The paper overviewed the recovery methods of germanium, summarized the feature of those methods such as leaching with sulphuric acid, chlorination leaching- distillation, alkali decomposion, leaching with hydrofluoric acid, extracting, reduction and leaching germanium with microorganism. And introduced the principles ,technologies and disadvantages of those methods. Finally, prospected that microwave pretreatment technology and microwave directly leaching can be used in traditional methods such as acid leaching and alkali decomposion to improve the recovery rate of germanium by change insoluable germanium into soluble germanium and upgrade the leaching rate of germanium.

A microwave carbonthermal nitridation method under the condition of nitrogen at atmospheric pressure was used to the synthesis of vanadium nitride from vanadium pentoxide and carbon black. In the present work, the effects of synthesis temperature, flowing rate of nitrogen, heating rate and soaking time on the apparent density and the nitrogen content of the microwave sintered samples were studied. The experimental data indicated that the apparent density and the nitrogen content of the microwave sinter sample was 4.1 g/cm3 and 13.8 %, respectively under the optimum conditions of flowing rate of nitrogen 50 L/h, heating rate of 6 °C/min to 1400 °C and soaking time of 50 min. The denser pellet was preferred to generated in the centre of the samples of which was beneficial to the expulsion of stoma and the diffusion of nitrogen due to the opposite temperature gradient compared with traditional heating.

The TG and DTG curves of self-made ZnO precursor were studied by the thermo-gravimetric analysis method in N2 atmosphere from 25°C to 650°C at the heating rate of 5, 10 and 15°C/min. The TG curve showed that the decomposition process started at about 150°C and finished at 300°C, in accordance with the temperature range of the decomposition from basic zinc carbonate to zinc oxide. The first level chemical reaction based on Coats-Redfern method was applied to estimate the activation energy of the decomposition. The correlation factor was about 0.99, and the calculated average activation energy was 33.89kJ/mol. Active zinc oxides were perpetrated by microwave heating at 350°C for 30min. Their composition and surface morphology were investigated by using scanning electron microscope and X-ray diffraction and its quality can reach the first-grade standard of HG/T2572-94.

The leaching tests of nickel supported activated carbon under normal pressure in (NH4)2SO4were studied. The effects of experimental condition, such as initial concentration of (NH4)2SO4, liquid-to-solid ratio, leaching time and leaching temperature on the leaching rate of nickel, were investigated. The results show that the leaching rate of nickel is 96.12% with initial concentration of (NH4)2SO4of 7.5%, liquid-to-solid ratio of 2, leaching time of 5h and leaching temperature of 25°C. The morphology of nickel supported activated carbon before and after leaching was characterized by XRD, which proved the effective separation of nickel and activated carbon. The leaching rate of nickel was also shown better at room temperature and atmospheric pressure. Moreover, it needn’t equipments enduring high-pressure and high temperature in the leaching process, thus reducing the costs of leaching equipments greatly. This work provides a new way to the comprehensive utilization of nickel-containing activated carbon.

The mechanical behavior of rocks is nonlinear. Most conventional calculation of stress around the mining hole is based on a linear Mohr–Coulomb failure criterion. In the past few years, there has been an increasing recognition that stress–strain relations do not remain linear, even for low stress levels, and the strength parameters of both geomaterials depend on stress levels. In recent years, many efforts have been focused on stability problems of geotechnical structures with the theoretical and numerical method. In order to further understand the stress state to predict the safety degree of mining hole, in this paper, analysis for the safety status of rock mass material in mining hole using the theoretical and numerical method are done to give guidance for the real practice.