铌钽矿中铀钍的直接萃取分离测定

铌钽矿中小量铀钍的测定一般采用分别测定法,步骤较繁,时间较长。1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(PMBP)萃取铀钍希土等元素的性质已有许多报导并作过综述。但应用于易水解元素铌钽钛锆等矿石中萃取铀钍希土元素时,仍需预先进行分离。在有机络合剂存在下,用PMBP萃取铀钍希土元素的行为,迄今未作过系统的报导。     

不同类型协萃剂与PMBP协同萃取铀和稀土元素的研究及其应用

PMBP(1-苯基3-甲基-4-苯甲酰基吡唑酮-5)是萃取稀土、钛、锆、铀和钍等金属离子的优良萃取剂,国内外已有报导。为使PMBP能直接从含有易水解的铌、钽、钛和锆等溶液中萃取分离出稀土、铀和钍,我们曾研究在酒石酸等络合剂存在下用PMBP萃取铌、钽、钛、锆、钨、钼、铁、铀和稀土     

N、N'-二乙基-N、N'-二苯基脲的萃取性能和二硝酸二(N、N'-二乙基-N、N'-二苯基脲)合铀酰(Ⅱ)配合物的合成、结构研究

O引言 铀和钍燃料后处理广泛采用三丁基磷酸酯(TBP)作为萃取剂来分离铀和钍.然而在辐照下,TBP的降解产物二丁基磷酸酯(DBP)和一丁基磷酸酯(MBP)对裂变元素如锆和铌有较强的配位能力.     

薄层色层在无机分析中的应用——Ⅲ.铌和钽及贵金属的分离

seiler曾作阳离子三、四组,碱金属,卤素,各种磷酸根,以及铜、钴、镍、铀和镓的分离及检定^[1]。作者亦曾研究钛、锆、钍、钪、铌和铀的分离^[2],吴孟炎曾作金、银、硒和碲的分离,均获良好效果。本文报告用反相两种方式研究铌和钽及贵金属的薄层层析行为。铌和钽及贵金属分离良好。铌和钽分离后经光谱检查铌中无钽,钽中无铌。此外,还比较铌、钽的薄层与纸层析。     

土壤对外源钍的吸附行为表征

外源钍对土壤的污染风险和程度取决于钍在土壤中的吸附行为. 以包头稀土工业区土壤样品和土壤环境矿物组分为研究对象, 通过静态吸附方法研究外源钍在土壤样品和环境矿物组分(高岭土、蒙脱土、碳酸钙、水合氧化铁/锰和腐殖酸)上的吸附, 并对吸附行为进行了表征. 结果表明, 土壤样品对外源钍有很强的吸附能力, 对加入的外源钍(10^-4 mol/L)吸附率在97%以上; 土壤环境矿物组分对加入的外源钍(1 g/L)吸附率在28%～46%之间. 通过扫描电镜-能谱(SEM-EDS)分析可知, 外源钍进入土壤后与矿物组分发生相互作用, 可能形成了稳定化钙质钍碳酸盐和钍磷酸盐; 傅里叶变换红外光谱(FTIR)分析表明, 钍是与土壤环境矿物组分上的活性吸附位点发生相互作用而吸附并保持在土壤中, 是物理吸附和化学吸附共同作用的过程; X射线衍射分析(XRD)表明, 土壤在吸附钍前后, 其矿物组分基本相同, 而矿物晶体相态发生明显变化. 由于不同土壤矿物组分对钍的吸附方式不同, 导致吸附的钍以不同形态存在于土壤中.     

易解石族矿物的化学特征

易解石族矿物具有十分复杂的化学组成,根据现代矿物学分类的原则,可将其分为8个矿物种:易解石、钇易解石、钕易解石、钍易解石、铌易解石、钕铌易解石、维易解石及瑞易解石。易解石族矿物成分的变化与地质产状有密切联系。在某些易解石中富含的镧、铈、钕、铕、镝、钇、铌及钽等元素,可将其综合利用。     

X射线荧光光谱法测定化探样品中主、次和痕量组分

采用粉末样品压片制样,用PW2440X射线荧光光谱仪对化探样品中氯、溴、硫、氧化钠、氧化镁、三氧化二铝、二氧化硅、磷、氧化钾、氧化钙、钛、锰、三氧化二铁、钴、铌、锆、钇、锶、铷、铅、钍、锌、铜、镍、钒、铬、钡、镧、铈、钕、钪、镓、砷、铪等34个组分进行测定。讨论了微量元素的背景选择和谱线重叠校正及氯测定的问题。使用经验系数法和康普顿散射线作内标校正基体效应,经标准物质检验,分析结果与标样值吻合,用GBW 07308国家一级标准物质作精密度试验,统计结果RSD（n=12）除砷、钒、镍、铜〈6．0％,溴、硫、铈、铪、钕、钪、氧化钠、镧、铬、钴和钍〈14．0％以外,其余各组分均小于3．0％。     

氯代磺酚 S 光度法测定矿石中锆(铪)

我们在试验氯代磺酚S光度法测定铌的条件时,锆(铪)有正干扰。因此,我们探讨了用该试剂测定锆(铪)的适宜条件、干扰离子及消除方法。进而拟定了测定矿石中锆(铪)的光度法。本法的优点是选择性较好、灵敏度较高,可在常温下显色。能允许较大量钍、铀、稀土和钛的存在。当同时存在铌时,     

电感耦合等离子体质谱法测定矿物渣中微量铀和钍

采用改进的微波消解程序处理矿物渣样品,用185Re作为内标同位素,以在线内标加入法补偿样品的基体干扰,提出了测定矿物渣中微量铀和钍的电感耦合等离子体质谱法.铀和钍的方法检出限分别为0.017,0.021 ng·g-1;铀和钍的平均加标回收率(n=6)分别为99.0%,101.3%;相对标准偏差(n=6)分别为4.02%和3.54%.两种标准物质中铀和钍的测定结果与标准值相符合.     

