Using walnut shell biochar(WSBC)prepared by pyrolysis as the carrier,Sb(Ⅲ)was first ad-sorbed from aqueous solution to realize resource utilization.Subsequently,Sb(TPA)MOF@WSBC compo-sites were synthesized in situ with Sb(Ⅲ)adsorbed on the WSBC surface as the metal center and tereph-thalic acid(TPA)as the organic ligand.The microstructure and surface characteristics of the materials were characterized by SEM,XRD,FT-IR,BET,XPS,etc.The effects of adsorbent dosage and wastewater pH value on Sb(Ⅲ)adsorption by three adsorbents(WSBC,Sb(TPA)MOF,Sb(TPA)MOF@WSBC)were comparatively investigated.The adsorption mechanism of the composite toward Sb(Ⅲ)was elucida-ted using adsorption kinetics,thermodynamics,and adsorption isotherm models,and its reusability was evaluated through cyclic regeneration experiments.The results show that the Sb(TPA)MOF@WSBC composite exhibits octahedral Sb(TPA)MOF particles uniformly dispersed and loaded on the WSBC surface.Compared with WSBC and Sb(TPA)MOF,the composite possesses a significantly increased specific sur-face area and pore volume,which can provide abundant adsorption active sites.With the increase of adsor-bent dosage,the adsorption capacity of Sb(Ⅲ)(calculated by unit mass of adsorption material)decreases significantly.With increasing pH value,the adsorption capacity of Sb(Ⅲ)first decreases and then increa-ses.When the initial concentration of Sb(Ⅲ)in the wastewater is 20 mg/L,pH is 8,and the solid-liquid ra-tio of adsorbent to wastewater is 0.5 g/L,the equilibrium adsorption capacity of Sb(TPA)MOF@WSBC composite for Sb(Ⅲ)is 2.9123 mg/g.The adsorption behaviors of three adsorbents all fit the Lagergren second-order kinetic model and the Langmuir adsorption isotherm model,indicating monolayer adsorption.Thermodynamic analysis demonstrates that the adsorption process is spontaneous,exothermic and accom-panied by a decrease in entropy,and lower temperatures are more favorable for the adsorption reaction.In addition,the Sb(TPA)MOF@WSBC composite exhibits excellent recycling stability,and its adsorption mechanism is dominated by hydrogen bonding,Sb(Ⅲ)-πinteraction and coordination complexation.This study provides a novel composite adsorbent for the treatment of antimony-containing wastewater.

This paper reviews the research progress of pressure ammonia leaching technology in the extrac-tion of nickel,cobalt,molybdenum and other metals,as well as the comprehensive utilization of secondary resources.The technology exhibits remarkable advantages in improving metal recovery,reducing environ-mental pollution,and enhancing resource utilization efficiency,thus playing a significant role in promoting green metallurgy and the sustainable utilization of resources.The main challenges faced in the practical ap-plication of pressure ammonia leaching technology are also discussed,and its future development trends are prospected.This paper aims to provide a theoretical reference and practical guidance for the further optimi-zation and upgrading of this technology,its industrial promotion,and the green and efficient development of complex nonferrous metal resources.

Ti(C,N)-based cermets have become ideal substitutes for traditional WC-based cermets owing to their abundant resources,low cost,and excellent physicochemical properties.Nanometer Ti(C,N)-based cermets exhibit significant advantages in cutting processing,advanced ceramics,hard coatings,and other fields due to grain refinement and further improved hardness and toughness.Preparing nano-Ti(C,N)pre-cursor powders with controllable grain size and favorable dispersibility is an effective strategy to enhance the performance of cermets.This paper summarizes the synthesis technologies and recent advances in ultra-fineano Ti(C,N)powders worldwide,and provides an in-depth analysis of the reaction mechanisms,process characteristics,and product properties of each method.Although carbothermal reduction and nitri-dation is the dominant technique for industrial production,it still suffers from drawbacks such as high en-ergy consumption and uneven particle size distribution.Other methods also face challenges including grain agglo-meration and broad particle size distribution.In the future,efforts should focus on developing preparation processes with high efficiency and economic viability,achieving precise control over the grain size of Ti(C,N)solid-solution powders,and effectively alleviating agglomeration,thereby laying a solid foundation for the widespread promotion and in-depth application of Ti(C,N)-based cermets in industrial field.

