(中南大學 礦物工程系， 長沙 410083)
摘 要: 通過對鋁土礦焙燒后堿浸脫硅的研究，獲得常壓堿浸脫硅的工藝條件為：礦粉粒度<0.076 mm占80%～85%，溶出時間2 h，ρ(Na2Ok)＝100～150 g/L, L/S＝4, 溶出溫度90～95 ℃, 攪拌速度950 r/min。在此溶出條件下，回轉窯焙燒礦的脫硅率可達55.20%，精礦A/S＝9.90，與加壓溶出條件下取得的脫硅效果相當。
關鍵字: 一水硬石型鋁土礦； 化學選礦； 脫硅
（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
