Analysis of impurities in high-purity aluminum oxide by glow discharge mass spectrometry

A method has been developed for determining trace components in high-purity aluminum oxide powder for making sapphire single crystals. The analyses have been performed with VG9000 glow-discharge mass spectrometer which provided a sensitivity at the sub-ppm level. To analyze nonconducting specimens, a secondary cathode made of high-purity Ta foil was employed. Effects have been determined from factors that influence the sensitivity. Mathematical simulation has been used in calculating the effects of molecular ions on the results. Isotopes are identified that provide the necessary analysis sensitivity and accuracy. The method allows one to distinguish impurities adsorbed on the particles from those that enter into the crystal lattice.     

用ICP-AES分析高纯黄金中的杂质

研究了采用ICP-AES分析高纯黄金中的杂质时选择分析参数的思路和仪器分析参数的确定,并对方法的准确度、精密度及检出限作了相应的讨论。实验表明,采用ICP-AES分析高纯黄金,与GB/T11066—89的分析方法相比,具有分析速度快、准确度高、精密度好、检出限低的特点。ICP-AES分析测定可以使Ag、Cu、Fe、Pb、Sb、Bi的方法检出限分别达到1.6×10-9,1.3×10-9,1.5×10-9,2.8×10-9,9.0×10-9,10×10-9,完全可以满足高纯黄金中微量杂质的分析测定。     

ICP-AES法直接测定高纯氧化钇和氧化钇铽共沉物中非稀土杂质

采用JY-ULTIMA②型等离子光谱仪,建立了用ICP-AES法测定高纯氧化钇和氧化钇铽共沉物中9种非稀土杂质的分析方法。确定了合适的分析谱线和最佳工作条件。方法简单、快速,在实际应用中获得满意结果。     

Removal of impurities from scandium chloride solution using 732-type resin

The deep removal of Al, Fe(Ⅱ/Ⅲ), Ca, Zr, Ti and Si from scandium chloride solution was carried out by using 732-type strong acid cation exchange resin. The effects of pH value, contact time and complexing agents(EDTA) on the purification process are investigated. The results indicate that the 732-type resin have a good scandium selectivity and the adsorption order is Sc Fe(Ⅲ)Al Ca Zr Ti Si in the pH range of 1-3. The separation of Sc and Zr, Si, Ti can be directly carried out because the resin have a good adsorption effect on Sc, AI and Fe(Ⅲ) but poor adsorption effect on Zr, Si and Ti under the condition of pH = 2.5 and contact time 180 min. The Fe(Ⅱ), Ca and Al are selectively adsorbed on the resin by adding reducing agent ascorbic acid and EDTA into the solution for reducing Fe(Ⅲ) to Fe(Ⅱ) and complexing Sc.By using two-step ion exchange adsorption separation method, the removal rates of Fe(Ⅲ), Ti, Al, Ca, Zr and Si are 95.5%,99.8%,100%,98.2%,98.6% and 100%,respectively.     

High-temperature compatibility of refractory metals with scandium oxide

Conclusions Chemical reaction between Sc₂O₃ and Ta, Mo, and W is not observed when they are heated to 2100°C in a protective medium for 4 h. The depth of diffusion of the metal into the oxide is less than the resolving power of the microscope (1). It is, therefore, theoretically possible to use scandium oxide as a dispersion-strengthening phase for metal artifacts of Ta, Mo, and W, for coating these artifacts with Sc₂O₃, etc.Translated from Poroshkovaya Metallurgiya, No, 1, pp. 83–87, January, 1968.     

Preparation of ultra-high pure scandium oxide with crude product from titanium white waste acid

Recovery of scandium from titanium white waste acid is an essential source of scandium. Simple and economical production of high purity scandium remains a challenge. A new extractant, N,N,N',N'-tetracyclohexyl-diglycolamide (TCHDGA), was synthesized, and the separation performance of scandium from impurity metal ions (Ti, Mn, Ba, Fe, Al and Mg) was investigated. The effects of mixing time, acid concentration and temperature on the scandium extraction were considered. The extraction mechanism was studied by infrared spectroscopy and the Equimole Series Method. Under optimized conditions, the extractant shows a strong affinity to scandium in the nitric acid medium and high extraction separation factors between scandium and these impurity metal ions. A process for the purification of scandium was established. The crude product obtained from titanium white waste acid, 95% purity scandium oxide, can be purified to 99.99% after only one step of extraction, scrubbing, and stripping. This technology is economical and straightforward and can realize the high-value recovery of scandium in the titanium white waste acid.     

