氨碱法制纯碱废渣制备免烧砖

Preparation of baking-free brick by soda residue

利用氨碱法生产纯碱产生的废弃物——碱渣为主要原料制备免烧砖,研究了碱渣、粉煤灰、钢渣和石粉等不同含量对免烧砖强度的影响,优化了配比。研究表明:碱渣、粉煤灰、钢渣、石粉质量配比为4∶3∶2∶1时,免烧砖的7d和28d的抗压强度分别达到了14.0MPa和20.6MPa,吸水率为13.4%;扫描电镜表征结果,免烧砖内部颗粒分布均匀,界面结合良好;X-射线衍射表征其主要矿相为CaCO_3、Ca_2SiO_3Cl_2、Ca_3Si_6O_(12)(OH)_6·5H_2O。实验结果表明,免烧砖能有效利用碱渣,工艺简单,成本低。

Soda residue was used for preparing baking-free brick which originated from producing soda ash by ammonia-soda process. The effect of soda residue,fly ash,slag and powder with different contents on the strength of the baking-free brick was studied and the optimal admixture ratio was determined. The results showed that,7 d and 28 d strength of the prepared baking-free brick could reach 14. 0 MPa and 20. 6 MPa,respectively,with a water absorption of 13. 4%,when the mass ratio of soda residue,fly ash,slag and powder was 4∶ 3∶ 2∶ 1.The results of SEM showed that,even granules,showed well interface bonding and dense brick. The results of XRD represented the main minerals of baking-free brick were CaCO_3,Ca_2SiO_3Cl_2,Ca_3Si_6O_（12）（OH）6·5H_2O. Therefore,the soda residue can be used for preparation of baking-free brick,with simple machining technology and low cost.