Pelletization of magnetite ore with colemanite added organic binders

A new generation binder consisting of an organic binder and a borate salt was tested as an alternative to bentonite in magnetite ore pelletization. Carboxyl methyl cellulose (CMC), Ciba DPEP06-0007 and corn starch, and calcined colemanite were used as organic binders and the borate salt, respectively. They were added to the pellet feed separately and in different combinations at several addition levels. It was found that the use of organic binders is sufficient in terms of wet pellet quality; however, they fail to render the required compressive strength to pre-heated and fired pellets. Therefore, organic binders and calcined colemanite were used together so that wet pellets, pre-heated and fired pellets would be of the required quality. The results showed that the use of an organic binder together with calcined colemanite indeed yielded pellets with equal or better wet and indurated pellet qualities compared to the pellets produced with bentonite binder alone.     

Investigation of the hydrogenation reactivity of some organic substrates using an electrocatalytic method

The hydrogenation reactivity of some classes of organic substrates (α,β-unsaturated ketones, benzaldehydes and acetophenones) was investigated using an electrocatalytic method (undivided cell, nickel sacrificial anode and water/methanol solvent). During the process a nickel deposit is produced on the cathode surface, at the same time that hydrogen is generated by water reduction. Nickel deposit morphologies (catalyst surface) were investigated, taking into account different cathode matrix materials (Cu, Ni, Fe, Fe/Ni (alloy 64:36)). The electrocatalytic method was evaluated by electrochemical efficiency of the hydrogenation process ((hydrogenation theoretical charge/experimental charge) × product yield). It was observed that Ni deposit/Ni cathode matrix ensemble exhibits slightly better catalytic activity, likely due the nanostructure of the nickel deposit. Moreover, the reactivity order determined through the electrochemical efficiencies (α,β-unsaturated ketones > benzaldehydes > acetophenones) is the same as that found in the literature.     

Investigation of flow properties of asphalt binders containing polymer modifiers

Modified asphalts using polymeric additives, including isotactic polypropylene (iPP) and different degrees of chlorinated polypropylene (CPP), have been prepared and examined using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), rotational viscometer, and dynamic shear rheometer (DSR) in this study. The results of DSC studies show that different levels of the crystallization occur in asphalt/iPP blends because most of the crystallinity of iPP remain intact in the blend, while those asphalt samples having CPP tend to affect the thermal behavior in the DSC thermograms because of increasing the amorphous region of CPP. From the images of SEM, the distinctions of the phase distributions between the asphalt/iPP and asphalt/CPP blends illustrate that the chlorine content in CPP is a significant factor in controlling its compatibility with asphalt. The rheological studies show that the asphalt blends containing CPP (26 wt% of Cl) exhibit higher viscosity in terms of higher temperature to get Newtonian behavior and display superior rutting resistance to avoid permanent deformation at high temperature. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Investigation of ionic polymer cathode binders for microbial fuel cells

Microbial fuel cell (MFC) air cathodes examined here were made using poly(phenylsulfone) (Radel^®) binders sulfonated to various ion exchange capacities (IECs). We examined the effect of increasing the IEC of poly(phenylsulfone) Radel binders from 0 to 2.54 meq/g on cathode performance using linear sweep voltammetry (LSV), impedance, and single chamber air-cathode MFC tests. Unsulfonated Radel, which is a non-ionic, hydrophobic polymer, showed the highest current in LSV tests and the lowest charge transfer resistance. Increasing the binder IEC resulted in a decreased current response in LSV tests and an increased charge transfer resistance from 8 to 23 Ω. It is proposed that the presence of sulfonate groups in the cathode binder impeded the oxygen reduction activity of the cathodes by adsorption of the sulfonate to catalytic sites and by impeding proton diffusion to the catalyst surface. The unsulfonated Radel binder produced the most stable performance, and eventually the highest power density, in MFCs operated over 20 cycles (55 days). These results suggest that the use of a non-ionic binder is advantageous in an MFC cathode to facilitate charge transfer and stable performance in the neutral pH conditions found in MFCs.     

Two-component aqueous epoxy binders free of volatile organic content (VOC)

Water-borne two-pack coatings based on a novel epoxy resin emulsion, cross-linked with three different amine group containing curing agents, are discussed. The aqueous binders developed at the Research Laboratory at Dow Deutschland Inc. are free of volatile organic content. The epoxy resin emulsion has a low MFFT (minimum film formation temperature) and is hence capable of forming a continuous film at low temperatures and good emulsifying properties. The interaction is discussed between the epoxy emulsion, pigments and hardeners which are in aqueous solution, emulsion or hydrophobic (non-aqueous) form. Some of the described systems will gain interest in a wide range of applications because of their excellent properties, including adhesion to various substrates, resistance to chemicals, solvents and water, hardness and toughness. The predicted major applications for such systems include concrete, plastic and wood coatings, and anti-corrosive systems for steel and other metals.     

