Effect of waste serpentine on the properties of basic insulating refractories

Basic insulating refractories were fabricated by the pressing route using dead-burned magnesia, pure calcined alumina, expanded perlite, and calcined waste serpentine as starting raw materials in four compositions from F1 to F4. Periclase and forsterite were major phases in F1 and F2 compositions, while spinel was also detected in the XRD patterns of F3 and F4 samples. Quantitative phase analysis showed that F4 sample sintered at 1450?°C has the highest forsterite content among all other samples. On the other hand, it has lower thermal conductivity compared to F1 to F3, and even lower than aluminosilicate IFBs with the same bulk density. It is concluded that forsterite is a highly insulating material, compared to periclase, corundum, periclase-spinel, aluminosilicates, such as mullite, etc.     

蛇纹石综合利用新工艺

采用循环活化酸浸新技术，提出了以蛇纹石为原料制取轻质氧化镁和水玻璃的新方法，研究了主要工序的最佳工艺条件，此条件下，蛇纹石中MgO的平均浸出率及酸浸滤饼中活性二氧化硅的浸出率均在97％以上，酸滤液中Mg^2 回收率大于96％。制得的轻质氧化镁和水玻璃质量符合国家标准，蛇纹石中氧化镁的回收率大于90％。     

金川矿石中脉石矿物易浮原因的探讨

通过对金川原矿矿石性质研究和精矿及尾矿中硫化矿物的XPS表面测试、扫描电镜统计及能谱测试,探索了金川矿石中脉石矿物易浮的原因。结果表明,金川硫化物表面易与镁结合,蛇纹石表面常有墨铜矿及羟镁硫铁矿,这两个矿物在蛇纹石表面形成使蛇纹石向滑石转变,蛇纹石表面已滑石化或为蛇纹石与滑石的过渡相,这是造成金川脉石矿物易浮且难以抑制的原因。     

柠檬酸在蛇纹石/镍黄铁矿浮选分离中的作用

通过浮选实验、沉降实验、吸附量实验、Zeta电位测试和DLVO理论计算,考察柠檬酸在蛇纹石/镍黄铁矿浮选分离中的作用,分析柠檬酸的作用机理。结果表明：在弱碱性pH条件下,蛇纹石的加入降低了镍黄铁矿的回收率,而柠檬酸处理后的蛇纹石不会影响镍黄铁矿的浮选。机理分析表明：蛇纹石与镍黄铁矿表面带有相反电荷,能通过静电作用罩盖在黄镍铁矿表面,影响其浮选;柠檬酸能够溶解蛇纹石表面荷正电的镁离子,使蛇纹石表面电位发生变化,此时,蛇纹石与镍黄铁矿之间存在较强的排斥作用,从而减弱蛇纹石在镍黄铁矿表面的附着,消除其对镍黄铁矿的抑制作用。     

Enhancement of pentlandite surface magnetism and implications for its separation from serpentine via magnetic separation

The magnetism of pentlandite surface was enhanced through the selective precipitation of micro-fine magnetite fractions on pentlandite surfaces. This was achieved through adjustment of slurry pH and addition of surfactants. The results showed that at pH 8.8 with the addition of 100 g/t sodium hexametaphosphate, 4.5 L/t oleic acid, and 4.5 L/t kerosene, significant amount of fine magnetite particles adhered to the pentlandite surface, while trace amount of coating was found on serpentine surfaces. Thus, the magnetism of pentlandite was enhanced and pentlandite was well separated from serpentine by magnetic separation under the magnetic field intensity of 200 kA/m. Scanning electron microscopy (SEM) and zeta potential measurement were performed to characterize changes of mineral surface properties. Calculations of the extended Derjaguin–Landau–Verwey–Ocerbeek (EDLVO) theory indicated that, in the presence of surfactants the total interaction energy between magnetite and pentlandite became stronger than that between magnetite and serpentine. This enabled the selective adhesion of magnetite particles to pentlandite surfaces, thereby enhancing its magnetism.     

Performance of serpentine channel based Li-ion battery thermal management system: An experimental investigation

Thermal management of large-scale Li-ion battery packs is of great significance to their safety and life cycle, which would impact their applicability in electric vehicles. Of the many strategies developed for this purpose, indirect liquid cooling has already demonstrated quite high potentials in thermal regulation of such battery systems. In this study, a compact lightweight serpentine wavy channel configuration was chosen to construct an indirect liquid cooling system for a battery module of cylindrical Li-ion cells. The serpentine channel has a number of six internal minichannels. Experimental test data were used to conduct a comprehensive thermal analysis to examine the highest temperature, the maximum temperature difference, and the heat accumulation percentages, and so forth within the battery pack. Results have revealed the ability of the cooling system to maintain the module temperature within appropriate working conditions for electric vehicle applications for most cycling tests including two driving cycles. Furthermore, the analysis insights raised by this study could be useful in understanding the cooling performance of the liquid-based thermal management systems for electric vehicles.     

蛇形防护布线设计

高速电路中蛇形线可作为传统防护布线的替代方案，但其提出过程未曾考虑如何进行合理的设计。文中基于蛇形防护布线的外形特征影响耦合参数的原理，通过全波求解器建立蛇形防护布线模型，分析了其端接策略以及特征变化对应的远端串扰变化规律，得出了蛇形防护布线的合理设计方法。结果表明，短路策略作为最佳策略，且在信号边沿变化较快的情况下，应采用线宽小、高度高和长度短的蛇形线作为防护布线。     

阻尼多楔带传动系统建模及带滑移控制分析

考虑多楔带的阻尼特性和带在带轮上的蠕变对带张力的影响,建立了阻尼多楔带传动系统旋转运动模型,给出了带张力和各带轮的旋转角位移的数值计算方法,并引入了滑移因子预测滑移现象的发生.分析研究多楔带阻尼对系统运动特性的影响,及当多楔带传动系统结构参数确定时,张紧器预载荷、安装角对带滑移的影响.建立的阻尼多楔带传动系统旋转运动模型和数值求解方法为带传动系统的研究提供了理论依据,对带滑移控制的分析为带传动系统的设计提供了参考.     

蛇纹石酸浸提镁残渣制备硅酸锂及其性能研究

以蛇纹石酸浸提镁残渣为硅源,碳酸锂为锂源,通过高温固相反应合成了硅酸锂高温固碳材料,探究了煅烧时间、气氛以及物料配比对合成材料高温固碳性能的影响。采用热重-差热综合热分析仪(TG-DTG)研究了蛇纹石酸浸提镁残渣型硅酸锂的CO2吸收性能,并通过扫描电子显微镜(SEM)与X射线衍射仪(XRD)对合成材料的微观形貌与结构特征进行了表征。结果表明:蛇纹石酸浸提镁残渣型硅酸锂具有较好的CO2吸收性能,吸收量可达26.66%;与市售Si O2为硅源相比,蛇纹石酸浸提镁残渣型硅酸锂材料煅烧合成时间缩短,高温固碳性能更优。