硫酸镁—氨气法生产氢氧化镁          下载免费PDF全文

宋雪雪  李丽娟  时东  张波  姬连敏  刘志启  聂锋  王念贻  曾忠民  宋福根 《盐湖研究》2013,(4):42-48

以硫酸镁和氨气为原料,直接制备高浓度阻燃剂氢氧化镁。通过单因素实验确定了最佳工艺条件,搅拌强度450r／rain,氨镁摩尔比2．4：1,氨气加入流量500mL／min,陈化时间60min,反应温度60℃,硫酸镁浓度2．50mol／L。用扫描电镜、X射线衍射仪和激光粒度仪表征产品的形貌、结构及粒度。在最佳工艺条件下得到,D5012．06μm,D90 18．99μm,料浆浓度7．37％,Mg收率68．02％,氢氧化镁纯度96．75％。  相似文献   

电感耦合等离子体发射光谱法测定铝土矿中的稀土氧化物     

胡璇 《岩矿测试》2020,39(6):954-960

采用电感耦合等离子体发射光谱法（ICP-OES）测定铝土矿中的稀土氧化物时，酸溶往往造成溶样不彻底，高温碱熔时大量的熔剂会降低稀土元素的发射强度，同时由于稀土氧化物含量（0.0010%~0.050%）较低，存在铝、铁等基体干扰，难以准确测定。本文采用氢氧化钠熔融铝土矿样品，熔融物用热水浸取，三乙醇胺溶液掩蔽铝和铁，乙二胺四乙酸二钠溶液络合钙、镁等干扰元素，稀土氢氧化物留存于沉淀中，沉淀经盐酸溶解进入待测液，从而将稀土元素与熔剂和基体元素分离。实验结果表明：标准溶液无需基体匹配，各稀土氧化物标准曲线的线性相关系数均不小于0.9999，检出限在0.0002%~0.0015%之间；按照实验方法分析实际样品中稀土氧化物的含量，测定结果的相对标准偏差（RSD，n=6）为2.0%~4.6%，回收率为85.2%~104.4%。本方法与电感耦合等离子体质谱法（ICP-MS）相比，两种方法的测定结果无显著性差异。  相似文献   

氢氧化镁作为吸附剂的应用研究进展          下载免费PDF全文

霍闪  卿彬菊  邓小川  朱朝梁  温现明  史一飞  邵斐 《盐湖研究》2014,(4):57-60,66

由于氢氧化镁具有较强的吸附特性,且具有活性强、缓冲性好、无腐蚀性等特点,作为一种安全、无毒的吸附剂,在环保领域有较广泛的应用。全面综述了氢氧化镁作为吸附剂在各种水质废水(包括酸性废水、印染废水、含重金属工业废水、含磷和铵城市废水)处理,以及在海(卤)水除硼和烟气脱硫等方面的应用研究。  相似文献   

硬脂酸及其盐表面改性氢氧化镁的研究进展          下载免费PDF全文

张东生  刘志启  李丽娟  朱黎霞  时东  张波  李慧芳 《盐湖研究》2012,20(4):63-66

介绍了阻燃剂氢氧化镁的特性及阻燃机理,包括固相阻燃机理、气相阻燃机理和协效阻燃机理。列举了常用的表面改性剂。简述了硬脂酸及其盐改性氢氧化镁的方法和机理,影响改性的因素以及改性效果的评测手段。对改性氢氧化镁的应用进行了概述。  相似文献   

硅烷偶联剂改性氢氧化镁的研究进展          下载免费PDF全文

王念贻  刘志启  李丽娟  朱黎霞  时东  宋雪雪  姬连敏  张波 《盐湖研究》2013,(4):53-59

氢氧化镁是一种重要的无卤阻燃剂,为了改善其阻燃效率低、与高分子材料相容性差等缺点,通常需要使用阻燃添加剂对其进行特殊处理,使之具备更好的阻燃性能。主要介绍了氢氧化镁作为阻燃剂的特性及其阻燃机理;硅烷偶联剂的结构特点及改性氢氧化镁的方法和机理;影响改性的因素以及改性效果的测评方法,并对硅烷偶联剂改性氢氧化镁的研究进展进行了概述。  相似文献   

牛磺酸和布洛芬插层MgAl-LDHs药物缓释材料制备及其结构研究     

谢襄漓  周翔  曹伟城  臧梦璐  施莲香  王林江 《矿物学报》2012,32(4):481-485

采用焙烧还原法制备了牛磺酸/层状双氢氧化物插层复合物(TAU-LDH)和布洛芬/层状双氢氧化物插层复合物(IBU-LDH)。研究了插层复合物中TAU和IBU在模拟人体内肠道pH值(pH=7.4)的磷酸缓冲溶液(PBS)中的缓释性能。XRD和FT-IR分析表明,TAU和IBU阴离子成功进入到LDHs层间形成插层复合物,IBU-LDH插层复合物的结晶性能优于TAU-LDH。UV-Vis分析表明,存在于LDHs层间的TAU和IBU在缓冲溶液中具有明显的缓释特性。复合物中的TAU 40 min释放85%,180 min释放完全;IBU 40 min释放88%,180 min释放完全。IBU-LDH插层复合物的药物缓释特性优于TAU-LDH插层复合物。  相似文献   

