X射线荧光法测定纯铝制品中的杂质元素

本文主要介绍铝粒、铝线、铝块等纯铝制品中主要杂质元素的X射线荧光测定法。利用光谱标准物质,优化分析条件,建立纯铝制品中各杂质元素的分析曲线, 此方法精密度好,准确度高,操作简便、快速,能够适应生产快速检验的需要。     

基于电感耦合等离子体高纯镁基氧化物中共存元素光谱特征

研究高纯镁基氧化物中共存元素在电感耦合等离子体焰中光谱特征及规律。通过试验研究了含镁基体和不含镁基体条件下,钾、钠、钙、铅、铁、镉、硼、硫、硅、铝、锰11种元素的分析谱线、高频发生器功率、垂直观测高度、雾化器流量在电感耦合等离子体焰中的光谱特征,优选了产生最大信背比的光谱参数。模拟高纯系列镁基氧化物基体,进行共存元素与背景发射光谱特征的研究,为建立高纯镁基氧化物中痕量杂质元素的检测方法奠定了基础。     

辉光放电质谱法测定超高纯铝中痕量杂质元素EI北大核心CSCD

采用辉光放电质谱法(GDMS)分析超高纯铝样品(含铝量≥99.9995%)中B,Mg,Si,P,Cl,Ti等44种主要杂质元素,并且与电感耦合等离子体质谱法(ICPM S)进行对比,主要杂质元素含量检测结果一致。本工作对质谱干扰的排除和预溅射过程时间的确定进行了讨论,采用高纯铝标样对高纯铝中26种主要元素相对灵敏度因子(RSF)进行校正和验证,并考察了检测结果的准确性和精密度。结果表明,GDMS是超高纯铝样品直接测定的最有效手段之一。     

辉光放电质谱法测定超高纯铝中痕量杂质元素

采用辉光放电质谱法(GDMS)分析超高纯铝样品(含铝量≥99.9995%)中B,Mg,Si,P,Cl,Ti等44种主要杂质元素,并且与电感耦合等离子体质谱法(ICPM S)进行对比,主要杂质元素含量检测结果一致。本工作对质谱干扰的排除和预溅射过程时间的确定进行了讨论,采用高纯铝标样对高纯铝中26种主要元素相对灵敏度因子(RSF)进行校正和验证,并考察了检测结果的准确性和精密度。结果表明,GDMS是超高纯铝样品直接测定的最有效手段之一。     

铜铁试剂—氯仿萃取分离铬天青-S比色测定钢中铝

采用铜铁试剂-氯仿萃取分离钦、钒、铁、锆、铌、钽等干扰元素之后,用铬天青-S比色测定铝,提高了方法的选择性和准确度,操作简易快速。适用于铁基、镍基和钛基合金中铝的快速分析。 (一)主要试剂铬天青-S:(0.05％;5％乙醇溶液)。铝标准溶液:(1毫克铝/毫升)。称取光谱纯铝粉1.000克于250毫升烧杯中,加入30％氢氧化钠30毫升,加热溶解后,移入1000毫升容量瓶中,加水约     

金属材料分析方法的选择和施行第二讲 纯铝的分析及其方法的选择

1　纯铝分析的目的和要求纯铝的分析有两个目的 ,一是了解其纯度 ,即铝的含量是多少 ?二是了解含有哪些主要杂质成分 ,各有多少量 ?根据这两方面的信息即可对材料的品级作出判别。根据我国现行的标准 ,工业用纯铝分为高纯铝和纯铝。两者又按纯度和主要杂质元素 (硅、铁、铜 )的含量分别细分为 5个牌号和 6个牌号 ,见表 1。由表 1可知 ,5个牌号高纯铝的含铝量间距相差很小 ,仅为ｗＡｌ0 .0 2 %～ 0 .0 5 % ;6个牌号纯铝的含铝量间距也只相差ｗＡｌ0 .1%～ 0 .3%。现有的高含量铝的测定方法 ,其分析相对误差约为 0 .2 %～ 0 .3%。显然用直接测…     

光电直读光谱仪在铀化合物微量杂质元素分析上的应用

本文叙述用磷酸三丁酯聚三氟氯乙稀粉反相分配色层法使铀与微量杂质元素分离并以光电直读光谱测定铀化合物中微量杂质元素。由于采用控制试样法,方法简便、快速、适用于例行分析。     

