氢氧化钠浸取-浸取渣熔融法从炼钢厂烟尘中提取锌的研究

Extractability of zinc from two types of electric arc furnace (EAF) dusts containing 24.8% and 16.8% of zinc respectively (denoted as Sample A and Sample B) were tested using direct alkaline leaching followed by fusion of the resulting leaching residues with caustic soda. The experimental results show that the extraction of zinc is heavily dependent on the contents of iron in the dusts. The higher iron content, the lower extraction of zinc is obtained. 53% and 38% of zinc can be extracted when both dusts were directly contacted with 5 mol.L-1 NaOH solution for 42 h. The remaining zinc left in the leaching residues, which supposed to be present as zinc ferrites, can be further leached when the residues were fused with caustic soda. Quantitative extraction of zinc can be obtained from the leaching residue of Sample A while only 85% from Sample B. The extractability of zinc from dusts with various contents of iron is compared. The production flowsheet for zinc from the dusts using the process proposed is d     

表面活性剂在气/液界面上扩散控制的吸附动力学(英文)

For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate （SDS） solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion.     

借助变阱宽方阱链流体状态方程模拟非电解质体系表面张力和粘度(英文)

The equation of state(EOS)for square-well chain fluid with variable range(SWCF-VR) developed in our previous work based on statistical mechanical theory for chemical association is employed for the correlations of surface tension and viscosity of common fluids and ionic liquids(ILs).A model of surface tension for multi-component mixtures is presented by combining the SWCF-VR EOS and the scaled particle theory and used to produce the surface tension of binary and ternary mixtures.The predicted surface tensions are in excellent agreement with the experimental data with an overall average absolute relative deviation(AAD)of 0.36%.A method for the calculation of dynamic viscosity of common fluids and ILs at high pressure is presented by combining Eyring’s rate theory of viscosity and the SWCF-VR EOS.The calculated viscosities are in good agreement with the experimental data with the overall AAD of 1.44% for 14 fluids in 84 cases.The salient feature is that the molecular parameters used in these models are self-consistent and can be applied to calculate different thermodynamic properties such as pVT,vapor-liquid equilibrium,caloric properties,surface tension,and viscosity.     

预分散溶剂萃取分离苯酚溶液的研究

Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient and very quick. The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation, reduction of interracial mass transfer and low interfacial mass transfer areas in solvent extraction process. In present paper, colloidal liquid aphrons are successfully generated using kerosene as a solvent,tributyl phosphate(TBP) as an extractant, sodium dodecyl benzene sulphate(SDBS) as surfactant in aqueous phase and Tween-80 in oil phase. Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column. It has been found that the PDSE process is more suitable for extraction of dilute solutions. It has also been discovered that the PDSE process has a great advantage over traditional single-stage extraction process.     

偶联阳离子表面活性剂和常用阴离子表面活性剂混合溶液的相分离和微观结构

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-l,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.     

The Effects of Oxidative Pretreatment of Zinc-containing Dust on Contents of Iron and Manganese in Ammoniacal Leaching Solution and Product ion of Zinc Oxide

The zinc-containing dust was oxidatively pretreated with calcium hypochlorite,subsequently leached with ammonia/ammonium bicarbonate solution to obtain the ammoniacal leaching solution,and zinc oxide was produced by ammonia distillation of the ammoniacal leaching solution and subsequent calcination. The elements of iron and manganese could not be detected in ammoniacal leaching solution,and the extraction rate of zinc was 98.2% in ammoniacal leaching process. The zinc oxide content in the product is 99.5%(ω),and the contents of iron and manganese in the product were 0.002 8‰ and 0.000 84‰(ω), respectively. The analyses of the valence states of iron and manganese in the zinc-containing dust with and without pretreatment were performed by chemical analysis and XPS,and the possible oxidation mechanism of the oxidative pretreatment of the dust was discussed. It is concluded that Fe 2+-oxide and Mn 2+-oxide in the dust were oxidized to Fe 3+-oxide and/or its hydrate and Mn 4+-oxide and/or its hydrate by calcium hypochlorite during the oxidative pretreatment process,respectively.     

