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Cubic Pd nanocrystals (CPNCs) as one of typical nanostructures are generally fabricated using I− or Br− as capping ions. However, which ion, I− or Br−, exclusively mediates the growth of CPNCs in a given reaction system is not well understood. Herein, regardless of I− or Br− as the capping ion, we successfully achieved CPNCs in the same reaction system simply by adjusting the pH. Based on the Finke–Watzky kinetic model, an increase in pH accelerates the overall reduction rate of Pd2+, and the formation of CPNCs only occurs over the range of specific solution reduction rate constants (k1). This kinetically illuminates that the reduction rate of Pd2+ is the physicochemical parameter that determines which ion, I− or Br−, dictates the growth of CPNCs. Also, density functional theory (DFT) calculations further elucidate the dependence of the reduction rate of Pd2+ on pH and the configuration of the activated Pd2+ complex.

Integration of 1D, core/shell, and jagged features into one entity may provide a promising avenue for further enhancing catalyst performance. However, designing such unique nanostructures is extremely challenging. Herein, 1D serrated Au/Pd core/shell nanowires (CSNWs) with jagged edges were produced simply by a one-pot, dual-capping-agent-assisted method involving co-reduction, galvanic replacement, directional coalescence of preformed nanoparticles, and site-selective epitaxial growth of Pd. Au/PdCSNWs, compared with the commercially available Pd/C, exhibited enhanced electrocatalytic performance towards liquid fuel oxidation because of the synergistic effect of the electronic structure and low-coordinated jagged edges.

The reduction kinetics of hematite in the presence of coke as a reductant was studied via isothermal and non-isothermal thermodynamic analyses. The isothermal reduction of hematite was conducted at a pre-determined temperature ranging from 1423 to 1573 K. The results indicated that a higher reduction temperature led to an increased reduction degree and an increased reduction rate. The non-isothermal reduction of hematite was carried out from room temperature to 1573 K at various heating rates from 5 to 15 K·min−1. A greater heating rate gave a greater reduction rate but decreased reduction degree. With an increase in temperature, both the reduction rate and the reduction degree increased at a smaller rate when the temperature was less than 1150 K, and they increased at a higher rate when the temperature was greater than 1150 K before completion of the reduction reaction. Both the isothermal and the non-isothermal reduction behaviors of hematite were described by the Avrami–Erofeev model. For the isothermal reduction, the apparent activation energy and pre-exponential factor were 171.25 kJ·mol−1 and 1.80 × 105 min−1, respectively. In the case of non-isothermal reduction, however, the apparent activation energy and pre-exponential factor were correlated with the heating rate.

Cubic Pd nanocrystals (CPNCs) as one of typical nanostructures are generally fabricated using I- or Br- as capping ions. However, which ion, I- or Br-, exclusively mediates the growth of CPNCs in a given reaction system is not well understood. Herein, regardless of I- or Br- as the capping ion, we successfully achieved CPNCs in the same reaction system simply by adjusting the pH. Based on the Finke-Watzky kinetic model, an increase in pH accelerates the overall reduction rate of Pd2+, and the formation of CPNCs only occurs over the range of specific solution reduction rate constants (k1). This kinetically illuminates that the reduction rate of Pd2+ is the physicochemical parameter that determines which ion, I- or Br-, dictates the growth of CPNCs. Also, density functional theory (DFT) calculations further elucidate the dependence of the reduction rate of Pd2+ on pH and the configuration of the activated Pd2+ complex.

The effect of Z-164D dispersant on the grinding efficiency of oolitic hematite was studied. The content of-0.074 mm in the ground product was increased by 30.15% by using Z-164D dispersant which weight was 2% of oolitic hematite compared without using any dispersant under the optimal technological conditions of the grinding aid experiment. It was considered that the content of-0.074 mm in the ground product was increased by 26.52% by using Z-164D dispersant which weight was 1%, so it was confirmed that the weight of Z-164D dispersant was 1% of oolitic hematite from the perspective of economic benefit finally. On this basis, the absorption characteristics of the Z-164D on the oolitic hematite surface which could change the pulp viscosity and the surface experience of particles were studied and the mechanism how Z-164D dispersant improved the grinding efficiency of oolitic hematite was revealed.