Selectively recovering scandium from high alkali Bayer red mud without impurities of iron,titanium and gallium

Experimental results here can give some new insights into the mechanism of selective recovery of scandium and sodium from high alkali Bayer red mud(RM) through sulfation-roasting-leaching process. Effects of roasting and leaching conditions including roasting time, roasting temperature, concentrated H_2SO_4 addition, leaching temperature, leaching time and liquid to RM solid ratio on the leaching rates of calcium, iron, aluminum, silicon, sodium, titanium, scandium and gallium were studied and analyzed, suggesting that roasting temperature and roasting time were the two primary constraints on selective recovery of Sc and Na. High leaching temperature also brought a negative effect on the iron leaching rate. Phase transitions and thermal behaviors of sulfated RM indicated that sodium had an inhibitory action on the liberation of SO_2 or SO_3 from metal sulfates, which should follow the decomposition order of TiOSO_4Ga_2(SO_4)_3Fe_2(SO_4)_3NaFe(SO_4)_2NaAl(SO_4)_2~Al_2(SO_4)_3Na_3Sc(SO_4)_3Na_2SO_4CaSO_4. After water leaching, solid-liquid separation could be carried out extremely smoothly and 95 wt.% Na+, ~60 wt.% Sc in [Sc(H_2O)_x(SO_4)_n]~(3–2n)(x≤6) with impurities of 0 wt.% Fe~(3+), 0 wt.% Ti4+, 0 wt.% Ga~(3+), 7 wt.% Al~(3+), ~29 wt.% Ca~(2+) and ~3 wt.% Si~(4+) could be leached into leachant under the optimized roasting and leaching conditions. The alkali-free residue obtained could then be employed as iron-making or building materials.     

The removal of cadmium impurities from cobalt–nickel solutions by precipitation with sodium diisobutyldithiophosphinate

Cadmium sometimes occurs as a minor impurity in cobalt–nickel solutions which are to be processed by solvent extraction for the recovery of cobalt. However, the organophosphorus reagents used for this purpose extract cadmium in preference to cobalt. Consequently, the feed solutions must be pretreated for the removal of cadmium in order to avoid contamination of the final product. This note describes a selective method of removing cadmium by precipitation as its diisobutyldithiophosphinate complex.     

我国氧化钪生产的现状及其发展

综述了氧化钪生产的原料、工艺及设备、产品质量及产量、应用及市场等,对氧化钪生产中存在的问题进行了讨论并提出了建议.     

辉光放电质谱法测定棒状高纯镁中12种杂质元素

建立了辉光放电质谱法(GD-MS)测定棒状高纯镁中Al、Si、Ca、Cr、Mn、Fe、Ni、Cu、Zn、Sn、Pb、Bi共12种主要杂质元素的方法。试验表明:棒状样品的放电表面积小、放电容易不稳,将放电电流设在47.0mA、气体流量设在599mL/min时,基体信号稳定且强度可满足测试的要求;预溅射15min可完全消除样品表面的Na、Fe、Ca等元素的污染。²⁷Al、²⁸Si、⁵²Cr、⁵⁵Mn、 ⁵⁶Fe、⁵⁸Ni、⁶³Cu、⁶⁴Zn、²⁰⁸Pb、²⁰⁹Bi丰度最高,在中分辨下分析即可得到较好的结果;由于存在⁴⁰Ar对⁴⁰Ca的干扰,所以选择⁴⁴Ca作为分析同位素,在中分辨下进行分析即可得到较好的结果;¹²⁰Sn与⁴⁰Ar⁴⁰Ar⁴⁰Ar在分辨率大于7960时才能完全分开,所以在高分辨模式下以¹²⁰Sn为测定同位素进行测定。按照实验方法对棒状高纯镁中12种杂质元素进行测定,相对标准偏差(RSD,n=5)为1.8%~10.9%,所有分析结果的标准偏差(SD,n=5)要小于国家标准方法GB/T 13748中的重复性限量;测定值与电感耦合等离子体质谱(ICP-MS)法及电感耦合等离子体原子发射光谱(ICP-AES)标准加入法的结果进行比对,大部分元素符合性较好,由于棒状镁样品的相对灵敏度因子(RSF)与标准RSF存在差异,Fe、Cu、Zn元素测定值差别较大,但是测定结果对高纯物质纯度定级无太大影响。     

氧化锌碱法脱氯工艺研究

用碳酸钠碱液对氧化锌粉浆化除氧,控制温度80℃以上、液固比5:1、碱浓度2%以上、反应时间1 h,氧化锌含氯可降至0.05%以下。工业生产应用时,采用逆流二段洗涤工艺,恒定碱量,通过降低液固比、提高碱浓度,氧化锌含氯降至0.03%以下。     

