拜耳法赤泥的处理和利用

TREATMENT AND UTILIZATION OF RED MUD[HJ*4/5〗 DERIVED FROM BAYER PROCESS

解决了与赤泥有关的环境相容性问题。拜耳法赤泥与适量的石灰混合，经石灰消化、水热处理、煅烧处理和碱液溶出，可从赤泥回收７０％以上的Ａｌ２Ｏ３和９０％以上的Ｎａ２Ｏ，并使不溶残渣中Ｎａ２Ｏ含量降到１％以下。分离的铝酸钠溶液被送往拜耳法溶出料浆稀释过程，分离的残渣被进一步在７５０～９５０℃煅烧，制得活性βＣ２Ｓ为主的胶凝材料。

The environmental pollution problem related to red mud derived from Bayer process has been resolved. By mixing red mud with lime calculated and subseqent process including lime slaking with an amount of water, and the mixtures being hydrothermal treated and calcination treated and lixiviated with soda liquor as well, 70% of tatal Al 2O 3 and 90% of total Na 2O were recovered from red mud, and Na 2O content in residue was decreased to 1%. Sodium aluminate solution separated was sent to dilution process of Bayer digested liquor and residue separated was subjected to calcine at 750～950 ℃ and then active belit cement material mainly composed of β C 2S was goten.