Oolitic iron ore is one of the most important iron resources. This paper reports the recovery of iron from high phosphorus oolitic iron ore using coal-based reduction and magnetic separation. The influences of reduction temperature, reduction time, C/O mole ratio, and CaO content on the metallization degree and iron recovery were investigated in detail. Experimental results show that reduced products with the metallization degree of 95.82% could be produced under the optimal conditions (i.e., reduction temperature, 1250°C; reduction time, 50 min; C/O mole ratio, 2.0; and CaO content, 10wt%). The magnetic concentrate containing 89.63wt% Fe with the iron recovery of 96.21% was obtained. According to the mineralogical and morphologic analysis, the iron minerals had been reduced and iron was mainly enriched into the metallic iron phase embedded in the slag matrix in the form of spherical particles. Apatite was also reduced to phosphorus, which partially migrated into the metallic iron phase.

Three-dimensional (3D) cubic superstructures of PtPd nanocubes were achieved by spontaneous adjustment of PtIV reduction kinetics, and exhibited enhanced catalytic activity and long-term durability towards methanol oxidation compared with the state-of-the-art Pt/C. This work demonstrates the first example of designing 3D shaped architectures of PtPd nanocubes for methanol electrooxidation.

The internal parameters of ball mill are very important in the grinding process and have significant impact on the grinding results. Accurate measurement of the internal parameters of ball mill is crucial and indispensable for optimization and control of grinding process. In this paper, a novel tri-sensor measurement method was used to measure the external signals (i.e., bearing pressure, sound intensity and power consumption) of ball mill. Mathematical models, which link the external signals of ball mill with its internal parameters, were established to predict the internal parameters of ball mill. Experimental results showed that the mathematical models could directly predict the internal parameters of ball mill once the external signals were obtained. The tri-sensor measurement method and the mathematical models proposed in this paper provided a new way and solid basis for optimization and control of ball milling.

Dongguashan copper ore is one of a complex copper sulphide ores containing various metal minerals in Tong ling area. In this paper, in order to simplify the complexity of traditional lime process, the process of Cu-S bulk flotation-regrinding-separation is discussed and exploited. A good quality of Cu concentrate and S concentrate are obtained respectively after Cu-S separation by using calcium hypochlorite as depressant. A good separation results are derived through this process, and high efficiency of calcium hypochlorite used as depressant and feasibility of the process are confirmed.

An extension of the classical Obriemoff experiments has been set up to measure the fracture energy of mica. This experimental system will be entirely independent of slurry rheology. CTAB (Cetyl Trimethyl Ammonium Bromide), sodium tripolyphosphate, sodium hexametaphosphate, and tri-sodium citrate are used as grinding aids in this study and the fracture energy has been measured for mica in air, water, and water with the addition of various concentrations of these grinding aids. The results show that the fracture energy of mica in water is about half of what it is in air. Grinding aids are shown to reduce the fracture energy of mica, but not dramatically. Addition of grinding aids reduces the fracture energy by a further 10-20%, with tri-sodium citrate appearing to be the most effective. For each grinding aid there appears to be an optimal concentration, typically around 10 mmol. An experiment is also done with sodium chloride at a range of concentrations to investigate the mechanism of these grinding aids, but no reduction in fracture energy (compared to water) was observed, hence the molecular-level mechanism of action of these grinding aids remains unclear. The effect of solution pH values on the fracture energy are also investigated using tri-sodium citrate and sodium chloride. The results show that the solution pH value may effect on the fracture energy of mica. So, in practice, both concentration and pH value of solution are important for getting better grinding results.

The synthesis of nanometer calcium carbonate was strengthened using ultrasonic technology. In the presence of ultrasonic, the effects of initial reaction temperature, density of Ca(OH)2 and flow rate of CO2 on nanometer calcium carbonate particles’ size were investigated in this paper. The homogeneous dispersion nanometer calcium carbonate particles which size were 20~30nm were synthesized using ultrasonic reactor.

Titanate coupling agents KR-TTS is used to modify nanometer calcium carbonate and the modified powder is characterized. The modification mechanisms of nanometer calcium carbonate is also investigated in this paper. Experiment results show that the optimum conditions of dry modification method as follows: the dosage of KR-TTS titanate coupling agents is 2%, mass ratio of KR-TTS titanate coupling agents to liquid organic solvent is 1:1, modification temperature is 70°C, modification time is 20 minutes, stirring rate is 650rpm. Under the optimum conditions, activity index of modified nanometer calcium carbonate is 100%. The activity index Measurement indicates that modified nanometer calcium carbonate become hydrophobic instead of hydrophilic. IR analysis shows that chemical bonds are formed between titanate coupling agents and nanometer calcium carbonate particles.