Based on practical situation of rare earth industrial chain,production process and rare earth materials that could produce solid wastes on batch were discussed.Formation cause,formation volume,composition analysis and...Based on practical situation of rare earth industrial chain,production process and rare earth materials that could produce solid wastes on batch were discussed.Formation cause,formation volume,composition analysis and comprehensive utilization of the solid wastes of rare earth hydrometallurgy slag,electrolysis slag,Fe-based rare earth permanent magnetic materials,Co-based rare earth permanent magnetic materials,rare earth hydrogen storage materials,rare earth polishing powders and rare earth catalysts were ...展开更多
The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic ...The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.展开更多
Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typ...Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.展开更多
The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb2O3 and Sb2O5 obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric ...The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb2O3 and Sb2O5 obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric acid as stabilizer. Effects of main factors were investigated. The theories on thermodynamics, kinetics and electrical double layer（EDL） were used to analyze the experimental phenomena and results. The results show that no aging time is the most beneficial to forming colloid, when molar ratio of phosphoric acid to antimony is in the range from （0.8） to 1.0 and 1.0 to 1.3, the particle sizes of sol with the concentration of 10% and 15% antimony pentoxide by mass are both smaller. With increasing concentration of the mixture of antimony oxide from 10% to 20%, the reaction time decreases from 90 to about 30min, but the optimized range of molar ratio of H3PO4 to antimony increases. The reaction temperature is not the main factor on particle size with the existence of H3PO4 in the temperature range from 60 to 90℃.展开更多
Recycling industrial solid waste not only saves resources but also eliminates environmental concerns of toxic threats.Herein,we proposed a new strategy for the utilization of petrochemical-derived carbon black waste,a...Recycling industrial solid waste not only saves resources but also eliminates environmental concerns of toxic threats.Herein,we proposed a new strategy for the utilization of petrochemical-derived carbon black waste,a waste vanadium-bearing resource(V>30000 ppm(10−6)).Chemical leaching was employed to extract metallic vanadium from the waste and the leachate containing V was used as an alternative raw material for the fabrication of vanadate nanomaterials.Through the screening of various metal cations,it was found that the contaminated Na^(+)during the leaching process showed strong competitive coordination with the vanadium ions.However,by adding foreign Ce^(3+)and Y^(3+)cations,two rare-earth vanadates,viz.,flower-like CeVO_(4)and spherical YVO_(4)nanomaterials,were successfully synthesized.Characterization techniques such as scanning electron microscopy,transmission electron microscopy,X-ray diffraction,energy-dispersive X-ray spectroscopy,Fourier-transform infrared,and N2 physisorption were applied to analyze the physicochemical properties of the waste-derived nanomaterials.Importantly,we found that rare-earth vanadate catalysts exhibited good activities toward the semi-hydrogenation ofα,β-unsaturated aldehydes.The conversion of cinnamaldehyde and cinnamic alcohol selectivity were even higher than those of the common CeVO_(4)prepared using pure chemicals(67.2%vs.27.7%and 88.4%vs.53.5%).Our work provides a valuable new reference for preparing vanadate catalysts by the use of abundant vanadium-bearing waste resources.展开更多
文摘Based on practical situation of rare earth industrial chain,production process and rare earth materials that could produce solid wastes on batch were discussed.Formation cause,formation volume,composition analysis and comprehensive utilization of the solid wastes of rare earth hydrometallurgy slag,electrolysis slag,Fe-based rare earth permanent magnetic materials,Co-based rare earth permanent magnetic materials,rare earth hydrogen storage materials,rare earth polishing powders and rare earth catalysts were ...
文摘The project for treating MSW of 200 tons each day was built in Yibin, Sichuan Province of China. The disposal processes are: separation and selection of usable resources; compost and fermentation of “heavy” organic waste (kitchen, garden composting rubbish); incineration of “light” waste (plastic, paper, wood and bamboo etc.) and landfill of inorganic waste. The thermal energy generated in the process can be used as 1/3 of the whole energy for drying fertilizers. In the process, there is no wastewater drainage, and air emissions can be effectively controlled by a series of measures. The sanitary and environmental indicators of disposal site meet the national standards. This project has worked well for two years. It not only disposes of and reduces the MSW, but also retrieves the resource effectively. The organic fertilizer has been applied in the ten thousand acres of fields, with productivity increase by more than 10%.
基金support was received the Science&Technology Foundation of RIPP(PR20230092,PR20230259)the National Natural Science Foundation of China(22278419)the Key Core Technology Research(Social Development)Foundation of Suzhou(2023ss06).
