(中南大学 矿物工程系， 长沙 410083)
摘 要: 通过对铝土矿焙烧后碱浸脱硅的研究，获得常压碱浸脱硅的工艺条件为：矿粉粒度<0.076 mm占80%～85%，溶出时间2 h，ρ(Na2Ok)＝100～150 g/L, L/S＝4, 溶出温度90～95 ℃, 搅拌速度950 r/min。在此溶出条件下，回转窑焙烧矿的脱硅率可达55.20%，精矿A/S＝9.90，与加压溶出条件下取得的脱硅效果相当。
关键字: 一水硬石型铝土矿； 化学选矿； 脱硅
（Department of Mineral Engineering, Central South University，Changsha 410083, P.R.China）
Abstract:The technology of desilicationdigestion by alkali leaching at normal atmospheric pressure was studied. The optimum parameters are: thegrinding fineness of 80%～85% roasted ore being <0.076 mm, digestion time 2 h, Na2Ok=100～150 g/L, the mass ratio of liquid to solid L/S=4, digestion temperature 90～95 ℃, the agitating speed 950 r/min. Under the digestion rules, therate of desilication and A/S(the mass ratio of aluminium to silicium) of the concentrate were as high as 55.20% and 9.90, respectively. The results are as good as those obtained with pressurization.
Key words: diasporic bauxite； chemical concentration； desilication
