An efficient defluorination agent (NY-Z02) was used to remove fluoride from high-salt fluoride-containing wastewater generated in the process of recycling spent batteries. The effects of pH value, reaction temperature, reaction time and dosage of defluorination agent on fluoride removal effect were investigated. On this basis, a two-stage fluoride removal process was put forward, with which a pilot test was carried out. Results show that by using a single-stage fluoride removal process, a reaction runs at 20 ℃ for 20 min with pH of 7.0 at the end and by adding defluorination agent at an amount of 1.2%, resulting in the fluoride concentration in the wastewater decreased to 12.5 mg/L. While by using a two-stage fluoride removal process, with addition of defluorination agent at an amount of 1.0%, the fluoride concentration in the wastewater can be decreased to 12.4 mg/L. In the pilot test with the dosage of defluorination agent reduced to 0.768%, the fluoride concentration in the wastewater after fluoride removal process met the requirement of enterprise (F≤20 mg/L). It is found that during the removal process with agent NY-Z02, fluoride ions in wastewater react with the agent and form precipitate of AlF₃, or together with Al (OH)₃ are removed by flocculation and precipitation. It is shown that this process has good fluoride removal effect without bringing in any impurities.

Blown zinc powder, electric furnace zinc powder, zinc alloy powder and distilled zinc powder were respectively taken in the test of cobalt removal by arsenic trioxide purification process to investigate influences of several factors on cobalt removal effect, including an adding amount of zinc powder, temperature and time of reaction, a mole ratio of copper to cobalt and a mole ratio of antimony to cobalt. Results show that when copper sulfate is added with copper and cobalt in a mole ratio of 5.0, potassium antimony tartrate is added with antimony and cobalt in a mole ratio of 0.5, a reaction at 90 ℃ for 90 min, with rotation speed of 300 r/min and addition of zinc powder at an amount of 2 g/L, the cobalt removal rates by using 4 different kinds of zinc powder are 95.73%, 96.15%, 95.94% and 94.87%, respectively, indicating the cobalt removal effect of different powder in the following descending order: electric furnace zinc powder > zinc alloy powder > blown zinc powder > distilled zinc powder.

Base on the study on homogenization behavior of blast furnace slag (BFS) by dynamic viscosity experiment, a kinetic model was constructed for molten slag conditioning process. The homogenization state of BFS was verified and the final granulation effect was analyzed. It is found that the homogenization time becomes shorten first and then prolonged as the addition of conditioner increases, which is the shortest when an addition of conditioner is at an amount of 15.43%. As for BFS with grain size greater than 1.75 mm, the homogenization time increases obviously. As slag temperature increases, the homogenization time is gradually shortened. Based on the comparison with the composition and mineral phases of fully homogenized BFS, it is verified that homogenization is completed when viscosity value becomes stable. The granulated slag particles with size mainly in the range from 1 mm to 2.5 mm present approximately normal distribution, and the homogenized BFS has amorphous phase content higher than 85%, meeting the requirements in the national standard.

In order to achieve utilization of antimony and alkali in arsenic-alkali slag and solidification of arsenic, a new processing technique, consisting of separation antimony by water leaching, arsenic precipitation by hydrothermal reaction with lime, and alkali extraction by evaporation, was proposed to treat arsenic-alkali slag. Results show that water leaching at 90 ℃ for 5 h with liquid-solid ratio of 3∶1 can result in the leaching rate of arsenic up to 97.96% and the leaching rate of antimony just 0.72%. The obtained leaching residue only contains 0.09% arsenic, presenting effective separation between antimony and arsenic. With calcium and arsenic in a molar ratio of 1.43, hydrothermal reaction at 170 ℃ for 2 h can lead to an arsenic precipitation rate up to 99.68% and the solution after precipitation with arsenic and alkali in a mass ratio of 1.65‰, also presenting a good separation effect. Finally, the concentration and crystallization process by evaporation can generate crystalized alkali containing only 0.14‰ arsenic, which can meet the technical requirement for alkali in antimony refining.

With Ca (NO₃)₂·4H₂O and Al (NO₃)₃·9H₂O as raw materials and urea as precipitant, a precursor Ca-Al-LDHs was prepared by microwave heating and hydrothermal synthesis. A product of Ca-Al hydrotalcite (Ca-Al-LDOs) was obtained after roasting, and it was used to adsorb fluorine in wastewater. It is found that Ca-Al-LDOs are of typical layered structure similar to hydrotalcite. With pH of 2, initial concentration of F^- ion at 500 mg/g, adsorbent dosage of 2.5 g/L and reaction time of 180 min, the adsorption capacity reaches 173.9 mg/g and the removal rate of fluorine reaches 92.01%. It is found that the process of adsorption conforms to the Freundlich adsorption isotherm mode, and its kinetics conforms to the quasi-second-order kinetic model. The adsorbent Ca-Al-LDOs can be reused after desorption, with defluorination rate keeping at 68.92% after 8 cycles of regeneration.

