Investigation of Optical and Electrical properties of Rock Samples from Darfur Using Spectroscopic Techniques

Abstract

The main objectives of this research study were to know rock contents to classify their types through multi spectroscopic techniques and analyzing their electrical and optical properties. Energy Dispersive X-ray Fluorescence analysis showed that the major revealed composition as Al2O3, SiO2, SO3, Fe2O3, CaO and TiO2. X-ray Diffraction scanning tests of the of rocks indicated the peaks corundum, quartz, rutile, albite, anorthite, orthopyroxene and feldspar composition the most the rock samples were quartz as main content except sample one was corundum as the basic compound, the comparison between x-ray fluorescence and x-ray diffraction results there is a similarity to determine the fundamental body of the rocks. for more investigation and delicacy Energy Dispersive X-ray Spectrometry coupling with Scanning Electron Microscope scan analyzing indicated that presence of the trace elements as Fe, Au, K ,and Ca, the weight percent wt.t of silicon has the great majority in the mast rock samples with the standard label of SiO2. Laser-induced breakdown spectroscopy was used to detect rare earth elements in the rock samples. Elemental analysis has revealed trace and rare elements are present through spectral lines of low and high intensity and appropriate wavelength range between (420 and 720 nm). Rare earth elements such as Ce, Pr, Eu, and Gd were identified in spectra recorded from the samples and selected as the main targeted elements to study their properties. revealed that the number of average concentrations was 3919, 1153, 6823, and 2638ppm in all samples. Through the spectral lines, the most appearance elements were Aluminum, Silicon, Iron, Sulfur, