锡石多金属硫化矿降砷的探讨

通过对毒砂矿物性质的分析,探讨硫化矿降砷及锡石多金属硫化矿选别试验,得出锡石多金属硫化矿浮选降砷的有效抑制剂为TS-1新药剂。用云锡摇床处理硫精矿降砷效果好,除砷效率接近80%。     

钻孔灌注桩桩底后注浆机理与应用研究

系统阐述了持力层为砾石层的钻孔灌注桩的桩底后注浆机理和工艺,并给合工程实际分析研究了注浆压力、浆液浓度、注浆量、注浆半径和注浆效果。     

水泥稳定砂砾土在公路路面基层施工工艺

分析天然砂砾土在公路路面基层施工中的成功应用,闹述一种合理利用当地自然资源的途径。     

研磨轮结构参数对工件加工精度的影响

通过建立研磨轮和工件的相对运动数学模型，得出研磨轮在工件上的切削运动轨迹方程，由此得到超精密平面研磨中，不同结构参数研磨轮的滑移轨迹长度，引入精度系数的概念，用于评价不同结构参数研磨轮对工件的加工效果，采用微粒金刚石研磨轮对单晶硅和压电陶瓷材料进行研磨实验的结果表明，使用设计合理的研磨轮可以提高研磨的加工精度。     

国产大型木片洗涤系统的配套设计与生产运行

国内某厂的木片杂质含量较高,并由于贮存时间过长,木片部分纤维腐烂变质。通过配套国产木片洗涤系统,在设计能力2100t/d下砂石的洗涤去除率达80%左右;在1200t/d的生产能力下沙石的洗涤去除率达90%左右,使木片含砂率降低到0.03%左右,且去除了部分腐朽变质的纤维。经洗涤水槽沉淀后洗涤水的循环利用率为60%左右。     

韶钢120 t转炉除尘水处理系统存在问题及对策

分析韶钢120t转炉除尘水处理系统存在问题及原因，结合现场实践提出改进措施及解决此类问题的观点和思路。     

砂面铝型材不同表面预处理对比研究

对砂面铝型材不同表面预处理条件下砂面形成机理以及由此引起的型材表面微观形貌和表层组织结构的不同作了分析,指出了它们对阳极氧化膜层性能可能产生的影响.     

曝气沉砂法处理生活污水的研究

利用实验室曝气沉砂池装置处理模拟生活废水,根据称量过滤所得悬浮物的质量分数,对曝气沉砂池处理工艺进行研究。认为曝气使废水中溶氧量大大增加,加速分解废水中的有机物,故悬浮物量比曝气前少;实验中沉淀时间越长,上层水悬浮物则越少,故沉淀20min后,所测得悬浮物最少。     

On the influence of single grit micro-geometry on grinding behavior of ductile and brittle materials

Recently it has been proven that highly engineered grinding/polishing tools can be manufactured with controlled shapes and distributions of abrasives. This research is directed to understand the influence of the shapes of the micro-cutting edges (i.e. circular/square/triangular base frustums generated by laser ablation), emulating grits of these engineered abrasive tools, on the material removal mechanism for workpiece materials of different mechanical properties (ductile – copper, brittle – sapphire). 2D/3D micro-profilometry, scanning electron microscopy supported by sensory signals (e.g. cutting forces) enabled to understand the relationship between the ploughing/shearing of ductile and brittle behaviour materials upon the number and orientation of the cutting edges that emulate the tested single grit shapes. It was found that for copper the increase in number of cutting edges (NoCE) of the grits results in more localised material pile-up and the reduction of plastic deformations with inherent decrease of specific cutting force; nevertheless, it became apparent that to diminish specific cutting forces, both NoCE and effective contact area between the grit and workpiece material need to be considered. For sapphire, shearing/fracturing phenomena were preponderant in the material removal mechanism when using square/triangular shaped grits while major plastic deformations were found for circular base frustum; significant reduction of specific cutting forces were noted with the increase of NoCE. This preliminary work enables the understanding on the implications of using particular grit shapes when utilising the novel edge-controlled grinding/polishing tools for machining ductile/brittle workpiece materials.     

Examination of a grit-blasting process for thermal spraying using statistical methods

An experimental study was conducted to develop an understanding of how the grit blasting process, prior to plasma spray coating, affects various properties of the substrate and coatings. A statistical design of experiment approach was used and the results were analyzed using both the linear regression method and average response of factors calculations. The following process variables were studied: grit size (20, 36, 54), blasting pressure (20, 35, 50 psi), blasting duration (4, 6, 8 passes), blasting distance (4, 6 in.), and blasting angle (45°, 90°). Properties such as bond strength, grit contamination, surface roughness, and substrate distortion were evaluated and correlated to the process variables. Based on multiple linear regression results, it was shown that the bond strength can be improved by increasing all of the parameters within the range studied here. No relationship between the surface roughness and bond strength was observed. Grit contamination is mostly influenced by grit size, blasting pressure, and number of blasting passes. The average response method provided indications to the direction of modifying the required properties as a function of process variables. While the average response method agreed mostly with the linear regression predication, some differences are further discussed in the study.