微色谱柱分离-光度法测定高稀土铁矿石中的微量钍

采用HD-8微色谱柱对高稀土铁矿石样品(白云鄂博矿)中的钍进行分离富集,探讨了影响其分离富集的条件。实验表明,在4 mol/L HCl介质中钍可被树脂完全吸附,用3 mL 40 g/L草酸铵溶液可以从吸附柱上完全解吸钍,并结合偶氮胂Ⅲ分光光度法进行测定。所建立的方法适合于含铁、稀土量高的矿石样品中微量钍的分离与测定。     

Radioactive impact of a bauxite beneficiation plant in the Itea Gulf (Gulf of Corinth, Greece)

Activity concentration measurements of natural radionuclides performed by γ-ray spectrometry and ICP-MS in sediment samples from the Gulf of Itea and in surface soil samples collected from the surrounding area of a bauxite beneficiation plant, showed that (1) the breaker zone of the Itea Gulf, in the vicinity of the bauxite beneficiation plant, is contaminated with ²³⁸U, ²³²Th and ²²⁶Ra, (2) the activities in sediment samples from the rest of the Gulf were at the background level, and (3) enhanced activities of the ²³⁸U, ²³²Th and ²²⁶Ra were found in a number of soil samples due to bauxite dust deposition from the nearby beneficiation plant. The application of the optimized BCR sequential extraction procedure on the surface sediment samples showed that the U and Th were strongly bound to the sediments.     

Synthesis of nanozeolites type A and X from quartz-rich Cameroonian kaolin: application to the modification of carbon paste electrode for acetaminophen and epinine electrochemical sensing

Journal of Solid State Electrochemistry - Nanozeolites A and X were synthesized via hydrothermal method using fine fraction of beneficiated clay. The beneficiation was achieved by collecting fine...     

Composition of Lean Apatite Ores from the Laokai Deposits

X-ray powder diffraction and X-ray fluorescence analyses of lean apatite ores from the Laokai deposits were performed. The test sample was divided into 11 fractions, each being analyzed for phosphorus and the major associated impurities. The chemical composition of the lean apatite was found to be virtually independent of particle size, thereby the primary beneficiation of the raw material being excluded.     

X射线荧光光谱粉末法监控蓝晶石生产流程

利用已有准确结果的蓝晶石选矿流程试样制备两个标准系列(原、尾矿和精矿),试样经机械研磨至~#300目(50μm)及用经验系数法校正矿物效应,颗粒效应及基体效应。本法有快速、简易、成本低等特点,所得结果与化学分析相吻合。可满足生产要求。     

贵州织金三甲寒武系戈仲伍组含磷岩系稀土富集规律研究

对贵州织金三甲地区寒武系底部戈仲伍组含磷岩系稀土元素、微量元素和一些常量元素等在剖面上的变化规律进行系统的研究，并结合剖面上小壳动物化石富集特点，认为寒武系底部戈仲伍组中有两个磷和稀土成矿期，稀土含量与磷含量成显著的正相关关系，而与小壳动物化石丰度没有显著相关性。     

Determination of gold in low grade ores and concentrates by anion exchange separation followed by neutron activation

The beneficiation of tailings from Kolar Gold Mines involves the flotation of sulphides. Appreciable amounts of arsenic and antimony are expected to accompany gold in this process. The activation analysis of gold in these samples is facilitated by a preseparation of gold from arsenic and antimony. The present paper describes a method for the rapid analysis of gold in the concentration range 0.5 to 50 ppm using a simple pre-irradiation separation, with the recovery of gold being evaluated by an isotope dilution technique using¹⁹⁸Au tracer.     

Determination of calcium oxide in calcined phosphate ores

It has been shown that an existing procedure to differentiate calcium oxide from the carbonate and silicate of calcium can be used in the presence of the phosphate, fluoride and sulphate of calcium, and of the carbonate and oxide of magnesium. It is based on the reaction in aqueous solution of calcium oxide with sucrose to form calcium saccharate, and subsequent titration with oxalic acid solution. The method has application for a direct chemical determination of calcium oxide in phosphate rock where calcination of accompanying carbonate is necessary in beneficiation processes.     

极谱法测定矿石中高含量钨

提出了用JP-303型智能化极谱仪,测定≥1%以上钨的极谱分析法。拟定方法与现行采用的"硫氰酸盐"分光光度法相比,有着测定范围宽(WO3含量在X%～XX%),快速、简便、准确的优点。方法的标准曲线相关系数0.999,样品加标回收率为98.4%～101.4%,可用于WO3的选冶生产控制分析,效果良好。     

Rice hull as a renewable raw material and its processing routes

It was shown that rice hull has a unique composition and can be used as a renewable raw material. A method for rice hull conversion into polyfunctional materials was proposed, which gives a solid product, a liquid organic product, and a mixture of noncondensable gases. The solid product is suitable as a filler for elastomers, fodder supplement for farm poultry, and sorbent for noble and rare metal recovery. The liquid product acts as a highly selective collector of lead minerals in beneficiation of complex rebellious ores, plant growth stimulant, and antiseptic agent. The mixture of noncondensable gases can be used for carbon black production or as a high-calorific fuel.