According to the characteristics of high-content aluminum and low-content lithium in hydrochloric acid leaching solution of a clay-type lithium ore in Hubei Province, lithium and aluminum were firstly separated by adopting calcination at 390 ℃ for 2.0 h. Then, the calcined residue, without grinding, was leached at 90 ℃ for 1 h with water in a volume ratio of 3∶1. After the leaching process, the leaching rate of lithium reached 93.85%, and no aluminum was detected in leaching solution, indicating a good Li-Al separation result. An analysis of chemical composition of calcined residue and leaching residue show that after water leaching, the main metal elements in the calcined residue, such as lithium, kalium, sodium, calcium and magnesium, all are leached into the lixivium, and the main composition of leaching residue are alumina and iron oxide.

Mo (VI) and Cu (II) in aqueous solution were extracted by using an aqueous two-phase system consisting of isodecanol polyoxyethylene ether (E-1006) and ammonium sulfate ((NH₄)₂SO₄) for the first time, and a phase diagram of the system was also obtained. Effects of initial pH of aqueous phase, temperature of system, and concentrations of E-1006 and (NH₄)₂SO₄ on Mo-Cu separation effect were also investigated. The results show that with pH of 2.0, temperature of 313.15 K, and both E-1006 and (NH₄)₂SO₄ at concentration of 150 g/L, the extraction efficiency of Mo (VI) is 96.08% and the separation factor for Mo (VI) and Cu (II) is 5 131.45.

An acoustic emission (AE) test of granite under uniaxial step loading was carried out, and the evolution characteristics of AE frequency, event incidence and fractal dimension of the sample at each load-holding stage before occurrence of instability and fracture were analyzed. The results show that the high-frequency signal first decreases and then increases with the increase of stress in the process of step loading; and macro-instability occurs in the sample at the last stage of step loading, at which the internal micro-cracks in the sample undergo from stable propagation to unstable propagation. The incidence of acoustic emission events decreases gradually as time is prolonged. At the last stage of step loading, the incidence of acoustic emission events decreases first and then increases, unstable fracture in the rock increases and micro-cracks gradually merge and coalesce to form macro-cracks, resulting in overall instability and fracture of the sample; with the increase of stress, the fractal dimension of acoustic emission decreases after an initial increase, and the rock fracture develops gradually in an order way from a disorder way.

Manganese-rich phase with low impurity content was prepared with manganese sulfate crude solution by precipitation. A single-factor experiment was carried out to explore effects of reaction time, reaction temperature, pH value and feeding speed of precipitating agent on precipitation efficiency, and then the content of impurity in the finally prepared manganese-rich phase was also analyzed. After the leaching solution with Mn²⁺ in mass concentration of 38 g/L, and pH of 8.0 was precipitated at 60 ℃ for 4 h, with R as precipitating agent fed at a speed of 0.5 L/h, the conversion rate of Mn²⁺ was 94.3%. The ICP and EDS analyses showed that there were low content of impurity ions (K, Na, Ca, Mg) in the precipitate of manganese-rich phase.

Ginkgo biloba biochar-based fertilizer prepared with Ginkgo biloba was used for remediation of heavy metal contaminated soil. After 4 d remediation at 30 ℃ by adding 4% ginkgo biloba biochar-based fertilizer, the stabilization efficiencies of Pb, Cd, and Cu can reach 89.5%, 97.5%, and 74.9%, respectively. It is shown that the contents of acid extractable Pb, Cd and Cu decrease from 43.81%, 60.53% and 65.31% to 12.21%, 52.75% and 60.47% respectively; the contents of reducible Pb and Cd decrease from 11.12% and 36.35% to 10.02% and 33.71% respectively; the contents of oxidizable Pb and Cd decrease from 14.36% and 0.76% to 11.61% and 0.74%, respectively, while the content of oxidizable Cu increases from 11.13% to 14.12%; the contents of residual Pb, Cd, and Cu increase from 30.71%, 2.36%, and 22.33% to 66.16%, 12.80%, and 24.19%, respectively. It is concluded that with strong stability and a good remediation effect at low cost, such ginkgo biloba biochar-based fertilizer shows a good application prospect in remediation of heavy metal contaminated soil.