Grinding high-quality and art glass with diamond grinding wheels with organic binders

It has been found that using the new organic binder MV1 with grinding powder with grain size 45/38 µm instead of the binder M2-01 with micropowder grain size 30/40 µm increases the productivity of the final diamond grinding of high-quality and art glass by a factor of 2–2.5 without any subsequent chemical polishing and decreases the roughness of the worked surface by 20% with 14–28% higher specific consumption.     

Investigation on some physicochemical properties of guest-conjugated and -incorporated hybrid organic/inorganic linear-dendritic nanocarriers

Benzyl alcohol, as a model compound in conjugation, and 1-(2-pyridylazo)-2-naphtol (PAN), as a lipophilic dye molecule in encapsulation, were exploited using linear-dendritic ABA amphiphilic triblock copolymers, which is known as “hybrid macromolecules”, containing silicon atoms by two methods. In the first route, benzyl alcohol was attached to the Si-Cl peripheral groups of the hybrid in different generations to synthesize host-benzyl alcohol conjugates. In the second procedure, PAN as the guest molecule was incorporated into different generations of the synthesized hybrid. Binding capacity and incorporation content (IC) of different generations of the hybrid were investigated using conventional methods such as nuclear magnetic resonance and UV–vis spectroscopy. It was observed that the IC, hydrolytic behavior and the release rate from the prepared micellar structures can be tuned by either external parameters such as pH or internal parameters such as hydrophilic/lipophilic ratio by developing generations. Dynamic light scattering and transmission electron microscopy experiments depicted diameter of the prepared nanocarriers between 100 to 250 nm. The release of guest molecules from the carriers was evaluated at pH 1, 7.4 and 10. Briefly, the prepared micelles can play a role as carrier with tunable release rate without sacrificing their micellar stability.     

Strength development and hydrate formation rate. Investigation on anhydrite binders

It does not seem possible to obtain an accurate correlation between the strength development and the rate of calcium sulfate dihydrate formation in anhydrite binders. Investigations on the hydration and hardening of anhydrite samples from different origins allows us to point out that the representation of strength versus the calcium sulfate dihydrate content of the hardened material leads to a diagramm with very scattered experimental points. That is due to a large variation in both the porosity and the crystal habit of dihydrate crystal which are directly connected to the nucleation rate during the hydration reaction. This observation is certainly not limited to anhydrite binders.     

Effects of binders and organic vehicles on the emission properties of carbon nanotube paste

The different inorganic binders and organic vehicles were used to synthesize carbon nanotube (CNT) paste for field emission display. The morphologies, thermal and emission properties of the CNT paste with different components were investigated. The uniformity, the adhesion, and emission properties of CNT paste was improved when an inorganic binder changed from a glass frit to spin on glass (SOG). The current density increases by 5 times in magnitude when the ethyl cellulose solution was used instead of to acryl solution. The fabricated CNT emitter using photosensitive CNT paste showed high brightness of 18,000 cd/m² at low operating voltage of 1200 V.     

Immobilization of heavy metals in a contaminated soil using organic sludge char and other binders

The applicability of tannery (TSC) and dye sludge char (DSC) as a binder to immobilize heavy metals (Zn, Cu and Ni) in soil was investigated. The toxicity characteristic leaching procedure (TCLP) was used to estimate the immobilization efficiency for single-binders (TSC and DSC) and binary-binders (TSC or DSC combined with tripostassium phosphate (K₃PO₄) diammonium phosphate (DAP), lime or ladle slag). The immobilization efficiencies of Zn, Cu and Ni by TSC amendment were 84.2, 100.0 and 40.0%, respectively, which were higher than 28.5, 100.0 and 54.9% by DSC amendment for a binder dose of 0.80 g char/g soil. The binary-binder enhanced Zn immobilization to 56.3 and 97.2% at 0.6 g-DSC/0.06 g-Ca(OH)₂ and 0.4 g-TSC/0.08 g-Ca(OH)₂, respectively per 1 g dried soil. The immobilization efficiencies of heavy metals increased with aging for the DSC-binary binders, but not for TSC-binary binders.     

Ecological problems due to the use of organic binders in the production of fibrous heat-insulating materials

The standards for maximum permissible emission of contaminating substances into the atmosphere from enterprises producing fibrous heat-insulating materials take into account emissions formed in processing the basic inorganic raw materials and do not reflect emissions of the products of decomposition of auxiliary organic substances participating in the technological process (organosilicon liquids, mineral oils, bitumens). Investigations show that for any technology the main products of the decomposition of these materials are more toxic than the inorganic components of the emissions.Translated from Ogneupory, No. 10, pp. 6–7, October, 1995.     

二氧化氯有机稳定化的探讨

用乙二胺四乙酸二钠(EDTA)对二氧化氯进行稳定化实验,使用紫外分光光度法检测二氧化氯的浓度,测定了反应物之间的化学计量关系,分析了酸度对EDTA的影响,根据EDTA配合物的结构提出两者不可能形成配合物而是发生了氧化还原反应,并据此解释了化学计量关系、红外图谱、二氧化氯释放等实验现象.     

