Experiments were carried out to compare dephosphorization performance of CaCO₃, Na₂CO₃ and CaF₂ in direct reduction roasting process of high-phosphorus hematite. It is found that Na₂CO₃ presents the best dephosphorization performance, followed by CaCO₃. The molecular dynamics simulation was conducted to calculate the distribution of bridging oxygen and the mean square displacement (MSD) of oxygen atoms during the roasting process of the system with three different additives respectively, and the dephosphorization mechanism of CaCO₃, Na₂CO₃, CaF₂ during the direct reduction process of high-phosphorus hematite was explored. The results show that the mechanism of dephosphorization by additives is to inhibit reduction of apatite by increasing the content of free oxygen or the MSD of oxygen atoms in the system and reducing the oxygen atoms shared by Si and P in the system. It is found that the dephosphorization performance of additives is positively correlated with the MSD of oxygen atoms in the system.

High purity sodium aluminate was prepared with sodium aluminate solution by adopting a process consisting of evaporation, cooling crystallization, and dewatering for purification. The effects of additives on caustic ratio and crystallization products, as well as the function and behavior of sodium aluminate solution during evaporation and crystallization were studied. The results show that with NaOH as an additive, the caustic ratio of the solution system can be increased, and the product from evaporation and crystallization can be converted to NaAlO₂. By using NaAlO₂ as seed crystal and adjusting the caustic ratio of system to 1.36 with NaOH, the product of NaAlO₂ with purity of 88.1% can be obtained after evaporation at 100 ℃ for 2 h with stirring rate of 300 r/min. Then, after 1 h dewatering at 200 ℃ and 1 h purification with alcohol at 100 ℃, a kind of solid NaAlO₂ can be obtained with purity of 93.8% and crystal particles of 5-25 μm.

The key factors of pile foundation settlement were explored for the slope under vertical load by using grey relational analysis, and it is found that each factor is in the following descending order by its influence: elastic modulus > slope distance > slope gradient > internal friction angle > cohesion > soil density > poisson's ratio of soil > pile length > pile diameter. In order to optimize the parameters of support vector regression (SVR) model, a novel HGWO-SVR model was proposed by integrating the differential evolution-enhanced gray wolf algorithm (HGWO). Compared with GWO-SVR and GS-SVR models, this model presents obvious advantage in prediction, with high accuracy and minor error. A settlement prediction model for pile foundation of slope was constructed based on HGWO-SVR model, and the prediction results were compared with those values calculated with existing settlement formulas. The results show that the maximum percentage error between the prediction value of HGWO-SVR model and the calculated value is 6.55%, thus verifying that this model is feasible in settlement prediction for pile foundation of slope.

High pressure grinding roll (HPGR) was used to comminute a copper smelting slag. An open-circuit test, edge-product cycling test and closed-circuit ball mill test were carried out using HPGR. The particle size of various products were measured, and the grinding results after HPGR were compared with those obtained after jaw crushing. The results show that after copper smelting slag is processed using HPGR and ball mill, the fine particle fraction of the products increases obviously, and the grindability increases by about 36 percentage point. It can be concluded that HPGR approach favors upgrading of grinding efficiency and beneficiation index in processing copper smelting slag.

By means of X-ray diffraction, optical microscopy, scanning electronic microscopy, mineral liberation analysis and chemical analysis, the paigetite ore from Wengquangou mine in Liaoning Province was studied in terms of its chemical component, mineral composition and content, and the occurrence state of main minerals. After main dissemination characteristics of target minerals and key factors in mineralogy influencing beneficiation performance were ascertained, some corresponding separation techniques were proposed.

Based on the studies of catalytic pyrolysis for high-sulfur waste residue (HSWR), it is found that after 90 min pyrolysis at a temperature of 600 ℃, with Fe₂O₃ as a sulfur fixation agent in a mass ratio of 1.5∶1 with HSWR, the total desulfurization rate can be around 85%. The volatile sulfur-containing complex organic matter in HSWR could be transformed into stable inorganic matter, among which the amorphous sulfur could be transformed into crystalline sulfur with purity over 95%. In the residue left after pyrolysis process for desulfurization, the main components include inorganic salts such as sodium sulfate and carbon black. The exhaust gas is mainly composed of simple molecular organics such as CH₄ and C₂H₄, and a small amount of inorganic compounds such as CO, SO₂, CO₂ and HCl. The pyrolysis process for desulfurization consists of four stages: firstly, the amorphous elemental sulfur is vaporized and then crystallized to form crystal sulfur; secondly, as for the elemental sulfur with attachment of organic matter and in a relatively more stable structure, its bond with the hydroxyl or carboxyl of organic phase is broken, leading to sulfur emitted into the atmosphere; at the third stage, the sulfur-containing organic phase is deactivated at the methylene and submethyl sites to form HCl, H₂S and carbon black, which are then adsorbed by sulfur-fixation agent and converted into sulfate; at the fourth stage, the carbon-carbon bond between nitrogen heterocyclic hydrocarbons becomes unstable after grouping, and is broken into small organic molecules such as CH₄ and C₂H₄, as well as carbon black and a trace of H₂. Meanwhile, C—N/C—NH_x bonds are broken into NO_x/NH₃, and C—S/C—SO₃H bonds are broken into H₂S and SO₂, which are then adsorbed by sulfur fixation agents and converted into sulfate.

