某难处理金矿热压预氧化—氰化工艺研究

国内某难处理金矿金品位为14.80×10-6,含有0.47%的有机碳,95%以上的金为金属硫化物包裹金,常规氰化浸出率仅有21.89%。采用酸性热压—氰化工艺,研究矿浆浓度、时间、温度、氧分压和转速条件等因素对金氰化浸出率的影响。结果表明:采用热压预氧化处理金矿石能有效打开金包裹,硫氧化率98%,预处理后金的氰化浸出率97%。     

Fluorescence Properties of Eu3+/Gd3+/Citric Acid Mixed Complexes Doping in Silicon Rubber Matrix

Series of doped rare earth complexes-EuxGd(1-x)(CA)3·nH2O (CA=citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x)(CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.     

Sandwich Structure-like Meshes Fabricated via Electrospinning for Controllable Release of Zoledronic Acid

Novel sandwich structure-like nanofiber muLtilayered meshes were fabricated via electrospinning. The purpose of the present work was to control zoledronic acid release via the novel structure of sandwich structure-like meshes. The in vitro release experiments reveal that the drug release speed and initial burst release were controllable by adjusting the thicknesses of electrospun barrier mesh and drug-loaded mesh. Compared with those of other drug delivery systems, the main advantages of the sandwich structure-like fiber meshes are facile preparation conditions and the generality for hydrophobic and hydrophilic pharmaceuticals.     

冶炼烟气硫酸净化工艺对制取试剂硫酸的影响研究

利用某铅锌冶炼厂冶炼烟气硫酸为原料,经分析化验,原料酸中杂质含量较高,直接蒸馏对试剂硫酸的质量影响较大。因此,在蒸馏前需对原料酸进行净化处理,对原料酸的净化工艺进行了试验研究,采用经过净化的原料酸制取的试剂硫酸产品指标达到国家标准GB/T625-2007化学纯指标要求。     

碟式分酸器在烟气制酸装置中的应用

对低气速填料塔,分酸均匀尤其重要。碟式分酸器的显著优点是分酸均匀、调节范围宽。以400kt/a烟气制酸装置为例,介绍了冷却塔和干吸塔碟式分酸器的设计参数和调节性能,冷却塔在于稀酸雾粒的均匀长大,减少喷淋密度对干燥和吸收效率均有利,细小雾粒的蒸发是干燥效率的控制步骤。减小塔底气液温差可相应减少吸收塔内化学酸雾。     

柠檬酸对钨酸及磷钨酸的催化活性的改进

以磷钨酸/钨酸-柠檬酸为催化体系,在无有机溶剂和相转移剂的情况下,催化30%过氧化氢氧化环己酮合成己二酸。当磷钨酸∶柠檬酸∶环己酮∶过氧化氢=1∶20∶400∶200(0物质的量比,磷钨酸用量为0.25mmol)时,使用柠檬酸来调节钨酸催化活性,反应8h时,己二酸分离产率达81.2%、产品熔点为150￣153℃;以钨酸为催化剂,当钨酸∶柠檬酸∶环己酮∶过氧化氢=1∶2∶40∶200(物质的量比,钨酸用量为2.5mmol)时,反应8h,己二酸分离产率只有82.5%、产品熔点为150￣153℃。反应时间在2￣8h内,随反应时间的延长,己二酸分离产率增大,而8h后略有下降。     

浅谈有色冶炼厂污酸及酸性废水处理的新工艺和新技术

硫酸的再利用是污酸和酸性废水处理最核心的目标。污酸所含的硫酸量大,通过新工艺对其除杂浓缩后获得的稀硫酸加以利用,可避免产生大量废渣。结合设计实践,本文介绍了有色冶炼污酸和酸性废水处理中出现的新工艺和新技术,分析了其工作原理、适用场合、优势和缺点。     

斜管沉降槽回收浓废酸中的偏钛酸

钛白生产水解后浓废酸经过吸滤，滤液含１．３～１８．７ｇ／ＬＴｉＯ２的偏钛酸，它的回收可降低产品原料单耗３～４％，提高废酸质量，有益于废酸综合利用，减少产品单耗。本文以工厂实例介绍了料管沉降槽回收偏钛酸的装置设计与应用。     

