铁离子对硫化矿发电浸出过程影响的机理研究

本研究采用双电池体系考察了铁离子对硫化矿的FeCl3浸出过程的影响.研究结果表明,Fe3 对所研究各硫化矿发电浸出的影响效果类似:阴极电解液中Fe3*仅在较低的FeCl3浓度范围内(<0.1～0.2 mol L1)对发电浸出速率有显著影响.对各矿物提出了相应的反应机理,建立了各体系发电浸出速率与[Fe3 ]的动力学关系,对镍精矿、铜精矿、闪锌矿及方铅矿体系分别为:模型与实验结果吻合.     

碳糊电极在硫化矿发电浸出过程中的应用研究

应用线性电势扫描法研究硫化矿的纯矿电极与碳糊电极体系在氯化钠电解液中的电化学行为.结果表明,乙炔黑在硫化矿浸出过程中起到电催化作用,加入乙炔黑的碳糊电极较之纯矿电极,其发电浸出输出电流和电压均有一定程度的增加,同时活化能较传统浸出的低.     

稀土与天青石共伴生矿焙烧及浸出过程研究

稀土与天青石共伴生多金属矿主要由稀土氟碳酸盐和天青石组成,研究了含稀土和锶的混合矿的焙烧及浸出过程,考察了焙烧温度、焙烧时间、浸出初始酸浓度、浸出温度、浸出时间等对浸出率的影响,获得优化的工艺参数为:焙烧温度500℃,焙烧时间2 h,浸出初始酸浓度1.0 mol.L-1,浸出温度35℃,浸出时间1 h,稀土浸出率达95%以上,锶浸出率小于5%,几乎不进入溶液相而保留在固相浸出渣中得以分离和富集。     

浸矿过程离子型稀土矿孔隙结构演化规律研究

离子型稀土在浸出过程中,内部微观的孔隙结构会发生不同程度的变化。采用室内模拟浸矿实验对比分析了纯H_2O和不同浓度的(NH_4)_2SO_4溶液浸出过程中稀土内部孔隙结构的变化规律。实验结果表明:稀土矿体试样浸矿过程孔隙结构随浸矿时间发生变化,主要体现为孔隙率增加,孔隙半径增大。用纯H_2O浸矿时,试样的孔隙率随浸矿时间略有起伏,但总体呈现增大趋势。在有效浸矿时间内,相比纯H_2O,(NH_4)_2SO_4溶液浸出过程矿体试样孔隙率和孔隙半径明显增加,且随着浸矿液浓度增大,变化愈发明显。由此,稀土浸矿过程化学置换反应和溶液渗流过程均可诱发矿体孔隙结构发生变化,在浸出过程中,化学置换反应的影响明显高于溶液渗流。     

还原焙烧红土矿的硫酸浸出动力学

研究了选择性还原焙烧红土矿的硫酸浸出动力学.实验考察了浸出温度(30 ℃～70 ℃)和硫酸浓度(0.01～0.5 mol·l-1)对Ni、Fe浸出率的影响.结果表明:红土矿的选择性还原焙烧可增快Ni的浸出而抑止Fe的溶解.Ni的浸出动力学可用Avrami方程描述,其浸出反应的表观活化能为(15.40±0.18) kJ·moL-1.Fe的浸出受内扩散过程控制,浸出的表观活化能为(55.16±1.37) kJ·moL-1.     

苯酚在含氯体系中的电化学氧化

以Ru-Ir/Ti三元电极作阳极电解处理苯酚废水,研究废水中Cl-初始浓度对处理效果的影响.结果表明,在一定的电解时间内,苯酚的电化学氧化符合一级动力学方程;废水中Cl-的初始浓度越大,苯酚完全被氧化所需的时间也越短,即其表观速率常数越大.苯酚在Cl-体系中降解的中间产物主要有4-氯苯酚,1-氯苯酚,2,4-二氯苯酚,2,6二氯苯酚,2,4,6-三氯苯酚及各种短链脂肪酸和氯代醇等;最终产物是CO2、CHCl2和CHCl3.电解中间体的生成和降解速率随废水中Cl-初始浓度的增加而增大.据此,导出苯酚在含Cl-体系中电化学氧化的反应途径.     

