共查询到20条相似文献,搜索用时 109 毫秒
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以拜耳法赤泥和85%工业磷酸为原料制备三聚磷酸铝。拜耳法赤泥通过高温烧结改性,用碳酸钠碱溶法溶出改性赤泥中的铝,制备高活性氢氧化铝凝胶,烘干得到氢氧化铝干胶。采用氢氧化铝干胶与工业磷酸,通过中和反应、缩合反应、水化反应,制备三聚磷酸铝。最佳工艺参数:磷酸与氢氧化铝体积质量比(mL/g)为30/10,缩合温度为290℃,缩合时间为4 h,中和温度为常温,加水量为10 mL。对样品进行了化学分析、红外光谱分析和盐雾试验测试,结果表明样品为合格的三聚磷酸铝产品,防腐性能达到工业指标。 相似文献
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主要介绍了一种高浓度氧化铝凝胶(氢氧化铝凝胶)的制备方法,即以碳酸钠和三氯化铝为原料,水为溶剂,乙酸为稳定用添加剂的制备路线,并且也介绍了使用特定的胶溶剂一价强酸-盐酸,硝酸将凝胶溶为氧化铝溶胶的方法。 相似文献
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生态化利用粉煤灰制备高纯超细氢氧化铝 总被引:3,自引:0,他引:3
采用矿物改性活化粉煤灰中Al2O3,消除阻止C2S晶相转变的干扰因素,实现了粉煤灰活化烧结料100%的自粉化,自粉化料平均粒径小于1μm;用质量分数为8%的碳酸钠溶液从活化粉煤灰中以NaAlO2形式提取铝组分,提取率大于75%;研究了表面活性剂种类与掺量、碳化速度、NaAlO2浓度、溶液pH值等因素对制备高纯超细Al(OH)3粉体的影响,找出了主要影响因素及最佳工艺参数,制备出了疏松无团聚的高纯超细Al(OH)3粉体,纯度大于99.9%,平均粒度小于200nm。 相似文献
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以99.99% 高纯铝板为阳极原料,采用电化学方法制备氧化铝前体氢氧化铝,讨论分析了氢氧化铝的焙烧温度、保温时间对制备高纯超细氧化铝的影响,考察了不同电流密度放电对氧化铝形貌和粒度的影响。结果表明:在70 mA·cm-2的较高电流密度下铝/空气电池放电过程可得到平均粒度为268 nm的氢氧化铝;制备的氢氧化铝经洗涤,在1400℃焙烧,保温3 h,可得到平均粒度为200 nm,形貌为近似球状的99.99% 的超细氧化铝粉体;而低电流密度所得氧化铝颗粒团聚严重。主要原因是高电流密度使放电过程中产生的氢氧化铝晶体的介稳区宽度变窄所致。 相似文献
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Processing and kinetics studies on the alumina enrichment of coal fly ash by fractionating silicon dioxide as nano particles 总被引:1,自引:0,他引:1
Coal fly ash produced in the northern China is a potential bauxite substitute for aluminum production because of its high alumina content. However, this industrial application has been limited for its high silicon content. Alumina enrichment by removing silicon becomes a key technology for its utilization. A novel process was developed to fractionate the coal fly ash into high purity nano silicon particles and aluminum enriched residual ash. The procedure has major steps as sodium silicate dissolution with sodium hydroxide, first carbonation to remove impurities, second carbonation to precipitate silicon, and silicon precipitate recovery as a mesospheric nano particles product. Morphological and X-ray diffraction evidences indicated the glassy amorphous silicon content of the ash was dissolved in the sodium hydroxide solution whereas mullite remained in the residue. Kinetics study indicated that the second carbonation was a kinetically second order medium fast multi-phase reaction in which sodium silicate was precipitated as silicic acid. It was found that the reaction was controlled by the mass transferring resistance in the liquid membrane. These nano silicon dioxide particles were in size of 50 nm with a purity of 96%. Alumina content in process residue was slightly increased from 42.00 to 49.20%. Silicon dioxide content was reduced from 48.89 to 30.26%. Ratio of alumina/silica was increased from 0.86 to 1.63. 相似文献
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利用综合热分析仪分析技术、激光粒度分析、扫描电镜和X射线衍射研究了粒度对氢氧化铝在低温相变转化成勃姆石过程的影响,并采用Kissinger方程、Ozawa方程和Crane方程进行了不同粒度的氢氧化铝在低温相变过程的动力学参数计算。结果表明:普通砂状氢氧化铝在相变过程有2个较为明显的吸热峰,将砂状氢氧化铝研磨至中位径D50在12μm左右时,相变过程仍然有2个明显的吸热峰;当氢氧化铝中位径D50在1μm左右的氢氧化铝,相变过程则只有1个吸热峰。根据Kissinger方程和Ozawa方程计算结果,随着粒度的降低,其相变活化能也相应的降低,说明降低氢氧化铝粒径,有利于勃姆石的制备。根据XRD图谱显示,低温煅烧后,样品的主要物相为勃姆石,此外还含有少量的三水铝石,粒径越细,煅烧后样品中勃姆石含量越高。 相似文献
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Fred N. Tebbe Patricia A. Morris Roger H. French Uma Chowdhry Robert L. Coble 《Journal of the American Ceramic Society》1988,71(4):204-C
Aluminum hydroxide obtained by hydrolysis of triethylaluminum is free of uranium and thorium at detection limits of 1 to 9 parts per billion (ppb). Other impurities commonly associated with aluminum oxides are present at low levels (Fe, ∼ 1 ppm; Si, 3 to 6 ppm). When the organoaluminum is intentionally contaminated with an iron salt, purity is restored by a simple distillation. 相似文献
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研究了基体接枝甲基丙烯酸(MAA)对AI(OH)3填充线性低密度聚乙烯(LLDPE)力学性能的改善。接枝反应在密炼机中采用固相接枝方法进行。红外光谱分析表明在聚乙烯基体上进行了接枝反应。力学性能测试表明当AI(OH)3填充量较小时断裂强度和伸长率略有下降,而对于高填充量的复合材料,强度和伸长率得到了明显的改善。断面扫描电镜结果表明基体接枝改善了填料在复合材料中的分散状态。 相似文献
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《中国生物制品学杂志》2010,(12)
目的观察冻干A群脑膜炎球菌多糖-破伤风类毒素结合疫苗的稳定性,并比较A(lOH)3佐剂和磷酸盐缓冲液(PBS)复溶疫苗的免疫效果。方法将冻干疫苗于2~8℃放置36个月,每隔6个月取样,测定游离多糖含量、分子大小等,观察疫苗的稳定性。分别用A(lOH)3和PBS两种稀释液复溶疫苗后,计算吸附率并免疫小鼠,采用ELISA法测定小鼠血清中抗多糖IgG抗体滴度。结果疫苗于2~8℃放置30个月,各项质量指标均合格。A(lOH)3稀释液复溶疫苗的吸附率为100%。以两种稀释液复溶的疫苗均可诱导小鼠产生高滴度的抗多糖IgG抗体及免疫记忆反应,且A(lOH)3稀释液明显优于PBS稀释液。结论冻干A群脑膜炎球菌结合疫苗具有良好的稳定性,A(lOH)3佐剂可作为其稀释液。 相似文献