YG8 cemented carbide samples were treated with pulsed magnetic fields having different magnetic field intensity(0.5 T,1.0 T and 1.5 T),and the effects of pulsed magnetic fields on the microstructure, mechanical properties and tool cutting performance of the cemented carbide were studied.The results show that as the intensity of the pulsed magnetic field increases, both the hardness and transverse fracture strength of the cemented carbide samples gradually increase, and the cutting performance of the cemented carbide tools also gradually improves.The pulsed magnetic field provides the driving force for the movement of the dislocations in the cemented carbide, which results in easier dislocation multiplication and slippage to form high-density dislocation cells and significantly improve material mechanical properties and tool cutting performance.

电信诈骗在原有作案手法的基础上手段翻新,作案者冒充电信局、公安局等单位工作人员,使用任意显号软件、VOIP电话等技术,以受害人电话欠费、被他人盗用身份涉嫌经济犯罪、没收受害人所有银行存款进行恫吓威胁,诱骗受害人汇转资金。防范电信诈骗,请特别注意以下几点:1.要注意避免个人资料外泄,对不熟悉的金融业务尽量不要在ATM机上操作,应到柜面直接办理。切勿相信"银行账户涉及犯罪"等谎言。

Extraction method was employed to recover molybdenum from the high-sulphate ammonium molybdate solution obtained by the pressurized oxidized ammonia leaching-purification process of molybdenum concentrate.The effects of 2-octanol concentration, acid dosage, O/A phase ratio and oscillation time on Mo extraction were investigated.The results show that the optimal extraction conditions are 2-octanol volume fraction of 15%,1∶1 sulfuric acid dosage of 10% feed liquid volume, O/A phase ratio of 1.2/1 and oscillation time of 5 min.Through single-stage extraction, washing and single-stage stripping, the average Mo extraction rate reaches 99.61%,the Mo stripping rate is close to 100%,and the average Mo and SO₄^2-contents are 161.99 g/L and 18 g/L,respectively, realizing the efficient recovery of molybdenum.

Taking 6 kA rare earth electrolyzer as the research object, rare earth metals were prepared by electrolysis using fluorine salt system, and the effects of electrolysis temperature, oxide addition rate and metal extraction mode on the content of oxygen and titanium in rare earth metals were studied in combination with field production conditions and GDMS detection results.The results show that the oxygen and titanium content in rare earth metals can be stably controlled when rare earth metals are siphoned out of the oven, electrolytic temperature is controlled at 1 040~1 060 ℃,and oxide addition rate is 7~8 kg/h.The oxygen content in rare earth metals is less than 0.010% and the titanium content is less than 0.012%.

Taking Pr-NdCl3 feed solution prepared from mixed rare earth ore as the research object, the extraction of non-RE impurity of aluminum from high concentration Pr-NdCl3 feed solution was carried out with naphthenic acid-isooctanol-sulfonated kerosene as the extraction organic system.The effects of naphthenic acid concentration, organic saponification degree, phase ratio and extraction temperature on aluminum removal rate, rare earth loss rate and separation coefficient βAl/RE were investigated.The results show that when the concentration of naphthenic acid is 0.53 mol/L and the degree of organic saponification is 50%,more than 99% of Al in Pr-NdCl3 feed solution can be extracted and separated under the conditions of room temperature and 0.5∶1 phase ratio of organic phase and Pr-NdCl3 feed solution with Al content less than 0.35 g/L,and the rare earth loss rate is about 3%,which meets the requirement of Pr-NdCl3 feed solution for aluminum content.Under the optimum conditions, the extraction has fast phase disengagement, no third phase and no emulsification, which provides basic data for the production process of continuous extraction and separation of aluminum from Pr-NdCl3 feed solution.

Carbothermal reduction process was used to roast rare polymetallic mixed concentrate, and XRD,SEM and EDS were used to study the changes in the morphology and phase of the mineral during roasting.The results show that during roasting at low and medium temperatures, the main changes in minerals are as follows: Fe metallization rate gradually rises, Fe in iron ore is reduced, Fe encapsulated in silicate mine-rals precipitates and forms elementary substance, and Nb, Mn and Ti associated with iron minerals form oxides, which are not reduced by carbon, while rare earth minerals are stable and non-reactive, except for the partial decomposition of bastnaesite.As the roasting temperature increases, elemental Fe and SiO2 react to form FeSi by carbothermal reduction, bastnaesite is gradually decomposed, ZrSiO₄ begins to be pyrolyzed to form small particles of ZrO₂,and other metal compounds are stable.

Three rounds of technological improvement were carried out on the reverberatory furnace smelting process for the recovery of tin, antimony and bismuth.The main measures were employed of adding water-cooled flue, replacing solid fuels with gas fuels and increasing oxygen enriched smelting.The technological improvement has a significant effect and promotes the development of reverberatory furnace smelting technology in the direction of environmental protection and energy saving, making a demonstration for the industry to promote the upgrading of reverberatory furnace smelting technology.

The 92 W alloy with 0.15% La₂O₃ was prepared by conventional powder metallurgy method, the effects were investigated of coarse and fine tungsten powder with two different particle sizes sintered at 1 490~1 520 ℃ on mechanical properties and microstructure of the prepared high density 92 W alloy.The results show that with the increase of sintering temperature, the tensile strength of the alloy prepared with fine tungsten powder decreases, elongation increases, and impact toughness increases at first and then decreases, while the tensile strength of the alloy prepared with coarse tungsten powder increases at first and then decreases, and the elongation and impact toughness increase.Thus, different sintering temperatures should be adopted for the best comprehensive mechanical properties of tungsten alloy with La₂O₃ prepared with tungsten powder of different particle sizes.The aggregation and segregation of La₂O₃ particles in the alloy become more and more obvious with the continuous increase of sintering temperature.The grain size of tungsten alloy prepared with fine tungsten powder is coarser than that of the alloy prepared with coarse tungsten powder at lower sintering temperature, but the result is opposite when sintering is carried out at higher temperature.

Under the synergistic action of microwave-ultrasonic, Dy₂O₃ precursor(Dy(OH)CO₃·H₂O) was prepared by the reaction of a certain concentration of DyCl₃ solution with urea as precipitant, and then the nano spherical Dy2O3 was obtained by calcination.The effects of Dy³⁺ concentration, urea concentration and ultrasonic power on the morphology of Dy₂O₃ precursor were explored.The morphology and microstructure of Dy₂O₃ precursor before and after calcination were characterized, and the calcination decomposition mechanism was analyzed by scanning electron microscope, synchronous thermal analyzer, X-ray diffractometer, and Fourier infrared spectrometer.The results show that Dy(OH)CO₃·H₂O with uniform particle size, smooth surface, good dispersion and particle size of about 220 nm can be obtained under the conditions of Dy³⁺ concentration of 0.045 mol/L,urea concentration of 2.5 mol/L,microwave power of 500 W,ultrasonic power of 800 W,ultrasonic mode of 1∶2,reaction time of 1 h and reaction temperature of 90 ℃.The precursor can be completely decomposed at the calcination temperature of 800 ℃,and nano spherical Dy₂O₃ with particle size of about 200 nm can be obtained.