A new process of smelting laterite by lowtemperature reduction and microwave irradiation

A new smelting process for the reduction of laterite with a relatively high yield of Ni has been presented in this paper; particularly, this process has been underwent industrialized experiment in China. This new process was based on the following fundamental research results. (1) Since nickel oxide can be reduced more easily than iron oxide, the nickel content of the produced ferronickel alloy increases significantly when the quantity of coal that is mixed with laterite ore is optimized, leading to a right oxygen potential of gas for reduction reaction. (2) When laterite is reduced at 1150°C, only 75% of the reduced ferronickel product can be magnetically separated from slag, although more than 95% Ni has been reduced from laterite. (3) The key technology is to realize a fast carburization at 1300°C by microwave irradiation, which causes ferronickel fines grow to a large size in the semi-melting state so that they can be separated magnetically with a high efficiency. The first demonstration production line with an annual capacity of 100 kt green balls has been established in China. The Ni content reaches 13.5%, moreover, both P and S contents are also within the expected range

A monodisperse transmembrane α-helical peptide barrel

The fabrication of monodisperse transmembrane barrels formed from short synthetic peptides has not been demonstrated previously. This is in part because of the complexity of the interactions between peptides and lipids within the hydrophobic environment of a membrane. Here we report the formation of a transmembrane pore through the self-assembly of 35 amino acid α-helical peptides. The design of the peptides is based on the C-terminal D4 domain of the Escherichia coli polysaccharide transporter Wza. By using single-channel current recording, we define discrete assembly intermediates and show that the pore is most probably a helix barrel that contains eight D4 peptides arranged in parallel. We also show that the peptide pore is functional and capable of conducting ions and binding blockers. Such α-helix barrels engineered from peptides could find applications in nanopore technologies such as single-molecule sensing and nucleic-acid sequencing

Functional analysis of the K30 polysaccharide transporter Wza

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A new process of smelting laterite by lowtemperature reduction and microwave irradiation

A new smelting process for the reduction of laterite with a relatively high yield of Ni has been presented in this paper; particularly, this process has been underwent industrialized experiment in China. This new process was based on the following fundamental research results. (1) Since nickel oxide can be reduced more easily than iron oxide, the nickel content of the produced ferronickel alloy increases significantly when the quantity of coal that is mixed with laterite ore is optimized, leading to a right oxygen potential of gas for reduction reaction. (2) When laterite is reduced at 1150°C, only 75% of the reduced ferronickel product can be magnetically separated from slag, although more than 95% Ni has been reduced from laterite. (3) The key technology is to realize a fast carburization at 1300°C by microwave irradiation, which causes ferronickel fines grow to a large size in the semi-melting state so that they can be separated magnetically with a high efficiency. The first demonstration production line with an annual capacity of 100 kt green balls has been established in China. The Ni content reaches 13.5%, moreover, both P and S contents are also within the expected range

Diverse reactivity of a tricoordinate organoboron L2PhB: (L = oxazol-2-ylidene) towards alkali metal, group 9 metal, and coinage metal precursors

The reactivity of a tricoordinate organoboron L2PhB: (L = oxazol-2-ylidene) 1 towards metal precursors and its coordination chemistry were comprehensively studied. While the boron center in 1 is reluctant to coordinate to the alkali metals in their trifluoromethanesulfonate salts (MOTf) (M = Li, Na, K), the unprecedented compound 2 containing two L2PhB: units linked by a cyclic Li(OTf)2Li spacer was obtained from the reaction of 1 with LiOTf. Treatment of 1 with group 9 metal complexes [MCl(COD)]2 (M = Rh, Ir) afforded the first zwitterionic rhodium(I)–boronium complex 3 and the iridium(III)–borane complex 4, respectively. The reaction pathway may involve C–H activation followed by proton migration from the metals to the boron center, demonstrating the first example of the deprotonation of metal hydrides by a basic boron. In the reactions with coinage metals, 1 could act as a two-electron reducing agent towards the metal chlorides MCl (M = Cu, Ag, Au). Meanwhile, the reaction of 1 with gold chloride supported by a N-heterocyclic carbene (NHC) produced a heteroleptic cationic gold complex [(L2PhB)Au(NHC)]Cl (6) featuring both carbene and L2PhB: ligands on the gold atom. In contrast, an isolable gold chloride complex (L2PhB)AuCl (8) was obtained by direct complexation between 1 and triphenylphosphine-gold chloride via ligand exchange. X-ray diffraction analysis and computational studies revealed the nature of the B:→Au bonding interaction in complexes 6 and 8. Natural Population Analysis (NPA) and Natural Bond Orbital (NBO) analysis support the strong σ-donating property of the L2PhB: ligand. Moreover, preliminary studies showed that complex 8 can serve as an efficient precatalyst for the addition of X–H (X = N, O, C) to alkynes under ambient conditions, demonstrating the first application of a metal complex featuring a neutral boron-based ligand in catalysis.Published versio

Enhanced photoluminescence property of sulfate ions modified YAG:Ce3+ phosphor by co-precipitation method

The sulfate ions modified YAG:Ce3+ phosphors were prepared by co-precipitation method and characterized by X-ray diffraction, transmission electron microscopy, and photoluminescence. Effects of sulfate ions on the photoluminescence (PL) property of the as-prepared YAG:Ce3+ phosphors were studied, with sodium dodecyl sulfate (SDS) being added to R3+ (Ce3+, Y3+, Al3+) ions. Results indicated that pure YAG:Ce3+ phosphors with different ratios of sulfate ions could be easily obtained by calcining the as-synthesized precursor at 950 °C for 2 h, the YAG:Ce3+ phosphors with an optimal mass ratio of 3.5 wt.% SDS had the highest emission intensity and the best dispersion behavior, and the fluorescence decay of the as-obtained YAG:Ce3+ phosphors was related to the lattice defect, reabsorption and cross correlation. Furthermore, thermal quenching properties of the YAG:Ce3+ phosphors and the YAG:Ce3+ phosphors with 3.5 wt.%SDS were also discussed, indicating that the YAG:Ce3+ with SDS phosphors could have potential applications in the daylight LEDs or warm white LEDs.Accepted versio