共查询到19条相似文献,搜索用时 220 毫秒
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晶种分解是拜耳法生产氧化铝的关键工序之一,晶种分解最终得到质量好的氢氧化铝和苛性比值较高的种分母液,从而提高拜耳法的循环效率。简单介绍拜耳法氧化铝生产影响晶种分解过程的主要因素及种分分解率和产品粒度的控制。 相似文献
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以硝酸铝和铝酸钠溶液为主要原料,加入适量添加剂,采用中和法制备氢氧化铝晶种,并将该晶种加入铝酸钠溶液中进行种分分解,制备出亚微米氢氧化铝粉体。在添加剂为乙酸、中和反应温度为60℃、搅拌速度为400 r/min、种分分解过程分解首温为60℃、分解末温为55℃、分解时间48 h、晶种添加量(晶种的质量分数,下同)为2%的条件下,制备出了粒度中位径(D_(50))在1.80μm左右,比表面积<5.0 m~2/g的亚微米氢氧化铝粉体,该粉体结晶完整,形貌为块状。该氢氧化铝粉体和目前EVA阻燃剂所用国外氢氧化铝产品相比,在粒度分布、比表面积、吸油率和形貌成型度等方面都差异不大,可以替代国外同类产品。 相似文献
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分析了影响氢氧化铝产品25B质量的主要因素,制订了将收尘粉料做为氢氧化铝种分分解晶种的方案,不仅解决了25B产品质量不稳定的问题,同时为收尘粉料找到了有效的应用途径。 相似文献
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晶种技术在窑外分解窑上的应用孙勇,谢朝晖,王德厚中国建筑材料研究院水泥所(100024)水泥晶种技术自问世以来,已在立窑厂广泛应用,取得了显著提高产量,降低能耗的良好效果。1992年4月我们又在广东省茂名市水泥厂窑外分解窑上进行了晶种料的煅烧试验,也... 相似文献
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通过正交实验,得出聚合度不同的聚氧乙烯基烯丙酯大单体的最佳合成条件:采用丙烯酸与聚乙二醇的摩尔比为1.2:1.0,阻聚剂为聚乙二醇质量的0.40%,对甲苯磺酸用量为丙烯酸用量的10%,反应温度为95℃,在充分搅拌的情况下进行烯丙酯大单体的合成。通过对自由基共聚合的聚合工艺实验,找出了最佳共聚合工艺:n(MAS):n(AA):n(PA)=1.5:5.0:1.25,在85℃不断搅拌下反应时间4h得到聚羧酸系减水剂。将自制的聚羧酸减水剂按相关行业标准进行性能检测并与其它商品减水剂进行性能比较,结果表明,该减水剂除具有很高的分散性外,还具有控制坍落度损失小及抗压强度比高等优点。 相似文献
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考察了12.7m^3和15.0m^3聚合釜在生产羧基丁苯胶中搅拌功率、搅拌级别、桨叶端速和传热能力以对聚合温度及产品质量的影响。结果表明,在传热能力强,搅拌级别适中的情况下,聚合温度容易控制,产品质量好,转化率较镐,能耗和物耗较低。 相似文献
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介绍了氯碱生产中电解盐水中氯酸盐的分解试验,并根据试验结果确定氯酸盐分解的最佳条件是:氢离子浓度0.8 - 1.0 mol/L、分解温度90 ~95℃、分解时间15 ~20min. 相似文献
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A detailed mechanism analysis of cellulose pyrolysis was carried out according to the previous experimental results. On the basis of the Brodio-Shafizadeh model, a modified two-stage model was proposed to simulate the formation and decomposition of active cellulose (AC) and several main organic compounds, such as levoglucosan (LG), hydroxyl-acetaldehyde (HAA), acetol and furfural etc. During pryolysis, the temperature rise of cellulose can be divided into three stages. In the second stage, cellulose undergoes a main decomposition process in which the reaction temperature remains rather low because of the endothermic cracking of glucosidic bond of AC during the formation of LG. The components density of bio-oil, including LG and other competitive compounds, increased rapidly with the increase of temperature during the first stage. However, in the main decomposition process, LG density in bio-oil had an obvious decrease, while the competitive products appeared to increase gradually, which means the ring-opening and reforming reaction of pyranoid ring are superior to LG formation in high temperature.The secondary reaction of volatile components occurs largely in gaseous phase rather than in the solid phase. Short residence time of volatile materials in high temperature region will be advantageous to a high production of LG,which may otherwise decompose quickly under high temperature. An optimum yield of LG could be obtained when radiant source temperature is in the range of 730---920K and gas residence time is less than 1 s. In addition, the reaction temperature has a stronger effect than gas residence time on the formation of HAA, acetol, formaldehyde and furfural etc. 相似文献
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Yongli WANG Shuyuan MA Xiaodong Lü Chuang XIE 《Frontiers of Chemical Science and Engineering》2012,6(4):423
5-(Difluoromethoxy)-2-mercapto-1H -benzimidazole (DMB) was precipitated by adding acetic acid to the DMB sodium salt solution. The spherical agglomeration of DMB during the reactive crystallization in a batch crystallizer was monitored by real-time Particle Video Microscope (PVM). We found that the low feeding rate of acetic acid, high crystallization temperature, low agitation rate or adding seed crystal can facilitate the formation of spherical agglomerates. By using a simple model, the mean crystal agglomerate size of DMB thus predicted is generally in agreement with the experimental data. In addition, the crystallization process of DMB was optimized by a new control strategy of supersaturation to avoid disadvantages brought by agglomeration. 相似文献
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乌桕籽的含油率高达40%,是生产生物柴油的优质原料。本研究采用绿色环保节能高效的乌桕籽油提取方法,以高压蒸汽作为水剂提取油脂的方法,进行了相关工艺的实验研究,以乌桕油脂皂化物为研究对象,通过微波极化皂化物羧基端促进脱羧制备优质烃类燃料。探讨了料液比、烘烤时间、烘烤温度、pH值、高压蒸汽处理时间等因素对油脂提取率的影响。微波裂解所得到液态产物为皂类干重的60%以上,裂解液态产物的密度为0.865 g/cm3,黏度2.73 mm2/s,与柴油的性质基本相似。研究结果为利用乌桕籽油生产生物柴油的工业化提供了一定基础。 相似文献