Applying Terahertz Time-domain Spectroscopy To Research The Mineral Crystal Property

In company with the oil-gas exploration being more and more difficult,more information about the mineral should be provided in diverse ways,so that we can develop a synthetic solution in rock diagenetic systems research combining the advantages of different methods.For a better understanding of the mineralization mechanism and processes,we applied Terahertz time-domain spectroscopy(THz-TDS)as a non-destructive,contact-free tool for identifying the different stages of the rock evolution.Furthermore,Scanning electron microscope(SEM),X-ray diffractogram(XRD)and optical microscope as supplementary methods provide more information for us to understand the evolutionary regime of the mineral.The shape,number and size of fluid inclusions in halite crystals grown at different temperatures are different and can directly show the composition,temperature and pressure of the ore-forming fluids.The relationship between absorption coefficient and temperature exhibited the nonlinear features at different frequencies,a fitted regression curve can present accordingly and the evolutionary regime of halite rock(early diagenetic phase,late diagenetic phase and approximate metamorphic phase)can be indicated by the absorption coefficient in the THz region.The present study of identification based on THz-TDS was in good agreement with XRD and optical microscopes,realizing a lead in evolution of rock reservoir diagenetic systems study.In order to understand the influence of temperature on the structure and properties of KCl,the selected sample was get at different temperature.Terahertz time-domain spectroscopy has been used to probe the potassium,exhibiting different spectral signals in the terahertz band,and photographs were taken via SEM and optical microscopes in an attempt to provide some reference data for better understanding the composition and characteristic analysis of geological diagenetic research.Mineral spectrum characteristics are determined by component and structure,mineral mixture make the mixed spectrum complex.Some studies on the mixtures grown in different temperature and in different ratios of weight have been done for better testing and analysis of mineral spectrum characteristics.The results show that the absorption coefficient and refractive index of the mixture can be distinguishes from pure crystals.To improve the efficiency of exploration,THz technology for rock information extraction is an important approach which can be applied to resource exploration.