十二烷基磺酸钠/异辛烷/正构醇/水微乳状液的相行为及其结构转变的研究

The forming mechanism of microemulsion of sodium dodecyl sulfonate.alcohols,water and isooctane was studied,with particular emphasis on the effect of molecular weight and concentration of alocohols.Phase diagram of the four components,alcohol, sodium dodecyl sulfonate,water and isooctane,was used as a means of study,through which the microemulsion regions were determined.Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at km=2(km=Wn-pentanol/WSDS)is presented. The variation of conductivities of different microemulsion samples with water was measured.From the conductivities we investigated a change in structure from water droplets in oil(W/O)at low water content to liquid crystal at intermediate water content and a structure of oil droplets in water(O/W)at high water content.     

喷射状态下大孔径复合筛板塔中的液滴分布

The droplet size distribution with large-holed compound sieve tray operating in the spray regime is measured by using a double electrical probes technique in a cold model column of 400 mm diameter. The results indicate that the hole F-factor Fo and surface tension are the main factors which influence the liquid dispersion expressed by the Sauter mean diameter D32. A correlation of D32 on surface tension, viscosity, F-factor, weir height and liquid flow rate is proposed.     

鼓泡塔中低浓度表面活性剂对CO2吸收传质系数的影响（英文）

The effect of different surfactants (n-octyltrimethylammonium bromide (OTABr), sodium dodecyl benzene sulfonate (SDBS) and Tween 80) with different critical micelle concentrations (CMC) on the CO2 absorption into aqueous solutions in a bubble column is analyzed in the present work. The presence of these surfactants in-creased the gas–liquid interfacial area, and decreased the liquid phase mass transfer coefficient, but with signif-icant different extent. The results indicated that the CMC can be a key parameter affecting the mass transfer of CO2 absorption into a dilute aqueous solution of a surfactant. Sardeing's model was used to fit the experimental data successfully by re-correlating the parameters.     

Hydrothermal synthesis of calcium sulfate whisker from flue gas desulfurization gypsum

Plenty of flue gas desulfurization (FGD) gypsum generated from coal-fired power plants for sulfur dioxide se-questration caused many environmental issues. Preparing calcium sulfate whisker (CSW) from FGD gypsum by hydrothermal synthesis is considered to be a promising approach to solve this troublesome problem and uti-lize calcium sulfate in a high-value-added way. The effects of particle size of FGD gypsum, slurry concentration, and additives on CSW were investigated in this work. The results indicated that fine particle size of FGD gypsum and moderately high slurry concentration were beneficial for crystal nucleation and growth. Three additives of magnesium chloride, citric acid, and sodium dodecyl benzene sulfonate (SDBS) were employed in this study. It was found that mean length and aspect ratio of CSW were both decreased by the usage of magnesium chloride, while a small quantity of citric acid or SDBS could improve the CSW morphology. When multi-additives of citric acid-SDBS were employed, the mean length and aspect ratio increased more than 20%. Moreover, surface morphology of CSW went better, and the particle size and crystal shape became more uniform.     

表面活性剂对HCl-FeCl3溶液中锌精矿在浆萃取浸出率的影响

The effects of surfactant on the solvent extraction in leaching sphalerite were investigated. It is found that sodium dodecyl sulfonate is the effective surfactant in improving the zinc recovery from sphalerite in the aqueous FeCla-HCl-tetrachloroethylene system. Through the measurements of surface tension and viscosity of the sphalerite slurry modified with different surfactants, it is concluded that sodium dodecyl sulfonate in the concentration range of 0.05 to 0.2g@L-1 can improve the viscosity of sphalerite slurry in the water, decrease the surface tension of leaching solution, prevent the aggregation of ore particles, and give very high zinc extraction .     

