煤矸石中微量钪的分光光度法测定

在 (CH2 ) 6 N4 HCl缓冲溶液中 ,研究了微量钪 (Ⅲ ) 埃铬菁R(ECR) 溴化十六烷基吡啶 (CPB)之间的配合反应。结果表明 ,在pH 6.0的(CH2 ) 6 N4 HCl缓冲溶液中和OP乳化剂的存在下 ,有色溶液的最大吸收波长为 60 0nm ,表观摩尔吸光系数为 2 .0× 10 5L·mol- 1 ·cm- 1 。钪 (Ⅲ )的质量浓度在 0～ 0 .2 0 μg·ml- 1 范围内符合比耳定律 ,钪 (Ⅲ )的加标回收率在 97.2 %～ 10 4.1%之间 ,RSD(n =6)为 2 .9%～ 6.1%。结合PMBP 甲苯萃取分离 ,测定了煤矸石中的微量钪     

赤泥中微量钪的分光光度法测定

研究了钪 与氯代磺酚S(CSPS)之间的络合反应 ,加入乳化剂OP能提高反应的灵敏度。结果表明 ,在 0.1mol/L一氯乙酸 (CH2 ClCOOH)和乳化剂OP的存在下 ,有色溶液的最大吸收波长为 64 0nm ,表观摩尔吸光系数为 5.42× 10 4 。钪 质量浓度在 0～ 0.2 5mg/L范围内符合比尔定律 ,加标回收率在 98.4%～ 10 3.5 %之间 ,RSD(n =6)为 2.8%～ 5.2 %。用本法测定了赤泥中的微量钪 ,结果满意     

离子交换树脂分离-分光光度法测定赤泥中钪

赤泥用硝酸、氢氟酸和硫酸溶解,过强酸型树脂(Dowex50W-X8(H⁺型))交换树脂柱,用2 mol/L 盐酸多次淋洗,再用5 mol/L 盐酸洗脱富集在交换分离树脂柱上的钪,加热蒸干,再加高氯酸冒烟至尽干,依次加入10 mol/L 过氧化氢和6 mol/L盐酸,加热至尽干,用2 mol/L盐酸溶解并转移到分液漏斗中,依次加入磺基水杨酸、溴甲酚绿,再用氨水和盐酸调节溶液至黄色。再加入偶氮氯膦-PN(CPA-PN)进行显色并与钪形成α型络合物,用20 mL 0.02 mol/L 1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(PMBP)-苯萃取该络合物。于分光光度计波长680 nm处测量其吸光度,从校准曲线上查得钪含量,以此建立了离子交换树脂分离-分光光度法测定赤泥中钪的方法。结果表明,溶液中钪质量浓度在0.01~0.48 μg /mL范围内与吸光度呈线性,校准曲线的线性相关系数r=0.998 9,表观摩尔吸光系数为3.86×10⁴ L·mol^-1·cm^-1,方法中钪的检出限为0.42 μg/g。干扰试验结果表明,溶液中5.0 μg ScⅢ的测定结果相对误差不超过±5%时,BO₃^3-(600),NH₄Ⅰ(200),CaⅡ(100),RE₂O₃(60),BeⅡ(30),FeⅢ、AlⅢ、MnⅡ(25),ZrⅣ(4),TiⅣ、TaⅤ(2)不干扰测定。按照实验方法测定赤泥实际样品中钪,结果的相对标准偏差(RSD,n=6)为2.5%～3.9%,并与电感耦合等离子体原子发射光谱法测定结果相吻合。     

赤泥盐酸浸出液中钪的分光光度测定

考察了温度、时间、显色剂用量、酸度对待测溶液吸光度的影响,结果表明:温度对吸光度值不产生大的影响,在室温下测试即可;溶液显色在前8min内不稳定,其显色时间一定要达到10 min,溶液颜色保持16h不发生太大的变化;显色剂氯代磺酚C和Sc(Ⅲ)1∶1络合稳定,其溶液加入量确定为3ml;酸度对吸光度有较大的影响,待测溶液...     

