Electrochemical and spectroscopic study of interfacial interactions between chalcopyrite and typical flotation process reagents

Comparative voltammetry and differential double-layer capacitance studies were performed to evaluate interfacial interactions between chalcopyrite (CuFeS₂) and n-isopropyl xanthate (X) in the presence of ammonium bisulfite/39wt% SO₂ and caustic starch at different pH values. Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, contact angle measurements, and microflotation tests were used to establish the type and extent of xanthate adsorption as well as the species involved under different mineral surface conditions in this study. The results demonstrate that the species that favor a greater hydrophobicity of chalcopyrite are primarily CuX and S0, whereas oxides and hydroxides of Cu and Fe as well as an excess of starch decrease the hydrophobicity. A conditioning of the mineral surface with ammonium bisulfite/39wt% SO₂ at pH 6 promotes the activation of surface and enhances the xanthate adsorption. However, this effect is diminished at pH ≥ 8, when an excess of starch is added during the preconditioning step.     

Formation mechanism of the graphite-rich protective layer in blast furnace hearths

A long campaign life of blast furnaces is heavily linked to the existence of a protective layer in their hearths. In this work, we conducted dissection studies and investigated damage in blast furnace hearths to estimate the formation mechanism of the protective layer. The results illustrate that a significant amount of graphite phase was trapped within the hearth protective layer. Furthermore, on the basis of the thermodynamic and kinetic calculations of the graphite precipitation process, a precipitation potential index related to the formation of the graphite-rich protective layer was proposed to characterize the formation ability of this layer. We determined that, under normal operating conditions, the precipitation of graphite phase from hot metal was thermodynamically possible. Among elements that exist in hot metal, C, Si, and P favor graphite precipitation, whereas Mn and Cr inhibit this process. Moreover, at the same hot-face temperature, an increase of carbon concentration in hot metal can shorten the precipitation time. Finally, the results suggest that measures such as reducing the hot-face temperature and increasing the degree of carbon saturation in hot metal are critically important to improve the precipitation potential index.     

界面裂纹的Cell-Based光滑有限元法研究

为提高求解含界面裂纹结构断裂参数的精度,基于界面断裂力学和Cell-Based光滑有限元法,提出了求解双材料界面裂纹断裂参数的Cell-Based光滑有限元法,给出了求解应力强度因子的光滑子域交互积分法,对含中心界面裂纹双材料无限板进行了模拟,并与FEM计算结果和解析解进行了对比,讨论了光滑子元数和单元个数与正则应力强度因子的关系及其收敛性.数值算例结果表明该方法具有很好的收敛性和精度,可为研究人员和工程师设计制造多层材料提供必要参考.     

油菜薄层细胞培养中不同光质对愈伤组织诱导和增殖的效应

本实验以油菜(Brassica napus L.)花序轴薄层细胞为外植体,基本培养基为MS,附加不同浓度和比例的NAA和6-BA组合。接种后,选取白光、植物生长灯、红光、蓝光四种不同光质的光进行光照,以黑暗为对照,置恒温培养柜中培养,探讨不同光质对愈伤组织诱导和增殖的效应。结果表明:在相同或不同的培养基上,不同光质对愈伤组织的诱导效应都不同,蓝光,红光对油菜愈伤组织诱导具有明显的促进作用。在相同培养基中,不同光质处理对愈伤组织的增殖效应也不同,蓝光、红光对愈伤组织增殖的促进作用也是明显的。     

从石油中间产品合成表面活性剂AS-4Ⅰ.AS-4水溶液与原油体系的界面活性

以石油中间产品为原料,合成了烃基苯磺酸盐表面活性剂ＡＳ－４。考察了盐浓度,碱浓度和ＡＳ－４ 浓度对ＡＳ－４ 水溶液与原油体系的动态界面张力的影响。结果表明,当Ｎａ２ＳＯ４ 浓度为５～１５ｇ／Ｌ,ＮａＯＨ 浓度为５～１０ｇ／Ｌ,ＡＳ－４ 浓度为０．１～０．５ｇ／Ｌ的条件下,ＡＳ－４ 水溶液与原油体系的动态界面张力具有１０－ ３ｍ Ｎ／ｍ 以下的超低最小值。还研究了ＡＳ－４ 表面活性剂的组成（不同的异构体）对其水溶液与原油体系的动态界面张力的影响。     

采用高压水射法处理新老混凝土粘结面的试验研究

采用高压水射法对新老混凝土粘结面进行冲毛处理,粘结面的粗糙度以灌砂平均深度定量描述,以三种喷射水压力处理得到了不同粗糙度的粘结面,发现随着喷不压力的增大,粘结面的粗糙度增大,粘结劈拉强度提高。     

非离子表面活性剂静吸附特性研究

针对S/P二元复合体系在油层岩石上的吸附问题,利用室内仪器等检测分析方法,对无碱二元复合体系在润湿和非润湿大庆油砂吸附后活性剂体系浓度、界面张力进行了测定评价.结果表明：二元体系表面活性剂在大庆油砂上的吸附等温线为“S”型,最大吸附量为2.43mg/g;更换油砂单次吸附时,吸附次数增加,界面张力增加,活性剂浓度降低;,二元体系经聚合物和污水浸泡的油砂第三次吸附时界面张力由10-3mN/m上升到10-1mN/m;多次吸附对二元体系界面张力的影响很小。随着吸附次数的增加,活性剂浓度逐渐降低。     

热障涂层热不匹配残余应力的分析研究

广泛应用于高温部件的热障涂层,在热载荷作用下各层间所集聚的残余应力是导致其层裂和失效的重要原因。针对热障涂层由于热不匹配产生的残余应力,建立了相应的平面应变模型,研究了温度与涂层厚度对界面残余应力和陶瓷层内最大残余应力分布的影响。结果表明,陶瓷层内的残余应力主要表现为横向压缩应力,且最大值位于距陶瓷层表面1/3厚度处;界面残余应力相对较小,但在自由边界处有应力集中现象;随着温度的升高应力值在增大,陶瓷层厚度增加会改变结构厚度方向上的应力分布,且厚度增加使陶瓷层内残余应力值和界面残余应力值减小。     

大庆长垣以东裕民地区扶余油层物源分析

物源方向研究对古地貌和古构造恢复、沉积砂体的空间展布和物性分布等具有重要的意义。从重矿物组合特征、ZTR指数、泥岩颜色、砂砾岩厚度、沉积相等方面对物源方向进行判断。研究表明,大庆长垣以东裕民地区扶余油层来源于南部长春怀德沉积体系。古物源方向影响沉积砂体的空间展布,控制了大庆长垣以东裕民地区扶余油层沉积体系分布格局,砂体厚度、砂岩展布方向和物源方向有很好的匹配关系。     

基于分层模糊控制的移动机器人路径规划

针对移动机器人的路径规划中,应用模糊控制算法时模糊控制变量过多以及响应速度较慢等问题,简化模糊控制器与移动机器人本身的关系,设计出一种简单的双层模糊控制器实现算法,第一层模糊控制器以距离和方位角为输入量,转角为输出量;第二层以距离和转角为输入量,步长为输出量。解决了一般模糊控制器中规则库爆炸的问题,提高移动机器人路径规划算法的效率。经MATLAB仿真,证明算法有效性。