橡胶胶乳的硫化——Ⅰ.胶乳硫化基本规律的初步探讨

本文系统地研究了胶乳种类、胶乳浓度、硫化温度、硫磺用量以及促进剂用量等五个主要因素对天然胶乳硫化过程的影响,并且阐明了在硫化过程中胶乳胶膜物理性能、结合硫量以及橡胶交联度之间的相互关系。 实验结果说明,胶乳中非橡胶成分在硫化初期不仅不促进硫化而且还阻碍硫化进程,在硫化的中期与后期它的促进效果才明显地显示出来。非橡胶成分含量愈高其硫化胶乳胶膜物理性能愈低。在一定范围内随着胶乳浓度的降低硫化速度稍有增加。随着硫化温度的升高胶乳硫化速度将相应加速,但在我们使用的硫化体系条件下温度过低与过高时其对硫化速度的影响减弱,最适宜的硫化温度是60—70℃。硫磺用量增加到一定程度后它对胶乳硫化速度即不再产生影响,在胶乳硫化过程中所能达到的结合硫量远远低于硫磺在橡胶中的溶解度。在通常用量下促进剂S.D.C.用量愈大其硫化促进效果亦愈大,在用量为0.125—0.25％之间其促进效果有一明显的转折。 硫化胶乳胶膜性能与橡胶交联度及结合硫量之间有一定的依赖关系。各种不同的影响胶乳硫化的因素都不改变这一依赖关系。在胶乳硫化过程中硫磺的交联效率是不恒定的,胶乳在硫化时主要是形成多硫键。在胶乳硫化时结合硫磺中的相当一部分并不对交联键的形成作出贡献。 胶乳硫化动力学基本     

铜离子在合金硫化镍矿浸出过程的化学动力学

建立了在常压氧化硫酸浸出合金硫化镍矿过程中通氧反应结束后铜离子浸出镍的动力学方程,反应的表观活化能为129.88 kJ.K-1.mol-1.根据该动力学方程,可以进一步对硫酸氧化浸出合金硫化镍矿过程中镍的浸出速率进行推导.     

氧化钙对流化床燃煤飞灰中砷的淋滤特性影响

在实验室小型流化床实验装置上,利用添加氧化钙研究了原煤中钙硫比变化对燃煤过程中砷在飞灰中的富集规律和飞灰中砷的浸出特性的影响。实验结果表明,增加钙硫比能有效促进砷在飞灰中富集,降低砷的排放。砷与氧化钙的反应受制于钙的硫化反应控制。飞灰中砷的浸出与滤液pH值关系显著,碱性飞灰导致滤液pH值增大,能有效抑制飞灰中砷的浸出。碱性飞灰中砷的浸出历程为飞灰中砷在短时间内快速溶出;随着滤液pH值增大,溶出的砷与钙发生二次反应形成钙砷化合物沉淀,降低滤液中砷浓度。     

硫化矿机械活化机理研究现状与展望

随着矿产资源的日趋贫乏,迫切需要新工艺强化难处理多金属复杂矿的湿法冶金过程.而机械活化作为强化湿法冶金过程的常用方法,可有效地强化大多数难浸硫化矿的湿法冶金工艺,而对少数难浸硫化矿湿法冶金过程的强化效果不明显.因此,有必要探索不同硫化矿的机械活化机理和机械活化效果的基础理论问题,推动湿法冶金理论向可预见性和实用性方向发展.本文在综述国内外学者对固体机械化学理论研究的基础上,结合作者已有的研究工作,系统地综述了硫化矿机械活化机理的研究现状,并对今后的研究工作进行了展望.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。