高炉瓦斯泥压块循环应用于电炉泡沫渣的研究

对高炉瓦斯泥应用于电炉造泡沫渣进行了实验室试验和现场试验研究.确定了冷压块工艺和现场应用工艺.试验结果表明:瓦斯泥的压块可以起到强化泡沫渣生成的作用,但瓦斯泥压块的加入量有个合适的范围.压块加入后,压块中的铁和碳通过反应参与了泡沫渣的生成;压块中的锌和铅被快速还原,进入二次粉尘.瓦斯泥压块加入电炉,对钢水和渣没有产生可觉察的影响.在此过程中,压块中的有价资源得到了循环利用.     

SiCP增强泡沫铝基复合材料制备工艺及润湿性研究

对采用熔体发泡法直接制备碳化硅颗粒增强泡沫铝基复合材料进行了探索，讨论了制备过程中SiCp与铝液间的润湿性、发泡工艺参数与温度控制等对制备工艺的影喻。表明该工艺简单，易于操作，不需任何增粘措施，处理后的SiCp浸润性好且分布均匀，孔洞分布均匀。     

CaCO3发泡剂制备泡沫铝工艺研究

用CaCO3作发泡剂，用熔体发泡法制备泡沫铝，即Al—Si12在熔融状态下，加入活性剂Mg粉，再与SiC颗粒混合均匀，然后加入发泡剂(CaCO3)搅拌，进行保温发泡，最后冷却。结果表明，对于Al—Si12的合金，用CaCO3作为发泡剂，制备出孔隙结构均匀，平均孔隙率最大、结构均匀的泡沫铝的最优条件是：CaCO3含量1．2％～1．8％，加热温度680～700℃之间，保温时间4～8min之间。     

Amino acid composition,foaming, emulsifying properties and surface hydrophobicity of mustard protein isolate as affected by pH and NaCl

Amino acid composition, protein hydrophobicity, foaming and emulsifying properties of mustard protein isolate at pH 3, 5, 7 and in 0.05 and 0.1 m NaCl were studied. Glutamic (19.18 ± 0.30%) and aspartic (7.49 ± 0.11%) acids were the dominants. Foaming ability was enhanced by NaCl. Time to reach 75 mL foam was 23% higher in water than in NaCl. Drained volume after 10 min was concentration dependent and was the lowest in 0.05 and 0.1 m NaCl at protein concentration of 2.5% and 5%. The emulsifying properties were pH and concentration dependent, and the best results were obtained at pH 3, corresponding to the highest positive charge density of the protein surface. The highest emulsion stability (90.22 ± 3.52%) was obtained in 0.05 m NaCl and 5% protein concentration, whereas the lowest (63.00 ± 1.06%) was in water at all protein concentrations. Protein hydrophobicity was low and depended of pH but not of NaCl.     

Piezoresistivities of vapor‐grown carbon fiber/silicone foams for tactile sensor applications

Due to the growing demand for tactile sensors, the possibility of detecting an external uniaxial pressure by the piezoresistive measuring of a conductive filler/elastomer composite was investigated. A series of piezoresistive models are discussed. Novel highly sensitive piezoresistive foams with excellent elasticity were fabricated using vapor‐grown carbon fiber (VGCF), two‐component silicone elastomer and a new type of thermally expandable micro beads foaming agent to overcome the disadvantages of the silicone elastomer in the utilization of a tactile sensor. Deformations of the foams caused by uniaxial pressure were observed using scanning electron microscopy from cross‐sections. Effects of the VGCF and the foaming agent on the piezoresistivitiy were investigated. The piezoresistive mechanisms of the foams are discussed according to the measurements, and good fit was found between the theoretical calculations and the experimental piezoresistivity measurements. It is found that the addition of the micro beads foaming agent can improve the piezoresistivity of the VGCF/silicone foam and increase the sensitivity and repeatability for its application in a tactile sensor. © 2016 Society of Chemical Industry     

Effect of laboratory foamer on asphalt foaming characteristics and foamed mixture properties

