配料组成与合成温度对蛇纹石合成堇青石的影响

Effects of formulation and temperature on synthesis of cordierite from serpentine

以连云港市东海蛇纹石粉为主要原料,辅以α-Al2O3和石英粉高温合成堇青石,分别配成符合理论组成的配方,SiO2质量分数比理论组成分别多5和10百分点的配方,以及Al2O3质量分数比理论组成分别多5和10百分点的配方,经球磨、造粒、烘干、冷等静压成型后,分别在1 050、1 100、1 150、1 200和1 250℃保温2 h,然后检测试样的显气孔率、体积密度和常温抗折强度,并进行XRD和SEM分析。结果表明:合成的堇青石呈较完整的六方柱状形貌;增大石英粉的添加量能降低材料的合成温度,制得致密度较高的堇青石材料;增大α-Al2O3添加量,合成的堇青石气孔较多,结构疏松。

Cordierite was prepared at high temperatures using serpentine powder from Donghai Lianyunga- ng as the main starting material,adding α-Al2O3 and chiometric,SiO2 addition 5% or 10% higher than the quartz powder. Five formulations were adopted： stoi- stoichiometric,and AI203 addition 5% or 10% higher than the stoichiometric. The batched materials were ball milled, granulated, dried, cold isostatic pressed and fired at 1050,1 100,1150,1 200,and 1250 ℃ for 2 h,respectively. The apparent porosity,bulk density and cold modulus of rupture of the prepared specimens were tested, and specimens were analyzed by XRD and SEM. The results show that the synthesized cordierite has a complete hexagonal columnar mor- phology;increasing quartz powder addition reduces the synthesis temperature,obtaining denser cordier- ite;increasing α-Al2O3 addition leads to porous cordierite with a loose structure.