蒸压制度对赤铁矿尾矿蒸压砖强度的影响

研究了蒸压制度对赤铁矿尾矿-石灰-黄沙体系蒸压砖抗压强度的影响，确定了原料中尾矿、石灰、黄沙的质量比为70∶15∶15，成型压力为20 MPa的砖坯的适宜蒸压制度为：升压时间2.1 h，蒸汽压力1.2 MPa，恒压时间6 h，降压时间3.5 h。利用XRD、DSC对蒸压砖抗压强度形成机理进行了探讨，结果表明，赤铁矿尾矿－石灰－黄沙体系在1.2 MPa蒸汽压力下首先生成了水石榴石，而后生成CSH(Ⅰ)凝胶和高强度的托勃莫来石，随着蒸压时间的延长，托勃莫来石逐渐转化成强度相对较低的硬硅钙石。

Effect of Autoclaved Schedule for Compressive Strength of Hematite Tailing Bricks

Effect of autoclaved schedule for compressive strength of hematite tailing-lime-yellow sand system was studied.The suitable autoclaved schedule was that rise time,autoclave pressure,autoclave time,and decompression time were 2.1 h,1.2 MPa,6 h and 3.5 h,respectively,when the quality ratio of hematite tailings∶lime∶yellow sands was equal to 70∶15∶15 and forming pressure was 20 MPa.The mechanism of Effect of autoclaved schedule for compressive strength was discussed by XRD and DSC.The results show that in the hydration reaction process,hydrogarnet is firstly generated,and then CSH(I) and high-strength tobermorite under the condition of 1.2 MPa autoclaved pressure.With autoclave continuing,tobermorite is gradated into relative low-strength xonotlite.