Study on purification and application of novel precipitant for ceria-based polishing powder

Novel precipitant prepared through carbonation with MgCl2 wastewater generated from rare earth extraction separation process and low-price dolomite as raw materials was studied in this paper. The purification methods of novel precipitant by adding appropriate oxidizing agent were studied. It was found that optimal purification result could be achieved with sodium hypochlorite as iron removal reagent and the iron removal rate could reach up to 90% when the adding amount was 0.1 vol.%. During the preparation, the particle size and distribution of ceria-based polishing powder were affected obviously by the parameters such as concentration, reaction temperature and feeding rate. The results showed that ceria-based polishing powder with D50 =2.5-3.5 μm and the particle size distribution of 0.65-0.75 μm could be prepared when the concentration of CeCl3 was 0.6 mol/L, the reaction temperature was maintained at 50 °C and the feeding speed was controlled at 25 ml/min. Compared with commercial powder, the self-made polishing powder had roughly the same cutting amount, but the surface finish of polished glass was better than that of commercial polishing powder.     

城市化与环境水文

本文从环境水文的角度，探讨了城市化发展过程中所带来的有关气象，水文，水资源等方面的问题，并提出了一些建议。     

稀土行业运行逐步回归合理区间

<正>2014年前3季度,稀土行业运行情况总体平稳,生产企业基本按照国土资源部和工信部下达的计划指标安排生产,延续了上半年的平稳态势。因此,今年前3季度稀土产品供给端没有出现大的波动。从经营数据来看,目前稀土行业正在筑底,逐步摆脱类似2011年的虚假繁荣,进入回归理性、稳健的发展阶段。行业运行平稳,逐步回归理性2014年前3季度,稀土行业运行情况总体平稳,生产企业基本按照国土资源部和工信部下达的计划指标安排生产,延续了上半年的平稳态势。因此,今年前3季度稀土产品供给端没有出现     

稀土消费需求有所回暖

正行业运行总体平稳,下行压力依然存在1.工业生产稳定运行2014年上半年,国土部下发《国土资源部关于下达2014年度稀土矿钨矿开采总量控制指标的通知》(国土资发〔2014〕65号),确定2014年度全国稀土矿(稀土氧化物REO)开采总量控制指标为105000吨,其中离子型(以中重稀土为主)稀土矿指标17900吨,岩矿型(轻)稀土矿指标87100吨;工信部下达2014年(第一批)稀土生产总量控制计划,冶     

活性肽-N对D-半乳糖致衰老小鼠的作用效果

为了探讨一种新型抗衰老活性因子——活性肽-N食用后的抗衰老作用,本研究通过给小鼠连续皮下 注射D-半乳糖（200 mg/（kg·d）,以体质量计,下同）建立衰老模型,造模的同时开始灌胃2.5、25.0、 125.0 μg/（kg·d）活性肽-N复乳,连续9 周。分别采用旷场实验和Morris水迷宫实验检测小鼠的运动探究能力和学 习记忆能力。上述行为学实验后,对小鼠血清中谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）活力、丙 二醛（malondialdehyde,MDA）含量及脑组织中的乙酰胆碱酯酶（acetyl cholinesterase,AChE）活力进行测定。结 果表明,与衰老模型组相比,活性肽-N复乳高剂量组能显著提高衰老小鼠的运动探究能力,改善其学习记忆能力, 提高血清中的GSH-Px活力28.38%（P＜0.05）,降低MDA含量26.19%（P＜0.05）,同时降低脑组织中的AChE活 力23.26%（P＜0.05）。综合结果表明该活性肽-N对D-半乳糖致衰老小鼠具有明显的抗衰老作用。     

P（AA/AMPS）与P（AM/AA/AMPS）水溶液高温降解机理研究

为研究丙烯酰胺类聚合物在水溶液中的高温降解机理,以丙烯酰胺（AM）、丙烯酸（AA）、2-丙烯酰胺-2-甲基丙磺酸（AMPS）为单体制备了P（AA/AMPS）、P（AM/AA/AMPS）两种模板聚合物,将两种聚合物分别在200、220、240 ℃下进行降解实验,使用FTIR、¹H-NMR、XPS、GPC、TG-IR 等分析聚合物及其降解产物。研究结果表明,丙烯酰胺类聚合物在水溶液中的高温降解行为主要发生在不抗温的侧基,表现为主链次甲基含量的下降。次甲基断键后,主链断裂导致聚合物的相对分子质量降低,降解过程中生成二氧化碳、氨气等小分子。两种聚合物在热重测试中抗温能力与水溶液中的抗温能力矛盾,因此评价丙烯酰胺类钻井液处理剂抗温能力时不能以热重分析结果作为标准。     

稀土消费需求有所回暧

1．工业生产稳定运行2014年上半年,国土部下发《国土资源部关于下达2014年度稀土矿钨矿开采总量控制指标的通知》（国土资发[2014]65号）,     

Study on preparation and application of novel saponification agent for organic phase of rare earths extraction

In view of the problem of ammonia-nitrogen wastewater pollution in rare earths extraction and separation, the novel saponification agent of organic phase, which is magnesium bicarbonate solution, was prepared with the natural rich and cheap dolomite as raw material through carbonation process. The behavior and purification of main impurities ions in the carbonation process as well as the application effect of the novel saponification agent in the extraction and separation was researched. The results showed that the concentration of Fe, Al, Si impurities ions was less than 5 ppm in the saponification agent through the development of effective removal technology, respectively. When the novel saponification agent was used in the extraction and separation, magnesium utilization rate was more than 95%, and rare earths extraction rate above 99.5% has achieved. Therefore, the technology could replace ammonia-water to saponify the organic phase in rare earth extraction and separation process.     

锡锑行业仍将承压运行

<正>2015年,宏观经济形势对下游重点消费领域的影响,仍是决定未来锡锑行业走势的关键因素。初步预计,2015年国内锡价将承压震荡上行;锑品供应水平较2014年有所下降,消费量变化不大。市场价格仍有进一步下探的空间。2014年我国锡锑工业运行情况1.锡产量平稳增长,锑产量同比下滑国家统计局数据显示,2014年1-11月,我国锡精矿产量9.1万吨(金属量,下同),同比增长13.3%;精锡产量16.8万吨,同比增长20.9%,增速快于2013年同期。支撑精锡产量平稳增长的主要因素是原料供给增加。一     

基于逐步回归的投影寻踪水文预报模型研究

基于中长期水文预报模型中的逐步回归和投影寻踪模型的特点,构建了耦合水文预测模型,并对宜昌站的实测流量资料和多年逐月气象资料进行验证.结果表明,拟合与预报的结果相对误差均小于20%,该模型预报精度高、效果较好,有一定实用价值.