The properties of castables for iron main trough have been improved by means of increaing the castable's critical size and adding expandable mate-rial ,The precast blocks made from this castable have been used as ...The properties of castables for iron main trough have been improved by means of increaing the castable's critical size and adding expandable mate-rial ,The precast blocks made from this castable have been used as the scum wall of the main trough in Baosan I& s Co.,Which have solved the problems usually occurred in this area,such as serious ero-sion,easy craking and lower service life.展开更多
Aluminum spent potlining (SPL) was employed as both the fluxing agent and a source of carbonaceous reductant for the carbothermic reduction of chromite, aiming to allow effective separation of alloy from the slag comp...Aluminum spent potlining (SPL) was employed as both the fluxing agent and a source of carbonaceous reductant for the carbothermic reduction of chromite, aiming to allow effective separation of alloy from the slag component. The experimental results show that the carbonaceous component of the SPL is more reactive towards chromite reduction compared to graphite. The formation of refractory spinel (MgAl2O4) on chromite particles hinders further reduction and alloy growth. The slag-making components of the SPL (e.g. nepheline and NaF) form molten slags at low temperatures (~1300℃) and partly dissolve the refractory spinel as well as the chromite. Destruction of the spinel layer with enhanced mass transfer greatly improves the alloy growth, which can be further promoted by reduction at a higher temperature (e.g. 1500℃). Ferrochrome alloy particles grow large enough at 1500℃ in the presence of SPL, allowing effective separation from the slag component using elutriation separation.展开更多
The anaerobic oxidation of methane （AOM） has strongly developed at Core A, Site 79 of the middle Okinawa Trough, East China Sea, and a large amount of authigenic pyrite is preserved in the surface sediment. In this ...The anaerobic oxidation of methane （AOM） has strongly developed at Core A, Site 79 of the middle Okinawa Trough, East China Sea, and a large amount of authigenic pyrite is preserved in the surface sediment. In this study, we analyze the characteristics of the authigenic pyrite and its sulfur isotopic values. The authigenic pyrite is stripy and tubular, and there were foraminifera compartments filled with pyrite. The pyrite is extracted using chromium reduction, and the values of δ348 are found to lie between -41.20‰ and 8.92‰ V-CDT. The bulk pyrite tends to be more enriched in 348 with increasing depth. Particularly, the 834S value of the pyrite lies between -32.73%o and -41.20‰ V-CDT above 278 cmbsf, but it quickly increases below this depth （-21.49%o-8.92‰ V-CDT）. At the same time, the total sulfur content of the pyrite shows an abrupt increase above 100 cmbsf but is otherwise stable between 1.04% and 0.55% below 100 cmbsf. The stable and negative values of 8345 and the decreasing values of total sulfur above 278 cmbsf indicate reduced AOM activities in 17.18-5.3 ka. In addition, the increasing δ34S and pyrite content indicate strong AOM development and methane seep below 278 cmbsf in 18.8-17.18 ka. In particular, the highest positive value of δ34S occurring in 18.78 ka indicates the most intense AOM activity. The shallow sul- fate-methane interface （SMI） and high methane flux below marine sediments also strongly support this activity.展开更多
文摘The properties of castables for iron main trough have been improved by means of increaing the castable's critical size and adding expandable mate-rial ,The precast blocks made from this castable have been used as the scum wall of the main trough in Baosan I& s Co.,Which have solved the problems usually occurred in this area,such as serious ero-sion,easy craking and lower service life.
基金funded by NRCan under the Rare Earth Elements and Chromite R&D Program
文摘Aluminum spent potlining (SPL) was employed as both the fluxing agent and a source of carbonaceous reductant for the carbothermic reduction of chromite, aiming to allow effective separation of alloy from the slag component. The experimental results show that the carbonaceous component of the SPL is more reactive towards chromite reduction compared to graphite. The formation of refractory spinel (MgAl2O4) on chromite particles hinders further reduction and alloy growth. The slag-making components of the SPL (e.g. nepheline and NaF) form molten slags at low temperatures (~1300℃) and partly dissolve the refractory spinel as well as the chromite. Destruction of the spinel layer with enhanced mass transfer greatly improves the alloy growth, which can be further promoted by reduction at a higher temperature (e.g. 1500℃). Ferrochrome alloy particles grow large enough at 1500℃ in the presence of SPL, allowing effective separation from the slag component using elutriation separation.
基金supported by the National Natural Science Foundation of China(Grand Nos.4130606241104086)+2 种基金the Key Laboratory of Gas Hydrate Foundation(Grand Nos.SHW[2014]-DX-03SHW[2014]-DX-04)the Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology Foundation(Grand No.MRE 201213)
文摘The anaerobic oxidation of methane （AOM） has strongly developed at Core A, Site 79 of the middle Okinawa Trough, East China Sea, and a large amount of authigenic pyrite is preserved in the surface sediment. In this study, we analyze the characteristics of the authigenic pyrite and its sulfur isotopic values. The authigenic pyrite is stripy and tubular, and there were foraminifera compartments filled with pyrite. The pyrite is extracted using chromium reduction, and the values of δ348 are found to lie between -41.20‰ and 8.92‰ V-CDT. The bulk pyrite tends to be more enriched in 348 with increasing depth. Particularly, the 834S value of the pyrite lies between -32.73%o and -41.20‰ V-CDT above 278 cmbsf, but it quickly increases below this depth （-21.49%o-8.92‰ V-CDT）. At the same time, the total sulfur content of the pyrite shows an abrupt increase above 100 cmbsf but is otherwise stable between 1.04% and 0.55% below 100 cmbsf. The stable and negative values of 8345 and the decreasing values of total sulfur above 278 cmbsf indicate reduced AOM activities in 17.18-5.3 ka. In addition, the increasing δ34S and pyrite content indicate strong AOM development and methane seep below 278 cmbsf in 18.8-17.18 ka. In particular, the highest positive value of δ34S occurring in 18.78 ka indicates the most intense AOM activity. The shallow sul- fate-methane interface （SMI） and high methane flux below marine sediments also strongly support this activity.
