As for pipes with different lengths, with heave compensation device replaced by elastic constraint, a vibration equation was established by using energy integration approach, and the dynamic response of lifting pump installed at different positions of pipes was analyzed by finite element method. Results show that the harmonic response of stress excited by the following single loads was in an ascending order: torque, wave in longitudinal direction, and a combination of wave and current in horizontal direction. Under excitation by all these three loads with the same phase, the harmonic response of the system increased significantly. When the installed lifting pump was changed from a high position to a low position, the maximum equivalent stress of pipeline increased after an initial falling down. The installation position of lifting pump on the pipe corresponding to the minimum of the maximum equivalent stress was the suboptimal installation position. Based on the suboptimal installation position for the lifting pump on the pipeline with specific length, an empirical formula was established for the suboptimal installation position, which can provide reference for the quantitative design of lifting system.

In order to comprehensively recover fluorite resources from the tailings left after hot flotation of scheelite, a beneficiation process consisting of regrinding, water displacement and concentration, and fluorite flotation was proposed. It is shown that with the feed ore with CaF₂ grade of 25.47%, a fluorite concentrate can be obtained with CaF₂ grade and recovery at 92.35% and 60.59% respectively.

A study on the separation of a copper-lead-zinc sulfide ore from Yunnan was presented by adopting a Cu-Pb-Zn full selective flotation process. The mineral liberation degree was enhanced by adopting fine grinding of raw ore and selective regrinding of lead roughing concentrate. A combined usage of depressants sodium sulfite and zinc sulfate benefited the synergistic effect and selectivity in depressing, and collectors Z-200, ethionitrogen and BK906 exhibited high selectivity. Under optimized parameters, a copper concentrate with Cu grade of 22.78%, Cu recovery of 83.28%, Pb content of 3.01% and Zn content of 4.23%, a lead concentrate with Pb grade of 75.86%, Pb recovery of 82.75%, Cu content of 0.17% and Zn content of 1.64%, and a zinc concentrate with Zn grade of 51.87%, Zn recovery of 93.16%, Cu content of 0.24% and Pb content of 0.31%, were obtained.

The influence of roasting on mineral decomposition under stable magnetic field was investigated. A direct reduction roasting experiment without carbon presence was performed for Bayan Obo lean iron, with roasting temperature of 950 ℃ and magnetic induction density of 1.02 T. Based on the analysis of the loss rate of mineral weight, mineral phase transformation and micro-morphology change by means of TG-DSC, XRD and SEM-EDS, the phase evolution law for rare earth minerals, gangue minerals and iron minerals under magnetic field was revealed. The results show that the decomposition time of bastnaesite is shortened by about 20 min after applying a stable magnetic field, and even the monazite with extremely low decomposition rate is almost completely decomposed after 60 min-roasting process. It is found that magnetic field can promote the decomposition and transformation of gangue minerals that cannot be decomposed without application of magnetism, and also accelerate the migration of alkali metal ions and the replacement of Fe²⁺ with fayalite.

Rhodococcus opacus (R opacus) was taken as a microbe collector in a flotation experiment to investigate the recoveries of cassiterite, calcite and quartz pure minerals. The results show that, with pulp pH as 4 and R opacus dosage as 1.24 g/L, the recoveries of these three minerals were correspondingly 82.07%, 45.42% and 13.66%. The interaction mechanism between R opacus and cassiterite was investigated by measuring zeta potential and surface tension. Finally, an open-circuit flotation experiment of tin ore was carried out with R opacus as the collector and sodium silicate as the depressant, showing that the grade of tin concentrate was improved from 3.98% to 23.83%.

The phase composition and morphology of a molten mixture of steel slag and furnace slag prepared at a high temperature was analyzed by X-ray diffraction and SEM-EDS scanning electron microscope to investigate the effect of MgO doping. The results show that MgO doping can effectively inhibit the formation of MgFe₂O₄ phase and non-gel Ca₂Al₂SiO₇ phase, and promote the formation of MgFeAlO₄ phase, thus increasing the melting point of the mixed slag. It is found that the mixed slag after doping 2% MgO presents a layered structure on its cross section. The inner layer has an increased proportion of MgFeAlO₄ phase, with uniform and fine pores; and the MgFeAlO₄ phase is wrapped by MgFe₂O₄ spinel with layered structure in the middle part; and the outer layer has Ca₂Al₂SiO₇ phase with uniform pores and moderate density. The mixed slag with such kind of structure is suitable to be used as the filter material for removing heavy metal ions.

An introduction of preparation method of Fe/Al₂O₃ ceramet composites is presented. The combination mechanism of Fe-base and ceramic phase in the preparation process of Fe/Al₂O₃ cermet composites, as well as the optimization of preparation technique and material properties are all expounded based on the principle of powder metallurgy. Finally, the future direction for Fe/Al₂O₃ cermet composites research is also predicted.

With sodium bicarbonate as a precipitant, praseodymium neodymium oxide was prepared by feeding step by step in a positive sequence. The effects of pH value at the end of precipitation and precipitation temperature on particle size and impurity content of the precursor and product of praseodymium neodymium oxide were all investigated. The results show that precipitation at 50 ℃ with pH value of 5.10 at the end can prepare a praseodymium neodymium oxide powder with a median particle size D₅₀ of 21.45 μm and narrow particle size distribution. It is sphere-like powder formed by flake crystallization agglomeration, with the content of Cl^-and Na₂O at 0.017% and 0.012%, respectively, indicating higher than the national standards.

A kind of similar rock material was prepared with gypsum and quartz sand, and influence of seven factors on the strength index of the material was analyzed by performing laboratory tests. The results show that curing temperature and material density are in positive correlation with material strength index, while curing humidity, sand-to-binder ratio, ash-to-paste ratio, fine-grained quartz sand content, as well as water content are in negative correlation with material strength index. Based on the calculation of the sensitivity indices of different influencing factors, it is found that material strength has a sensitivity of only 4.5% to curing temperature, a sensitivity of 104.9% to sand-binder ratio. Factors of curing temperature, water content, material density, curing humidity, ash-to-paste ratio, fine-grained quartz sand content and sand-to-binder ratio are in an ascending order in terms of their sensitivity to uniaxial compressive strength; while factors of sand-to-binder ratio, ash-to-paste ratio, material density, curing humidity, water content, fine-grained quartz sand content and curing temperature are in a descending order in terms of their sensitivity to tensile strength.

An experimental study was carried out for sulfur reduction and upgrading of a high-sulfur antimony-gold bulk concentrate from Russia with Sb grade of 24.58%, Au content of 76.92 g/t and S content of 14.46%. A closed-circuit flotation test was conducted using a new collector CJ-201 and a new depressant CJ-5S. The Sb and Au grades in the antimony concentrate attained respectively 42.26% and 92.36 g/t, with the corresponding recoveries of 88.04% and 62.18%. With this approach, a antimony-gold concentrate product with high content of antimony and low content of sulfur can be separated out from antimony-gold bulk concentrates collected in a Russian mine.