表面活性剂在红土镍矿高压酸浸中的抑垢作用

研究了红土镍矿浸出过程中高压釜结垢与抑垢问题。采用XRD和SEM分析研究了表面活性剂十二烷基苯磺酸钠对结垢物相和形貌的影响,并考察了表面活性剂对矿浆性质的影响。研究发现十二烷基苯磺酸钠可以减小矿浆表面张力和黏度,添加量为70 mg·L^-1时抑垢效果显著,对镍浸出率影响不明显,可以缓解红土镍矿高压酸浸过程中反应器结垢问题。     

十二烷基苯磺酸钠表面张力的研究

通过表面张力的测定,研究了浓度、温度对溶液表面张力的影响,同时考察无机盐浓度对溶液表面张力的影响.结果表明:十二烷基苯磺酸钠溶液表面张力随浓度的增加、温度的升高和无机盐浓度逐渐的增大而降低,最终确定其CMC值为1.47×10-3mol/L,由于键能和水合离子半径的原因,NaCl对十二烷基苯磺酸钠表面张力的影响明显于KCl.     

两性/阴离子表面活性剂复配体系性能研究

采用环氧氯丙烷与磷酸二氢钠反应制备中间体,再与十二叔胺反应,制备甜菜碱型磷酸酯两性表面活性剂,并与十二烷基苯磺酸钠(SDBS)进行复配。测定复配前后产品的表面张力、临界胶束浓度、泡沫稳定性和乳化能力等性能。结果表明,在最佳合成工艺条件下,甜菜碱型磷酸酯两性表面活性剂的表面张力为30 mN/m,临界胶束浓度为7.98 g/L。对于复配体系,当甜菜碱型磷酸酯表面活性剂与SDBS以质量比6∶4进行复配时增效作用最好,其表面张力为23 mN/m,临界胶束浓度为4.84 g/L,对松节油的乳化性能较好。     

Effect of hydrotropes on the aqueous solution behavior of surfactants

Aqueous solutions of surfactants—cationic: tetradecyltrimethylammonium bromide (C₁₄TABr); anionic: sodium dodecyl sulfate (SDS); and nonionic: polyoxyethylene t-octylphenol (trade name Triton X-102, also called OPE-8)— in the presence of three hydrotropes, viz., sodium xylene sulfonate, sodium p-toluene sulfonate, and sodium chlorobenzene sulfonate, were examined by measuring surface tension, viscosity, and cloud points for the nonionic surfactant. The results show a marked decrease in the critical micelle concentration with increase in hydrotrope concentration for C₁₄TABr, a marginal decrease for SDS, and very little change for OPE-8 up to 0.1 M hydrotrope. The viscosity of cationic surfactant solutions showed a remarkable increase in the presence of trace amounts of hydrotropes (up to 15 mM). In contrast, the SDS solution showed only a slight increase in viscosity at high hydrotrope concentration (150 mM), and the viscosity of the OPE-8 solution remained constant. The cloud point of OPE-8 increased in the presence of hydrotropes, unlike its behavior with the simple salt NaCl. The strong dependence of the solution behavior of cationic surfactants on the presence of hydrotropes is discussed in terms of electrostatic interaction.     

Influence of nonionic surfactant additive on the properties of ionic surfactant solutions

The interaction of sodium dodecyl sulfate with a nonionic surfactant (a block copolymer of ethylene oxide and propylene oxide) has been investigated by the measurement of conductivity, surface tension and viscosity. The break point on the equivalent conductivity-square root of concentration diagram which gives the critical micelle concentration (cmc) of sodium dodecyl sulfate became less definite by the addition of the nonionic surfactant, because of the decrease in conductivity below the cmc and increase above the cmc. The steep decrease in reduced viscosity took place in dilute concentration of sodium dodecyl sulfate solutions. In the surface tension vs. concentration diagram, the concentration at which the two linear portions of the curve intersect represents the cmc. The addition of nonionic surfactant decreases this crossed point of sodium dodecyl sulfate and finally obscures the crossed point. These reults are interpreted in terms of an interaction between sodium dodecyl sulfate and nonionic surfactant.     

