A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry packag...A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry package and the coexistence theory of slag structure were adopted for theoretical analysis. The gas-based reduction was carried out using a fixed bed reactor and the ore sample of 80 g with an average particle size of 2 mm were reduced using CO or H2 at temperature of 1 073 K for 5 hours. 50 g of the reduced sample with 3.0% CaO as additive was then subjected to melt separation in an electric furnace at temperature of 1 873 K under Ar atmosphere. In each run, SEM, EDS, optical microscopic examination and chemical analysis of the reduced ore sample, the metal sample and the slag sample were conducted. Results of all gas-based reduction experiments showed that iron metallization ratios were some 65% and the phosphorus compounds in the ore remained unchanged. It was agreed well with the simula- tions except for the iron metallization rate being less than predicted value; this difference was attributed to kinetics. Results of melt separation experiments showed that P content in metal samples is 0.33% （metal sample from H2 reduction product） and 0.27% （metal sample from CO reduction product）. The phosphorus partition ratios of both cases were less than predicted values. Some P in the metal samples existed as slag inclusion was considered to be the reason for this discrepancy.展开更多
Poly(propylene carbonate phthalate)(PPC-P)is a chemically modified poly(propylene carbonate)(PPC)biodegradable thermoplastic by introducing phthalic anhydride(PA)as the third monomer into the copolymerization of propy...Poly(propylene carbonate phthalate)(PPC-P)is a chemically modified poly(propylene carbonate)(PPC)biodegradable thermoplastic by introducing phthalic anhydride(PA)as the third monomer into the copolymerization of propylene oxide(PO)and CO_(2).To enhance the thermal and mechanical properties of PPC-P,a branching agent pyromellitic anhydride(PMDA)was introduced into the terpolymerization of PO,PA and CO_(2).The resulting copolymers with branched structure,named branched PPC-P,can be obtained using metal-free Lewis pair consisting of triethyl borane(TEB)and bis(triphenylphosphine)iminium chloride(PPNCl)as catalyst.The products obtained were analyzed by NMR spectroscopy and their thermal,mechanical properties and melt processability were evaluated by DSC,TGA,tensile test and melt flow index(MFI)measurement.The obtained branched PPC-P has a high molecular weight up to 156.0 kg·mol^(-1).It shows an increased glass transition temperature(Tg)higher than 50℃and an enhanced tensile strength as high as 38.9 MPa.Noteworthily,the MFI value decreases obviously,indicative of an improved melt strength arising from the branched structure and high molecular weight.What is more,the branched PPC-P exhibits reasonable biodegradability,which demonstrates the great potential as a new green thermoplastic for the family of biodegradable plastics.展开更多
The cast structure of a K465 nickel-based superalloy with different temperatures of melt superheating treatment was studied. It is shown that melt superheating treatment plays a significant role in the grain size and ...The cast structure of a K465 nickel-based superalloy with different temperatures of melt superheating treatment was studied. It is shown that melt superheating treatment plays a significant role in the grain size and carbide morphology. With increasing melt superheating temperature (below 2023 K),the grain size increases obviously and the carbide morphology is changed from a blocky to a script-like shape. However,when the melt superheating temperature is between 2023 K and 2123 K,the grain size decreases gr...展开更多
A series of melting experiments was carried out at 1 650℃ and 1.00-3.00 GPa using alkaline basalt as starting material. The compositions of quenched basaltic glasses in the products were detected by electron micro pr...A series of melting experiments was carried out at 1 650℃ and 1.00-3.00 GPa using alkaline basalt as starting material. The compositions of quenched basaltic glasses in the products were detected by electron micro probe. Their CIPW norms were calculated and their refractive indices were determined by the oil-infused method. The Raman spectrum of the quenched basaltic glasses indicates that their main structural species are monomer [SiO4]4-, chain [Si2O6]4- and sheet [Si2O5]2- . The relationship at the same temperature between the proportions of integrated areas of structural species, and compositions and pressures was discussed.展开更多
基金Sponsored by National Natural Science Foundation of China and Baosteel(50834007)
文摘A new method （gas-based separation plus melt separation） has been proposed to remove phosphorus of the high phosphorus iron ore which was 1.25 % of phosphorus content and 50. 0% of iron content. HSC chemistry package and the coexistence theory of slag structure were adopted for theoretical analysis. The gas-based reduction was carried out using a fixed bed reactor and the ore sample of 80 g with an average particle size of 2 mm were reduced using CO or H2 at temperature of 1 073 K for 5 hours. 50 g of the reduced sample with 3.0% CaO as additive was then subjected to melt separation in an electric furnace at temperature of 1 873 K under Ar atmosphere. In each run, SEM, EDS, optical microscopic examination and chemical analysis of the reduced ore sample, the metal sample and the slag sample were conducted. Results of all gas-based reduction experiments showed that iron metallization ratios were some 65% and the phosphorus compounds in the ore remained unchanged. It was agreed well with the simula- tions except for the iron metallization rate being less than predicted value; this difference was attributed to kinetics. Results of melt separation experiments showed that P content in metal samples is 0.33% （metal sample from H2 reduction product） and 0.27% （metal sample from CO reduction product）. The phosphorus partition ratios of both cases were less than predicted values. Some P in the metal samples existed as slag inclusion was considered to be the reason for this discrepancy.
基金financially supported by the National Natural Science Foundation of China(No.51673131)the Fundamental Research Funds for the Central Universities(No.171gjc37)。
文摘Poly(propylene carbonate phthalate)(PPC-P)is a chemically modified poly(propylene carbonate)(PPC)biodegradable thermoplastic by introducing phthalic anhydride(PA)as the third monomer into the copolymerization of propylene oxide(PO)and CO_(2).To enhance the thermal and mechanical properties of PPC-P,a branching agent pyromellitic anhydride(PMDA)was introduced into the terpolymerization of PO,PA and CO_(2).The resulting copolymers with branched structure,named branched PPC-P,can be obtained using metal-free Lewis pair consisting of triethyl borane(TEB)and bis(triphenylphosphine)iminium chloride(PPNCl)as catalyst.The products obtained were analyzed by NMR spectroscopy and their thermal,mechanical properties and melt processability were evaluated by DSC,TGA,tensile test and melt flow index(MFI)measurement.The obtained branched PPC-P has a high molecular weight up to 156.0 kg·mol^(-1).It shows an increased glass transition temperature(Tg)higher than 50℃and an enhanced tensile strength as high as 38.9 MPa.Noteworthily,the MFI value decreases obviously,indicative of an improved melt strength arising from the branched structure and high molecular weight.What is more,the branched PPC-P exhibits reasonable biodegradability,which demonstrates the great potential as a new green thermoplastic for the family of biodegradable plastics.
文摘The cast structure of a K465 nickel-based superalloy with different temperatures of melt superheating treatment was studied. It is shown that melt superheating treatment plays a significant role in the grain size and carbide morphology. With increasing melt superheating temperature (below 2023 K),the grain size increases obviously and the carbide morphology is changed from a blocky to a script-like shape. However,when the melt superheating temperature is between 2023 K and 2123 K,the grain size decreases gr...
文摘A series of melting experiments was carried out at 1 650℃ and 1.00-3.00 GPa using alkaline basalt as starting material. The compositions of quenched basaltic glasses in the products were detected by electron micro probe. Their CIPW norms were calculated and their refractive indices were determined by the oil-infused method. The Raman spectrum of the quenched basaltic glasses indicates that their main structural species are monomer [SiO4]4-, chain [Si2O6]4- and sheet [Si2O5]2- . The relationship at the same temperature between the proportions of integrated areas of structural species, and compositions and pressures was discussed.