In the United States, mechanical foaming is the most popular method for producing warm mix asphalt, which is the latest technology implemented to reduce the production temperature and/or enhance the compactability of asphalt mixtures. Three commonly used commercially available laboratory foamers to produce asphalt foams include the Wirtgen WLB 10S (Wirtgen foamer), the InstroTek Accufoamer (InstroTek foamer) and the Pavement Technology Inc. Foamer (PTI foamer). Though these foamers have been widely used in research studies and construction practice, it is still unknown whether they produce asphalt foams with the same quality and quantity. In this study, asphalt foaming characteristics produced by these three laboratory foamers were measured using a non-contact test set-up consisting of a laser device and a digital camera, and compared in terms of instantaneous volume expansion, foam stability and surface area evolution of foam bubbles. Additionally, the workability, coatability and mechanical performance of foamed mixtures prepared using these same laboratory foamers were compared against the conventional hot mix asphalt (HMA). Test results indicated that foamed asphalts produced by the Wirtgen foamer had the largest volume expansion and greatest foam stability, followed by those produced by the InstroTek foamer and the PTI foamer. The optimum foaming water content (W_opt) was determined for each laboratory foamer based on the workability and coatability results of the corresponding foamed mixtures. In addition, the performance evaluation of the foamed mixtures produced at W_opt values indicated equivalent mixture stiffness but greater moisture susceptibility as compared to the conventional HMA.     

聚丙烯珠粒发泡研究进展

聚丙烯(PP)珠粒发泡材料具有优异的耐热、隔音、抗冲击以及耐化学腐蚀等性能,近年来被广泛应用在包装、建筑、汽车等行业。PP在其熔点温度附近的熔体强度会急剧下降,低熔体强度导致其难以得到好的泡孔结构,所以PP珠粒发泡的技术难度大,目前只有少数国家掌握了PP珠粒发泡的技术,因此PP珠粒发泡的研究受到了国内外的广泛关注。文中从制备工艺、发泡装备、性能改进、表征方法等方面综述了近年来国内外PP珠粒发泡的研究动态,并对该领域今后的研究方向进行了展望。     

Key Production Parameters to Obtain Transparent Nanocellular PMMA

Transparent nanocellular polymethylmethacrylate (PMMA) with relative density around 0.4 is produced for the first time by using the gas dissolution foaming technique. The processing conditions and the typical characteristics of the cellular structure needed to manufacture this novel material are discovered. It is proved that low saturation temperatures (−32 °C) combined with high saturation pressures (6, 10, 20 MPa) allow increasing the solubility of PMMA up to values not reached before. In particular, the highest CO₂ uptake ever reported for PMMA, (i.e., 48 wt%) is found for a saturation pressure of 20 MPa and a saturation temperature of −32 °C. Due to these processing conditions, cell nucleation densities of 10¹⁶ nuclei cm⁻³ and cell sizes clearly below 50 nm are achieved. The nanocellular polymers obtained, with cell sizes ten times smaller than the wavelength of visible light and very homogeneous cellular structures, show a significant transparency.     

应用组合起泡剂优化黑、白钨混合浮选

针对湖南某钨选厂使用杂醇类起泡剂BK205所产生的泡沫小、性脆、泡沫层薄等不利于二次浮选的特点,采用BK205与新型醚类起泡剂CU组合使用以便实现矿石中钨矿物的高效回收。结果表明,在采用BK205与新型醚类起泡剂CU组合质量比为3∶1、先BK205后CU的加药方式下,小型闭路试验得到精矿WO3品位为30.13%,回收率为78.98%。工业试验表明,组合起泡剂不仅改善浮选泡沫,减少药剂用量,降低药剂成本,而且能获得比原起泡剂更好的工业指标,使钨矿物得到更高效的回收。     

纳米氧化锌在天然橡胶发泡中的活化作用

以天然橡胶(NR)为基体,偶氮二甲酰胺(AC)为发泡剂,比较了纳米氧化锌和普通氧化锌对NR纯胶和NR混炼胶发泡的活化作用,并研究了纳米氧化锌对NR发泡胶料硫化的影响。结果表明,粒径较小且分布均匀的纳米氧化锌无论是在NR纯胶还是在NR混炼胶中,都能使AC的分解峰值温度低于用粒径较大的普通氧化锌活化时AC的分解峰值温度,且随着纳米氧化锌用量的增加,AC的分解峰温逐渐下降;在NR发泡胶料中,2份纳米氧化锌可达到甚至超过5份普通氧化锌的硫化效果。