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以铝热法生产金属铬的炉渣为原料,研究了从铬渣中回收Cr2O3的生产工艺条件。研究表明,铬的转化率受焙烧条件和浸出条件的影响。铬的浸出率随着焙烧过程焙烧时间、温度、物料比的增加以及物料粒度的减少而增加;随浸出固液比、时间和温度的升高而增大。设计L18(37)正交试验,由级差分析得:焙烧温度是影响浸出率的主要因素,其次为焙烧物料比、焙烧时间、粒度、固液比、溶出时间、溶出温度,并确定了焙烧的最佳实验条件。 相似文献
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实验以矾浆为原料,利用酸熔法从中提取氢氧化铝。考察了固液比、反应温度、硫酸浓度等因素对氢氧化铝提取率的影响,通过正交试验确定了最佳的工艺条件,硫酸浓度为60%,固液比1∶3,反应温度为175℃,在此条件下氢氧化铝的提取率可达87.07%。 相似文献
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采用正交试验分别对微波和超声波方法抽提褐煤黄腐酸类物质的工艺进行了研究和对比。结果显示,微波抽提较优的条件为压力0.6MPa、抽提温度150℃、固液比1:10(g/mL)、抽提时间8min;超声提取较优的条件为超声频率50KHz、加热温度60℃、固液比(g/mL)1:20、超声时间30min。并采用元素分析及官能团测定... 相似文献
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The objective of this study was the examination and development of a solvent-free spheronization process as a manufacturing tool for sustained release matrix spheres. Extrudates prepared from a binary lipid mixture with different amounts of Dynasan 114® and Witocan 42/44® and theophylline as model drug were processed in systematic spheronization experiments by varying pellet formulation and spheronizer-jacket temperature. The rounding procedure of the pellets was investigated by analyzing spot samples after different processing times. The obtained pellets were characterized according to their shape, size distribution, porosity and drug release properties. Round lipid pellets with a mean aspect ratio below 1.1 and a narrow particle size distribution with median equivalent diameters around 1.5 mm could be obtained. The pellets showed sustained drug release properties and porosities below 1%. The spheronization process was shown to be strongly temperature- and formulation dependent. The material temperature during the process was influenced by the adjusted jacket temperature and friction- and shear forces between the rounded particles; control of material temperature seems to pose the challenge in the investigated process. 相似文献
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为探索铠装硅酸盐胶黏剂在特殊环境下的绝缘特性,本文制备不同碱金属离子含量及固液配比的硅酸钾胶黏剂样品,将其固封于不锈钢管体中,在潮湿环境与高温条件下分析其绝缘性能并进行失效分析。结果表明:在潮湿环境中,胶体中的固液配比及碱金属(K+)含量会影响铠装试样的整体绝缘性能,当固液配比为2∶1时,硅酸钾与硅溶胶质量比在(2~1)∶1之间时,其绝缘效果较佳;在高温条件下,随着温度的升高及保温时间的延长,铠装壳体中部分合金元素渗入胶体表面,造成样品绝缘性能较大幅度的下降。 相似文献
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Antibiotic drug releasing from chitosan and acylchitosan microspheres was studied. The acylchitosan microspheres were prepared by modifying the microencapsulation process from spray‐drying to spray in‐liquid coagulating process for the improvement of chem‐physical properties of polymer in controlling the release of antibiotic drug. A higher yield of microspheres was recovered by this improved process. Crystallinity, swelling ability, and the morphology of various microspheres were investigated by X‐ray, water adsorption, and scanning electron microscopy studies. Results show that by modifying the microencapsulation process from spray‐drying to spray in‐liquid coagulating process, the chemical properties of the microsphere were varied from a hydrophilic chitosan microsphere to a hydrophobic acylchitosan microsphere, while the physical structure of the microsphere was varied from a porous chitosan microsphere to a dense acylchitosan microsphere. For the reasons, drug release rate of acylchitosan microspheres prepared by the novel spray microencapsulation method were apparently depressed, and the long‐acting release of antibiotic drug was possible to be achieved. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 747–759, 1999 相似文献
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含铟氧化锌烟尘加压硫酸浸出工艺优化 总被引:1,自引:0,他引:1
对含铟氧化锌烟尘加压浸出进行正交实验及单因素实验,考察各因素对浸出的影响. 结果表明,各因素对铟浸出率的影响显著程度为初始硫酸浓度>液固比>压力>温度>时间,对锌浸出率为初始硫酸浓度>液固比>温度>时间>压力. 优化工艺条件为温度140℃,釜内压力0.6 MPa,时间90 min,液固比8 mL/g,初始硫酸浓度160 g/L,搅拌速率500 r/min. 该条件下锌和铟浸出率分别达99%和91%以上,锌与铟可同时高效浸出,浸出液残酸低,工艺稳定性好 相似文献
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为了提高植物甾醇在体内的生物利用度,促进其在医药中的广泛应用,在制备的植物甾醇液体自微乳基础上,进一步利用喷雾干燥制备固体自微乳,以提高其长期储存稳定性。首先筛选了载体材料的种类和用量,然后以集粉率为考察指标,在单因素实验的基础上进行响应面优化,确定喷雾干燥的最优工艺参数。结果表明,最优载体为胶体二氧化硅,在载体与自微乳的质量比为1:1、喷雾干燥的进风温度为120℃、进料速度10 mL/min、进风流量540 L/h,此时得到的集粉率为49.36%,与理论预测值基本一致。制得的S-SMEDDS为白色粉末,平均载药量为1.00%,重新分散在水中能形成淡蓝色澄清透明的乳液,再分散粒径为27.20±1.15 nm,多分散系数为0.137±0.010。药物以无定形的状态被吸附在胶体二氧化硅的孔径中,在不同的pH条件下,释放度有所不同,但与原料药相比,释放效果有了很大改善。 相似文献
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以氟尿嘧啶为模板药物,以甲基丙烯酸羟乙酯为骨架单体,以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂合成印迹水凝胶,并通过扫描电镜、红外光谱及差示热量扫描等测试手段对凝胶进行了表征,结果表明:制备的印迹水凝胶表面无孔、光滑,氟尿嘧啶与其中的单体通过氢键结合成了复合物,同时经处理后凝胶中已不再残留未反应的单体。印迹水凝胶的吸水溶胀性能实验结果显示其吸水溶胀性能随制备中模板药物的含量的增加而增强,同时同一凝胶的溶胀速度与溶胀率随体系pH值的升高而增强。在氟尿嘧啶溶液中测定水凝胶的药物负载量,结果显示:印迹水凝胶的药物负载能力明显强于非印迹水凝胶,同时印迹水凝胶(8∶1)对药物的负载能力强于印迹水凝胶(4∶1),药物负载量高达0.0914 mg/g。在模拟体液中测试水凝胶对药物的释放效果结果显示:印迹水凝胶对药物的缓释作用明显优于非印迹水凝胶,并且印迹水凝胶(8∶1)对药物的缓释效果优于印迹水凝胶(4∶1),对药物的释放平缓,同时,释放体系pH值的升高不利于印迹水凝胶的药物缓释效果。 相似文献