我厂2kt/a硫酸干燥塔带酸原因探讨

对我厂 2kt/a硫酸系统干燥塔引起带酸原因的喷淋密度、喷淋酸的温度、分酸装置、除沫装置、塔入口酸雾、水份等要素进行全面分析     

H酸和芝加哥酸对黄玉的抑制性能

H酸与芝加哥酸是同分异构体,它们有相同的分子式和相同的官能团,只是磺酸根取代位置不同,属同系列同分异构体。H酸对锡石的抑制能力很弱而对黄玉的抑制能力很强,因此用十一烷基1,1-二羧酸作捕收剂、用H酸作抑制剂,能从黄玉与锡石的混合物中浮出锡石。根据浮选药剂的同分异构原理,芝加哥酸与H酸有相同分子式和相同的官能团,只是官能团的取代位置异构,应具有与H酸相接近的抑制性能。试验结果表明二者对黄玉都具有极相近的抑制能力。     

含砷难处理金精矿的催化氧化酸浸（COAL）新工艺开发

介绍了催化氧化酸浸（COAL）新工艺开发及产业化的情况,该工艺可以在100 ℃及0.4 MPa氧分压条件下对含砷金矿进行处理,金和银的回收率都可达到92%～96%。较低的工业压力和温度使设备简单、易于开工,基建投资和维修操作费用均较传统加压浸出工艺明显降低。在小型试验基础上,开发出100 m3加压浸出反应釜,并在招远金矿建成了100 t/d的工业试验及生产厂,工业试验证实金和银回收率分别为 93%～95%和 92%～96%,与小型试验结果一致。在操作参数及设备形式调整后,本工艺亦可适用于高砷高碳金精矿的处理。     

酸雨对钢质储酸罐腐蚀的分析

针对株洲冶炼厂硫酸库储酸罐外表的腐蚀情况进行分析，认为当地的降雨情况、空气温度、风向等因素对加剧储酸罐的腐蚀有相当重要的影响。提出在储酸的建设中，如果能结合具体情况深入探讨环境因素对腐蚀的影响，将有助于进一步降低防腐成本、延长储酸罐的使用寿命。     

硫酸/草酸体系下拜耳法赤泥中铁铝浸出行为的差异

为探清赤泥中的Fe、Al在硫酸/草酸体系中浸出行为差异,比较研究了两种酸浸体系下广西某铝厂拜耳法赤泥中Fe、Al的浸出规律及机制。主要考察了酸浸过程因素对Fe、Al浸出效果的影响,比较分析了最佳试验条件下拜耳法赤泥中Fe、Al在不同酸浸体系的浸出差异,并通过浸出动力学和热力学分析阐述了硫酸/草酸体系下Fe、Al的浸出过程机理。研究表明,试验条件下,硫酸对Fe、Al的浸出效果均优于草酸;酸性溶液中赤泥各元素的浸出具有阶段性,其中Al的浸出优先于Fe;硫酸/草酸体系中对Fe浸出的效果差异主要体现在无机酸酸根和有机酸酸根供电子能力和作用机制不同,对Al浸出的效果差异主要体现在对赤泥中铝氧化物的作用机制不同。这一发现对充分利用不同酸处理赤泥、优化分离提取赤泥中有价金属提供了新思路。     

Cytotoxicity of hemolytic, cytotoxic necrotizing factor 1-positive and -negative Escherichia coli to human T24 bladder cells

Approximately one-half of Escherichia coli isolates from patients with cystitis or pyelonephritis produce the pore-forming cytotoxin hemolysin, a molecule with the capacity to lyse erythrocytes and a range of nucleated cell types. A second toxin, cytotoxic necrotizing factor 1 (CNF1), is found in approximately 70% of hemolytic, but rarely in nonhemolytic, isolates. To evaluate the potential interplay of these two toxins, we used epidemiological and molecular biologic techniques to compare the cytotoxicity of hemolytic, CNF1(+), and CNF1(-) cystitis strains toward human T24 bladder epithelial cells in vitro. A total of 29 isolates from two collections of cystitis-associated E. coli were evaluated by using methylene blue staining of bladder monolayers at 1-h intervals after inoculation with each strain. Most (20 of 29) isolates damaged or destroyed the T24 monolayer (less than 50% remaining) within 4 h after inoculation. As a group, CNF1(+) isolates from one collection (11 strains) were less cytotoxic at 4 h than the CNF1(-) strains in that collection (P = 0.009), but this pattern was not observed among isolates from the second collection (18 strains). To directly evaluate the role of CNF1 in cytotoxicity of hemolytic E. coli without the variables present in multiple clinical isolates, we constructed mutants defective in production of CNF1. Compared to the CNF1(+) parental isolates, no change in cytotoxicity was detected in these cnf1 mutants. Our results indicate that CNF1 does not have a detectable effect on the ability of hemolytic E. coli to damage human bladder cell monolayers in vitro.     