In the uninjected LFP cathode sheets,the LFP cathode material is not involved in the charge-dis-charge deintercalation of lithium ions,and its structure remains intact,which provides a stable raw material for the repair of LFP cathode material.The separation of LFP cathode material from current collector alu-minum foil is a key issue in the pretreatment process of electrode repair.In this paper,the domestic tech-nologies for stripping uninjected LFP cathode sheets are systematically reviewed,and the principles,advan-tages and disadvantages of various wet and dry stripping technologies are analyzed and compared.Among them,the pyrolysis stripping method combines wet and dry stripping technologies,and there is no waste water generated.It is an efficient stripping method with industrial mass production prospects.In order to reduce the cost,improve the quality of stripped products and maximize the resource utilization of uninjected LFP cathode sheets,the industrialization of stripping of uninjected LFP cathode sheets must control the process parameters,optimize equipment selection,and reduce environmental pollution.

FeCoCrNiMo_0.75 high-entropy alloys prepared by vacuum arc melting were subjected to laser sur-face remelting modification treatment.The effects of different laser powers(300~1500 W)on the remel-ted microstructure,hardness,and friction and wear properties of FeCoCrNiMo_0.75 alloy were investigated using XRD,SEM-EDS,a microhardness tester,and a reciprocating friction and wear tester.The results show that the thickness of the remelted layer increases with increasing laser power.The microstructure of the alloy without remelting treatment is mainly composed of FCC,σphase andμphase.After remelting at low power(300~600 W),the phase composition does not change significantly.When the laser power is in-creased to 900~1500 W,theμphase in the remelted microstructure disappears.Laser remelting can signi-ficantly refine the eutectic microstructure of the alloy and improve its surface hardness and friction and wear properties.Among them,FeCoCrNiMo_0.75 high-entropy alloy remelted at 600 W laser power has the optimal comprehensive performance,with the highest average hardness of the remelted layer(573 HV_0.2).In addition,its friction coefficient,surface roughness,and volumetric wear rate are all the lowest,and the volumetric wear rate is reduced by 85.5%compared with the alloy without remelting.In terms of wear mechanisms,the room-temperature wear mechanism of the alloy without remelting is mainly abrasive wear and fatigue wear.However,after the alloy is subjected to laser surface remelting treatment,its wear mecha-nism is mainly abrasive wear.

The rare earth concentrate was treated by ball milling and sulfuric acid leaching,and then Cu and Fe were loaded on the mineral surface by hydrothermal method to prepare modified rare earth concentrate catalysts.The effects of Cu and Fe mass ratio,roasting temperature and other factors on the performance of the catalyst were studied.By XRD,SEM,EDS,BET,H2-TPR and XPS,the surface morphology,micro-structure,redox ability and element valence distribution of the catalyst were analyzed,and the mechanism of denitration performance improvement was clarified.The results show that the loading of Cu and Fe on the rare earth concentrate catalyst treated by ball milling and acidification modification can effectively im-prove the denitration performance of the catalyst.When the mass ratio of Cu to Fe is 0.75∶1,the NO_x conversion rate of the catalyst is the highest,reaching 96%at the flue gas temperature of 350°C,which is 77 percentage points higher than that of the raw ore.The introduction of Cu species helps to improve the denitration activity of the catalyst in the low temperature stage.After loading Cu and Fe,the relative con-tent of Fe³⁺ on the surface of the catalyst increases,and Fe₂O₃ can act as active sites to improve the deni-tration performance of the catalyst.The relative content of lattice oxygen increases,and the valence change of Ce on the mineral surface is not inhibited,ensuring the conversion of oxygen species.

