锶废渣制备锶盐酸浸取工艺关键参数的实验研究

以碳还原天青石生产碳酸锶的锶废渣为原料,采用盐酸为浸取剂,研究了锶废渣制备锶盐酸浸取工艺中锶渣粒径、浸取温度、浸取时间、溶液酸度等参数对锶浸取率的影响。在此基础上利用正交实验对锶渣酸浸取工艺进行优化。得到锶废渣酸浸取锶的最佳工艺：锶渣粒径为0.062 mm、反应时间为2 h、反应温度为30 ℃、浸取液pH为0.1。该研究可为提高锶资源的利用率提供参考。     

Use of chitosan complex with aminophosphonic groups and cobalt for the removal of Sr2+ ions

We briefly describe the adsorbent performance of the chitosan complex with aminophosphonic groups and cobalt in the removal process of Sr²⁺ ions from aqueous solutions. The strontium adsorption was studied as a function of pH, contact time, and initial strontium concentration. Adsorption isotherms such as Langmuir, Freundlich, Dubinin–Radushkevich, and Temkin were used to analyze the equilibrium data at different concentrations. The kinetics of the Sr²⁺ sorption was analyzed using the pseudo-first-order and pseudo-second-order kinetic models. The results clearly indicate that the chitosan complex with aminophosphonic groups and cobalt is an efficient adsorbent with respect to its capacity to absorb Sr²⁺ ions from aqueous solutions.     

铜矿石中铋的测定

铜矿石试样经王水分解后,在10%王水介质中,于223.06nm处用原子吸收分光光度计测定铋。此法适用于铜矿石中0.020%～3%的铋的测定。     

以天青石矿为原料生产高纯硫酸锶工艺研究

针对青海天青石矿的特点以及高纯硫酸锶的市场特性、生产关键技术与配套工艺的关键性问题,提出具有针对性、先进性并可实现产业化的生产高纯硫酸锶的工艺方案。重点提出了以碳还原法加工天青石矿制取高纯硫酸锶的工艺路线。通过单因素实验确定了最佳工艺条件：煅烧温度为1 200 ℃,天青石精矿和煤粉的质量比为5∶1,硫化锶浸取温度为90 ℃,氢氧化锶溶液和稀硫酸的质量比为1∶1.1。在此条件下,高纯硫酸锶的平均收率为95.53%。实验制备的硫酸锶产品为白色,纯度为99.3%,各项指标达到化学纯的要求。     

Structural and thermal behavior of 45S5 Bioglass®-based compositions containing alumina and strontium

The present research exposes the influence of 2 mol% of Al₂O₃ and 2 mol% SrO in 45S5 Bioglass^®-based compositions. Four compositions were produced to elucidate the difference in how both oxides influence structure and thermal behavior separately and their synergy when together. Thermal properties, crystallization tendency, and sintering behavior was evaluated by differential scanning calorimetry, hot stage microscopy, and dilatometry. Changes of medium-range structures were characterized by Qⁿ distribution of Raman spectroscopy and evaluation of ³¹P, ²⁷Al, ²³Na, and ²⁹Si environment obtained by magic angle spinning nuclear magnetic resonance. Despite Qⁿ distribution was predominantly Q² in all samples, the composition criteria used enabled improved processing and stabilibity characteristics. The addition of Al₂O₃ and SrO promoted larger sinterability parameter (S_c) which indicates better sintering behavior, the glass stability against crystallization doubled (K_H) compared to 45S5 and the processing window enlarged from 106 to 171.     

SrBi4Ti4O15/Ag复合材料的制备及其介电特性

采用固相烧结工艺制备了SrBi4 Ti4O15(SBTi)/Ag铁电复合材料,用X射线衍射、光学金相显微镜和扫描电子显微镜对材料的组成和微观结构进行了研究,并测量了样品的介电温度谱。结果表明：复合材料是由SBTi和Ag两相组成。金属Ag的加入使SBTi铁电陶瓷的烧结温度从1120℃降低到950℃以下。随着烧结温度的提高,Ag颗粒的尺寸增大,但SBTi晶粒并无明显变化。Ag的加入可以适当提高铁电陶瓷从室温到200℃的介电常数,但对材料的介电损耗影响很小。同时Ag的加入抑制了介电温度曲线介电常数的Curie峰。     

燃烧法快速合成铝酸锶基质长余辉发光材料

以燃烧法快速合成了Eu^2 ,Dy^3 掺杂的铝酸锶发光粉,发光粉经自然光激发可观察到明亮的黄绿光,余辉可达12h以上。用X射线粉末衍射、扫描电镜、透射电镜等分析了合成物的物相组成、显微结构与粒度等。结果表明;合成的发光粉主晶相是SrAl2O4,扫描电镜下呈卷曲片状,透射电镜下的一次粒子呈不规则粒状,粒子直径大多分布在60～100nm以内。通过对荧光分光光度计所测定的合成样品的激发光谱、发射光谱和衰减曲线等光谱分析发现;合成物的发光是Eu^2 的4f^65d^1→4f^7的电子跃迁,而发光体的长余辉特性是由于发光体中Dy^3 的空位陷阱作用。     

Sol-Gel Glass-Encapsulated Crown Ethers for the Separation and Preconcentration of Strontium from Acidic Media

Extraction chromatography employing an inert polymeric support impregnated with a crown ether (typically, 4,4’,(5’)-di-(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6)), either neat (i.e., undiluted) or as a solution in 1-octanol, has previously been shown to provide an effective means for the isolation of radiostrontium from a variety of sample types for subsequent determination. In this study, sol-gel chemistry has been employed to prepare sorbents in which DtBuCH18C6 is encapsulated in a silica matrix. The resultant materials have been evaluated for their ability to retain strontium ion and compared to a commercially available extraction chromatographic (EXC) resin. Certain of the new materials are shown to provide uptake efficiencies comparable to those obtained with the commercial resins, although unless a porogen is employed, the kinetics of strontium uptake are significantly slower. In contrast to conventional EXC materials, however, strontium uptake by DtBuCH18C6-loaded glasses does not increase in proportion to the amount of extractant present, indicating that not all of the crown ether present is available for interaction with the metal ion.     

一种回收利用锶盐残渣制备碳酸锶的新方法

碳粉还原天青石水浸取锶盐生产工艺会产生大量的废渣,造成环境污染。本方法通过酸溶将可溶性锶盐溶解分离出来,再经过除杂过滤,得到锶母液。锶母液在低温条件下碳化,澄清后得到的沉淀,经漂洗、过滤、烘干得到碳酸锶成品。该工艺使废渣中的锶回收率达到90%以上。所得产品的各项技术指标符合HG/T 2969—2010《工业碳酸锶》的行业技术要求,而且形成的碳酸锶粒径小、用途广、经济价值更高。     

钛酸锶钡铁电薄膜的制备与性能优化研究

综述了目前钛酸锶钡(BST)铁电薄膜最为常用的4种制备工艺:磁控溅射法(Magnetron Sputtering)、脉冲激光沉积法(PLD)、溶胶-凝胶法(Sol-gel)、金属有机物化学气相沉积法(MOCVD)。并介绍了在优化BST铁电薄膜性能方面所作的工作和取得的成果。