高炉渣合成NaA沸石及影响因素

Synthesis of NaA Zeolite from Blast Furnace Slag and Investigation of Influencing Parameter

从高炉渣中提取二氧化硅作为合成沸石的硅源,用水热合成法合成了高炉渣沸石。采用X射线衍射、扫描电子显微镜、能谱等手段研究了温度、水热时间、原料配比等合成参数对沸石合成的影响。研究Na含量和碱度对沸石合成的影响。结果表明:随原料中n(Si O2)/n(Al2O3)摩尔比提高,合成的沸石晶型由A型向X型转变。温度、水热时间和碱度对于结晶形貌有显著影响,特别是随碱度的提高产生晶粒细化,而Na含量对沸石合成的影响微弱。最适宜的高炉渣沸石合成条件为:原料摩尔比n(Si O2):n(Al2O3):n(Na2O):n(H2O)=2:1:6:240,合成温度为100℃左右,合成时间大于5 h。

Zeolite of blast furnace slag（BFS） was synthesized via a hydrothermal method with silica from BFS as a raw material. The influences of crystallization temperature, crystallization time, raw material ratio and Na2O-to-H2 O ratio（i.e., sodium content and alkalinity） on the synthesis product were investigated. The results show that the key factor affecting the crystalline type is n（Si O2）/n（Al2O3） mole ratio, and the crystalline type of zeolite transforms from A to X when n（Si O2）/n（Al2O3） mole ratio increases. Crystallization time, crystallization temperature and alkalinity all have effects on the crystal morphology, and the increase of alkalinity produces the effect of grain refining. However, sodium content has a slight effect on the experimental results. It is indicated that the zeolite of BFS can be synthesized under suitable conditions（i.e., the molar ratio of n（Si O2）：n（Al2O3）：n（Na2O）：n（H2O） of 2：1：6：240, the synthesis temperature of 100 ℃, and the synthesis time of 5 h）.