The extraction of vanadium from stone coal was carried out by the process of acid mixing pelleting,high temperature curing and column leaching.Also,the study discussed the leaching effect of vanadium from raw ore affected by process conditions such as the amount of sulfuric acid,the amount of water supplement for curing,the binder dosage,the curing temperature,the curing time,the particle size of the cured material and the spraying intensity.The results show that the leaching rate is 76.99%when the conditions of the process are as follows:The particle size of the raw ore is less than 12 mm;the water content of the raw ore is 10%;the amount of sulfuric acid is 20%;the binder dosage is 0.05%;the curing temperature is 135 C;the curing time is 10 h;the particle size of the cured material is less than 8 cm;the liquid-solid ratio of leaching section is 1.5:1;the spraying intensity is 15 L/(m²·h).After the leaching residue is washed four times(the liquid-solid ratio of washing section is 1.5:1),the leaching rate of vanadium can be increased to 87.48%,and the content of V₂O₅,in the tailings can be reduced to 0.11%.The research can provide important reference for the industrial production of the heap-leaching of vanadium ore.

The technology of recovering beryllium and useful resources from the waste slag produced in the melting and casting process of beryllium-copper alloy was studied.Using ESR waste slag as a covering agent,beryllium-copper waste slag was refined and purified in a vacuum induction furnace under the protection of a molten slag layer.The Yuanbao ingots obtained after refining and casting can be used as interalloys for producing beryllium-copper alloy ingots to replace expensive beryllium-copper master alloys.The recovered ESR waste slag can be recycled for the recovery treatment of beryllium-copper waste slag,and can also be used as a flux for the manufacture of ceramics,glass,etc.after impurity removal and purification.The experimental results show that adjusting the slag viscosity to about 0.09 Pa·s under the optimal mass ratio of ESR waste slag to CaF₂ is beneficial to the improvement of metal yield and Be yield.When the vacuum degree is below 0.07 MPa,the Yuanbao ingots with no pores and uniform internal microstructure are obtained by vacuum refining.The successful research and development of this technology not only enables the comprehensive utilization of beryllium-copper waste slag as resources,turns waste into treasure,greatly reduces production costs and increases metal recovery rate,but also solves the environmental problems caused by long-term storage of beryllium-copper waste slag.

There are a lot of metal elements in fly ash,which has a certain extraction value.In this paper,the existing state of lithium in fly ash and the economical efficiency of lithium extraction are analyzed.Also,the research progress of lithium leaching technology from fly ash and the separation extraction technology of lithium from the leaching solution is reviewed.The key nodes of lithium extraction from fly ash are briefly discussed,giving reasonable suggestions and research directions.

Aiming at the recycling with high value of the lithium-extracted tailings from lithium iron phosphate battery waste,dissolution process conditions of the lithium-extracted tailings with hydrochloric acid were optimized and leaching kinetics was studied.The effects of hydrochloric acid concentration,solid-toliquid ratio and leaching time on the dissolution efficiency of the lithium-extracted tailings were mainly studied,and the leaching kinetics of the main component iron phosphate in hydrochloric acid solution was investigated.The results show that under the conditions of hydrochloric acid concentration 3 mol/L,liquidsolid volume-to-mass ratio 15 mL/g,reaction time 4 h and leaching temperature 30℃,the dissolution rate of lithium-extracted tailings reaches 92.4%.The leaching process of iron phosphate in hydrochloric acid conforms to the shrinking core model without a solid product layer,with an apparent activation energy of 25.45 kJ/mol,representing that the leaching process is controlled by internal diffusion.The iron phosphate powder was prepared by precipitation of the leaching solution.The XRD pattern of the product matches well with the standard pattern of iron phosphate,and its EDS pattern shows that P,Fe and O are evenly distributed.Therefore,the prepared powder is judged to be iron phosphate,its iron-phosphorus molar ratio is 0.97 and the content of other elements is scarce,which meets the industry standard of battery-grade iron phosphate and can be used in battery production.

Coal gangue is a kind of solid waste containing gallium,which has an important recycling value.The experimental study was carried out on the extraction of gallium from coal gangue by enhanced leaching,and the influences of such leaching parameters as sulfuric acid concentration and calcium fluoride dosage on leaching efficiency of gallium were investigated.The results show that the addition of calcium fluoride could accelerate the dissolution of gallium,significantly improve the leaching efficiency of gallium,and reduce the consumption of sulfuric acid.The leaching efficiency of gallium in coal gangue reaches 95%under the conditions of coal gangue particle size of less than 0.045 mm,sulfuric acid concentration of 20%,calcium fluoride dosage of 5%,leaching temperature of 80 C,liquid to solid ratio of 7.5 mL/g,stirring speed of 400 r/min and reaction time of 120 min.This study may provide a new idea for the efficient recovery of gallium from coal gangue.

Gallium and iron from sulfuric acid leaching solution of coal gangue were separated by extraction with 2-ethylhexyl phosphate mono-2-ethylhexyl ester(P507).The effects of solution pH value,P507 concentration,oscillation time,oscillation intensity and extraction temperature on the extraction efficiency of gallium and iron were investigated.The results show that the single-stage extraction rate of Ga³⁺reaches 82%while that of Fe²⁺is lower than 18%,under the conditions of A/O ratio of 1:1,P507 concentration of 20%,solution pH value of 1.5,oscillation time of 15 min,oscillation intensity of 200 r/min and extraction temperature of 35℃.The extraction experiments were performed by changing the A/O ratio,and then the equilibrium isotherm of gallium extraction was determined.Under the condition of 4:1 A/O ratio,the theoretical extraction stage of gallium is four,and the extraction rate of gallium is 98.4%while the extraction rate of iron is 17.4%,and the extraction rate of other metal ions is less than 10%.Therefore,the selective extraction of gallium from sulfuric acid leaching solution of coal gangue could be realized.

The research status and development trend of bismuth pyrometallurgical and hydrometallurgical processes are reviewed.The characteristics,application scope and existing problems of bismuth metallurgical process in the research stage and industrial production practice are clarified.A method for extracting bismuth from bismuth sulfide concentrates by oxygen pressure leaching with methanesulfonic acid as the leaching agent is proposed.This method has the advantages of high bismuth leaching rate,ittle corrosiveness to the reactor,and no SO emission in the process,and has a good development prospect.

The effects of carbon ion irradiation at 7oo C on the surface morphology,microstructure and surface hardness of pure tungsten were studied by scanning electron microscopy,transmission electron microscopy and nanoindenter.The results show that carbon ion irradiation can lead to irradiated pits on the surface of the samples,and the size of the pits increases with the increase of irradiation dose.Carbon ion irradiation produces a large number of dislocation loops inside the sample,and the size and number density of the loops increase with the increase of radiation dose.Also,carbon ion irradiation causes a severe irradiation hardening effect on the tungsten surface,and the surface hardness of the samples increases significantly with the increases of irradiation dose.The average hardness of the tungsten surface reaches 15.85 GPa when the irradiation dose reaches 8.0 dpa.The dislocation loops generated by irradiation are the main cause of the irradiation hardening.

Tungsten(W)and oCr13Al steel were jointed in vacuum under the conditions of 5 MPa pressure and heat preservation at 1120 ℃ for 60 min with 90W-8.5Fe-1.5Cr(w/%)mixed powder as the interlayer and pure copper foil as the brazing filler metal.The particle size distribution and morphology of the WFe-Cr mixed powder were studied by laser particle size analyzer and SEM,and the microstructure,composition,mechanical properties and fracture characteristics of the joints were studied by SEM,EDS and electronic universal tester.The results show that the joint is composed of tungsten base metal/W-Fe-Cr heavy alloy layer/steel base metal,in which the W-Fe-Cr heavy alloy layer is formed through solid-phase sintering of W-Fe-Cr mixed powder.Also,the W-Fe-Cr heavy alloy layer/tungsten base metal interface is brazed through an extremely thin brazing seam,while the W-Fe-Cr heavy alloy layer/steel base metal interface is joined by brazing at first and then solid-phase diffusion welding.High-energy ball miling of W-Fe-Cr mixed powder plays a key role in densification and homogenization of W-Fe-Cr heavy alloy layer under relatively low jointing pressure.The shear strength of the tungsten/steel joints is 41 MPa and all joints were fractured near the interface of tungsten base metal and W-Fe-Cr heavy alloy layer with brittle fracture characteristics.This study provides a new idea for the design of tungsten/steel joint interlayer with adjustable linear expansion coefficient and without active element Ni,which is useful for further improving the applicability of tungsten/steel joint structure in nuclear fusion reactors.

LaB₆ nanopowders were successfully prepared by calciothermic reduction method for the first time.The effects of reduction temperature on the phase composition,morphology and particle size of powder products were studied by X-ray diffractometer(XRD)and field emission scanning electron microscope(FE-SEM),and the optical absorption properties of nanopowders were characterized by UV/VIS/NIR spectrophotometer.The results show that the prepared LaB₆ nanopowders have a simple cubic single-phase crystal structure,good crystallinity and nearly spherical particle morphology with an average grain size of(35±6)nm.With the increase of reaction temperature,the particle size of the powders increases and the particle morphology shifts to cubic shape.The absorption spectrum shows that the LaB₆ nanopowder prepared at 800℃has strong absorption properties in the ultraviolet and near-infrared regions,and its maximum transmission light wavelength is 595 nm,which is essentially in agreement with the first-principles calculation results of LaBe₆.