Reactivity of some organic compounds with supercritical water

This study was initiated to determine some of the chemical reactions that occur during the supercritical fluid extraction of coal, using model compounds to simulate molecular structures found in coal. Water was chosen as the fluid because of its unique chemical and physical properties at critical conditions. Two primary functions of coal processing are the removal of heteroatoms and the depolymerization of larger molecules, thus the reactions of quinoline and isoquinoline were extensively examined, with very brief studies made of benzonitrile, aniline, tetralin, dihydroanthracene and ethylbenzene. In addition, since ZnCl₂ has been used as a hydrogenation catalyst and in the hydrocracking of aromatics, it was added in some experiments to increase the reactivity of some of the compounds. It was found that the compounds studied were more reactive and reached by different mechanisms in the presence of supercritical water than when undergoing inert pyrolysis. The product distributions from the two quinolines indicated that they reacted by very different mechanisms; possible reaction schemes for these are discussed. In addition, it was found that about 70% of the nitrogen from the consumed quinolines and aniline was removed in the water layer as ammonia, that alkyl sidechains on aromatics were somewhat reactive and that some carbon atoms are oxidized by the water thus providing a source of hydrogen for the formation of other products.     

Carbonization of petroleum binders. 2. Oils from carbonization of petroleum binders

Changes of composition, structure, and contents of some functional groups, of oils from petroleum binders, in relation to temperature of carbonization from about 710 K to 1200 K have been investigated. Oils from carbonization of petroleum binders are of hydrocarbon type, and their elemental compositions are almost independent of carbonization temperature. During the thermal decomposition of these binders, about 75–80 wt % of gaseous and vapour products are emitted. As carbonization temperature increases, molecular weights of the oils increase from about 250 to about 290; their density, index of refraction, and molar refraction increase. Structural analysis of the oils showed that they contained about 30% of cyclic hydrocarbons (aromatic and cycloalkane) as well as alkanes. The number of rings in the average structural unit of oil increases with increase of carbonization temperature, especially the number of aromatic rings. About 60–70 vol % distills before 633 K under atmospheric pressure; the distillate is paraffinic, while the residue after distillation is aromatic-alicyclic. Oils from carbonization of P-70 asphalt have similar compositions and chemical natures, but lower molecular weights, than oils from carbonization of residues after vacuum distillation of crude oil. Oils from carbonization of pitch are decidedly aromatic.     

Effect of elevated temperature on alkali-activated geopolymeric binders compared to portland cement-based binders

This research focused on developing thermally-stable materials based on alkali-activation of slag, fly ash, and metakaolin compared to portland cement mixtures by using a hierarchical approach to material design. At lower length scales, X-ray diffraction (XRD) characterized the mineralogy that coupled to higher length scale experiments using thermogravimetric analysis (TGA) for determining the materials thermal stability. Additionally, high-energy X-ray computed microtomography (μCT) determined the best-performing material formulation that minimized thermal damage when exposed to high temperatures (650 °C). The thermal loading was ramped up to 650 °C from ambient temperature in 60 s and then held for a total of 10 min. The μCT identified that the alkali-activated fly ash mortar had less initial porosity than the ordinary portland cement mixtures, with more than 66% of the pores between 20 and 50 μm in diameter. Consequently, the alkali-activated fly ash mortar was able to dissipate approximately 565 °C in just 50 mm of material, outperforming all the other mixes studied in this paper with μCT confirming minimal damage after the temperature exposure.     

水杨醛类席夫碱有机光致变色化合物的研究

水杨醛缩芳胺类席夫碱具有良好的光致变色或热致变色性质.论述了制备水杨醛缩芳胺类席夫碱光致变色化合物的3种方法,简单地分析了光致变色的主要影响因素,阐明了水杨醛缩芳胺类席夫碱基于分子内的质子转移的光致变色机理.综述了水杨醛缩芳胺类席夫碱有机光致变色化合物的研究状况,并对此类光致变色材料的研究应用前景进行了展望.     

Thermorheological properties of asphalt binders

The rheological properties of different types of asphalt binders were studied and compared considering their constituents and physical characteristics. The saturate, aromatic, resin, and asphaltene (SARA) analysis and differential scanning calorimetry (DSC) have shown their individual constituents and two distinct glass transition temperatures, indicating the phase changes of the two main components of the asphalt binders, namely asphaltenes and maltenes. Rheological characterization was performed over a wide range of temperatures (−10°C-60°C) showing that these materials may exhibit viscoelastic solid to viscous liquid behaviour. Master curves of complex viscosity, storage modulus, and loss modulus were constructed by applying the time-temperature superposition principle, which was found applicable over the temperature range considered. Stress relaxation and steady-shear test were applied to the samples in order to determine their rheological behaviour in the nonlinear viscoelastic regime (viscosity and nonlinear relaxation modulus). The rheological results were modelled and revealed that the Kaye-Bernstein-Kearsley-Zappas (K-BKZ) constitutive equation is suitable in representing the rheological behaviour of asphalts. The SARA analysis and rheological measurements were found to be compatible.