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Taking a tailings in Inner Mongolia as the research object, the process mineralogy was studied. The results of multi-element analysis showed that the REO content in the raw materials was 6. 2%, and the results of mineral composition analysis showed that the rare earth minerals were mainly cerium fluorocarbon and monazite, and also contained a small amount of cerium fluorocarbonite and Yellow River minerals. The gangue minerals were mainly iron minerals, fluorite, pyroxene, amphibole, and so on. The results of particle size sieve analysis showed that the particle size was 62.9% passing 25 µm, and the fine particle size of rare earth minerals would adversely affect the flotation recovery. The adsorption kinetics were studied, and the effects of P8 dosage and pH value on the floatability of the minerals were investigated by the adsorption kinetics study, and the optimal pH value of the fluorocerite flotation was 9. The kinetic fitting of P8 adsorption by the kinetic equation shows that P8 has strong capture ability, and the appropriate dosage can completely float the basilite. In the flotation tests, the hydroxamic acid collector P8 has good capture performance and selectivity, and the sodium silicate having good inhibitory effect on gangue minerals pyroxene and amphibole minerals were used as inhibitors. FM-132 was used as foaming agent. Laboratony experiments were carried out to determine the optimal flotation conditions such as collector dosage, inhibitor dosage, slurry concentration, flotation temperature and flotation time. Through a locked-cycle process of one roughing and two cleanings, a rare earth concentrate with a grade (REO) of 51.85% and a recovery of 79.12% can be obtained, which can effectively separate and recover the rare earth minerals in the tailings, and provide technical support for the recovery and application of rare earth in the industry, so as to realize the efficient utilization of rare earth resources. [ABSTRACT FROM AUTHOR]

NbC particle reinforced copper matrix composites with 1%, 2%, 3% and 4% NbC were prepared via microwave sintering using niobium carbide particles and electrolytic copper powder as raw materials. The effects of niobium carbide mass fraction and microwave sintering temperature on the properties of copper matrix composites were investigated by observing the microstructure and testing the density, hardness, and conductivity. The results show that the NbC particles in the copper matrix can be evenly distributed on the matrix except for a small amount of particles that agglomerate and grow up; with the increase of sintering temperature, the density, conductivity and hardness of copper matrix composites increased: the density increased from 5.8 g/cm³ to 7.208 g/cm³ ; the conductivity increased from less than 10% IACS to 63.8% IACS. The hardness increased from 35 HV to 64.5 HV. With the increase of the mass fraction of the reinforced phase, the hardness increased from 36 HV to 64.5 HV at 1 000 °C, the density decreased from 7.208 g/cm³ to 5.86 g/cm³, and the conductivity decreased from 63.8% IACS to 24.1% IACS. When the mass fraction of NbC is 1%, the influence of sintering temperature is obvious. When the sintering temperature is 1 000 °C, the conductivity reaches the maximum, which is 63.8% IACS. [ABSTRACT FROM AUTHOR]

For the meting process of glass-ceramics, the melts are simulated by using analytically pure materials high temperature. The effects of La2O3 on the viscosity and structure for the CaO-SiO2-MgO-Al2O3 melt are studied via both rotating-cylinder method and Raman spectroscopy. The results show that the viscosity and viscous flow activation energy decreases as the La2O3 content increases. The addition of La2O3 destroyed the silicate structural units(Qn)m the met. The percent of Q¹,Q² units increases with increasing amount of La2O3. However, the percent of Q³ units decreases with increasing amount of La2O3. In addition, the percent of Q0 units are slightly dependent on the La2O3 content. It indicates that the addition of La2O3 increase the number of non-bridging oxygen in the state structural units and reduce the degree of polymerization. La2O3 pay a role as network modifier in the melt. [ABSTRACT FROM AUTHOR]