In response to the problems of high molybdenum loss and difficulty in molybdenum/talc separation existing in the desliming process of a high talc-type molybdenite ore from Henan, ZN-J1, a molybdenum depressant, was introduced in the desliming section to minimize efficiently the molybdenum loss. The feed ore with Mo grade of 0.116%, molybdenum sulfide percentage of 83.53% and talc content of 14.0% was processed by adopting a flowsheet, consisting of desliming, pre-flotation of molybdenum, regrinding, and molybdenum/talc separation, with a combination of sodium silicate and ZN-P1 as depressant. A closed-circuit test with the whole process produced a molybdenum concentrate with Mo grade of 47.68% and Mo recovery of 75.41%, respectively.

With Ba (OH)₂·8H₂O and Ti (OC₄H₉)₄ as raw materials, and isopropanol (IPA) as solvent, tetragonal-rich BaTiO₃(BTO) nanopowder was synthesized by adopting solvothermal process. Effects of Ba/Ti ratio, pH value, solvothermal temperature and time on synthesis of tetragonal-rich BTO powders were investigated, and the mechanism of IPA in the solvothermal process for synthesis of BTO powders was also characterized by X-ray diffraction and scanning electron microscopy. It is found that in the solvothermal process, IPA will preferentially provide certain—OH to promote the hydrolysis of Ti (OC₄H₉)₄, generating TiO₆ octahedra to interconnect with Ba²⁺, which is gradually transformed into the tetragonal phase BaTiO₃ with regular morphology after phase transition, dissolution of small particles, and recrystallization in a low alkalinity environment. Experimental results show that under the following conditions including Ba/Ti ratio of 1.6, pH of 10 for the system, a solvothermal process at 220 ℃ for 24 h, calcination at 950 ℃ for 2 h, the synthesized tetragonal-rich BTO nanopowder is well dispersed with regular morphology, square or nearly square shape, with c/a value of 1.009 4 and particle size of 124 nm on average.

Mg-1%Al alloy plates were rolled at different strain rates, and the effects of rolling strain rate on microstructure, mechanical properties and damping properties of Mg-1%Al alloy were investigated. As rolling strain rate increases, the average grain size and recrystallization volume fraction of Mg-1%Al alloy increase, while the tensile strength, yield strength and texture strength decrease. As the rolling strain rate increases, the elongation decreases after an initial increase, reaching the highest (25.33%) at a strain rate of 20 s^-1, and the damping performance at room temperature is also improved. The damping value is 0.061 with the strain amplitude of 0.1% at a strain rate of 30 s^-1, which is 1.5 times of that at a strain rate of 15 s^-1. At a certain strain rate, the damping performance decreases as strain frequency increases.

To solve the problem of unstable slurry, low density of sintered body, and high carbon residue, the effect of different resin monomer on additive manufacturing of 5052 aluminum alloy with light curing strategy was explored. It is found that different type of monomer can bring great impact to the process of additive manufacturing with light curing strategy and the properties of the following sintered product. When the aluminum slurry prepared with TMPTA or PEG400DA has viscosity higher than 30 Pa·s and settling time is more than 120 h, the formed aluminum alloy substrate has a complete structure with more pores on the surface. When the aluminum slurry prepared with PEG200DA or HDDA has viscosity less than 30 Pa·s and the settling time is less than 16 h, the formed aluminum alloy substrate has no pores on the surface, but is prone to have incomplete structure. When the aluminum slurry prepared with PS-PCL has viscosity less than 30 Pa·s, and is stable and not prone to settling, the formed substrate has a complete structure with no pores on the surface. When the aluminum slurry with solid content around 55% was prepared with PS-PCL, after additive manufacturing process and sintering, the obtained sintered product has the relative density higher than 95%, relativly lower carbon residue (0.259 17%) and relatively higher hardness (29.94HV), with obvious necking growth on the fracture.