In view of low prediction accuracy and slow speed of traditional prediction methods for strip crown, a weighted prediction model based on random forest (RF) and support vector machine (SVM) was established. The parameters of models based on RF, SVM, and a combination of RF and SVM were optimized respectively by adopting the improved coati optimization algorithm (ICOA), so as to improve crown prediction accuracy. A 1 580 mm production line of a hot-rolling mill in one company was taken in a simulation research on crown prediction based on its actual measurement. The root mean square error of the weighted prediction model based on RF and SVM is 2.23 μm. It is found that this weighted prediction model has its prediction accuracy increased by 7.08% and 2.62% respectively, compared with the models based on RF and SVM respectively.

Collophanite ore was taken in a test to explore the influence of fine particle entrainment content in return sand to grinding on grinding efficiency. It is found that the lower the fine particle entrainment content in return sand, the higher yield of the newly generated particles in the size range of -0.074 mm. Nevertheless, the increase in the yield of particles within the range of -0.025 mm has little to do with the entrainment content in return sand.

Acid mine drainage (AMD) and a pulp regulator, TY-308, were used combinedly for activation in flotation of highly alkali-depressed pyrite, in which AMD was used to neutralize the pulp alkalinity, and TY-308 used to reduce the negative effect of AMD on flotation. A closed-circuit test on flotation with the process consisting of one-stage roughing, one-stage cleaning and one-stage scavenging yielded a pyrite concentrate grading 48.73% S at 97.93% recovery. Compared with the practice using sulfuric acid as the activator, the sulfur recovery can be increased by 1.34 percentage points. Furthermore, not only the cost for AMD treatment will be significantly reduced, but the safety risk associated with the use of concentrated sulfuric acid can be avoided.

Based on the triboelectric charging characteristics of the main minerals of quartz, molybdenite and chalcopyrite in a copper-molybdenum ore, the enrichment effect and mechanism of triboelectrostatic separation of chalcopyrite from the mixture under different conditions were investigated. The triboelectric charging results show that after the interaction with the rotary charger under applied electric voltage, chalcopyrite, molybdenite and quartz are remarkably different in charge-mass ratio. In mineral processing tests, a rotary triboelectrostatic separator (RTS) was adopted to treat an artificial ore with chalcopyrite, molybdenite and quartz in a mass ratio of 1∶1∶8. The results show that with the applied voltage of the rotary charger at -14 kV, the charger rotation speed at 5 000 r/min and the co-flow air velocity at 2 m/s, a copper concentrate can be obtained with Cu grade up from 3.3% to 5.9% at Cu recovery of 90%, and with Cu grade up to 9.3% at a recovery of 50%.

Based on the study on reduction behavior of vanadium during the smelting of vanadium-bearing titanium concentrate in an electric furnace, the comprehensive recovery of vanadium resources was explored through experiments. The vanadium-bearing titanium concentrate from Yunnan Province was taken as raw material to carry out an industrial-scale smelting experiment in an electric furnace with different carbon ratios. Based on the thermodynamic theory, the distribution and influencing factors of vanadium element in slag-iron phase were all analyzed. The results show that with carbon ratio up from 6.5% to 14.0%, the mass fraction of TiO₂ in titanium slag increases from 54.12% to 92.51%, the proportion of vanadium element reduced into molten iron increases from 1.14% to 6.61%, and the proportion of vanadium element left in the titanium slag decreases from 92.95% to 88.17%. It is found that there is a small amount of vanadium in dust, accounting for about 5.5%, which has no significant correlation to carbon ratio. The smelting process of titanium slag is not conducive to vanadium reduction, which is principally attributed to carbon deficiency operation and low-basicity slag system. It is not economically feasible to extract vanadium from molten iron by smelting vanadium-bearing titanium concentrate in an electric furnace, so it is suggested that vanadium should be extracted from the vanadium mud obtained after refining and vanadium removal process of titanium dioxide.