加压氰化全湿法处理低品位铂钯浮选精矿工艺研究

针对前期研究提出的浮选精矿先经湿法预处理而后再加压氰化浸出铂族金属的全湿法新工艺，变动预处理反应过程各种工艺参数，考察了预处理对铜、镍氧化浸出以及对后续铂、钯氰化浸出指标的影响。试验结果表明，浮选精矿经预处理后不仅可有效回收浮选精矿中的铜等有价值有色金属，而且有利于后续加压氰化提取铂钯等贵金属。新工艺实现了全湿法直接处理低品位铂钯硫化浮选精矿的创新。     

中碳钢化学成分对CSP薄板坯表面纵裂的影响

从钢水化学成分影响高温力学性能的角度，研究了钢水主要成分对CSP薄板坯表面纵裂的影响。研究表明：在钢中其它成分相近的条件下，随着钢中锰含量的提高，钢的高温强度和塑性不断提高，裂纹敏感性逐渐下降；提高钢的高温强度和塑性的化学成分对减轻表面纵裂的发生有利。     

SHS法工艺参数对制备氮化硅粉体的影响

本文采用自蔓燃高温合成方法(Self-propagating High-temperature Synthesis)简称(SHS)合成氮化硅粉体,借助于XRD、SEM等检测方法,分析了自蔓燃高温合成氮化硅过程中氮气、温度、稀释剂与孔隙率等方面的影响。结果表明:只要最高燃烧温度不高于相应氮气压力下Si3N4的热分解温度,就可以用SHS方法合成Si3N4;氮气压力下硅粉的自蔓燃合成反应,必须要引入Si3N4稀释剂,来控制反应温度,以获得高α相含量的粉体。压坯气孔率控制在30%~70%,否则反应不能进行。研究发现SHS法可以制备纯度较高的氮化硅粉体。此法较传统方法合成的氮化硅设备简单,成本低廉,纯度高,填充性及烧结活性好。     

喷射成形时雾化压力与静压头对雾化熔滴尺寸影响的理论分析

本文建立了静压头、雾化压力与雾化熔滴尺寸的模型关系。雾化压力一定，雾化熔滴质量中值直径随静压头的减小而减小；静压头一定。雾化熔滴尺寸随着雾化压力的增加而减小。通过模型，调节雾化压力以适应静压头变化引起的金属液体质量流率变化，以期得到具有合适尺寸的雾化熔滴，优化沉积坯组织。     

SHS法工艺参数对NiZn铁氧体预烧料结构的影响

本文以还原铁粉、NiO、ZnO及Fe2O3为原料，利用自蔓延高温合成（SHS）法制备NiZnFe2O4预烧料，并且利用XRD图谱，Vegard定律等分析了产物结构。分析结果表明：SHS法可以制备纯度很高的NiZnFe2O4预烧料。试验发现，保温时间及粉料压坯密度均对SHS法制备的NiZnFe2O4预烧料的结构有一定的影响：随着保温时问的延长，产物的纯度提高，同时固溶体中的组元配比更接近配方比例；当粉料压坯相对密度为63％左右时，固溶体中的组元配比可达到配方比例。     

二硅化钼抗氧化性的研究进展

MoSi2具有良好的高温抗氧化性，但是低温容易发生“粉化瘟疫”现象。首先介绍了MoSi2及其复合材料低温“粉化瘟疫”的现象和机理，提出了预防“粉化瘟疫”的方法，然后介绍了MoSi2基复合材料的高温抗氧化性能以及抗高低温循环氧化的能力。总结认为低温加速氧化是MoSi2的本质现象，而“粉化瘟疫”不是MoSi2的本质现象。     

高性能可塑料的研制与应用

以特级高铝矾土为主要原料,加入适量复合微粉、膨胀剂、保湿剂,采用复合结合剂,能够生产出可塑性能优良、高温强度高的可塑料.     

回转窑生产高温氧化铝自控研究

前言/Preface高温氧化铝为白色粉末或细砂状,广泛应用于国民经济的各个领域,是一种用途广泛、性能优异、价格经济的无机非金属材料。近几年来,随着高科技产业的迅猛崛起,高温氧化铝的应用得到了迅速拓展。高温氧化铝一般是将氢氧化铝通过回转窑在一定温度下进行焙烧制得,生产过程中对温度控制的要求比较高,过高、过低或温度不稳定都会使焙烧所得的产品其结构发生变化,使产品质量波动。回转窑属于回转圆筒类设备。筒体内有耐火砖衬及换热装置,以低速回转,物料与热烟气一般为逆流换热,物料从窑的高端(又称冷端或窑尾端)加入。由于筒体倾斜安…     

Wear Resistance of CO2 Corrosion Product Scale Formed at High Temperature

 To investigate the correlation between structure characteristics and wear resistance of CO2 corrosion product scales at high temperature and high pressure, an autoclave was used to prepare CO2 corrosion product scales on N80 steel in carbon dioxide corrosion environment. The correlation between wear resistance of the scales and many other factors, such as temperature, pressure, morphology, structure, velocity of fluid medium, sand grain size, and so on, was comparatively analyzed by a self assembled wear device, and the scale morphologies before or after being worn were observed by scanning electron microscope (SEM). And then the surface grain size and thickness of scale were measured. The results showed that the cross section of the corrosion scale was of a double layer structure, the outer layer of which was composed of regular crystals, whereas the inner layer was a thin scale of fine grains. The outer grain size and thickness of scale varied with temperature, and the initial wear loss was consistent with the surface grain size; at the same time, the total wear loss corresponded to the thickness of scale. Compared to wear resistance in different depths of the scale, it was found that the structure of scale was a double layer structure in cross section, and the wear resistance of inner layer was better than that of the outer layer; the closer the scale to the matrix, the greater was the wear resistance of scale; and the larger the size or the higher the rotary speed of solid grain in multiphase flowing medium, the more was the wear loss of scale.     

Microstructure, Properties and Heat Treatment Process of Powder Metallurgy Superalloy FGH95

 Microstructure and properties of nickel based powder metallurgy (PM) superalloy were presented. Effects of nonmetallic inclusions and heat treatment on microstructure and properties were discussed. Development tendency of microstructure and properties of PM superalloy was presented.