Effect of particle size on the surface oxidation and flotation behavior of galena particles in lime system

ABSTRACT

In this research, the effect of particle size on the surface oxidation and flotation behavior of galena in the lime system was studied. Coarse (?0.074 + 0.038 mm), intermediate (?0.038 + 0.025 mm) and fine (?0.025 mm) galena particles were used in the experiment. The dissolution tests, flotation tests, and sorption tests were accomplished. Through further analysis by XPS, the effect of particle size and lime was observed. The decrease of mineral particle sizes increased the adsorption ratio of collector and the dissolution of galena, while the hydrophilic product OH^?/Ca(OH)⁺ produced by dissolution occupied the dominant position, which led to the minerals hydrophilic.     

聚丙烯纤维母粒着色生产技术

概述了聚丙烯母粒色纺的生产技术,提出了色母粒制备的质量要求:颜料粒径≤1.0μm,细且丝颜料粒径≤0.5μm;压力过滤值≤0.15MPa·cm~2/g;色母粒热稳定性280～300℃.色母粒的加入对纺丝工艺与产品质量指标有影响,喷丝板换板周期色纺丝约为本色纺的一半,纤维强力约降低10%.依据有关配色定律可优化配方工艺,降低成本,增加效益.     

甲酸甲酯合成与转化的催化技术

本文评述了甲酸甲酯(MF)合成与转化的催化技术,展示了从MF出发发展C_1化学的可能途径,在MF的合成方面详细地分析了从甲醇出发的羰化法、脱氢法和氧化法催化技术,简介了我们的有关研究工作。     

The effects of bleached and unbleached rosemary oleoresins on light-sensitized oxidation of soybean oil

Bleached and unbleached forms of a rosemary oleoresin (RO) in stripped and nonstripped soybean oil behave both as antioxidant and prooxidant in a light-induced oxidative system. At 0.02 and 0.05% levels, RO had the greatest antioxidant activity, while at 0.01 and 0.5% levels it had the highest prooxidant activity in both stripped and nonstripped soybean oil. Treatment of both soybean oil systems with tertiary butylhydroquinone controlled light-induced oxidation of the oil better than did the oleoresin treatments. The prooxidant activity of the 0.5% RO level was probably due to an excess of prooxidant components being carried into the oil at that level, whereas the reduced antioxidant activity at 0.01% was probably due to the low initial level of active antioxidant components being added to the oil. Published as Journal Series No. 10072, Nebraska Agricultural Research Division, Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919.     

Exploring single electrode reactions in polymer electrolyte fuel cells

Utilising a pseudo-reference electrode in polymer electrolyte fuel cells allows for the separation of anodic and cathodic contributions to the entire cell impedance. Modelling the impedance responses by using equivalent circuits inhibits the investigation of kinetic parameters of the basic electrochemical reactions, which take place at single electrode-electrolyte interfaces. Therefore, we evaluate single electrode impedance measurements by a kinetic model, which is based on specific reaction pathways, either for the oxygen reduction reaction (ORR) or the hydrogen oxidation reaction (HOR). As a consequence, it is possible to obtain kinetic parameters for the specific reaction of interest. Furthermore, the information gained from the single electrode impedance measurements and the kinetic model can give insight into single reactions steps. In particular, the ORR has to include a chemical step in the reaction pathway.     

阻燃增塑剂溴化及溴氯化石蜡的合成工艺

综述了阻燃增塑剂溴化及溴氯化石蜡的各种合成工艺路线，讨论了相应的合成反应机理．包括反应历程和有关化学热力学计算，简要介绍了安徽省化工研究院已工业化的溴化及溴氯化石蜡合成工艺的特点。     

An Experimental Study of Fatigue Strength for Adhesively Bonded Tubular Single Lap Joints

In this paper, manufacturing technology of the tubular single lap adhesive joint was studied to obtain reliable and optimal joint quality. In addition, a surface preparation method and a bonding process for the joint were devised. The effect of the adhesive thickness and the adherend roughness on the fatigue strength of the joint was experimentally investigated. From experiments, it has been found that the fatigue strength of the joint increased as the adhesive thickness decreased and the optimal arithmetic surface roughness of the adherends was about 2 μm.     

On the nature of the active state of silver during catalytic oxidation of methanol

Under the applied high reaction temperatures (900 K) the Ag surface is restructured and a tightly held oxygen species is formed on the surface (O) apart from O atoms dissolved in the bulk (O). Methanol oxidation to formaldehyde proceeds through this O species as demonstrated by application of a variety of spectroscopic techniques.     

光气生产技术及光气化产品开发进展

综述了光气生产工艺技术、安全措施及主要光气下游产品种类。介绍了国内外光气生产及应用现状，涉及一氧化碳制备、氯气干燥、光气合成、废气处理和安全生产等技术。简述了光气化产品开发研究方向，提出重点开发IPDI(异佛尔酮二异氰酸酯)、NDI(1，5-萘二异氰酸酯)、氯磺酰异氰酸酯和较大分子量的氯代甲酸酯等光气化产品。     

涤纶短纤维生产现状及发展趋势

对目前国内外涤纶短纤维生产的企业规模和工艺技术现状进行了分析比较，并论述了涤纶短纤维生产的经济规模和今后的发展趋势。