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采用直接沉淀法,以六水氯化镁(MgCl2·6H2O)和工业氨水(NH3·H2O)为主要原料,在室温下研究了乙醚对超细氢氧化镁制备的影响,并通过高压透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)等测试手段对产品的形貌、晶形结构和热行为进行表征.结果显示:当母液中加入乙醚且当其质量分数为80 %时,产品的过滤、干燥时间较未加入前分别减少了96 %和75 %,并有效抑制了NH4Cl·MgCl2·6H2O杂质的产生,制得了分散性良好的圆片状氢氧化镁粉体;当在乙醚-水体系中加入硬脂酸且当其含量为MgCl2·6H2O质量的 1.2 %时,产品完全由亲水性转变为疏水性,其形貌完全由六方片状转变为针状. 相似文献
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MAP法去除垃圾渗滤液中氨氮的实验研究 总被引:2,自引:0,他引:2
采用化学药剂MgCl2 ·6H2 O和NaH2 PO4 使NH 4-N生成磷酸铵镁 (MAP)沉淀 ,以去除垃圾渗滤液中高浓度的氨氮。结果表明 ,若投加MgCl2 ·6H2 O和NaH2 PO4 ,在最佳pH8.5条件下 ,控制Mg2 :PO3- 4:NH 4的比例为 1:1:1左右时 ,渗滤液中氨氮的去除率可达 98%以上。 相似文献
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本研究通过利用镁盐与上清液中的氮氮和磷酸根反应,形成磷酸铵镁沉淀,即鸟粪石晶体(MAP)。以MgCl2·6H2O和Na2HPO4·12H2O为沉淀剂,研究了影响该方法脱氮的因素。得出最佳工艺条件,反应时间为180min,pH值10,Mg:P:N的摩尔配比1:1:l,温度35℃,氨氮去除率为84.23%。 相似文献
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文章考察了采用硫氢化物-水热法制备氢化镁过程中硫氢化物分解工艺参数(加热速率、MgCl2初始浓度及添加剂)对水热产物形貌的影响。实验结果表明:加热速率越快或MgCl2初始浓度越低,形成的氢氧化镁颗粒越小,越容易水热改性,形成形貌规则、分散性好的氢氧化镁颗粒。添加少量乙醇(CH3CH2OH)有利于制备粒径较大且分散性较好的氢氧化镁水热产物,其它添加剂(CH4N2O,C10H16N2O6和CaCl2)对水热产物形貌无明显彩响。 相似文献
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无机镁铝阻燃剂及其应用发展趋势浅析 总被引:20,自引:1,他引:20
论述了无机氢氧化铝、氢氧化镁阻燃剂的作用机理 ,重点从超细 (粒径达 1~ 5 μm)、表面处理 (采用偶联剂对阻燃剂表面进行化学处理 )、复合 (利用化学共沉淀法制备出一种Al(OH) 3·6Mg(OH) 2 ·4.5H2 O复合阻燃剂 ) 3个方面分析了阻燃剂的阻燃性能的优劣及其应用发展前景 相似文献
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以聚乙烯吡咯烷酮为控制剂,氯化镁、氢氧化钠和氨水为原料,经静态反应制备出球形氢氧化镁前驱体,再经煅烧得到球形氧化镁。研究了控制剂种类、控制剂用量、反应物浓度、反应时间等因素对球形氧化镁形貌的影响,并用XRD、SEM等分析手段对产物做了表征。结果表明:在控制剂为聚乙烯吡咯烷酮、添加量为1.0%(质量分数)、氯化镁浓度为1.0 mol/L、氢氧化钠浓度为0.25 mol/L、反应时间为24 h的条件下,获得球形氢氧化镁前驱物;前驱物氢氧化镁在600 ℃下煅烧2 h,制得的球形氧化镁颗粒大小均匀、分散性好、球形度高,平均粒径为4.53 μm。 相似文献
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采用电石渣和盐湖氯化镁为原料制取氢氧化镁。电石渣(氢氧化钙)与氯化铵反应生成氨气,将氨气通入氯化镁溶液中制备氢氧化镁。通过单因素实验和正交实验得出最佳工艺条件:氯化铵与氯化镁物质的量比为5.0,氯化镁浓度为2.0 mol/L,反应时间为60 min,反应温度为25 ℃,陈化时间为2 h。在该条件下氢氧化镁的生成率可达到89%,纯度也可达到98%以上。通过X射线衍射(XRD)及扫描电镜(SEM)表征表明,氢氧化镁产品为片状,粒径在800 nm左右。采用该方法制备氢氧化镁,不仅可以解决电石渣和盐湖氯化镁的大量堆放问题,而且可以制备出高品质的氢氧化镁产品。 相似文献
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Kgabo P Matabola Elizabet M van der Merwe Christien A Strydom Frederick J W Labuschagne 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(12):1569-1574
BACKGROUND: The influence of different hydrating agents on the pH of the hydrating solutions, rate of hydration of MgO to Mg(OH)2 and product surface area was studied as a function of temperature of hydration. Hydrating agents used were aqueous solutions of ammonium chloride, magnesium acetate, magnesium nitrate, nitric acid, acetic acid, magnesium chloride, sodium acetate and hydrochloric acid and distilled water as control. These were chosen to determine either the effect of addition of a common ion, the effect of changing the solution pH or due to the presence of an acetate ion, found earlier to have a beneficial effect on the hydration of MgO. RESULTS: There was no significant difference in the hydration behaviour of the hydrating agents up to 50 °C, where less than 10% of magnesium hydroxide was formed. The amount of hydroxide increased at temperatures above 60 °C. When compared with the hydration in water, all the hydrating agents, with the exception of sodium acetate, showed a significant increase in the degree of hydration. Sodium acetate formed the lowest amount of magnesium hydroxide, ranging between 1.2 and 12.2% magnesium hydroxide. The largest percentage (56.7%) of magnesium hydroxide was formed from hydration in magnesium acetate. CONCLUSION: It seems that MgO hydration is a dissolution‐precipitation process controlled by the dissolution of MgO. The increased degree of hydration in magnesium acetate is possibly due to the presence of acetate and Mg2+ ions. Copyright © 2010 Society of Chemical Industry 相似文献
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Xingfu SONG Shuying SUN Dengke ZHANG Jin WANG Jianguo YU 《Frontiers of Chemical Science and Engineering》2011,5(4):416-421
Magnesium hydroxide with high purity and uniform particle size distribution was synthesized by the direct precipitation method using MgCl2 and NaOH as reactive materials and NaCl as additive to improve the crystallization behavior of the product. The particle size distribution, crystal phase, morphology, and surface area of magnesium hydroxide were characterized by Malvern laser particle size analyzer, X-ray diffraction (XRD), scanning electron microscope (SEM) and Branauer-Emmett-Teller (BET) method, respectively. The purity of products was analyzed by the chemical method. The effects of synthesis conditions on the particle size distribution and water content (filtration cake) of magnesium hydroxide were investigated. The results indicated that feeding mode and rate, and reaction temperature had important effects on water content and the particle size distribution of the product, and sodium chloride improved the crystallization behavior of magnesium hydroxide. The ball-like magnesium hydroxides with the particle size distribution of 6.0–30.0 μm and purity higher than 99.0% were obtained. This simple and mild synthesis method was promising to be scaled up for the industrial production of magnesium hydroxide. 相似文献
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