二乙基三胺五乙酸滴定法测定赤泥酸浸液中三氧化二钪

吸取10mL赤泥酸浸液于烧杯中,用氨水溶液调节溶液pH值为3.0~3.5并搅拌20min,经固液分离去除沉淀物,将滤液倒入500mL锥形瓶中,再用盐酸和氨水调节溶液pH值为1.6~6.0,加入5滴二甲酚橙指示剂,用二乙基三胺五乙酸(DTPA)标准溶液滴定至由酒红色变为亮黄色即为滴定终点。据此,建立了DTPA滴定法测定赤泥酸浸液中三氧化二钪的方法。考察了滴定pH值、三氧化二钪质量浓度、滴定温度、放置时间对测定结果的影响。结果表明:三氧化二钪质量浓度的检测范围为20~500mg/L,合适的滴定pH值范围为1.6~6.0,滴定温度为20~60℃;滴定前将溶液放置20min对测定无影响。共存元素干扰试验表明,将样品预先用氨水搅拌沉淀分离后再测定,可消除样品中铁和铝对测定的干扰;样品中其他共存元素不干扰测定。采用实验方法测定赤泥酸浸液中三氧化二钪的结果与电感耦合等离子体原子发射光谱法测得结果基本一致,相对标准偏差RSD(n=5)小于0.2%。     

ICP-AES测定氧化钴中杂质

利用仪器所带软件 ,拟定了氧化钴中铅、锌、铁、镉、铜、锰的分析方法 ,试验选定了各元素的分析谱线及仪器的工作参数。氧化钴试样用盐酸分解 ,在体积分数为 5 %的盐酸介质中同时测定 ,结果满意。     

微波消解萃取光度法测定高纯氧化铝中Fe_2O_3的研究

用硫酸(1+2)作溶剂,在230℃下采用微波炉消解进行样品前处理,在硫酸-盐酸介质中,以甲基异丁基酮(MIBK)萃取Fe(。Fe(在甲基异丁基酮中与硫氰酸钾、邻二氮杂菲显色形成红色三元络合物,其最大吸收波长为520 nm,表观摩尔吸光系数为5.38×104,10 mL试液中氧化铁质量在0~12.5μg范围内符合比尔定律。该方法选择性好,灵敏度高,适用于高纯氧化铝中质量分数0.000 5%~0.010%氧化铁量的测定。     

Effect of solid state impurities on the dissolution of Nickel oxide

The influence of two dopants: Li₂O and Cr₂O₃ on the dissolution of NiO has been investigated using dilute sulfuric acid solutions at 60 °C. The dissolution rate is decreased by chromium additions of up to 1.0 mol pct Cr₂O₃, but the addition of 1 mol pct Li₂O dramatically increases the dissolution rate. The results are interpreted in terms of the modification of the defect structure of NiO (p-type semiconductor with metal vacancies) by the dopants. It is proposed that Li⁺ doping increases the surface concentration of Ni³⁺ and that subsequent strong Ni³⁺-S _O4 ²⁻ interaction enhances NiO dissolution. The NiO-S _O4 ²⁻ surface interaction is confirmed with electrophoretic mobility measurements. A similar, though less pronounced, trend is observed when perchloric acid is used instead of sulfuric acid as the dissolution reagent. The difference in the behavior of the acids is attributed to differences in their affinities for the oxide surface.     

More effective removal of oxide inclusions from rail steel in the intermediate ladle

Thermodynamic analysis of the transition of nonmetallic inclusions from metal to slag shows that, in this transition, breakaway of the inclusions from the metal is thermodynamically impossible and the inclusions accumulate at the interface on the slag side. This obstructs subsequent inclusions arriving at the interface and hinders their removal from the steel. Therefore, the successful assimilation of inclusions by the slag calls for the renewal of the slag layer adjacent to the metal by kinetic means—for example, by injecting inert gas into the steel. Industrial tests of argon injection into the steel in the intermediate ladle in casting confirm that the content of oxide inclusions in the rails is reduced.     

氧化钙类杂质对铁水脱磷的影响分析

除尘灰制备炼钢脱磷剂极具实用价值,但其所含CaO类杂质却会影响脱磷.1 400℃条件下,参考Fe2O3-CaO-CaCl2系脱磷剂,分别利用不同摩尔比的Ca(OH)2、CaCO3替换脱磷剂中的CaO,对磷质量分数为0.3％的铁水进行了脱磷试验.同时,分别利用CaO、Ca(OH)2、CaCO3作为固定剂,研究了各自的铁水...