凹凸棒制作中空玻璃干燥剂的研究

Study on Preparation of Hollow Glass Desiccant With Attapulgite

由于凹凸棒晶内存在庞大的微细孔道网络,比表面积极大,表面活性非常高,吸附性能特别优异,而且由于其晶内大量孔道的存在,具有不小的空气容积,因而可以考虑用作干燥剂。主要通过加入吸湿剂来提高凹凸棒石粘土的吸附性能,加入黏合剂提高样品抗压碎力。根据国家标准来选择颗粒大小和烧结工艺。自制仪器测量样品的静态水吸附量、吸湿速率和抗压碎力。研究结果表明:通过XRD衍射图可以得知,样品中含有蒙脱石和坡缕石,这些杂质严重影响了凹凸棒吸湿后的颗粒结构和抗压碎力,使其在吸湿后膨胀开裂。加入CaCl_2比加入MgCl_2和CuSO_4的吸湿效果好,加入适量的Na_2SiO_3可以提高吸湿后的颗粒强度,提纯凹土与未提纯的吸湿效果相差不明显。烧结温度为350℃,时间为1 h,粒径为2.5~3.0 mm。最合适的配比是质量比为81%凹凸棒,15%CaCl_2,4%Na_2SiO_3,静态水吸附量为32.9%,吸湿速率1.06%。

There is a large micro-pore network in attapulgite crystal, so it has very big specific surface area, its surface activity is very high, adsorption performance is exceptionally good. Because of the presence of a large number of channels in its crystal, it has big air volume, so it can be used as a dry agent. In this paper, the hygroscopic agent was added to improve the adsorption properties of attapulgite clay, and the adhesive was added to improve the sample resistance to crushing force. According to national standards, the particle size and sintering process were determined. Static water adsorption capacity, moisture absorption rate and anti-crushing force of the sample were measured by home-made instruments. The results show that： XRD diffraction patterns prove that the samples contain montmorillonite and palygorskite, these impurities can seriously affect the structure and anti-crushing force of the attapulgite moisture particles, expansion cracking can appear after moisture absorption. The sample after adding CaCl2 has better hygroscopic effect than the samples after adding MgCl2 and CuSO4, adding an appropriate amount of NaSiO3 can improve the intensity of particles after the absorption, the difference of hygroscopic effect between purified attapulgite and non-purified attapulgite is not obvious. The suitable sintering temperature is 350 ℃, suitable sintering time is 1 h, the particle size is 2.5 - 3.0 mm. The most appropriate mass ratio is 81% attapulgite, 15% CaCl2 and 4% NaSiO3, static water adsorption capacity is 32.9%,moisture absorption rate is 1.06%.