Vipulanandan model for the rheological properties with ultimate shear stress of oil well cement modified with nanoclay

In this study, the effect of clay nanoparticles (NC) and temperature on the rheological properties with ultimate shear stress and weight loss of the oil well cement (class H) modified with NC was investigated. The NC content was varied between 0 and 1% by the weight of the cement. The total weight loss at 800 °C for the oil well cement decreased from 6.10% to 1.03%, a 83% reduction when the cement was mixed with 1% of NC. The results also showed that 1% of NC increased the rheological properties of the cement slurry. The NC modification increased the yield stress (τ_o) and plastic viscosity (PV) by 5%–65% and 3%–16% respectively based on the NC content and the temperature of the cement slurry. The shear thinning behavior of the cement slurry with and without NC has been quantified using the Vipulanandan rheological model and compared with the Herschel-Bulkley model. The Vipulanandan rheological model has a maximum shear stress limit were as the Herschel-Bulkley model did not have a limit on the maximum shear stress. Based on the Vipulanandan rheological model the maximum shear stress produced by the 0% and 1% of NC at the temperature of 25 °C were 102 Pa and 117 Pa respectively hence an increase of 15% in the ultimate shear stress due to the addition of NC. The addition of 1% of NC increased the compressive strength of the cement by 12% and 43% after 1 day and 28 days of curing respectively. The modulus of elasticity of the cement increased with the additional of 1% NC by 6% and 76% after 1 day and 28 days of curing respectively. Effects of NC content and the temperature on the model parameters have been quantified using a nonlinear model (NLM). The NLM quantified the effect of NC treatment on all the model parameters.     

还原参数对F-T合成Fe-Mn催化剂物相结构的影响

在浆态床反应器中研究了还原气氛和还原压力对微球状FT合成FeMn催化剂织构性质和物相结构变化的影响,结果表明以H2还原后的催化剂比表面积最大,而以合成气或CO还原时,因积炭堵塞孔道,导致催化剂比表面积大幅降低;随还原气氛中CO分压的增大,物相中铁碳化物含量增加,有利于催化剂的还原与碳化;当采用不同还原压力的合成气还原时,催化剂比表面积随还原压力的升高而下降,此外,较高的还原压力使反应器中H2O/H2比增大,导致催化剂中的部分铁碳化物再氧化,因此催化剂中的铁碳化物含量随着还原压力的升高先增加后减少。     

油焦浆枪的雾化性能及在电厂中的应用

介绍一种利用炼油厂下脚料油焦与水混合制作的油焦浆混合物及其特性,并简要介绍了将油焦浆替代电厂燃油时油焦浆枪的雾化性能、运行性能及在电厂中的实炉应用效果.结果表明,油焦浆枪雾化及运行性能良好,用油焦浆替代燃油不仅可行,而且效益可观.     

化学机械抛光浆料研究进展

化学机械抛光(CMP)作为目前唯一可以实现全面平坦化的工艺技术,已被越来越广泛地应用到集成电路芯片、计算机硬磁盘和光学玻璃等表面的超精密抛光.介绍了CMP技术的发展背景,以及目前国内外抛光浆料的研究现状,并根据CMP浆料磨料的性质,将其分为单磨料、混合磨料和复合磨料浆料,对每一种浆料做了总体描述.详细介绍了近年来发展的复合磨料制备技术及其在CMP中的应用,并展望了CMP技术的发展前景以及新型抛光浆料的开发方向.     

不同压力下螯合剂浓度在碱性Cu CMP中的影响

We propose the action mechanism of Cu chemical mechanical planarization(CMP) in an alkaline solution.Meanwhile,the effect of abrasive mass fraction on the copper removal rate and within wafer non-uniformity(WIWNU) have been researched.In addition,we have also investigated the synergistic effect between the applied pressure and the FA/O chelating agent on the copper removal rate and WIWNU in the CMP process.Based on the experimental results,we chose several concentrations of the FA/O chelating agent,which added in the slurry can obtain a relatively high removal rate and a low WIWNU after polishing,to investigate the planarization performance of the copper slurry under different applied pressure conditions.The results demonstrate that the copper removal rate can reach 6125 °/min when the abrasive concentration is 3 wt.%.From the planarization experimental results,we can see that the residual step height is 562 ° after excessive copper of the wafer surface is eliminated.It denotes that a good polishing result is acquired when the FA/O chelating agent concentration and applied pressure are fixed at 3 vol% and 1 psi,respectively.All the results set forth here are very valuable for the research and development of alkaline slurry.     

Characterization and optimization of copper chemical mechanical planarization

The feature scale planarization of the copper chemical mechanical planarization (CMP) process has been characterized for two copper processes using Hitachi 430-TU/Hitachi T605 and Cabot 5001/Arch Cu10K consumables. The first process is an example of an abrasive-free polish with a high-selectivity barrier slurry, while the second is an example of a conventional abrasive slurry with a low-selectivity barrier slurry. Copper fill planarization has been characterized for structures with conformal deposition as well as with bumps resulting from bottom-up fill. Dishing and erosion were characterized for several structures after clearing. The abrasive-free polish resulted in low sensitivity to overpolish and low saturation levels for dishing and erosion. Consequently, this demonstrated superior performance when compared to the International Technology Roadmap for Semiconductors (ITRS) 2000 roadmap targets for planarization. While the conventional slurry could achieve the 0.13-μm technology node requirements, the abrasive-free polish met the planarization requirements beyond the 0.10-μm technology node.     

纳米铜棒制备的新方法

介绍了一种制备纳米铜棒的新方法,该法采用非对称交流电作为电解电源,采用铜棒为电极,硫酸铜为电解液,在一定的电解工艺参数下,成功制备出纳米铜棒。通过XRD和TEM对制得的铜粉进行了表征分析,表明其为单质铜,且纯度很高,粒度分布均匀,结晶性很好。     

浅谈金川高冰镍传统精炼工艺技术改方案和镍产品结构调整

论述了金川有色金属公司现行高冰镍精炼工艺技改的必要性。在综合国内外高冰镍精炼技术的基础上,结合金川有色金属公司的实际,重点阐述了高冰镍硫酸湿法精炼和氯化精炼工艺的优缺点。指出,现行高冰镍精炼工艺的改造应吸取氯化精炼和硫酸湿法精炼两种工艺的长处,稳妥地向高冰镍全湿法精炼过渡。文中还对该公司镍产品结构调整提出看法。     

多级离心泵输送渣浆时的轴向力分析及技术改进

分析了多级离心泵输送渣浆时轴向力产生的原因,给出了轴向力的计算公式,提出了平衡轴向力的措施：（１）改进平衡盘,平衡板结构尺寸;（２）间隙密封表面喷焊镍基６０合金粉末。采用上述两项措施后,多级离心泵的大修寿命提高５￣６倍。     

S7.300型PLC在全自动在链阳极钢爪校直机中应用

全自动在链阳极钢爪校直机是用于铝电解组装车间的新型自动化设备。通过对该设备的结构、工作原理、液压系统及其操作要求的分析,研制了基于S7-300型PLC和PV1000触摸屏的控制系统。该系统具备自动加热、校直运行、在线监视、离线故障检测和多台设备协同工作的功能。描述了该控制系统的软、硬件设计方法及其特点。