有机合成中三氯化铝残留量的测定

本文研究了用空气一乙炔火邹原子吸收法间接测定有机 三氯化铝残留量的方法。利用铝对钙的干扰效应，在已知钙浓度的溶液中测定钙铝混合液的吸光度从而间接测定铝，经对有机合成样品中三氯化铝残留量的测定，方法旧可行的。     

硫磷铝锶矿制取磷酸的研究

硫磷铝锶矿是一种磷酸钙铁铝类磷矿,难溶于酸和碱,煅烧后的非晶质产物化学活性显著提高.本文进行了用稀磷酸浸取经过焙烧的硫磷铝锶矿的研究.用三因素二次回归法设计了17组正交实验,得到了磷酸浸取硫磷铝锶矿的数学模型,此模型可预测反应时间、反应温度和液固比三种因素对矿石中P2O5浸取率的影响.同时得出最佳反应条件是:反应时间120 min,反应温度85℃,液固比15∶1,此时的P2O5最高浸取率是95.4%.本文还研究了含有硫酸的磷酸对浸取过程的影响和锶在固相和液相中的分布,为下一步用湿法磷酸浸取和锶的回收作好准备.     

电感耦合等离子体发射光谱法测定铝锶中间合金中的杂质元素

建立了用稀王水消解铝锶中间合金样品,直接采用电感耦合等离子体发射光谱法测定样品中杂质元素的含量。本方法的加标回收率在95.0%～103.5%之间,相对标准偏差在0.66%～11.55%之间。样品测定与分光光度法及原子吸收光谱法的测定结果一致。能够满足快速准确测定铝锶中间合金中杂质元素的需要。     

铝的原子吸收光谱法测定

对铝的原子吸收光谱法测定进行了综述，介绍了测定的方法、测定时的干扰情况和干扰的消除、铝的原子化机理、以及各种测定方法的发展概况和应用。     

铝对EDTA直接滴定法测定铁的干扰

目前国内对于通用硅酸盐水泥、生料、熟料中铁和铝的测定,化学法主要按照GB/T 176-2008《水泥化学分析方法》,Fe2O3的测定采用EDTA直接滴定法,Al2O3的测定采用EDTA直接滴定法或硫酸铜返滴定法.即利用酸效应,控制不同的溶液pH值,在同一份溶液中连续测定铁、铝含量.通常认为在pH1.8～2.0直接滴定铁时铝不干扰测定,或者说控制好适宜的试验条件(酸度、温度)铝的干扰可以忽略不计.     

原子吸收分光光度法测定矿石中氧化镁的干扰研究

本法主要研究使用火焰原子分光光度法测定矿石中氧化镁含量过程中的干扰。分别验证了含二氧化硅、三氧化二铝、氧化钠、氧化钾这四种元素在不同浓度下,实验条件中不加入掩蔽剂(氯化锶)时,对氧化镁检测的干扰。验证了随着浓度的增大,硅元素对氧化镁测定产生负干扰,铝对氧化镁的测定产生正干扰,钾对氧化镁的测定产生正干扰,钠对氧化镁的测定产生正干扰,同时也验证了氯化锶对这四种元素均有很好的掩蔽效果。     

ICP-AES法测定载金树脂物料中铝、镁、锰、锶的含量

建立载金树脂物料中的铝、镁、锰、锶4种元素的分析检测方法。采用盐酸-硝酸-氢氟酸加热体系对试样进行溶解,并通过电感耦合等离子体原子发射光谱法同时测定铝、锰、镁、锶元素的含量。实验结果表明,20 g/t的载金树脂物料中铝、锰、镁、锶元素的质量分数分别为4 014、1 802、193.5、109.5μg/g,精密度实验的相对标准偏差为1.07%~3.29%,加标回收率为95.00%~104.40%。该方法快速、准确、稳定,适用于载金树脂物料中铝、锰、镁、锶元素的测定。     

磷矿中氧化鍶的快速重量法测定

磷矿中氧化锶的化学法测定,目前实用的方法是在PH为4.5的乙醇——水介质中,用EDTA掩蔽钙、铁、铝,以硫酸铵沉淀锶的重量法。该法测定手续繁长,且钙的干扰问题也未彻底解决。我们在该法的基础上做了较大改进,采用经灼烧之 矿样,用硫酸锶饱和过的希盐酸——硫酸铵溶液处理分离钙,用碳酸钠——三乙醇胺——氢氧化钠溶液煮沸转化硫酸锶来分离磷、铁和铝,最后用原法一次沉淀硫酸锶。 改进后的本法,经长时期生产实践验     

四川某地硫磷铝锶矿有用元素赋存状态和综合利用探讨

四川某地硫磷铝锶矿中除含主要元素磷、铝、铁、硫、锶、钛外,还含有丰富的稀土元素。利用等离子质谱分析(ICP-AES)、扫描电镜及能谱(SEM-EDX)、电子探针(EMPA)等分析手段查明了硫磷铝锶矿中主要元素及稀土元素分布规律及赋存形式。实验结果表明,77%的磷元素、97%的铝元素及大部分锶及稀土元素都分布于硫磷铝锶石中,黄铁矿中稀土元素富集低,铁、钛元素集中于独立矿物黄铁矿、锐钛矿中。     

铝的测定及干扰元素的分离

在氧化铝测定中，我们通常采用氟盐置换EDTA容量法测定氧化铝的含量。在pH=5.5～6的溶液中，加入过量一倍的EDTA后，煮沸数分钟使之与二价、三价、四价金属离子络合，用醋酸锌标准溶液滴定过量的EDTA，然后加入氟化钠，由于氟与铝的结合而释放出相应量的EDTA，再用醋酸锌的标准溶液滴定之，就可间接求出铝的含量。 本法选择性高，在滴定时可允许下述量各种物质存在：氯化钠5g，NH4Cl5g，SiO2 70mg，CaO25mg，氧化镁 100mg，铁30mg，铜20mg，镍20mg，铅20mg，锰1mg，磷20mg，数十毫克的镉、钴、铋、钡、锶以及钒酸根、氯根、硝酸根…     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。