金刚石微粉现场实时鉴别 便携显微镜

金刚石微粉是指颗粒度细于36/54微米的金刚石颗粒,有单晶金刚石微粉和多晶金刚石微粉。单晶金刚石微粉是由人造金刚石单晶磨粒,经过粉碎、整形处理,采用特殊的工艺方法生产。金刚石微粉硬度高、耐磨性好,可广泛用于切削、磨削、钻探等,是研磨抛光硬质合金、陶瓷、宝石、光学玻璃等高硬度材料的理想原料,但是价格较贵。     

再生微粉对混凝土的工作性及力学性能的影响研究

再生微粉是废弃混凝土颗粒整形过程中产生的细小粉状颗粒,其对环境以及人的身体健康造成威胁。本文研究其基本性能,并将其作为矿物掺合料制备混凝土,研究再生微粉不同掺量时对混凝土的工作性和抗压强度的影响,研究表明:再生微粉掺量的增加使得混凝土的需水量增大,因此其对混凝土的工作性产生不利影响;对于混凝土的力学性能,在再生微粉的掺量为10%以内,混凝土的抗压强度减小幅度较小,当掺量较大时,混凝土的抗压强度大幅减小。     

再生微粉对混凝土的工作性及力学性能的影响

再生微粉是废弃混凝土颗粒整形过程中产生的细小粉状颗粒,对环境以及人的身体健康造成威胁。但可将其作为矿物掺和料制备混凝土,为此研究其不同掺量时对混凝土的工作性和抗压强度的影响,结果表明:再生微粉掺量的增加使得混凝土的需水量增大,因此其对混凝土的工作性产生不利影响。对于混凝土的力学性能,在再生微粉的掺量为10%以内,混凝土的抗压强度减小幅度较小;当掺量较大时,混凝土的抗压强度大幅减小。     

不同来源α-Al2O3微粉对铝矾土质低水泥浇注料性能影响

探讨了将市售4种不同来源α-Al2O3微粉分别引入到铝矾土质低水泥浇注料中,4种α-Al2O3微粉分别命名为国产A、国产B、进口A、进口B。实验结果表明,进口A铝微粉由于具有双峰分布,且颗粒较细,因而其填充性较好,同时有助于体系内烧结;含有进口A铝微粉试样各项性能最好;国产B铝微粉由于粒度分布较宽,且颗粒较大,含有这种铝微粉的试样各项性能最差;国产A铝微粉颗粒分布也较窄,各项性能指标仅次于含有进口A铝微粉。     

再生微粉基本性能及活性试验研究

为探究再生微粉基本性能及活性,首先通过XRD和XRF分析各类再生微粉的化学与矿物组成,得出各类再生微粉SiO2的含量均较高.接着分别试验各类再生微粉的需水量比、流动度和烧失量,并结合BET和SEM进行分析,发现再生微粉的需水量比和流动度与其独特的微观形貌密切相关.之后测定了细度相近的不同种类再生微粉强度活性指数,参照粉煤灰强度活性指数试验方法进行,初步探究了不同种类再生微粉以及混合再生微粉的强度指数变化规律,得出再生砖粉的活性最好,强度活性指数可以达到76％.且当混合再生微粉中再生砖粉的含量达到75％以上时,混合再生微粉的强度活性指数可以达到70％以上.     

矿渣微粉的研制及应用研究

矿渣微粉作砼掺合料，有着很好的应用价值。用试验小磨进行了不同比表面积矿粉的性能试验，同时进行了不同矿粉掺量砼的性能试验。结果表明：矿渣微粉的活性指数高，流动性好。生产矿渣微粉的最佳粉磨比表面积为450—500m^2／kg。另外用矿粉代替部分水泥后，砼28d抗压值接近甚至高于对比样；且砼流动性改善明显，1h塌落度损失少；同时还降低了砼的生产成本。所以矿渣微粉是配制高强高性能砼的优质掺合料。     

矿渣微粉-糊精灰浆复合胶凝材料的试验研究

用矿渣微粉代替部分石灰,并对36组不同组分的矿渣微粉-糊精灰浆复合胶凝材料的力学性能和耐水性能进行试验研究.结果 表明,添加激发剂和砂含量为900 g时都可提高复合胶凝材料强度,且抗压强度随糊精浓度的增加而提高,矿渣微粉替代率为35％时28 d抗压强度较高,矿渣微粉替代率为25％时90 d抗压强度提高显著,当矿渣微粉替代率为25％、糊精浓度为16％、砂含量为900 g并添加激发剂时复合胶凝材料强度最好,其28 d抗折和抗压强度分别为0.62 MPa和3.95 MPa,90 d抗折和抗压强度分别为1.21MPa和8.31 MPa,且耐水性能达到27 d.用矿渣微粉代替部分石灰,可以提高糊精灰浆力学强度和改善耐水性能.     

