Application of the methylene blue test to cement raw materials

Characterisation of raw materials for Portland cement manufacture by use of the methylene blue adsorption method is discussed. The method is shown to be a simple, convenient ‘rule of thumb’ procedure. It provides a guide to the quantity and type of argillaceous minerals present in a given raw material sample.     

Poly(butylene terephthalate)–clay nanocomposites prepared by melt intercalation: morphology and thermomechanical properties

Nanocomposites based on poly(butylene terephthalate) (PBT) and an organoclay (Cloisite 30B) were prepared by melt blending using a twin‐screw extruder. Two kinds of PBTs, ie PBT‐A and PBT‐B, with different inherent viscosities (η_inh), were used for this study (η_inh of PBT‐A and PBT‐B were 0.74 and 1.48, respectively). Dispersion of the clay layers in the PBT nanocomposites was characterized by using X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile and dynamic mechanical properties and non‐isothermal crystallization temperatures of the nanocomposites were also examined. Nanocomposites based on the higher‐viscosity PBT (PBT‐B) showed a higher degree of exfoliation of the clay and a higher reinforcing effect when compared to the composites based on the lower‐viscosity PBT (PBT‐A). The clay nanolayers dispersed in PBT matrices lead to increases in the non‐isothermal crystallization temperatures of the PBTs, with such increases being more significant for the PBT‐B nanocomposites than for the PBT‐A nanoocomposites. Copyright © 2004 Society of Chemical Industry     

CuMgAl类水滑石的制备和表征

用盐-碱制备法合成了CuMgAl三元类水滑石化合物。探讨了原料配比、合成方式、水热处理温度和时间对合成过程的影响,筛选出合成HTLcs的适宜条件,并对HTLcs结构的热稳定性进行初步研究。结果表明,制备HTLcs主要取决于pH值,同时由于Cu2+的姜-太勒效应,合成结构单一的CuMgAl类水滑石要求原料配比中n(Cu)∶n(Mg)不得超过1.0,CuMgAl-HTLcs热稳定性较差,300℃焙烧2h结构破坏,600℃开始烧结,在300~500℃之间,随焙烧温度提高所得复合氧化物比表面积增大,最高可达200 m2/g。     

Electrochemical Aspects of Electroosmotic Dewatering of Clay Suspensions

An attempt is made to elucidate the electrochemical aspects of the electroosmotic dewatering (EOD) of clays as reported in some recent work, especially that on interrupted DC power electroosmotic dewatering published by Rabie, Mujumdar and Weber (2). These authors showed that the dewatering by EOD stops after the DC power has been on for several minutes or hours; on interruption of their power and on short-circuiting of the electrodes, conditions can be created again for some further dewatering by DC power EOD. This discovery, of Rabie et al. is interpreted as a fuel cell effect and it is shown that it affords clues to several other electrochemical strategies for the possible enhancement of the efficiency of the EOD by DC power.

Further, the open circuit potentials observed by Rabie et al. (2) on the interruption of DC power are given an electrochemical interpretation which leads to quantitative estimates in agreement with the experimental values.     

Ultrasound‐activated Knoevenagel condensation of malononitrile with carbonylic compounds catalysed by alkaline‐doped saponites

α,β‐Unsaturated nitriles have been synthesized by Knoevenagel condensation of a carbonylic compound with malononitrile, assisted by sonochemical irradiation. Two alkaline‐promoted clays (Li⁺‐ and Cs⁺‐exchanged saponites) have been employed as catalysts. The influence of the carbonylic compound (benzaldehyde or cyclohexanone) and the use of a solvent on the catalytic activity have been studied. Remarkable increase in the conversion values has been found when the reaction is activated by ultrasound, as compared with the thermal activation. In this green, solvent‐free procedure, α,β‐unsaturated nitriles have been produced in very high yields (97%) when the Cs⁺‐saponite is used as catalyst. Copyright © 2004 Society of Chemical Industry     

转炉出钢口套整体袖砖工艺技术开发

介绍了天津天铁冶金集团有限公司炼钢厂转炉出钢口袖砖工艺的开发过程，主要工艺参数的制定，实践证明，该工艺的应用取得了良好的使用效果。     

Metal sorption by biomass of melanin‐producing fungi grown in clay‐containing medium

The sorption of toxic metals by fungal mycelia grown in clay‐containing medium is reported in this work. Biomass of melanin‐producing microfungi of the genus Cladosporium (C cladosporioides, C resinae and C herbarum) and Aureobasidium pullulans, clay minerals and fungal mycelia grown in clay‐containing medium were compared for their equilibrium Cu and Cd uptake from pH‐buffered solutions using experimental sorption isotherms. Bentonite (Cherkassy) in the natural form was shown to be the best Cu sorbent compared with the other clays and clay minerals tested. Cu sorption isotherms fitted the Langmuir sorption model for all cases. Comparison of Cu and Cd uptake for biomass and bentonite showed a lower biomass uptake capacity but a considerably higher affinity of the biosorbent for the solute. The presence of kaolinite and palygorskite in the medium generally reduced both Cu and Cd sorption capacity and the metal‐binding ability of the fungal–clay mixtures. In contrast, addition of bentonite into the medium did not appreciably alter the Cd sorption ability but increased the sorption of Cu by A pullulans and C cladosporioides grown in this medium. A common feature for all fungi grown in the presence of bentonite was an increase in the Cu sorption capacity (Q_max) of the biomineral sorbents and a reduction in their affinity (Langmuir parameter b) compared with control biomass. A difference between predicted and experimental data obtained for biomass grown on bentonite medium was also observed. The connection between the sorption capacity of biomass grown in clay‐containing medium, mycelial morphology and the structure of fungal pellets is discussed and a mechanism for the changed sorption capacity of the combined biomineral sorbents is proposed which involves blocking or modification of binding sites on biotic and abiotic components of the ‘biomineral’ association. © 2002 Society of Chemical Industry     

Anhydrous esterification of myristic acid with propylene: Ion exchange resin and acid-treated clay as catalysts

Anhydrous esterification of myristic acid with propylene was carried out in the temperature range of 110–145°C and pressure from 190–195 psig in the presence of Amberlyst-15 (cation exchange resin) and Filtrol-24 (acid-treated clay) as catalysts. The product ester, isopropyl myristate finds use in cosmetic and topical medicinal preparations where good absorption through the skin is desired. Filtrol-24 is the catalyst of choice, and the recommended operating temperature is 130°C with a pressure of 190 psig.     

RH-KTB耐材长寿技术研究及应用

介绍了宝钢RH-KTB工艺条件下RH用镁铬砖的应用和提高浸渍管管龄、下部槽槽龄的方法.     

石灰竖窑工作衬砖蚀损机理的探讨

阐述了石灰竖窑的预热带、煅烧带和冷却带工作衬砖蚀损机理，并讨论了如何根据耐火砖性能和石灰竖窑不同区域的蚀损机理，选择耐火材料。