with increasing Fe3+/Sr2+ mole ratio and pH. SrFe12O19 exhibited face-centered and cubic closely-packed hexagonal structures. There were the strong diffraction peaks of Fe2O3 in the X-ray diffracto-gram of strontium ferrite. Strontium recovery ratio was 87.0%.展开更多
Strontium in celestine was activated in Twain-40 with the wetting and emulsifying methods. And strontium extract ratio increased providing that the negative effects of oxygen containing functional groups were eliminat...Strontium in celestine was activated in Twain-40 with the wetting and emulsifying methods. And strontium extract ratio increased providing that the negative effects of oxygen containing functional groups were eliminated on celestine surface. In the paper, the factors affecting the extraction of strontium in celestine were investigated with orthogonal experiments. The optimal conditions were described as follows: mass ratio of celestine to extracting aid=2.6:1, the solid-liquid ratio of extracting aid solvent composed was m(SDS): m(Twain 40): m(HCl)=6:1:2, when celestine was ground as small as less than 0.075mm in size, and extracted for 6 hours at 333K. The strontium extract ratio increased by 61.33% and reached 97.21%, while the ratio from the comparative experiment (without extracting aid agent) was only 35.88%. Extraction kinetics of strontium in celestine showed that the diffusion process was a controlling step, and the apparent active energy was about 14.1 kJ/mol. The research results were helpful to fully utilize strontium of celestine.展开更多
文摘The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorption rate was relatively high before 30 minutes, and then dropped. The saturated adsorption capacity (a) of Pb2+ and kinetic parameters (b, α , D and k) increased with increasing initial concentrations of Pb2+. These parameters (except a) decreased while Na+ was present in the solution. Furthermore, the smaller the rocks were in grain size, the bigger these kinetic parameters would be, though the parameter a was almost constant.
基金the Brainstorm Project Foundation by Scientific and Technological Committee of Chongqing(CSTC,2010AC7180)
文摘Strontium speciation transferring in strontium residue and mixing strontium ore are investigated with extracting experiment, X-ray powder diffraction(XRD), X-ray fluorescence spectrometer(XRF) and Atomic Absorption Spectroscopy(AAS). The results show that there are strontium carbonate, strontium sulfate, strontium sulfide, and a little amount of strontium silicate and strontium ferrite in strontium residue. Impurities in strontium residue mainly contain carbonate and oxide of calcium, iron, magnesium and aluminum etc. The amount of strontium sulfide in strontium residue is larger than that in strontium ore. And a little strontium silicate and strontium ferrite are found in strontium ore. It is concluded that acid soluble method is used firstly in the process of producing strontium carbonate from mixing strontium ore. In addition, mechanical smash method and surface active treatment to strontium samples are beneficial to the ratio-leaching increase of strontium. The research achievement helps to save energy and decrease pollutants emission in strontium processing industry.
基金Foundation by Scientific and Technological Committee of Chongqing(CSTC,2010AC4054)
文摘Strontium ferrite was prepared from Strontium Waste Residue (SWR) as a material. Strontium chloride was obtained by leaching SWR with ammonia chloride, and then SrCl2 was converted to SrCO3. Strontium ferrite (SrFe12O19) was formed by roasting the mixture of SrCO3 and FeCl3 in a proper proportion. The structure and magnetic susceptibility of strontium ferrite were investi-gated. The results showed that strontium conversion ratio increased with decreasing SWR grain diameter. The largest ratio was pre-sented when n(NH4Cl/Sr) was 3.6. What is more, the conversion process coincided with the kinetic characteristics of fractal reaction. The magnetic susceptibility of strontium ferrite decreased with increasing Fe3+/Sr2+ mole ratio and pH. SrFe12O19 exhibited face-centered and cubic closely-packed hexagonal structures. There were the strong diffraction peaks of Fe2O3 in the X-ray diffracto-gram of strontium ferrite. Strontium recovery ratio was 87.0%.
基金supported by the Chongqing Science & Technology Commission (CSTC, 2010AC7180)
文摘Strontium in celestine was activated in Twain-40 with the wetting and emulsifying methods. And strontium extract ratio increased providing that the negative effects of oxygen containing functional groups were eliminated on celestine surface. In the paper, the factors affecting the extraction of strontium in celestine were investigated with orthogonal experiments. The optimal conditions were described as follows: mass ratio of celestine to extracting aid=2.6:1, the solid-liquid ratio of extracting aid solvent composed was m(SDS): m(Twain 40): m(HCl)=6:1:2, when celestine was ground as small as less than 0.075mm in size, and extracted for 6 hours at 333K. The strontium extract ratio increased by 61.33% and reached 97.21%, while the ratio from the comparative experiment (without extracting aid agent) was only 35.88%. Extraction kinetics of strontium in celestine showed that the diffusion process was a controlling step, and the apparent active energy was about 14.1 kJ/mol. The research results were helpful to fully utilize strontium of celestine.