富集-萃取-分光光度法测定矿石中的痕量锰

研究了矿样分解后利用巯基树脂富集锰,洗脱分离后转化为高锰酸钾与溴化钾反应析出溴单质,采Br2-CCl4萃取光度法测定矿石中锰的方法。并对样品溶解方法、共存元素及其影响、内标元素的选择等进行了研究,建立的分析方法简便快速,精密度和准确度较好。通过方法的回收率实验,并与其它测定方法进行比较,得到了较为满意的结果。     

2,6-吡啶-二羧酸—溴化十六烷基三甲基铵体系荧光分光光度法测定痕量铕

提出了在表面活性剂存在下 ,2 ,6-吡啶 -二羧酸 (DPA)体系荧光分光光度法测定痕量铕 ,研究了最佳反应条件 ,铕的检出限可达 0.0 4 5ng/mL ,可允许存在一定量的其他共存稀土离子 ,并考察了Al3+,Fe3+,Ca2 +,Mg2 +离子对测定的影响 ,该法用于测定包头混合稀土氧化物中痕量铕 ,获得了较满意的结果。     

依来铬青R吸光光度法测定微量钒(Ⅳ)

在pH=4.7的六次甲基四胺缓冲介质中钒(Ⅳ)与依来铬青R、CPB形成蓝紫色的三元配合物,其组成为1∶3∶3,λmax=590nm,表观摩尔吸光系数为4.0×104L/mol·cm,钒在0～25μg/25mL范围内遵守比耳定律,用于钢中钒的测定,结果准确可靠。     

流动注射离子交换分离-分光光度法测定煤矸石中痕量钪

采用流动注射技术进行痕量钪的离子交换分离富集,在0.40 mol·L-1HBr介质中,Sc3+与Br-形成络阴离子,被离子交换树脂交换富集,用0.25mol·L-1HNO3-1.5%硫脲溶液洗脱,用对氯偶氮氯膦(CPA-pCl)分光光度法测定.有色络合物的最大吸收波长为615 nm,钪的质量浓度在0～1000μg·L-1范围内符合比耳定律,方法的检出限为1.2μg·L-1.经分离后,钪的测定灵敏度可提高数倍,大量共存离子不干扰钪的测定.该法已应用于煤矸石痕量钪的测定.     

邻苯二酚紫─溴化十六烷基吡啶分光光度法测定微量钛

本文研究了在溴化十六烷基吡啶（ＣＰＢ）存在下邻苯二酚紫（ＰＶ）与钛（Ⅳ）的显色反应,并用于光度法测定微量钛。反应适宜酸度范围为ｐＨ３～４．５,所形成配合物的最大吸收峰位于７３０ｎｍ处,其组成为Ｔｉ：ＰＶ：ＣＰＢ＝１：２：３,摩尔吸光系数ε＝７．８×１０￣４。钛（Ⅳ）浓度在２～１０μｇ／２５ｍｌ范围内服从比尔定律;该方法可用于钢铁和合金中微量钛的测定。     

钪(Ⅲ)—埃铬青R—溴化十六烷基三甲基铵显色反应的研究及应用

在pH6.2～6.8的溶液中,钪(Ⅲ)与埃铬青R(ECR)及溴化十六烷基三甲基铵(CTMAB)形成绿蓝色的三元配合物,其组成比Sc∶ECR为1∶3。三元配合物的最大吸收波长在615nm处,表观摩尔吸光系数为1.35×10~5。钪在0～7μg/25ml范围内遵守比尔定律。拟定的方法,经PMBP萃取分离之后,测定钨矿及其浸取渣中的微量钪,结果满意。     

赤泥硫酸浸出液中钪的萃取试验研究

针对赤泥的硫酸高压浸出液的性质,进行了P204萃取试验研究。通过考察萃取剂体积分数、萃取温度、水相中硫酸浓度等因素对钪、铁萃取分离的影响,得出了最佳萃取条件为萃取温度35℃,水相硫酸浓度4 mol/L,萃取剂体积分数5%,O/A=1∶3,萃取时间15 min,转速230 r/min,10级萃取;在最佳条件下,钪、铁分离效果较好,钪萃取率为92.10%、铁萃取率为1.13%。负载有机相经10级4 mol/L盐酸洗涤,杂质Fe的去除率为97.88%,钪损失率为0.24%;这表明P204能够很好地将萃取原液中的钪与杂质金属铁分离。     

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%。     

Separation and recovery of iron and scandium from acid leaching solution of red mud using D201 resin