表面活性剂对气体水合物生成过程的定量影响

为确定HCFC?141b水合物生成条件下阴离子表面活性剂十二烷基硫酸钠(SDS)和十二烷基苯磺酸钠(SDBS)的临界胶束浓度(CMC),在0~20℃温度下,通过圆环法实验研究了不同浓度表面活性剂溶液体系的表面张力,考察了表面活性剂对溶液体系表面张力的影响机理并通过C3H8水合物的生成过程实验进行了验证,确定了SDS和SDBS的临界胶束浓度. 结果表明,当SDS和SDBS的质量浓度分别低于500?10?6和100?10?6时,表面活性剂降低水表面张力的效果最明显,二者的CMC分别为1950?10?6和400?10?6,表面活性剂能明显缩短水合反应的诱导时间,提高了其平均生成速率.     

Surfactant-like Properties of Alkaline Extracts from Wastewater Biosolids

In order to assess the potential for utilizing wastewater biosolids as a source of useful substances, the surface activity of materials extracted from wastewater biosolids (activated sludge) by simple incubation with sodium hydroxide solutions at room temperature was assessed. The surface activity, measured by surface and interfacial tension methods, of the extracts was shown to be dependent on the extraction pH and the concentration of the organic matter solubilized in the alkaline solution. Increasing the extraction pH increased the surface activity of the extract (lower surface tensions), which is linked to the presence of more hydrophobic species in the extract. After adjusting the pH to more acidic values (e.g., pH = 4), the extracts retained their surface activity. The apparent CMC (critical micelle concentration) of pH 12.6 extracts was approximately 1,000 mg/L (based on total organic carbon or TOC), and the surface tension after CMC approximately 35 mN/m. While the CMC of the extract is significantly higher, when compared to a conventional surfactant, sodium dodecyl benzene sulfonate (SDBS, CMC ~ 25 mg/L), its surface tension at CMC was comparable. Above its CMC, the pH 12.6 extract had similar interfacial tensions than SDBS against toluene, heptane and hexadecane. Furthermore, the extract and SDBS had similar detergency performance for the removal of hexadecane from cotton. Skin corrosivity tests of the neutralized extracts show that they have comparable toxicity to conventional anionic surfactants such as sodium dodecyl sulfate. The potential use of these extracts in commercial products is discussed.     

Synthesis and Micellization Properties of New Anionic Reactive Surfactants Based on Hydrogenated Cardanol

We report the synthesis, characterization and micellization properties of two anionic reactive surfactants based on 3-pentadecyl phenol obtainable from a renewable resource, cardanol. The synthesis is achieved through simple chemical transformations, first converting the phenol to the acrylate that is sulfonated in a second step. The products were characterized by elemental analysis and spectroscopic techniques. The surfactant properties of the sulfonated acrylates were measured and compared with the standard non-reactive anionic surfactant sodium dodecyl sulfonate. The micellization behavior of aqueous solutions was studied using conductivity, surface tension measurements, and the fluorescence probe technique based on diphenyl hexatriene. Characterization by surface tension measurements facilitated the determination of basic surfactant properties like the critical micelle concentration (CMC), the surface tension at the CMC, surface excess and area per surfactant molecule. The Gibbs free energy of micellization showed a negative value suggesting spontaneous micellization in aqueous solution. The micellization of the surfmer with an ethylene spacer between the phenyl ring and the acrylate group seems to be enhanced as indicated by the lower surface excess and lower free energy. Its CMC was also lower.     

十二烷基苯磺酸钠与非离子氟碳表面活性剂复合驱油剂的研究

研究了十二烷基苯磺酸钠(SDBS)/氟碳Intechem-01表面活性剂(FC-01)复合驱油剂的性能,以驱油率、界面张力、与注入水和模拟地层水的配伍性为考察指标,正交实验结果表明,氟碳Intechem-01表面活性剂的质量分数为0.05%,十二烷基苯磺酸钠的质量分数为0.15%,碳酸钠、碳酸氢钠的质量分数都为0.25%时,复配体系的效果较好,且复配体系与定边油田采油注入水和模拟地层水有良好的配伍性。