海洋资源的化学XX盐化工废弃物高低温盐有效利用的研究

报道利用盐化工废弃物高低温盐制取无机阻燃剂氢氧化镁和具有广泛用途的氟硅酸钠的几种新方法。本文采用沉淀法，使高低温盐中的Ｍｇ２＋、Ｎａ＋得以有效的利用，其利用率可达１００％     

Use of Pitzer Equations to Examine the Formation of Mercury(II) Hydroxide and Chloride Complexes in NaClO<Subscript>4</Subscript> Media

The thermodynamic stability constants for the hydrolysis and formation of mercury (Hg²⁺) chloride complexes

高分散氢氧化镁的制备

以氯化镁和氨水为原料,进行各种工艺条件的试验,在此基础上通过加入外加剂获得过滤、洗涤性能良好的Ｍｇ（ＯＨ）２沉淀,并提高了产品的收率。根据试验得到最佳的工艺条件,制各出纯度高、成本低的氢氧化镁及氧化镁。     

A new hydrous phase δ-AlOOH synthesized at 21 GPa and 1000 °C

A new phase of AlOOH (tentatively called δ-AlOOH) was synthesized at 21?GPa and 1000?°C and its crystal structure was identified by a powder X-ray diffraction method. Rietveld refinement revealed that this aluminum oxide hydroxide has an orthorhombic unit cell, a?=?4.7134(1) Å, b?=?4.2241(1) Å, c?=?2.83252(8) Å, V?=?56.395 (5) ų, and Z?=?2 in the space group of P2₁?nm. A calculated density is 3.533?g?cm^?3, which is about 4.48 and 15.04% denser than that of diaspore and boehmite, respectively. The δ-[Al_0.86Mg_0.07Si_0.07]OOH is also stable at 21?GPa and 1000?°C, coexisting with majorite and phase egg, and its cell parameters are a?=?4.710(1) Å, b?=?4.215(1) Å, c?=?2.839(1) Å, and V?=?56.37(1) ų.     

Surface Acidity of Amorphous Aluminum Hydroxide

The surface acidity of synthetic amorphous AI hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous AI hydroxide rapidly transformed to crystalline bayerite at the alkaline condition （pH〉10）. The solution analyses after and during the titration Ksp=^aAl^3＋/aH^＋^3 ,was 10^10.3. The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved AI species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.     

镁源种类对制备碱式硼酸镁的影响

采用MgO、MgCl_2·6H_2O和Mg(NO_3)_2·6H_2O为原料,通过XRD、SEM、FTIR等测试方法,研究不同镁源对碱式硼酸镁形貌和组成的影响。在190℃条件下反应10 h,制备碱式硼酸镁(MgBO_2(OH))。结果表明,以MgO为反应物时,由于其反应活性较差,导致产物中出现大量氢氧化镁杂质;以MgCl_2·6H_2O为反应物时,所得产物长径比较小;以Mg(NO_3)_2·6H_2O为反应物时,得到分散性高、形貌规整的棒状产物。     

锰的迁移形式成矿机理新探

通过对锰氢化物、锰羰基化合物、锰羰基氢化物的形成条件和理化性质,现代火山气体化学成分,现代海底喷口热液流体成分,有关矿床矿物流体包裹体气相成分,有代表性锰矿物化学成分及铁锰结核的物质组构,菱锰矿的碳同位素组成、锰矿物的共生、伴生矿物组合的探究,认为锰氢化物、锰羰基化合物、锰羰基氢化物是原生锰矿的主要迁移形式.它们从地球深部强还原富H2、富CO高压环境通过断裂、裂隙随岩浆、热液迁移至地壳浅部,由于压力、温度骤降,氧逸度大增,H2和CO逃逸、氧化,锰氢化物、锰羰基化合物、锰羰基氢化物分解、氧化、硫化成原生锰矿,经氧化淋(浸)滤,形成锰的高价氧化矿物.     

牙膏用六水氯化锶的制备

以不同纯度的自制氢氧化锶为原料与盐酸充分反应,经提纯、结晶,制备六水氯化锶（SrCl2·6H2O）。通过X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）对SrCl2·6H2O的结构、形貌进行表征,通过能谱仪（EDS）和差热-热重分析仪（TG）对SrCl2·6H2O进行元素含量和热失重分析,并将制备的样品与中华人民共和国化工行业牙膏用氯化锶标准进行对比。结果表明,高纯氢氧化锶与分析纯盐酸制备的SrCl2·6H2O可以达到牙膏用标准。     

一种新溶剂体系对氢氧化镁的改性研究

水-TEA-TBP溶剂体系中,结合表面活性剂复配体对工业级Mg(OH)2进行水热处理,得到粒度分布窄、粒径小、分散性好的改性Mg(OH)2。讨论了溶剂体系中水-TEA-TBP的配比、Mg(OH)2浓度(mol/L)、矿化剂MgC l2用量(%)、表面活性剂用量(%)、水热温度(℃)和水热时间(h)等因素对Mg(OH)2的改性影响。     

An improvement in the small-volume technique for determining thorium-234 in seawater

The recently developed 2–5 L small-volume MnO₂ coprecipitation method for determining ²³⁴Th in seawater has provided a new way to substantially increase, both temporally and spatially, the sampling resolution of ²³⁴Th and ²³⁴Th-based particulate organic carbon export estimates in the upper ocean. In this study, we further optimize the technique by reducing reagent quantities and the use of an additional water bath heating step. This optimization allows the filtration of the MnO₂ precipitate onto a 25-mm diameter, 1.0 μm pore size QMA filter to be completed within < 30 min for unfiltered waters from the South China Sea. In addition, we have modified the MnO₂ purification procedure to allow for alpha spectrometric measurements of ²³⁴Th recoveries. Results from recovery experiments suggest that reagent amounts can be reduced to 0.0375 mg KMnO₄ and 0.1 mg MnCl₂·4H₂O per liter of sample, while still maintaining high ²³⁴Th recovery. This study further confirms that the addition of a yield monitor is necessary for the application of the small-volume method.