含白云石微粉水泥砂浆的抗硫酸盐侵蚀性能

为评估白云石微粉对水泥抗硫酸盐侵蚀性能的影响,以石灰石微粉为参照,研究了白云石微粉掺量(质量分数)分别为10%、20%、30%时,水泥砂浆在质量浓度为5%硫酸钠溶液中的变形和强度发展规律,并讨论了基于抗蚀系数的含碳酸盐岩微粉水泥抗硫酸盐侵蚀性能评价方法。结果表明:砂浆试体在Na_2SO_4溶液中的变形过程可分为稳定期、缓慢膨胀期和加速膨胀期3个阶段。除掺10%白云石微粉试体外,其余含碳酸盐岩微粉砂浆的膨胀率均大于空白样(PC)。与掺石灰石微粉试体相比,含白云石微粉试体起始膨胀的龄期滞后,同期膨胀小,且两者膨胀差异随龄期延长和掺量增加呈增大趋势。无论在水中还是在Na_2SO_4溶液中,掺碳酸盐岩微粉砂浆抗压和抗折强度发展趋势均与PC类似,但强度均降低,且掺量越大,强度降幅越大。与在水中养护时强度持续缓慢增长不同,掺碳酸盐岩微粉砂浆强度在Na_2SO_4溶液中经历先快速增长至峰值,而后降低的过程。与含石灰石微粉试体相比,含白云石微粉砂浆强度达到峰值的龄期滞后且后期强度高。标准规定的28 d抗蚀系数K_(28)不能确切反映含碳酸盐岩微粉水泥抗硫酸盐侵蚀性能。采用试体起始膨胀或强度达峰值龄期的抗蚀系数可提高判定结果的准确性和可靠性。     

明胶改性银微粉的电动电势和悬浮稳定性

用光照还原制备银微粉分散体系,测量了不同还原条件下所得改性银微粉的电动电势及等电点,讨论了还原条件对银微粉等电点的影响。通过不同光照时间、明胶浓度、酸度及盐度下所得银微粉分散体系的紫外-可见光谱的测试和分析,讨论了以上条件对生成的银微粉分散体系悬浮稳定性的影响。     

Al2O3微粉和SiO2微粉对刚玉-莫来石材料性能的影响

在板状刚玉细粉中添加粘土或Al2O3微粉和不同种类的SiO2微粉制成刚玉-莫来石试样,分别于1200℃、1400℃和1600℃保温5 h烧成后,测定试样的体积密度、显气孔率和烧后线收缩率,利用XRD分析了试样在不同温度段的莫来石生成量,研究了添加Al2O3微粉和不同种类的SiO2微粉对材料的烧结性能和莫来石化的影响,并利用SEM观察了试样的显微结构.结果表明(1)加入Al2O3微粉和SiO2微粉均有利于材料的烧结;加入SiO2微粉的纯度和晶形不同,对试样莫来石化的影响也不同,无定形态SiO2微粉(即硅灰)的纯度越高,试样的莫来石生成量也越高.(2)加粘土的试样,其显微结构中柱状莫来石的晶体特征比较明显;而加入SiO2微粉的试样,其莫来石晶体和刚玉晶体相互交错,晶粒较小.     

Solid‐state recycling of polyimide film waste

Possibility of the polyimide (PI) films waste recycling by solid‐state mechanochemistry was investigated in this study. Obtained PI powder was used for development of thermostable blends and multicomponent tribocompositions, which include additions of carbon black, ultradispersive diamond powder, and quasicrystalls. PI films waste treatment was provided in high‐energy planetary ball mill. Powder compositions were mixed by low‐energy planetary ball mill. Bulk samples were obtained by compression molding. Structural and thermal properties of initial polymers and composite materials were determined from scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis and fourier transform infrared spectroscopy. Tribological tests of composite materials were provided in dry sliding regime on “pin‐on‐disk” tribometer. Finally, optimal regimes of polymer composite materials producing were obtained. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

球磨机研磨体级配设计与计算

球磨机研磨体合理的级配,对提高磨机产量和产品质量、降低粉磨电耗,具有重大的作用。在总结几百家水泥厂磨机工艺技术员工作经验的基础上,根据笔者长期从事物料粉磨研究和实践的心得体会,综合考虑研磨体总装载量、各仓填充率、平均球径、物料水分、物料流动性、物料粒度、隔仓板形式、隔仓板篦缝大小、各仓长度、粉磨流程等因素,详细介绍了球磨机研磨体级配计算的方法、原理和步骤,并编制成“球磨机研磨体级配及补球计算程序”软件。     

Optimization of variables in grinding brass particles for paint and pigment industry

