矽卡岩型铁尾矿的活性激发及混凝土制备研究

Study on Activation of Skarn Iron Tailings and Preparation of Concrete

利用机械-热-化学协同活化工艺激发矽卡岩型铁尾矿活性,研究铁尾矿净浆的水化反应产物,以原始铁尾矿为细骨料制备混凝土并探究混凝土的最佳配比。结果表明,850℃煅烧80 min后加入2%的复合碱,再以300 r/min转速球磨100 min的铁尾矿活化效果最好,火山灰活性指数(PAI)值为0.75;活化铁尾矿净浆的水化产物为水化硅酸钙(C-S-H)凝胶和堇青石、钙矾石及结晶硅酸钙等;在固体废物使用率高达83%条件下,可制备出28 d抗压强度为31.2 MPa的铁尾矿混凝土。

The mechanical-thermal-chemical co-activation process was used to stimulate the reaction activity of skarn iron tailings,and the hydration reaction products of iron tailings net slurry were studied.The iron tailings concrete was prepared with original iron tailings as fine aggregate,and the optimal ratio of concrete was explored.The results show that calcination at 850℃ for 80 min,adding 2%compound alkali,and then grinding iron tailings at 300 r/min speed for 100 min,the activation effect is the best,PAI of activated iron tailings is 0.75.The hydration products of the net slurry of activated iron tailings are C-S-H gel,cordierite,ettringite and crystalline calcium silicate.Under the condition of solid waste utilization rate up to 83%,iron tailings concrete with 28 d compressive strength up to 31.2 MPa can be prepared.