文摘Mineral carbonation is a promising CO_(2) sequestration strategy that can utilize industrial wastes to convert CO_(2) into high-value CaCO_(3).This review summarizes the advancements in CO_(2) mineralization using typical industrial wastes to prepare ultrafine CaCO_(3).This work surveys the mechanisms of CO_(2) mineralization using these wastes and its capacities to synthesize CaCO_(3),evaluates the effects of carbonation pathways and operating parameters on the preparation of CaCO_(3),analyzes the current industrial application status and economics of this technology.Due to the large amount of impurities in solid wastes,the purity of CaCO_(3) prepared by indirect methods is greater than that prepared by direct methods.Crystalline CaCO_(3) includes three polymorphs.The polymorph of CaCO_(3) synthesized by carbonation process is determined the combined effects of various factors.These parameters essentially impact the nucleation and growth of CaCO_(3) by altering the CO_(2) supersaturation in the reaction system and the surface energy of CaCO_(3) grains.Increasing the initial pH of the solution and the CO_(2)flow rate favors the formation of vaterite,but calcite is formed under excessively high pH.Vaterite formation is favored at lower temperatures and residence time.With increased temperature and prolonged residence time,it passes through aragonite metastable phase and eventually transforms into calcite.Moreover,polymorph modifiers can decrease the surface energy of CaCO_(3) grains,facilitating the synthesis of vaterite.However,the large-scale application of this technology still faces many problems,including high costs,high energy consumption,low calcium leaching rate,low carbonation efficiency,and low product yield.Therefore,it is necessary to investigate ways to accelerate carbonation,optimize operating parameters,develop cost-effective agents,and understand the kinetics of CaCO_(3) nucleation and crystallization to obtain products with specific crystal forms.Furthermore,more studies on life cycle assessment(LCA)should be conducted to fully confirm the feasibility of the developed technologies.
文摘The stable colloidal antimony pentoxide was prepared by oxidation of the mixture of Sb2O3 and Sb2O5 obtained from arsenic-alkali residue by hydrometallurgical process, with hydrogen peroxide as oxidant and phosphoric acid as stabilizer. Effects of main factors were investigated. The theories on thermodynamics, kinetics and electrical double layer（EDL） were used to analyze the experimental phenomena and results. The results show that no aging time is the most beneficial to forming colloid, when molar ratio of phosphoric acid to antimony is in the range from （0.8） to 1.0 and 1.0 to 1.3, the particle sizes of sol with the concentration of 10% and 15% antimony pentoxide by mass are both smaller. With increasing concentration of the mixture of antimony oxide from 10% to 20%, the reaction time decreases from 90 to about 30min, but the optimized range of molar ratio of H3PO4 to antimony increases. The reaction temperature is not the main factor on particle size with the existence of H3PO4 in the temperature range from 60 to 90℃.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.U21A20324 and 21908073)the Natural Science Foundation of Fujian Province(Grant Nos.2019J01074 and 2021J06026)。
文摘Recycling industrial solid waste not only saves resources but also eliminates environmental concerns of toxic threats.Herein,we proposed a new strategy for the utilization of petrochemical-derived carbon black waste,a waste vanadium-bearing resource(V>30000 ppm(10−6)).Chemical leaching was employed to extract metallic vanadium from the waste and the leachate containing V was used as an alternative raw material for the fabrication of vanadate nanomaterials.Through the screening of various metal cations,it was found that the contaminated Na^(+)during the leaching process showed strong competitive coordination with the vanadium ions.However,by adding foreign Ce^(3+)and Y^(3+)cations,two rare-earth vanadates,viz.,flower-like CeVO_(4)and spherical YVO_(4)nanomaterials,were successfully synthesized.Characterization techniques such as scanning electron microscopy,transmission electron microscopy,X-ray diffraction,energy-dispersive X-ray spectroscopy,Fourier-transform infrared,and N2 physisorption were applied to analyze the physicochemical properties of the waste-derived nanomaterials.Importantly,we found that rare-earth vanadate catalysts exhibited good activities toward the semi-hydrogenation ofα,β-unsaturated aldehydes.The conversion of cinnamaldehyde and cinnamic alcohol selectivity were even higher than those of the common CeVO_(4)prepared using pure chemicals(67.2%vs.27.7%and 88.4%vs.53.5%).Our work provides a valuable new reference for preparing vanadate catalysts by the use of abundant vanadium-bearing waste resources.