Flaky metal powders commonly used as paint and pigments, are generally produced by grinding in ball mills or vibration mills. The key to good quality powder production is to optimize the processing parameters. In the present work grinding of brass particles is studied in detail in a laboratory size ball mill to determine the optimal levels of the ball to material ratio, type and amount of additives, mill speed, ball load, etc. The quality of the powder is assessed on the basis of water coverage, degree of flattening and luster by visual inspection. Preliminary results in a 35 cm diameter ball mill with 30% ball load show that a material to ball ratio of 0.067 with a 0.1% dosage of stearic acid is required for good quality powder. For determining optimal mill speed and ball size a 2² factorial design of experiment has been followed. It has been determined that to achieve best powder quality the mill must run at 70% critical speed and the ball size must not exceed 20 mm. The quality of the powder assessed through SEM study for surface morphology and particle size analysis compares very well with the industrial samples.     

微气孔球形药常压传火速度的测试方法

为了简便快速地测试微气孔球形药的常压传火速度,对靶线法、半圆槽法、直管法等传火速度测试方法进行了对比,研究了测试管材料的种类、外界气流、测试管长径比等条件对常压传火速度的影响规律。结果表明,在几种测试方法中直管法操作简便,偏差小,且不受外界气流的影响;随着测试管长径比的增加,直管法测得的传火速度逐步提高;采用底部开口状态测试管得到的测试结果比底部封闭的测试管得到的结果偏大近50%;采用透明的玻璃管作为测试管可以研究传火速度和药粒的点传火现象。采用透明玻璃管测试常压状态下微气孔球形药的传火速度是可行的。     

球磨机参数调节对细粉量的影响

通过正交试验得出了球磨参数与细粉量的关系，并提出研磨破碎区概念，给出了球磨效率关系式。     

行星搅拌球磨机超细粉碎机理分析

描述了行星搅拌球磨机的工作原理,针对物料在其中被粉碎时复杂的运动轨迹和受力方式,通过对超细粉碎过程的颗粒粉碎速度、颗粒碰撞速度的数学分析以及从流体力学角度对湿法粉碎机理的分析,综合分析了利用行星搅拌球磨机制备超细粉的机理。     

Optimized experimental design for natural clinoptilolite zeolite ball milling to produce nano powders

Nano powder of natural clinoptilolite zeolite was mechanically prepared by using a planetary ball mill. Statistical experimental design was applied to optimize wet and dry milling of clinoptilolite zeolite. To determine appropriate milling conditions with respect to the final product crystallinity, particle size and distribution, different milling parameters such as dry and wet milling durations, rotational speed, balls to powder ratio and water to powder ratio (for the wet milling) were investigated. Laser beam scattering technique, scanning electron microscopy and X-ray diffraction analyses were carried out to characterize samples. Results showed that larger than 1 mm particle size of clinoptilolite powder may mechanically be reduced into the size range of less than 100 nm to 30 μm by means of planetary ball milling.     

球磨法制备超细镍粉及其表征

为了获得在自然条件下稳定存在的超细镍粉,通过控制行星式高能球磨机的转速、研磨时间、磨球数、运转时间、暂停间隔、转动方向等参数对镍粉进行了研磨实验,并对不同参数下的研磨结果进行了测试表征。结果表明,在转速260 r/min、研磨时间19 h、运行时间3 min、暂停时间30 s、磨球数为10个、原料5 g且晴朗天气下实验,可以制备出亚微米级超细镍粉,并在空气中稳定存在。     

油性铝银浆的制备工艺及改进对策

本文阐述了制备油性铝银浆3个工艺过程。首先,简单介绍了球磨工艺过程中行星式球磨机的球磨机理及微球铝粉片状化过程,并讨论了用球磨机在球磨铝粉过程中的几个影响因素;其次,是分离工艺过程中筛分和过滤待改进的工艺条件;第三,探讨了捏合过程对整个产品体系稳定性的影响;最后,简易配制涂料,采用相关仪器对产品质量进行评价,并提出三方面的改进要求。     

Characterization of media mills based on mechanical energy applied to particles

This paper deals with the evaluation of characteristics of media mills having a different milling mechanism based on the mechanical energy applied to the particles to be processed during a milling treatment. Spherical copper powder was used as a stress-sensitive material and the milling treatment of the copper powder was carried out under various operating conditions using three types of media mills, a horizontal tumbling ball mill, vertical agitating ball mill and bead mill. The size distributions of copper powder before and after the milling treatment were measured and the deformation of copper particles was determined experimentally. The net energy applied to the copper powder was estimated from the plastic deformation of copper particles. It has been clarified that the applied energy depends strongly on the motion of media in the mill. By introducing two dimensionless parameters, which express the energy transfer efficiency from the kinetic energy of media to the particles and the motion of media in the mill, respectively, the media mills could be characterized on a uniform scale based on the applied energy regardless of milling mechanism.