Real-time analysis of metallic mineral grade and slurry concentration is significant for improving flotation efficiency and product quality. This study proposes an online detection method of ore slurry combining the P...
详细信息
Real-time analysis of metallic mineral grade and slurry concentration is significant for improving flotation efficiency and product quality. This study proposes an online detection method of ore slurry combining the Prompt Gamma Neutron Activation Analysis (PGNAA) technology and artificial neural network (ANN), which can provide mineral information rapidly and accurately. Firstly, a PGNAA analyzer based on a D-T neutron generator and a BGO detector was used to obtain a gamma-ray spectrum dataset of ore slurry samples, which was used to construct and optimize the ANN model for adaptive analysis. The evaluation metrics calculated by leave-one-out cross-validation indicated that, compared with the weighted library least squares (WLLS) approach, ANN obtained more precise and stable results, with mean absolute percentage errors of 4.66% and 2.80% for Fe grade and slurry concentration, respectively, and the highest average standard deviation of only 0.0119. Meanwhile, the analytical errors of the samples most affected by matrix effects was reduced to 0.61 times and 0.56 times of the WLLS method, respectively.
In this study, a series of aluminum borate ceramics (ABCs) with needle-like whiskers were obtained using a low-cost, solid-state, pressureless sintering ceramic route, without any additives during the preparation proc...
详细信息
In this study, a series of aluminum borate ceramics (ABCs) with needle-like whiskers were obtained using a low-cost, solid-state, pressureless sintering ceramic route, without any additives during the preparation process. The effects of different alumina/boric acid molar ratios and sintering temperatures on the phase composition, microstructure, mechanical properties, specific surface area, pore size distribution, and sub-cadmium neutron shielding properties of ABCs were studied using orthogonal experiments. It was observed that pure phase aluminum borate (Al18B4O33) ceramics could be obtained at 1100 degree celsius, forming a mass of needle-like whiskers. The whiskers' aspect ratio, fracture work, specific surface area, and pore size distribution of ABCs are maximized when ABCs are sintered at 1100 degree celsius with 9:6 alumina/boric acid molar ratio. In this condition, ABCs (0.5 cm) can shield 70% of sub-cadmium neutrons (E<0.4 eV). These findings demonstrate the great potential of aluminum borate ceramics for neutron shielding applications.
In accordance with the bending deformation of titanium alloy profile generated by hot extrusion, the hot stretch straightening assisted by resistance heating is an effective strategy to improve the straightness accura...
详细信息
In accordance with the bending deformation of titanium alloy profile generated by hot extrusion, the hot stretch straightening assisted by resistance heating is an effective strategy to improve the straightness accuracy. In order to reveal the heat transfer behavior and deformation mechanism of titanium alloy profile during hot straightening, this study focuses on Ti-6.5Al-2Zr-1Mo-1 V alloy thin-walled T-shaped profile with unequal thicknesses. The flow stress curves of profile within temperatures from 400 to 800 celcius, strain rate at 5 center dot 10(-4) s(-1) were obtained by uniaxial tensile tests. The thermal boundary conditions between profile and air were determined by using inverse analysis experiment. Then, the thermal-electrical-mechanical multi-field coupling numerical simulation model was established. The temperature distribution, stress distribution, and deformation of profile were investigated systematically. The results show that the non-uniform temperature field with low temperature in thinner wall region and high temperature in thicker wall region would form during resistance heating. The stress distribution of stretch straightening process was determined by the temperature distribution and the initial bending shape of profile jointly, thereby affecting the springback deflection and direction after unloading. The established numerical simulation models, which have been verified by process experiments, could lay foundation for the prediction and process optimization in hot stretch straightening of titanium profile.
暂无评论