Magnesite-bearing garnet Iherzolite from the Altyn Tagh, associated with garnet pyroxenite, and garnet-bearing felsic gneiss, crops out as lenses in Proterozoic gneiss about 100 km east of the Jianggelasayi River. The...Magnesite-bearing garnet Iherzolite from the Altyn Tagh, associated with garnet pyroxenite, and garnet-bearing felsic gneiss, crops out as lenses in Proterozoic gneiss about 100 km east of the Jianggelasayi River. The garnet Iherzolite, together with the eclogite in western Jianggelasayi, composes a high-pressure to ultrahigh-pressure metamorphic belt in the southern margin of the Altyn Tagh. Parageneses of minerals from magnesite-bearing garnet Iherzolite indicate that the rock evolved a multi-stage metamorphism. The peak-stage metamorphism produces an assemblage of Grt+Ol+Opx+Cpx±Mgs, in which A12O3 content of Opxis very low (0.30-0.66wt%). The calculated P-T condition of the peak stage is 3.8-5.lGPa and 880-970°C, some exsolution rods of clinopyroxene and rutile occur in the Grt and magnesite is rimed by dolomite and orthopyroxene, all implying that the peak stage was a UHP metamorphic process. Together with regional geological studies, isotopic dating and the discovery of coesite inclusions in展开更多
以菱镁矿煅烧制的得轻烧镁为原料,经消化、碳酸化制得碳酸氢镁溶液,采用活性炭为吸附剂脱除钙、铁等杂质,再热解、煅烧制得高纯氧化镁。研究了吸附温度和接触时间等因素对活性炭吸附除铁的影响,以及酸用量和时间对活性炭再生的影响。结...以菱镁矿煅烧制的得轻烧镁为原料,经消化、碳酸化制得碳酸氢镁溶液,采用活性炭为吸附剂脱除钙、铁等杂质,再热解、煅烧制得高纯氧化镁。研究了吸附温度和接触时间等因素对活性炭吸附除铁的影响,以及酸用量和时间对活性炭再生的影响。结果表明:在20℃下,吸附反应80 m in,最终的氧化镁产品中MgO含量大于99.5%,CaO含量小于0.09%,Fe含量小于0.05%;时间对再生效果影响甚微,活性炭再生效果良好,可以重复利用,为制备各种高纯氧化镁提供了一条新途径。展开更多
基金This work was supported by the National "973" Project (Grant No. G1999075508)the National Natural Science Foundation of China (Grant Nos. 49972063 and 40032010) the Teacher Fund of the Ministry of Education, and the Opening Fund of Key Laboratory of
文摘Magnesite-bearing garnet Iherzolite from the Altyn Tagh, associated with garnet pyroxenite, and garnet-bearing felsic gneiss, crops out as lenses in Proterozoic gneiss about 100 km east of the Jianggelasayi River. The garnet Iherzolite, together with the eclogite in western Jianggelasayi, composes a high-pressure to ultrahigh-pressure metamorphic belt in the southern margin of the Altyn Tagh. Parageneses of minerals from magnesite-bearing garnet Iherzolite indicate that the rock evolved a multi-stage metamorphism. The peak-stage metamorphism produces an assemblage of Grt+Ol+Opx+Cpx±Mgs, in which A12O3 content of Opxis very low (0.30-0.66wt%). The calculated P-T condition of the peak stage is 3.8-5.lGPa and 880-970°C, some exsolution rods of clinopyroxene and rutile occur in the Grt and magnesite is rimed by dolomite and orthopyroxene, all implying that the peak stage was a UHP metamorphic process. Together with regional geological studies, isotopic dating and the discovery of coesite inclusions in
文摘以菱镁矿煅烧制的得轻烧镁为原料,经消化、碳酸化制得碳酸氢镁溶液,采用活性炭为吸附剂脱除钙、铁等杂质,再热解、煅烧制得高纯氧化镁。研究了吸附温度和接触时间等因素对活性炭吸附除铁的影响,以及酸用量和时间对活性炭再生的影响。结果表明:在20℃下,吸附反应80 m in,最终的氧化镁产品中MgO含量大于99.5%,CaO含量小于0.09%,Fe含量小于0.05%;时间对再生效果影响甚微,活性炭再生效果良好,可以重复利用,为制备各种高纯氧化镁提供了一条新途径。
