Abstract: As a new type of thermal activation technology,microwave has the advantages of uniform heating,green and high efficiency. After microwave activation,the crystallographic properties of clay minerals change. It can be used as a reinforcing material for the development of high-silicon waste rock composite mineral materials. The changes in the mineral crystallographic properties of kaolin,and quartz (the main mineral component in high silica waste rock),before and after microwave activation are investigated. And the possibility of applying activation-modified kaolin as a reinforcing material for the preparation of kaolin-high silica waste rock high-value mineral materials is analyzed from the mineral crystallographic point of view. The changes of mineral crystallographic properties and micro-morphology of kaolin and quartz before and after microwave were characterized and analyzed by thermogravimetric analysis ( TG-DTG),X-ray diffraction ( XRD), scanning electron microscopy (SEM) and other detection methods. The results showed that kaolin is transformed from lamellar kaolin to acicular/ columnar mullite with enhanced structure at 2 kW-18 min after microwave activation;After microwave activation,some quartz changes from α-quartz state to β-quartz state at 2 kW-18 min,the quartz particles become smaller and the contact area increases,which is conducive to the interaction with other minerals. Under the action of microwave activation,kaolin-high silica waste rock composite mineral materials with different properties can be prepared by regulating the crystal phase changes of kaolin and quartz. 

Key words: microwave activation,kaolin,quartz,mineral crystallographic properties