用氯化镁生产氢氧化镁和氧化镁的方法

采用一种精制原料和两次煅烧工艺克服在Aman法分步精制原料和三次煅烧等现有工艺路线长、能耗高、生产成本高等不足，将煅烧温度分为：600－800℃轻烧，800－1200℃重烧，1200－1800℃死烧3个温度段，可以分别制得高纯的轻质、重质氧化镁和镁砂。大幅度缩短了工艺路线和生产周期并降低生产成本，成功解决了从原料直接生产氧化镁的技术难题，创造了氧化镁生产的又一方法。     

Sintering magnesium oxide made from magnesium hydroxycarbonate

Conclusions The studies have shown that the fine structure of activated MgO depends on whether the temperature regime under which the magnesium hydroxycarbonate is calcined is fast or slow. In the rapid activation regime, subdispersed particles of MgO with maximum defects of the crystal lattice are formed and this help the diffusion sintering of the MgO.The use of nonaqueous organic binding agents which burn out rapidly in the 300–460°C interval and (in the case of the slow activation regimes) the addition of chrome-spinel and ZrO₂ also improve the sintering of MgO.The high initial disperseness of MgO and the presence of a surface-active binder make it possible by firing at 1500–1600°C to produce a high-density material which is suitable for the manufacture of dense and thermal shock resistant periclase articles.Deceased.Translated from Ogneupory, No. 5, pp. 47–51, May, 1979.     

以活性氧化镁和氯化镁为原料合成氧化镁晶须

探讨了一种合成氧化镁晶须的新的工艺方法。首先以活性氧化镁和氯化镁为原料合成了前驱体碱式氯化镁晶须，接着将碱式氯化镁焙烧成氧化镁晶须。分别用X射线衍射仪（XRD）、扫描电镜（SEM）、热重分析仪（TGA）和化学分析，分析了中间体碱式氯化镁和产品氧化镁晶须的成分、形貌和热化学行为。探讨了各个工艺条件对产物的影响，探索出最佳的工艺条件：活性氧化镁与氯化镁的物质的量比在0．08左右，氯化镁溶液的浓度为3mol／L，反应温度40～50℃，陈化时间在48-72h，陈化温度50℃。在此条件下制得了形貌良好的前驱物碱式氯化镁晶须。将碱式氯化镁晶须焙烧，控制升温速率在2—5℃／min，采取分段升温方式升温至600℃，即可制得氧化镁晶须。制得的晶须长度在100μm左右，直径约0．5μm。     

由碱式碳酸镁制备过氧化镁

以碱式碳酸镁为原料,首先经过煅烧制备出活性较高的氧化镁,活性氧化镁再与过氧化氢溶液经反应、过滤及干燥制备出过氧化镁产品.研究结果表明,碱式碳酸镁的煅烧时间和煅烧温度对合成过氧化镁的活性氧含量有较大影响,最佳煅烧时间为2 h,煅烧温度为650℃;通过对反应液固比、反应温度及反应时间进行考察,确定了适宜的工艺条件:在室温下...     

Sintering of magnesium hydroxide obtained from magnesium chloride solutions

Conclusions We studied two batches of magnesium hydroxide obtained by precipitating out (using dolomite milk) from magnesium chloride solution formed when processing potassium ores.The effect of the compaction pressure, the firing temperature, and prior heat treatment on the sintering process of magnesium hydroxide was investigated.The experimental samples of magnesium hydroxide exhibit high sinterability and facilitate the production of periclase powders (powder bodies) having a porosity of 6.8–9.9% at a firing temperature of 1600°C. The degree of sintering of magnesium hydroxide increases with increasing compaction pressure and firing temperature. Prior heat treatment of the material at 800–1000°C intensifies the sintering process with simultaneous reduction of shrinkage.The studies conducted on the specimens prepared from a fired briquette established that the periclase (magnesite) powder obtained from magnesium hydroxide is suitable for the production of magnesia refractories.A. V. Kushchenko and G. G. Eliseeva (UkrNIIO) participated in this investigation.Translated from Ogneupory, No. 2, pp. 7–10, February, 1988.     

