Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morpholog...Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morphology of mesophase spheres and the structure of the MCMB carbonized at 1000℃ for lh using scanning electron microscope （SEM） and XRD, it was found that phenolic resin accelerated the formation and coalescence of mesophase spheres. Some of the obtained MCMB were hi- or tri-spheres with the distorted microtextural carbon layers. Hexamethylenetetramine in the pitch modified by phenolic resin accelerated the condensation of phenolic resin and consequently expedited the combination of mesophase spheres, which was proved by the formation of some tetra-spheres. Owing to the cross-linkage of the additives, MCMB with complex structure were obtained.展开更多
In order to research how lignite is utilized, two coal samples of seams 2 and 4 were taken from the Huangxian Basin, China. The samples were separated into vitrinite, sporinite, and resinite. Geo-chemical and pyrolysi...In order to research how lignite is utilized, two coal samples of seams 2 and 4 were taken from the Huangxian Basin, China. The samples were separated into vitrinite, sporinite, and resinite. Geo-chemical and pyrolysis methods were used to analyse three maceral groups and two seam samples. The results indicate that the resinite and sporinite groups have higher extract yields, S1, S2, HI values, and pyrolysis compounds. These differences may shed light on the usage of the Huangxian lignite. Seam 2 pro- duces more gas and oil than seam 4 does because seam 2 contains more resinite and sporinite macerals.展开更多
Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operation...Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operations. The longwalls are becoming wider and longer while retreat rates are continuously increasing due to significant improvements achieved in longwall equipment reliability and automation.This increased longwall productivity is placing significant emphasis on the reliability of longwall panel development. Although there have been significant improvements in the reliability of continuous miners and hydraulic drill rigs,the traditional resin encapsulated bolt installation is still the principal method used in all major coal-producing countries around the world. Anglo American realised an opportunity existed to introduce an alternative roof bolt installation technique called ‘‘spin to stall" in Australia.Spin to stall was first introduced in Anglo American Coal in South Africa where it has been successfully used for over a decade,though implementation of South African spin to stall resin in Australia has proven to be near impossible due to a significant difference in geotechnical conditions,mining method,and,subsequently,roof bolting equipment. Therefore,a new spin to stall development project was initiated between Anglo American Coal and Jennmar Australia(SPIN2STALLò). This paper summarises the journey of this project,the results,and the successful implementation of spin to stall achieved at Grasstree Mine.展开更多
基金Supported by the National Natural Science Foundation of China (No.50172034).
文摘Mesocarbon microbeads （MCMB） were prepared from coal tar pitch modified by phenolic resin and from the same pitch modified by phenolic resin and hexamethylenetetramine at 440℃ for lh. By investigating the morphology of mesophase spheres and the structure of the MCMB carbonized at 1000℃ for lh using scanning electron microscope （SEM） and XRD, it was found that phenolic resin accelerated the formation and coalescence of mesophase spheres. Some of the obtained MCMB were hi- or tri-spheres with the distorted microtextural carbon layers. Hexamethylenetetramine in the pitch modified by phenolic resin accelerated the condensation of phenolic resin and consequently expedited the combination of mesophase spheres, which was proved by the formation of some tetra-spheres. Owing to the cross-linkage of the additives, MCMB with complex structure were obtained.
基金Supported by Deutscher Akademischer Austauschdienst (DAAD)
文摘In order to research how lignite is utilized, two coal samples of seams 2 and 4 were taken from the Huangxian Basin, China. The samples were separated into vitrinite, sporinite, and resinite. Geo-chemical and pyrolysis methods were used to analyse three maceral groups and two seam samples. The results indicate that the resinite and sporinite groups have higher extract yields, S1, S2, HI values, and pyrolysis compounds. These differences may shed light on the usage of the Huangxian lignite. Seam 2 pro- duces more gas and oil than seam 4 does because seam 2 contains more resinite and sporinite macerals.
文摘Longwall mining is by far the most common method of underground coal extraction in Australia. The industry trends and expectations are placing increasing emphasis on the reliability and productivity of these operations. The longwalls are becoming wider and longer while retreat rates are continuously increasing due to significant improvements achieved in longwall equipment reliability and automation.This increased longwall productivity is placing significant emphasis on the reliability of longwall panel development. Although there have been significant improvements in the reliability of continuous miners and hydraulic drill rigs,the traditional resin encapsulated bolt installation is still the principal method used in all major coal-producing countries around the world. Anglo American realised an opportunity existed to introduce an alternative roof bolt installation technique called ‘‘spin to stall" in Australia.Spin to stall was first introduced in Anglo American Coal in South Africa where it has been successfully used for over a decade,though implementation of South African spin to stall resin in Australia has proven to be near impossible due to a significant difference in geotechnical conditions,mining method,and,subsequently,roof bolting equipment. Therefore,a new spin to stall development project was initiated between Anglo American Coal and Jennmar Australia(SPIN2STALLò). This paper summarises the journey of this project,the results,and the successful implementation of spin to stall achieved at Grasstree Mine.