发射光谱法测定钨酸锌单晶中的微量元素

有关纯钨和纯锌中杂质元素的光谱测定已有报道,而钨酸锌单晶中杂质元素的光谱测定至今尚未见到有关文献。本文采用粉末电弧发射光谱法同时测定钨酸锌单晶中的Ge、Mg、Si、Cd、Nb、Ce六个元素。相对标准偏差均小于14%,加料回收率在95～115%之间,实验证明本法能够满足分析任务的要求。     

高纯钼中痕量杂质元素的光谱分析

使用国产仪器、设备及材料,对钼中痕量杂质元素的光谱分析中各主要条件进行了试验与研究。确定直流电弧阳极激发,一次同时测定钠、镁、铝、铁、钴、镍、锰、铜、钛、钒、铬、硅、铅、铋、锡、锑、镉十七个杂质元素。测定下限为0.1～3ppm,测定下限总量为17.3ppm,单次测定标准偏差4.5～20%。实验部分1.仪器设备、材料及试剂光谱仪—WPG-100型平面光栅摄谱仪,一级光谱倒数线色散为8埃/毫米。光源—半导体硅整流设备GZH5-18型。电极—光谱纯石墨电极φ6毫米。     

化学光谱法测定6N氧化铈中14个稀土杂质元素

提出了二次分离富集－发射光谱法测定高纯氧化铈中１４个稀土杂质元素的方法。所建立的方法分离时间短，富集了倍数高，化学光谱测定下限为０．３３μｇ／ｇ，适用于６Ｎ的氧化铈中１４个稀土杂质元素的测定。     

阳离子交换树脂分离-铝试剂分光光度法测定土壤中铝形态

研究了铝试剂光度法测定土壤溶液中铝的最佳条件,着重探讨了共存离子,特别是土壤溶液中的无机离子和有机阴离子对测定铝的影响。采用阳离子交换树脂分离,建立了测定土壤溶液及天然水中铝形态方法。用该法可测定总反应性铝、总单核铝和稳定性单核铝。由总反应性铝减去总单核铝求得酸溶性铝。由总单核铝减去稳定单核铝求得不稳定单核铝。与阳离子树脂交换分离-邻苯二酚紫光度法进行了比较。结果表明：邻苯二酚紫光度法灵敏度较高,但铁的干扰较大。铝试剂光度法灵敏度略低,但铁的干扰较少。阳离子树脂交换分离-铝试剂光度法更适合于测定含铁量比较高的土壤溶液中的铝形态。     

Thermal Stability of Sol-Gel Hydrotalcites

Sol-Gel Hydrotalcites were synthesized using magnesium ethoxide and variable aluminum sources: aluminum acetilacetonate, aluminum chloride, aluminum nitrate and aluminum sulfate; in all cases, the gelation was done at pH 10. X-ray diffraction studies show that the crystallinity depends on the aluminum precursor used. The crystallinity was found in the order aluminum acetylcetonate>aluminum chloride>aluminum nitrate>aluminum sulfate. The precursor determines the sintering behavior as well.     

Removal of phosphate by aluminum oxide hydroxide

The development and manufacture of an adsorbent to remove phosphate ion for the prevention of eutrophication in lakes are very important. The characteristics of phosphate adsorption onto aluminum oxide hydroxide were investigated to estimate the adsorption isotherms, the rate of adsorption, and the selectivity of adsorption. Phosphate was easily adsorbed onto aluminum oxide hydroxide, because of the hydroxyl groups. The adsorption of phosphate onto aluminum oxide hydroxide was influenced by pH in solution: the amount adsorbed was greatest at pH 4, ranging with pH from 2 to 9. The optimum pH for phosphate removal by aluminum oxide hydroxide is 4. The selectivity of phosphate adsorption onto aluminum oxide hydroxide was evaluated based on the amount of phosphate ion adsorbed onto aluminum oxide hydroxide from several anion complex solutions. It is phosphate that aluminum oxide hydroxide can selectively adsorb. The selectivity of phosphate onto aluminum oxide hydroxide was about 7000 times that of chloride. This result indicated that the hydroxyl groups on aluminum oxide hydroxide have selective adsorptivity for phosphate and could be used for the removal of phosphate from seawater.     

Electrothermal volatilization of aluminum as 1-phenyl-3-methyl-4-benzoylpyrazolone[5] chelate for gaseous sample introduction in ICP-AES

Based on gaseous compound introduction as 1-phenyl-3-methyl-4-benzoylpyrazolone[5](PMBP) chelate of aluminum by electrothermal vaporization in ICP-AES, a method for determination of trace aluminum was developed. Trace aluminum was vaporized at temperature of 1000 degrees C, and the vaporization behavior of aluminum chelate was detailedly investigated. Under the optimum conditions, the detection limit of aluminum was 0.6 ng ml(-1), and the relative standard deviation for 0.1 mug ml(-1) aluminum was 4.7% (n=8). The proposed method was applied to the determination of trace aluminum in rice flour reference materials, and the results well agreed with the reference values.     