碱式氯化镁废渣生产氧化镁

由麦芽酚生产中的碱式氯化镁废渣为原料制取氧化镁。考察了温度及反应物用量对氧化镁产率和质量的影响。证明了该方法技术可行，能产生较好的经济效益，解决了废渣对环境的污染，产生了较好的社会效益。     

Manufacturing of magnesium hydroxide from natural magnesium chloride sources

Various processes for manufacturing magnesium hydroxide have been considered and tested in order to decide whether they can be employed to the full-scale production of this product from natural sources (bischofite and magnesium chloride brines). The process for the synthesis of magnesium hydroxide from magnesium chloride using sodium hydroxide has been improved.     

花瓣状纳米氢氧化镁及氧化镁的微波辅助合成

在微波辅助下,以硫酸镁、NH₃•H₂O-NH₄Cl缓冲溶液为原料,通过均相沉淀反应制备了纳米氢氧化镁,经煅烧又得到了纳米氧化镁。采用X射线衍射（XRD）、透射电镜（TEM）、扫描电镜（SEM）、热重分析（TG）等分别对纳米氢氧化镁和氧化镁的结构、形貌及热稳定性进行了分析测试。结果表明,纳米氢氧化镁的结晶性能较好,其形貌为由厚度约40 nm的纳米片团聚而成的花瓣状;纳米氧化镁亦保持了氢氧化镁花瓣状形貌。并对微波辅助下纳米氢氧化镁形成的可能机理进行了初步探讨。     

精炼镁渣制光卤石和硫酸镁工艺研究

介绍了从精炼镁渣中制取光卤石和硫酸镁的工艺过程是破碎制粉(粒径1—2mm)、稀H2SO4(浓度20％--30％)溶解、采用苦土粉中和过量酸，过滤除杂、中和、冷却、结晶工序。设计出制备工艺的最佳条件，并讨论了生产中的有关影响因素，最终生产出达标的合格产品。     

Surface properties of magnesium oxide obtained from basic magnesium carbonate: Influence of preparation conditions of magnesium carbonate

Surface area, total basicity and base strength distribution (weak, strong and intermediate strength basic sites) of magnesium oxide obtained from basic magnesium carbonate (by its decomposition at 873 K) prepared by precipitation using different magnesium slats, precipitating agents and precipitating conditions (viz. concentration of magnesium salt. pH, temperature, mode of mixing and ageing period) have been thoroughly investigated. The total basicity and base strength distribution of the different magnesium oxide samples have been determined by step-wise thermal desorption of carbon dioxide from 323 to 1253 K. The chemical composition of basic magnesium carbonate and the surface properties and carbon dioxide content of magnesium oxide are found to be strongly influenced by the aforementioned preparation conditions of basic magnesium carbonate.     

Thermal degradation of polyesters filled with magnesium dihydroxide and magnesium oxide

Magnesium dihydroxide (MDH) was evaluated as char promoter into different polymers exhibiting various chemical structures. Char promotion was characterized using thermogravimetric analysis and pyrolysis‐combustion flow calorimetry. Gases released during pyrolysis were identified using pyrolysis coupled gas chromatography/mass spectrometry and thermogravimetric analysis coupled Fourier transform infrared spectroscopy. Relationships between the MDH effect (according to the char content and its thermal stability) and the chemical structure of the host polymers were identified. It was shown that MDH can be a good char promoter for aromatic polyesters such as polybutylene terephtalate and polyethylene terephtalate. Char promotion can be considered as one of the main mode‐of‐action of MDH at low or moderate filler content. An optimum was observed at approximately 20wt.% of MDH. Magnesium oxide was also studied as substitute to MDH to avoid hydrolysis phenomena due to the water release. But it was demonstrated that MDH was more efficient as a char promoter for polybutylene terephtalate than magnesium oxide. Copyright © 2015 John Wiley & Sons, Ltd.     

水合氯化镁焙烧得到的氧化镁的水化研究

通过正交试验,考察反应温度、反应时间、氧化镁与反应液的固液比、水化剂对水合氯化镁焙烧得到的氧化镁水化的影响.采用X射线衍射、扫描电子显微镜、氮气吸附来表征产品.实验结果表明,氧化镁水化的最优组合是:反应温度为90℃,反应时间为4h,固液质量体积比为0.1 g/mL,水化剂采用氯化镁.水化剂、反应温度和反应时间对氧化镁水化的影响较大.反应温度升高,氧化镁的水化率增加;反应时间越长,氧化镁的水化率越高.反应温度对比表面积的影响比反应时间的影响大,而且70℃时得到的产品的比表面积最大,90℃时次之,50℃时最小.在常压条件下通过氧化镁水化制备高质量的氢氧化镁是比较困难的.     