精苯废酸焙烧制硫酸的试验研究

精苯废酸经过初步处理、静置分离去除酸焦油后送入硫酸生产装置沸腾炉沸腾层进行焙烧,通过高温裂解、吸收得到硫酸,将废物进行资源化处理利用。介绍了试验原理、生产工艺及操作参数的确定,按规模为年产1万t的粗苯精制加工装置产生废酸700t计,年效益可达15万元。     

Toxin-induced activation of the G protein p21 Rho by deamidation of glutamine

Pathogenic Escherichia coli are responsible for a variety of diseases, including diarrhoea, haemolytic uraemic syndrome, kidney infection, septicaemia, pneumonia and meningitis. Toxins called cytotoxic necrotizing factors (CNFs) are among the virulence factors produced by uropathogenic (CNF1) or enteropathogenic (CNF2) E. coli strains that cause diseases in humans and animals, respectively. CNFs induce an increase in the content of actin stress fibres and focal contacts in cultured cells. Effects of CNFs on the actin cytoskeleton correlated with a decrease in the electrophoretic mobility of the GTP-binding protein Rho and indirect evidence indicates that CNF1 might constitutively activate Rho. Here we show that CNF1 catalyses the deamidation of a glutamine residue at position 63 of Rho, turning it into glutamic acid, which inhibits both intrinsic GTP hydrolysis and that stimulated by its GTPase-activating protein (GAP). Thus, this deamidation of glutamine 63 by CNF1 leads to the constitutive activation of Rho, and induces the reorganization of actin stress fibres. To our knowledge, CNF1 is the first example of a bacterial toxin acting by deamidation of a specific target protein.     

Characterization of luminescent hydroxyapatite@terbium complex core-shell composites using chlorobenzoic acid as ligands

Three kinds of novel hydroxyapatite@terbium complex core-shell composites were synthesized with 2-chlorobenzoic acid, 4-chlorobenzoic acid, and 2,4-dichlorobenzoic acid as the ligand, respectively. The XRD, UV/vis absorption and FT-IR results show that terbium ions are coordinated with ligands and the corresponding complexes are successfully included into composites. SEM and EDS results reveal that Tb complexes are fully and homogenously coated on the surface of hydroxyapatite (HAP) microspheres consisting of a large number of nanosized crystals. The strongest luminescence properties are obtained when 2,4-dichlorobenzoic acid is used as ligand. The study on fluorescence lifetime of composites shows that the lifetime is inversely related to emission intensity. TGA-DSC results indicate that the core-shell composites have an excellent thermal stability. Therefore, the current core-shell structure provides a cost-effective route to manufacture of biocompatible and heat-resistant highly luminescent materials.     

硫酸厂浓酸泄漏事故原因分析及应急处理方法

在对硫酸中金属腐蚀机理分析的基础上,探讨了硫酸厂浓酸区域各种泄漏情况产生的原因,并且针对不同的泄漏情况,提供了相应的应急处理方法。     

浓缩法除去湿法炼锌污酸中的氟

研究了冶炼烟气制酸过程产生的洗涤污酸浓缩除氟的效果和回用到湿法炼锌系统的可行性,通过模拟污酸和工业污酸浓缩试验,分析了污酸脱氟效果。浓缩过程中,当污酸中硫酸浓度低于40%时,气相中的氟浓度低于液相,污酸中的氟浓度增加;当污酸中硫酸浓度高于40%时,污酸中氟的挥发性增加,氟浓度开始逐渐降低;当污酸中硫酸浓度大于45.59%,污酸中氟的浓度急剧降低,污酸浓度超过81.67%时,污酸中氟的脱除率高于99.17%,氟含量降低到237.45mg/L。     

磷钨酸催化剂催化合成缩酮

以磷钨酸为催化剂，系统探讨了丁酮、环己酮分别与乙二醇、1，2-丙二醇反应生成缩酮，乙酰乙酸乙酯分别与乙二醇、1，2-丙二醇反应生成苹果酯、苹果酯-B的优化条件。系统探讨了催化剂用量、反应物的物质的量之比、反应时间对产品收率的影响。结果表明，磷钨酸是合成缩酮的优良催化剂，在醇酮(酯)摩尔比为1．5：1，催化剂用量为反应物料总质量的0．5％，反应时间1．0h的优化条件下，苹果酯收率为82．2％，苹果酯-B收率为90．3％，环己酮乙二醇缩酮收率为74．0％，环己酮1，2-丙二醇缩酮收率为77．6％，丁酮乙二醇缩酮收率为52．4％，丁酮1，2-丙二醇缩酮收率为70．1％。