The widespread application of lithium-ion batteries(LIB)has led to the generation of massive spent batteries,triggering resource shortages and environmental risks.The recovery of high-value metals(e.g.,Co,Ni,Li)from these spent batteries is of significant economic and environmental significance.However,existing recycling technologies still face challenges in efficiency and sustainability.This paper re-views the latest research progress in pretreatment technologies for spent LIB recycling,covering discharge inactivation,disassembly and mechanical crushing,physical separation(such as eddy current separation,electrostatic separation,and gravity/wind separation),and binder removal.The literatures indicate that a key technical system—ranging from safe discharge treatment,automated disassembly and selective cru-shing for higher black mass recovery,and diversified physical separation for efficient component segrega-tion,down to binder removal which critically determines the efficiency of subsequent hydrometallurgy or flotation—could optimize the efficiency and sustainability of LIB recycling.Furthermore,this paper discus-ses the advantages and disadvantages of each pretreatment technology,along with the limitations and gaps of existing processes.It also outlines future research and industrialization directions,such as constructing a multi-stage integrated″discharge-crushing-screening-pyrolysis-separation″flowsheet to maximize recovery efficiency.This review provides a comprehensive reference for researchers and engineers in the LIB recy-cling field,emphasizing the critical role of pretreatment in building an efficient and environmentally sus-tainable battery circular industry.

In order to achieve efficient and balanced utilization of rare earth resources,this study used mis-chmetal(MM)rich in La and Ce as the main raw material.Nd/MM-Fe-B composite hot-pressed and hot-deformed magnets were fabricated by the dual main-phase process combined with spark plasma sintering(SPS)technology.The evolution of magnetic properties,microstructure and coercivity mechanism of mag-nets with different mischmetal contents was systematically investigated.The results show that when the ratio of mischmetal to total rare earth increases from 0 to 30.61%,the remanence of the magnet decreases from 13.38 kGs to 11.96 kGs,while the coercivity decreases from 12.79 kOe to 11.01 kOe.With increa-sing mischmetal content,the rare-earth-rich phase is squeezed out of grain boundaries at high temperature and high pressure,leading to an increased proportion of equiaxed coarse-grained regions and ultimately reducing the remanence and coercivity of the hot-pressed and hot-deformed magnets.The intergranular ex-change coupling of the magnets gradually weakens,the long-range magnetostatic interaction strengthens,the irreversible susceptibility decreases,the consistency of magnetization reversal deteriorates,the pinning effect weakens,and thus the coercivity degrades.

Submicron ammonium perrhenate was prepared via vacuum spray freeze drying.The effects of ammonium perrhenate solution concentration,feed pump flow rate and initial drying chamber temperature during vacuum spray freeze drying on the particle size and morphology of ammonium perrhenate and its re-duced rhenium powder were investigated by single-factor experiments and orthogonal experiments.The re-sults of single-factor experiments indicate that the atomizer is blocked due to the crystallization of super-saturated ammonium perrhenate at low temperature when the mass concentration of ammonium perrhenate exceeds 20 g/L.Submicron ammonium perrhenate particles with an average size of<1μm can be obtained only at a concentration of 20 g/L,and the corresponding reduced rhenium powder exhibits good morpho-logical heritability.Orthogonal experimental results show that feed pump flow rate is the key factor(range 78.34%)controlling the proportion of acicular morphology of ammonium perrhenate.The combination of low flow rate(e.g.,5 mL/min),medium-low temperature(e.g.,-50℃)and low concentration(e.g.,10 g/L)can significantly increase the acicular morphology proportion(up to 100%).This study reveals the regulation mechanism of droplet dispersion-crystallization kinetics on grain morphology,providing a basis for process parameter selection in the controllable synthesis of rhenium-based materials.