拜耳法生产砂状氧化铝种子分解工序工艺

种子分解是拜耳法生产氧化铝过程中一个十分重要的工序,且直接影响氧化铝的产量和质量。目前国内外生产砂状氧化铝有法铝Pechiney的一段分解工艺和美铝Alcoa的二段分解工艺。本文结合近年所设计氧化铝厂分解工艺及投资实际情况,对一段分解及二段分解进行对比。

Preparation and mechanical properties of in situ Al_2O_3/Al composites by adding NH_4AlO(OH)HCO_3

Aluminium matrix composite reinforced by Al2O3 particles was produced by adding NH4AlO（OH）HCO3 into molten aluminum.The mechanical properties and wear behavior of the as-fabricated composites were studied.The results show that during stirring γ-Al2O3 particles were formed via decomposition reaction of NH4AlO（OH）HCO3,and the distribution of Al2O3 particles is more uniform in the matrix aluminum than directly added Al2O3 into molten aluminum.The density and the hardness values of the as-fabricated composites increase with increasing the particle volume fraction,while the tensile strength of the composites decreases with increasing the volume fraction of the Al2O3 particles.The wear rate of the composites decreases with increasing the volume fraction of the particle and loading.The in situ formed Al2O3/Al composite by adding NH4AlO（OH）HCO3 shows more superior mechanical and wear behaviors than that prepared by directly adding Al2O3 particles.

炭素回转窑窑尾改进对产量的影响

国内炭素回转窑的产量与国外同种类型回转窑的产量存在一定的差距。本文对国内回转窑低产原因进行系统分析,并提出了提高回转窑产量的具体措施,即改变窑尾加料管安装位置、窑尾增设挡料圈,窑尾扩径等。