CAJ | 학술논문

对煤矸石进行热活化(一次活化),再进行热活化与化学活化复合的二次活化,以活化后溶出的硅铝为原料连续化合成了纯4A沸石;并探讨了一次活化和二次活化的机理.实验结果表明,一次活化过程中,煤矸石的物相组成和微结构明显改变,煤矸石的潜在活性被激发,高岭石转变成偏高岭石、无定形SiO_2和活性γ-Al_2O_3;二次活化过程中,一次活化后的煤矸石与Na_2CO_3混合煅烧后生成了溶于水的Na_2SiO_3和溶于碱的NaAlSiO_4,其中铝以NaAlSiO_4的形式存在,用蒸馏水浸取可单独脱除部分硅,平衡煤矸石的硅铝比,有助于铝的溶出;用溶出的硅铝连续化合成的4A沸石没有杂晶,纯度很高,结晶度为82%,白度为98,钙交换值为310 mg/g,收率为310～350 g/kg.
대매안석진행열활화(일차활화),재진행열활화여화학활화복합적이차활화,이활화후용출적규려위원료련속화합성료순4A비석;병탐토료일차활화화이차활화적궤리.실험결과표명,일차활화과정중,매안석적물상조성화미결구명현개변,매안석적잠재활성피격발,고령석전변성편고령석、무정형SiO_2화활성γ-Al_2O_3;이차활화과정중,일차활화후적매안석여Na_2CO_3혼합단소후생성료용우수적Na_2SiO_3화용우감적NaAlSiO_4,기중려이NaAlSiO_4적형식존재,용증류수침취가단독탈제부분규,평형매안석적규려비,유조우려적용출;용용출적규려련속화합성적4A비석몰유잡정,순도흔고,결정도위82%,백도위98,개교환치위310 mg/g,수솔위310～350 g/kg.
Coal gangue was treated by two successive activations namely thermal activation and thermal-chemical activation to dissolve silicon and aluminum for the following synthesis of 4A zeolites.Activation mechanism was studied.During first activation,mineral composition and microstruture of coal gangue encountered substantial change.Si-O and Al-O bonds were broken off,and kaolinite existing in coal gangue transformed into metakaolin,amorphous SiO_2 and activated γ-Al_2O_3.Potential activity of coal gangue was primarily excited.During second activation,by calcining the mixture of Na_2CO_3 with previously activated coal gangue,water-soluble Na_2SiO_3 and alkali-soluble NaAlSiO_4 formed.So part of silicate could be extracted out by distilled water,and this was preferable for further dissolve of aluminum.By appropriate adjustment of Si/Al ratio,4A zeolite with high purity,crystallinity of 82% and whiteness of 98,could be obtained from twice activated coal gangue.The yield and calcium exchangeability reached 310-350 g/kg and 310 mg/g,respectively.