As the hydrazine is toxic, the methods to detect hydrazine at low concentrations are essential in scientific research. This preliminary study reported on how to increase the efficiency of ZnO/reduced graphene oxide (r...As the hydrazine is toxic, the methods to detect hydrazine at low concentrations are essential in scientific research. This preliminary study reported on how to increase the efficiency of ZnO/reduced graphene oxide (rGO) by adding durian peel ash (DPA) and using three-electrode method. The ZnO/rGO composites were prepared using chemical reaction of graphene oxide (GO) with zinc chloride. The rGO was prepared by the chemical reduction of GO using hydrazine. The properties of the samples were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction, and Potentiostat/Galvanostat. The results showed that the optimal condition for the composite material was 70%DPA:30%ZnO/rGO with the sensitivity of 222.92 mA/mM<span style="white-space:nowrap;">·</span>cm<sup>2</sup> and the current density up to 116.50 ± 0.95 A/g. The relationship between the current and the hydrazine concentration was I (μA) = 48.69 + 21.91C (mM) with R<sup>2</sup> of 0.9870. The minimum concentration of hydrazine solution that the modified electrode can measure was 0.125 mM. The DPA powder can then be used to enhance the hydrazine detection efficiency at low concentrations.展开更多
A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in deta...A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free energy.The results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron oxides.Over the full temperature range,iron oxides were more easily reduced than zinc oxides.Regardless of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of Zn.When the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction temperature.As the C/O ratio increased,the metallization and dezincification rates first increased and then decreased.The effect of reduction time on BFA reduction was similar to that of reaction temperature.展开更多
为了分析瓦斯灰湿法脱硫工艺中锌浸出过程的动力学,以云南某高炉瓦斯灰为原料进行脱硫浸出锌试验,分别考察了反应温度、搅拌速度、进口SO_(2)浓度和进口流量对锌浸出率的影响,研究了锌的浸出动力学。结果表明:在反应温度为40℃、进气流...为了分析瓦斯灰湿法脱硫工艺中锌浸出过程的动力学,以云南某高炉瓦斯灰为原料进行脱硫浸出锌试验,分别考察了反应温度、搅拌速度、进口SO_(2)浓度和进口流量对锌浸出率的影响,研究了锌的浸出动力学。结果表明:在反应温度为40℃、进气流量为400 m L/min、搅拌速度为600 r/min、进口SO_(2)浓度为3.0 g/m^(3)的条件下,保证高脱硫率的同时锌的浸出率达到44.6%;在25~60℃条件下,反应表观活化能Ea=23.4 k J/mol,表明瓦斯灰脱硫中锌浸出过程遵循收缩核模型,过程受混合控制,采用半经验模型描述该过程,得到搅拌速度,进口SO_(2)浓度和进气流量的反应级数分别为0.3857、0.17569和0.48893,建立了半经验动力学方程。展开更多
文摘As the hydrazine is toxic, the methods to detect hydrazine at low concentrations are essential in scientific research. This preliminary study reported on how to increase the efficiency of ZnO/reduced graphene oxide (rGO) by adding durian peel ash (DPA) and using three-electrode method. The ZnO/rGO composites were prepared using chemical reaction of graphene oxide (GO) with zinc chloride. The rGO was prepared by the chemical reduction of GO using hydrazine. The properties of the samples were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction, and Potentiostat/Galvanostat. The results showed that the optimal condition for the composite material was 70%DPA:30%ZnO/rGO with the sensitivity of 222.92 mA/mM<span style="white-space:nowrap;">·</span>cm<sup>2</sup> and the current density up to 116.50 ± 0.95 A/g. The relationship between the current and the hydrazine concentration was I (μA) = 48.69 + 21.91C (mM) with R<sup>2</sup> of 0.9870. The minimum concentration of hydrazine solution that the modified electrode can measure was 0.125 mM. The DPA powder can then be used to enhance the hydrazine detection efficiency at low concentrations.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51704021)Key Research and Development Projects of Sichuan Province(021YFG0114)+1 种基金Key Research and Development Projects of Shandong Province(2021CXGC010209)the Joint Funds of the National Natural Science Foundation of China(U1560203).
文摘A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free energy.The results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron oxides.Over the full temperature range,iron oxides were more easily reduced than zinc oxides.Regardless of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of Zn.When the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction temperature.As the C/O ratio increased,the metallization and dezincification rates first increased and then decreased.The effect of reduction time on BFA reduction was similar to that of reaction temperature.
文摘为了分析瓦斯灰湿法脱硫工艺中锌浸出过程的动力学,以云南某高炉瓦斯灰为原料进行脱硫浸出锌试验,分别考察了反应温度、搅拌速度、进口SO_(2)浓度和进口流量对锌浸出率的影响,研究了锌的浸出动力学。结果表明:在反应温度为40℃、进气流量为400 m L/min、搅拌速度为600 r/min、进口SO_(2)浓度为3.0 g/m^(3)的条件下,保证高脱硫率的同时锌的浸出率达到44.6%;在25~60℃条件下,反应表观活化能Ea=23.4 k J/mol,表明瓦斯灰脱硫中锌浸出过程遵循收缩核模型,过程受混合控制,采用半经验模型描述该过程,得到搅拌速度,进口SO_(2)浓度和进气流量的反应级数分别为0.3857、0.17569和0.48893,建立了半经验动力学方程。