镁资源、镁质化工材料现状与前景

对镁资源、镁质化工材料现状与前景作了评述。介绍了中国镁质资源诸如菱镁矿、水镁石、水菱镁石、白云石、斜方云石、盐湖卤水和海水制盐工业副产--苦卤等。对世界镁化学制品生产企业近期变化和发展情况以及轻烧氧化镁（CCM）与氢氧化镁生产和应用进行了探讨,并展望了其发展前景。     

磷酸镁铵沉淀法去除镁盐结垢的研究

为了减轻硫酸钾生产过程中输送管道和结晶槽壁镁盐结垢的程度,提高生产效率,研究人员在实验室筛选了一种脱镁剂,对脱镁过程中脱镁剂添加量、脱镁温度和脱镁时间做了细致的研究,并应用于实际生产,取得了较好的效果。脱镁后过滤出来的磷酸镁铵作为缓释肥料使用,不但不会污染环境,还能为企业带来利润。     

氢氧化镁和氧化镁中酸不溶物的研究

产硝后的高镁卤水和硫氢化钡溶液进行反应，生成氢氧化镁，酸不溶物在0．3％（质量分数）左右，但将其煅烧成氧化镁后，酸不溶物高达1．2％-2．5％（质量分数），二者酸不溶物远不成比例关系。通过对样品在分析中穿滤对比、硫酸法测定酸不溶物、碘量法测定硫化物试验，确定在生产过程中，硫氢化钡被氢氧化镁吸附，经过高温煅烧，硫氢化钡被氧化成硫酸钡，成为氧化镁中的酸不溶物，这就是氧化镁和氢氧化镁中酸不溶物不成比例的主要原因。     

MAP法中镁沉淀药剂的对比

采用MAP法处理含有高浓度氨氮的垃圾渗滤液,磷酸根离子由Na2HPO4提供,镁沉淀剂选用MgSO4、MgCl2和MgO,并将海水作为新型的镁沉淀剂的替代品进行对比实验研究.综合考察与探讨了四种镁沉淀剂对氨氮的去除率、出水磷的残余量的影响,并对药品进行了成本分析.结果表明MgCl2的处理效果最好,而海水作为镁沉淀剂也有一定的优势.     

以氯化镁为原料制备氧化镁晶须的工艺研究

以氯化镁和碳酸钠为原料,通过前驱体烧结法制备氧化镁晶须.首先以氯化镁和碳酸钠为原料合成了前驱体碳酸镁晶须,接着将碳酸镁焙烧成氧化镁晶须.探讨了各个工艺条件对产物的影响,探索出最佳的工艺条件:氯化镁溶液的浓度为0.6mol/L,氯化镁和碳酸钠的摩尔比为1:1,陈化时间2h.在此条件下制得了前驱物碳酸镁晶须,将碳酸镁晶须焙...     

工业氢氧化镁制备高纯度氟化镁工艺探究

实验采用工业级高纯Mg(OH)2为原料,通过酸溶、除杂、氟化步骤成功制备了纯度在99％以上的高纯度MgF2.其中,HN03溶解能够对Mg(OH)2原料进行难溶除杂,随后通过草酸-双氧水法除去大部分金属离子杂质,最后与分析纯NH4F制备高纯度MgF2.实验结果表明,在25℃氟镁比为2∶1的条件下,制备得到的MgF2纯度最...     

EDTA容量法测定氟化镁中镁的改进

对GB/T 21994.4—2008氟化镁中镁含量的测定做了改进,即采用盐酸-硼酸-硫酸混合酸代替氢氟酸、硫酸分解试样,EDTA容量法测定氟化镁中镁。该法无需昂贵的铂皿,快速省时,测定结果准确有效。     

氯化镁喷雾热解制备氧化镁的研究

以青海盐湖氯化镁为初级原料,氯化镁经溶解、除杂、精制后采用喷雾热解法在立式热解炉中热解制备氧化镁。着重研究了喷雾热解的温度和进料量对氯化镁分解率的影响,最终确定的最佳工艺条件为：喷雾热解制备氧化镁时氯化镁的最佳热解温度为600 ℃,进料量为12 L/h。最佳工艺条件下氯化镁分解率在99%以上。该方法工艺流程简单、便于操作,是一种很有应用前景的氧化镁生产方法。