Red mud is a byproduct of alumina refining of bauxite ores, and is a significant source for extracting scandium. However, a large amount of iron in red mud makes it difficult to recover scandium because Fe(III) and Sc(III) have similar physicochemical properties. In this study, a new method was developed for selective separation of iron and scandium in acid leachate of red mud using D201 resin. Theoretical calculations indicate that the ferric species mainly exists as FeCl₃ or FeCl₄⁻ at chloride concentration above 6.65 mol/L, while scandium still exists as ScCl₂⁺, making it possible to selectively separate iron from scandium through anion resin adsorption. The factors affecting the adsorption of iron and scandium such as chloride concentration, resin dosage, adsorption time, and temperature were evaluated in batch experiments. The Langmuir model was successfully applied to both iron and scandium adsorption, and the maximum adsorption capacities of iron and scandium are 147.06 and 0.95 mg/g, respectively, indicating a significant difference between iron and scandium. Raman analysis further demonstrates that the iron is adsorbed onto D201 resin as FeCl₄⁻ anion.     

Extraction of scandium from red mud by acid leaching with CaF_2 and solvent extraction with P507

The extraction of Sc by acid leaching with CaF_2 and solvent extraction with P507 from red mud was proposed.The influence of acid leaching and solvent extraction on recovery of Sc was investigated.The CaF_2 can obviously improve the leaching efficiency of Sc and reduce the acid consumption.The leaching efficiency of Sc increases from 74% to 92% and the dosage of acid reduces under suitable conditions by adding 5% CaF_2.The minerals in red mud can easily be decomposed and leached into the acid solution with CaF_2 through analysis of XRD pattern.The particles of red mud become smaller and multihole.The Sc can be selectively extracted with 10% P507 at the pH value of 0.1 from the acid leaching solution.More than 98% of Sc and less than 10% of Al and Fe are extracted.The SC_2O_3 with purity of 99% is obtained after the process of reverse extraction with NaOH,H_2SO_4 dissolution,precipitation by oxalic acid and roasting at 750℃.     

Application of P507 and isooctanol extraction system in recovery of scandium from simulated red mud leach solution

The current recovery technique of Sc was complicated and the chemical consumption was high. This was due to the low content of Sc in resources and the difficulty of stripping. In this research, the isooctanol was added into the 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) extraction system to reduce the extraction and improve the stripping of Sc. The maximum stripping ratio of Sc from loaded organic phase by sulfuric acid can increase from 10% (without isooctanol) to 99% (with 15 vol% isooctanol). In the extraction test of the simulated red mud leaching liquor, the separation factors between Sc and Zr, Sc and Ti are 36 and 350, separately. At the same time, other metals are almost not extracted. The high selectivity and stripping of Sc suggest that the P507 with isooctanol extraction system can be applied in the practical Sc recovery process.     

巯基棉富集分光光度法测定石煤渣中痕量钽

痕量钽(被巯基棉预富集后用分光光度法进行测定。在H2SO4介质中,Triton X-100存在下,钽(与丁基罗丹明B(BRB)发生显色反应,生成摩尔比为1∶1的稳定络合物,络合物的最大吸收波长为565 nm,表观摩尔吸光系数为1.46×105L.mol-1.cm-1,钽的质量浓度在0~600μg/L范围内符合比尔定律。经巯基棉富集后,钽的测定灵敏度可提高数倍,大量共存离子不干扰钽的测定。建立的方法应用于石煤渣中痕量钽的测定,分析结果的相对标准偏差小于5%,加标回收率在97%~103%之间。     

水杨基荧光酮分光光度法测定煤矸石中痕量钇

研究了在NH4Ac缓冲溶液中,钇(Ⅲ)和水杨基荧光酮(SF)的络合显色反应。结果表明,在pH 7.0 NH4Ac的缓冲溶液和溴化十六烷基三甲基铵(CTMAB)存在下,有色溶液的最大吸收波长为560 nm,表观摩尔吸光系数为1.6×105,钇(Ⅲ)质量浓度在0~0.35 mg/L范围内符合比尔定律,加标回收率在98.8%~105.2%之间,RSD(n=6)为2.8%~5.2%。本法可用于测定煤矸石中微量钇。