晋北煅烧高岭土用煤矸石的应用矿物学特征

为了给晋北煅烧高岭土用煤矸石的评价和开发利用提供科学依据,采用XRD、XRF、SEM和白度计等现代分析测试技术,研究了晋北煅烧高岭土用煤矸石的应用矿物学特征。结果表明:1)根据造纸和涂料用煅烧高岭土的国家标准,晋北煤矸石主要可分为3种类型:合格原料、基本合格原料和不合格原料。2)与合格和基本合格原料相比,不合格原料煅烧产物的化学成分中SiO2、Al2O3、Fe2O3含量以及碱金属与碱土金属总含量都与前者有较大差异。3)合格和基本合格原料主要由高岭石(85%~94%)组成,不合格煤矸石矿物组合为高岭石(30%~60%)+石英(23%~38%)+伊利石(14%~26%),并含少量黄铁矿和白云石等杂质矿物,石英等杂质矿物和含铁矿物是分别导致煅烧产物化学成分和白度不合格的主要原因。4)合格原料中高岭石结晶度较好,主要为不规则片状、书册状和弯曲片状,片表面光滑,片径大小范围较大,为0.05~51.22μm,平均2.80μm,径厚比41.24。

Applied mineralogical characteristics of coal gangue,for preparing the calcined kaolin,in the northern Shanxi,China

In order to provide a scientific basis for the evaluation and utilization of coal gangue used for the calcined kaolin in the northern Shanxi,the applied mineralogical characteristics of the coal gangue have been studied in this paper by using modern analytical and testing techniques such as XRD,XRF,SEM,and whiteness meter.The results show that according to the China national standard of the calcined kaolin for papermaking and coatings,coal gangue samples in the northern Shanxi can be mainly classified into three types of raw materials including the qualified raw material,basically qualified raw material,and unqualified raw material.Compared with the qualified and basically qualified raw materials,the unqualified raw materials have relative obviously different contents of SiO2,Al2O3,Fe2O3,alkali metals,and alkaline earth metals.The qualified and basically qualified raw materials are mainly composed of kaolinite(85%-94%).However,the unqualified coal gangue is composed of kaolinite(30%-60%)+quartz(23%-38%)+illite(14%-26%),with a small amount of impurity minerals such as pyrite and dolomite.Impurity minerals such as quartz and iron-containing minerals mainly resulted in the unqualification of calcined products in terms of the chemical composition and whiteness.In the qualified raw materials,kaolinite which has relatively good crystallinity mainly occurred in forms of micro-sized irregular,book-like,and curved sheets which have smooth surfaces and sizes mainly ranging from 0.05μm to 51.22μm with average size of 2.80μm and the size/thickness ratio of 41.24.