即时合成Cu/Mg/Al层状双氢氧化物处理含Cu²⁺废水实验研究     

樊明德  陈天虎  彭书传 《岩石矿物学杂志》2012,31(3):447-453

在模拟含Cu2+废水中加入Mg2+和Al3+,以NaOH为沉淀剂,研究金属盐水解即时合成层状双氢氧化物去除Cu2+的可行性,同时考察了体系终点pH值、配料中Mg/Cu摩尔比值及反应温度和时间对Cu2+去除率的影响,探讨了Cu2+去除机理及层状双氢氧化物形成过程。结果表明,实验条件下体系终点pH值显著影响Cu2+去除率,在pH值8.0~11.0范围内去除效果较好,达99%以上。通过X射线衍射分析结合即时合成法特点,废水中Cu2+主要是在晶核生成阶段以Cu/Mg/Al三元层状双氢氧化物形式被去除;三元层状双氢氧化物的形成由反应体系中Al3+、Cu2+、Mg2+分步水解导致,最适pH值约为9.0。  相似文献   

Effects of fracture grouting with sodium hydroxide during electro-osmosis on clay     

Jun Wang  Ziyang Gao  Lingyu Li  Hongtao Fu  Yuanqiang Cai 《Marine Georesources & Geotechnology》2013,31(2):245-255

ABSTRACT

Electro-osmosis is a foundation treatment method for clay that is not widely used because of its nonuniform consolidation effect and high cost. To overcome these limitations, this study investigates fracture grouting. To determine the optimal grouting method, anode grouting, polyurethane grouting, and fracture grouting were first compared in one-dimensional electro-osmosis consolidation tests using self-made model boxes under an equal electric potential gradient, and then different solution concentrations were tested. By comparing the current, drainage rate, and coefficient of energy consumption during the electro-osmosis process, as well as moisture content, electrical conductivity, and shear strength after the tests, the moisture and shear strength of clay after electro-osmosis were found to be significantly improved by adding chemical reagents at the fracture. In addition, the optimum concentration of fracture grouting was determined to be 1.5%, and the shear strength after testing of clay that had been treated with sodium hydroxide was found to be higher than that of the control group. However, the effects of fracture grouting in the early stage were clearer than the effects of fracture grouting at later stages.  相似文献   

硅藻粘附性EPS提取方法的比较研究          下载免费PDF全文

于兆伟  谢雅清  张珮璇  鲍金  孙陈炼  靳翠丽  周晓见 《应用海洋学学报》2019,38(4):592-599

底栖硅藻是可见光能照射到的水下表面生物膜中的主要污损生物,胞外多聚物(Extracellular Polymeric Substances,EPS)是硅藻生物膜形成和发育过程中的关键物质,可溶性EPS和粘附性EPS的提取方法不同,对粘附性EPS的分离提取仍没有统一的方法。本研究选用了4种方法提取底栖硅藻(Amphora sp.)粘附性EPS:30℃水浴处理、70℃水浴处理、福尔马林-NaOH处理和阳离子交换树脂处理,研究了不同分离方法条件下,Amphora sp.粘附性EPS中各主要成分的提取量。结果表明,粘附性EPS中各主要成分普遍受提取方法的影响,其中DNA含量变化幅度最大,其次是蛋白质、总糖和糖醛酸含量,硫酸基含量受提取方法的影响最小。低温水浴处理提取效率低,高温水浴处理可能影响EPS的后续分析,阳离子交换树脂提取粘附性EPS的效果较好,但对细胞的破坏最严重,福尔马林-NaOH处理提取的EPS总量最高,提取总糖、糖醛酸的效果最好,而且没有造成严重的细胞破裂。因此福尔马林-Na OH处理是相对均衡和高效的提取硅藻粘附性EPS的方法。  相似文献   

Kaolinite – alkali interaction and effects on basic properties     

Puvvadi?Venkata?SivapullaiahEmail author  Manju 《Geotechnical and Geological Engineering》2005,23(5):601-614

The influence of type and amount of clays present in soils on their properties is well understood. The clays exert their influence through large specific surface area and charges on them. Their effect is mostly exhibited through inter particle bonding and subsequent particle associations. The mineralogical influence of soils in water is well documented. However, the change in soil water system because of presence some of the contaminants can greatly influence the soil behaviour. Some of the changes are due to formation of new compounds due to interactions between the soil and pollutant. The paper reports the effect of interaction of kaolinite mineral with alkali on the index properties of soils from which the geotechnical behaviour can be understood. Detailed X-ray diffraction studies have shown that sodium aluminum silicate hydroxide hydrate (NASH) is formed by clay alkali reactions. The type and amount of formation of the compound is influenced by the concentration of alkali solution. While the compound formed is in smaller quantities with 1 N NaOH solution, significantly high quantity is formed with 4 N NaOH solution. Presence of alumina is shown to play a significant role. It was observed that the formation of sodium aluminum silicate hydroxide hydrate is reduced in the presence of alumina. Specific gravity of contaminated clay soil was reduced which confirms the formation of new compounds. Water adsorption and specific surface area of soil are also influenced due to soil alkali interaction. The changes in the free swell and index properties of soil in the presence of alkali have been explained by the changes in soil fabric and the formation of new compound.  相似文献