晶种对高纯铝酸钠溶液碳分产物量化调控的研究

Study on quantitative regulation of carbonation product of high-purity sodium aluminate solution by seed

用晶种量化调控高纯铝酸钠溶液碳分产物,即在碳酸化分解的条件下,加入不同类型、不同量的一水软铝石晶种来诱导Al(OH)-4定向析出一水软铝石,改善产物晶型,粒度,制备出含大量一水软铝石的碳分产品。本文对晶种系数、晶种粒度、机械活化晶种在碳分过程的影响做了相应的研究。结果表明:在分解前中期,添加晶种对分解过程有明显促进作用,且晶种系数(S)增加分解效率提高;当晶种系数S在0.11~0.44增加时,产物中一水软铝石含量增加,且当S=0.44时,含量达到最大值86%,继续增加晶种系数产物中一水软铝石含量变化不大;相对于微米级晶种,添加纳米级一水软铝石晶种在强化铝酸钠溶液聚附,细化晶粒方面更有优势;机械活化后的晶种拥有更强的分解活性,使分解率和一水软铝石含量均有所提高。

The carbonation product of high -purity sodium aluminate solution is quantitatively regulated via the seed, namely that under the carbonation conditions, the various types and amounts of boehmite seeds are dosed to induce the precipitation of boehmite from Al （OH） 4^- , optimizing the crystal type and particle size of the product and making the carbonation product containing a large amount of boehmite. In the paper, the effects of seed coefficient, seed size and seed mechanical activation during carbonation process are studied, and its results indicate that in the earlier and middle stage of precipitati- on, the adding of seeds has a significant effect and the larger the seed coefficient, the higher precipitating rate （S） ; when the seed coefficient increases in the range of 0.11 -0.44, the generation of hoehmite increases, and when S =0.44, its content reaches the maximum as 86%, but there is no more significant change of the boehmite content if the coefficient keeps on increasing; compared with micro seed, the nano - particle seed has more advantages in the respect of strengthening agglomeration in sodium aluminate solution and refining the crystal particles ; the activity of seed is enhanced by mechanical activation, which results in the improvement of precipitation rate and the mass fraction of hoehmite.