煤系煅烧高岭土吸油值的影响因素

Factors influencing oil adsorption of calcined coal-series kaolin

涂布造纸填料用煅烧高岭土要求有较高的吸油值。本文针对市场上高吸油值煅烧高岭土资源短缺的现状,研究煅烧高岭土吸油值的影响因素,寻求提高煅烧高岭土吸油值的方法。实验以唐山煤系高岭土为原料,在600～1000℃范围内间隔50℃取点,分别煅烧3h。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)观察煅烧高岭土的形貌并鉴定其物相。计算煅烧高岭土的烧失量,并检测其pH值、比表面积、Zeta电位等参数,分析它们对煅烧高岭土的吸油值的影响。结果表明:750℃煅烧的高岭土吸油值最高,可达76.3g/100g;煅烧高岭土的Zeta电位、pH值、比表面积等对其吸油值的影响均较为显著,其中比表面积对吸油值的影响最大。

Calcined kaolin used in specific paper filler requires a higher oil absorption value. In view of the resource shortages of the calcined kaolin with high oil absorption value in the market, this study aims at investi- gating factors influencing the oil adsorption of the calcined coal-series kaolin and seeking for ways to improve the oil absorption value of calcined kaolin. Coal-series kaolin used as raw materials in this study was obtained from Tangshan area, which was calcined in the temperature range of 600 -- 1 000 ℃, with the interval of 50℃. Scanning electron microscope （SEM） and X-ray diffraction （XRD） were used to conduct morphologic observa- tion and phase identification of calcined kaolin respectively. Calculation of loss on ignition and detection of such parameters as pH value, specific surface area and Zeta potential were used to analyze their influences on oil adsorption value. The results show that the highest oil adsorption value of calcined kaolin is up to 76.3 g/100 g at the temperature of 750℃ ; and Zeta potential, pH value, specific surface area constitute the notable factors in- fluencing oil adsorption value, with the influence of specific surface area on the oil absorption value of the cal- cined kaolin being the greatest.