A technique process to remove impurities of calcium and magnesium from the leaching solution obtained after roasting plus leaching process of a sort of lepidolite was studied, and the effects of several factors on washing effect, including amount of sodium carbonate, solution pH, time and temperature of reaction and washing conditions, were all investigated. The results show that removal rates of calcium and magnesium can reach 99.9% and 93.1%, respectively, by adding sodium carbonate as precipitant at an amount of 2.21 mol/L, with pH of solution at 8.0, temperature of 25 ℃and time of 30 min. Then, the obtained calcium-magnesium residue was washed three times with a liquid-solid ratio of 1∶1, and 5 min for each time. As a result, products of calcium carbonate and magnesium carbonate can be obtained. It is concluded that this process, being simple and stable, can be adopted to effectively remove impurities of calcium and magnesium from leaching solution of lepidolite.

A micro- and nano-indentation test was performed for CoCrFeNiMn high entropy alloy. The relationship between the geometrically necessary dislocation (GND) density of CoCrFeNiMn and reciprocal value of real indentation depth (1/h) was obtained under different working conditions, and the influence of elastic factor (Δe) on GND density was also explored. The results show that GND density with the consideration of elastic deformation (ρ_Ge) presents a nonlinear relationship with 1/h, while GND density without the consideration of influence of elastic deformation (ρ_G) has a linear relation with 1/h. Based on the comparison of variation of ρ_G/ρ_Ge with the indentation depth, it is found that the ratio of ρ_G/ρ_Ge is 3-4 when the indentation depth is less than 500 nm, indicating that elastic factor can have an obvious impact on the GND density at shallow indentation. And, the ratio of ρ_G/ρ_Ge is approaching 1 when the indentation depth is up to 3 000 nm. It is shown that as indentation depth increases, dislocation slip gradually dominates deformation.

The out-of-life saggar after repeated use for LiCoO₂ sintering in industry was taken to explore its erosion mechanism during high temperature synthesis of LiCoO₂ by adopting fluorescence analysis, chemical composition analysis, X-ray diffraction analysis, microstructure and energy spectrum analysis. Results show that when saggar is used to hold basic cobalt carbonate and lithium carbonate and calcined at 950 ℃ for 15 h, it is eroded and damaged after 15 times of operation. During LiCoO₂ synthesis, saggar is mainly eroded by lithium ions, with the dominant erosion products including tetragonal LiAlO_2, α-LiAlO_2, LiAlSiO_4, Li₃AlSiO₅ and Li_3.17Si_0.7S_0.3O_4. Cobalt ions are not involved in the chemical erosion but the synthesized lithium cobalt compounds migrate along the pores and also deposit along the migrating pores of saggar.

A kind of flake graphite with grain size D₅₀ of 40.3 μm from Inner Mongolia was taken in a spherification test by adopting a QCJ vortex micropulverizer, and two kinds of spherical products with D₅₀ of 16.42 μm and 11.68 μm respectively were obtained, of which the corresponding tapped density increased from 0.46 g/cm³ to 0.95 g/cm³ and 0.80 g/cm³ respectively, presenting a total spherification rate of 50.48%. The spherical products were purified with mixed acid, with the fixed carbon content therein up to 99.95% and 99.97% respectively, and then the electrochemical performance of the products was tested. The anode material with those two products delivered initial discharge specific capacities of 366.60 mAh/g and 364.30 mAh/g, respectively, and presented initial charge-discharge efficiency of 93.40% and 92.32%, respectively. It is shown that the capacity retention rate can exceed 99% after 30 cycles at 0.1C current.

20CrMnTi alloy steel was precisely cut by turning instead of grinding using a polycrystalline cubic boron nitride (PCBN) tool. Based on analysis of the form and mechanism of PCBN tool wear during the cutting process, the influences of different cutting parameters on tool life and surface roughness of workpiece were studied. The results show that the tool is subjected to diffusion, chipping and severe oxidative wear. Among those three elements of hard material cutting, both feed rate and cutting speed bring great influence to tool wear, and feed rate has great influence on the surface roughness of machined workpiece.