天然水中可溶性硅酸与铝盐作用机理探讨

通过考察单核铝和溶解铝浓度的变化, 对天然水体中溶解性硅酸与铝盐的反应机理进行研究. 试验过程中, 采用8-羟基喹啉荧光分光光度法测定铝浓度并结合热力学计算进行机理验证. 结果表明: 单体硅酸和聚硅酸主要与溶液中的单核铝反应生成溶解性硅铝酸盐. 单体硅酸与单核铝的结合能力较弱; 聚硅酸与单核铝的结合能力则较强, 反应产物主要为二啮或三啮配合物. 溶液pH对反应过程有着重要影响, 偏碱性环境对硅酸与单核铝间的反应具有促进作用.     

化学浸提-分光光度法测定沙棘叶中不同形态铝

利用KCl、NH4Ac、HCl、NaOH四种浸提液将沙棘叶中的铝浸提溶出,得到沙棘叶中铝的不同化学形态,采用分光光度法定量测定,测定结果:沙棘叶中的Al3+为10.7%,Al(OH)2+和Al(OH)+2为2.1%,胶态Al(OH)03为34.3%,有机铝为53.0%.浸提液中铝的回收率为86.9%～101.0%.     

化学浸提法研究中药茯苓中活性铝的形态分布

利用KCl、NH4Ac、HCl、NaOH四种浸提液对中药茯苓中铝的存在形态分别进行浸取溶出,采用分光光度法对不同形态的铝含量进行测定,得到茯苓中活性铝的形态分布,有机铝含量占总量的58.9%;胶态Al(OH)3占总量41.1%;浸提液中铝的回收率为97.0%~109.3%。     

Hydrothermal Synthesis of Porous Al2O3/Al Metal Ceramics: II. Mechanism of Formation of a Porous Al(OH)3/Al Composite

The formation of a porous layer of aluminum hydroxide on the surface of aluminum particles and the aggregation of Al(OH)₃/Al composite particles were analyzed theoretically. It was found that the diffusion mass transfer of the hydroxo complexes of aluminum through the porous structure of a growing layer of aluminum hydroxide to the outer surface is a rate-limiting step in the synthesis of the porous composite. A model mechanism of formation of the porous composite was developed, and rate equations were derived for describing the growth of an aluminum hydroxide layer on the surface of an aluminum particle and changes in the degree of aluminum conversion and the contact radius between composite particles. Based on the developed mathematical model and experimental data, the diffusion coefficient of the hydroxo complexes of aluminum in the porous structure of aluminum hydroxide was calculated.     

Preparation of Mullite Fibers by the Sol-Gel Method

Mullite fibers were synthesized from an aqueous solution of aluminum isopropoxide, aluminum nitrate and tetraethylorthosilicate by the Sol-Gel method. The starting solution was prepared by adding aluminum isopropoxide and tetraethylorthosilicate simultaneously to an aluminum nitrate aqueous solution. The spinnability of the starting solution was investigated by varying the molar ratio of aluminum isopropoxide/aluminum nitrate in the solution. Gel fibers were obtained from solutions in a composition range of aluminum isopropoxide/aluminum nitrate of 3 to 5. Gels obtained from spinnable solutions appeared to have high homogeneity in the mixing of the Al/Si components, leading to a sharp 980°C exothermic peak in the DTA curve and a mullitization temperature of 1000°C. However, in the case of gels obtained from unspinnable solutions, a small 980°C exothermic peak was detected, and the mullitization temperature was as high as 1200°C, probably due to greater heterogeneity in the mixing of the Al/Si components.     

Synthesis and characterization of nanostructured aluminum borate by sol–gel method

Nanostructured aluminum borate was synthesized using sol?Cgel technique. X-ray diffraction study revealed that the synthesized aluminum borate was single crystal. These nanorods have very uniform diameter. High-resolution transmission electron microscope images indicate that aluminum borate is well crystallized. The alternating current (AC) conductivity of the aluminum borate was studied as a function of temperature and frequency. The AC conductivity mechanism of the aluminum borate was found to be proportional to ??^s. The exponent s is almost independent with temperature. This suggests that AC conductivity mechanism of the aluminum borate can be interpreted by localized hopping model.