以260-350 g/m2的芳纶无纺毡为基底层、40-60 g/m2的耐高温无纺布为保护层,通过静电喷雾将高温粘合剂均匀涂布在基底层上,再采用静电纺丝技术将直径150-400 nm的可溶性聚酰亚胺（P84）纳米纤维均匀纺制其上,附上保护层,热压固化使3层材料紧密结合,得到三明治结构的耐高温纳米纤维复合过滤毡,用其去除模拟气溶胶（粒径0.3-10μm的Na Cl）颗粒.结果表明,复合滤毡粘结强度超过1000 k Pa,粘合剂对基底性能影响较小,少量纳米纤维可有效提高材料的过滤效率,对粒径2.0μm以上和1.0-2.0μm Na Cl颗粒的过滤效率分别达100%和99.5%以上.
A novel process was proposed for the activation pretreatment of limonitic laterite ores by Na2CO3 roasting. Dechromization and dealumination kinetics of the laterite ores and the effect of particle size, Na2CO3-ore ma...
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A novel process was proposed for the activation pretreatment of limonitic laterite ores by Na2CO3 roasting. Dechromization and dealumination kinetics of the laterite ores and the effect of particle size, Na2CO3-ore mass ratio, and roasting temperature on Cr and Al extraction were studied. Experimental results indicate that the extraction rates of Cr and Al are up to 99%and 82%, respectively, under the optimal particle size of 44–74μm, Na2CO3-to-ore mass ratio of 0.6：1, and temperature of 1000 ℃. Dechromization within the range of 600–800 oC is controlled by the diffusion through the product layer with an apparent activation energy of 3.9 kJ/mol, and that it is controlled by the chemical reaction at the surface within the range of 900–1100 ℃ with an apparent activation energy of 54.3 kJ/mol. Besides, the Avrami diffusion controlled model with on apparent activation energy of 16.4 kJ/mol is most applicable for dealumination. Furthermore, 96.8%Ni and 95.6%Co could be extracted from the alkali-roasting residues in the subsequent pressure acid leaching process.
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