The effect of B_(2)O_(3) content on the viscosity of SiO_(2)−MgO−FeO-based molten slag system was investigated using the rotating cylinder method.The evolution process of the melt structure under different contents of...The effect of B_(2)O_(3) content on the viscosity of SiO_(2)−MgO−FeO-based molten slag system was investigated using the rotating cylinder method.The evolution process of the melt structure under different contents of B_(2)O_(3) was comprehensively studied via FTIR spectroscopy and a model for calculating the degree of polymerization was developed.The results showed that the viscosity of the molten slag decreased with the addition of B_(2)O_(3),which had a slight effect when its content exceeded 3 wt.%.As the addition of B_(2)O_(3) increased from 0 to 4 wt.%,the break temperature of the slags decreased from 1152 to 1050℃ and the apparent activation energy decreased from 157.90 to 141.84 kJ/mol.The addition of B_(2)O_(3) to the molten slag destroyed the chain silicate structure to form a more cyclic borosilicate structure.The Urbain model was improved to calculate the viscosity of the SiO_(2)−MgO−FeO-based slags,and the values were in good agreement with the experimentally measured values.展开更多
A series of 3.0Mo/(Hβ+γ-Al_(2)O_(3))samples withγ-Al_(2)O_(3)contents in the range of 0_100%(mass fraction)was studied by means of XRD,NH_(3)-TPD,TPR and BET determinations for characterizing their structures.The H...A series of 3.0Mo/(Hβ+γ-Al_(2)O_(3))samples withγ-Al_(2)O_(3)contents in the range of 0_100%(mass fraction)was studied by means of XRD,NH_(3)-TPD,TPR and BET determinations for characterizing their structures.The Hβzeolite structure in the 3.0Mo/Hβsample can be effectively stabilized by adding someγ-Al_(2)O_(3)to Hβzeolite.γ-Al_(2)O_(3)mainly favors the formation of polymolybdate or multilayered Mo oxide,while Hβmainly forms the Al_(2)(MoO_(4))_(3)species,as evaluated by the TPR technique.When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene,there exists a close correlation between the specific surface area and stability of the catalyst.The specific surface area of the catalyst shows the maximum when{(Hβ+}γ-Al_(2)O_(3))contains 30%γ-Al_(2)O_(3),which is in agreement with that of the time needed for the reaction stablization.In the case of maximum surface area,the rate of coke deposition is the minimum.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51774224)。
文摘The effect of B_(2)O_(3) content on the viscosity of SiO_(2)−MgO−FeO-based molten slag system was investigated using the rotating cylinder method.The evolution process of the melt structure under different contents of B_(2)O_(3) was comprehensively studied via FTIR spectroscopy and a model for calculating the degree of polymerization was developed.The results showed that the viscosity of the molten slag decreased with the addition of B_(2)O_(3),which had a slight effect when its content exceeded 3 wt.%.As the addition of B_(2)O_(3) increased from 0 to 4 wt.%,the break temperature of the slags decreased from 1152 to 1050℃ and the apparent activation energy decreased from 157.90 to 141.84 kJ/mol.The addition of B_(2)O_(3) to the molten slag destroyed the chain silicate structure to form a more cyclic borosilicate structure.The Urbain model was improved to calculate the viscosity of the SiO_(2)−MgO−FeO-based slags,and the values were in good agreement with the experimentally measured values.
基金the National Natural Science Foundation of China(No.20303019)the National 973 Project of China(No.2003CB615802).
文摘A series of 3.0Mo/(Hβ+γ-Al_(2)O_(3))samples withγ-Al_(2)O_(3)contents in the range of 0_100%(mass fraction)was studied by means of XRD,NH_(3)-TPD,TPR and BET determinations for characterizing their structures.The Hβzeolite structure in the 3.0Mo/Hβsample can be effectively stabilized by adding someγ-Al_(2)O_(3)to Hβzeolite.γ-Al_(2)O_(3)mainly favors the formation of polymolybdate or multilayered Mo oxide,while Hβmainly forms the Al_(2)(MoO_(4))_(3)species,as evaluated by the TPR technique.When used as the catalyst for the metathesis of butylene-2 and ethylene to propylene,there exists a close correlation between the specific surface area and stability of the catalyst.The specific surface area of the catalyst shows the maximum when{(Hβ+}γ-Al_(2)O_(3))contains 30%γ-Al_(2)O_(3),which is in agreement with that of the time needed for the reaction stablization.In the case of maximum surface area,the rate of coke deposition is the minimum.
