以富锰渣制备4A分子筛

Preparation of 4A molecular sieves from rich-manganese slag

研究了以富锰渣为原料，经过硫酸浸出、酸浸渣与碱固相高温煅烧熔融制备分子筛的工艺。以10％（质量分数）的硫酸为浸取介质，在90～100℃下反应2h，将富锰渣中锰、铁、钙、镁等可溶性物质溶出，液相中的锰用来制备硫酸锰。酸浸渣与碱固相反应，将硅铝溶出，补氢氧化铝，调整比例到4A分子筛合适的硅铝比，使溶液中各物质的量比为n（二氧化硅）／n（三氧化二铝）=2，n（水）／n（氧化钠）=28，n（氧化钠）／n（二氧化硅）=0．9。浓缩溶液至过饱和状态，在空气中冷却到30℃，再升温至90℃，恒温5h。加入氯化钠少许，放冷使之结晶。过滤并洗涤晶体至pH=9-10，于马弗炉中500℃左右煅烧1h即得4A分子筛产品。

The preparation of molecular sieves from rich - mangnese slag is studied. Which includes following steps ： the slag is first leached by sulfuric acid and then the leached slag and alkali are calcinated at high temperature. Taking 10% （ mass ） sulfuric acid as a leaching medium, the soluble matters in rich - manganese slag, such as Mn^4＋ , Fe^3＋ , Ca^2＋. and Mg^2＋ are solved out at 90 ～ 100 ℃ for 2 h. The Mn in liquid phase is used to prepare manganese sulfate,the leached slag reacts with alkali, the Si^4＋ and Al^3＋ are solved out and then adding Al （ OH ） 3 to adjust the ratio of reactants as n （ SiO2 ）/n （ Al2O3 ） = 2, n （ H2O ）/n （ Na2O ） = 28, n （ Na2O ）/n （ SiO2 ） = 0.9. The above solution is concentrated to supersaturated state,then cooled to 30 ℃ in air, aftarwards, raising the temperature to 90 ℃ for 5 h and adding a little amount of NaCl,cooled to form the crystal,then filtering and washing the crystal to pH =9 ～ 10. At last,the crystal is put in Muffle furnace for calcinating at 500 ℃ for 1 h, the 4A molecular sieve is obtained.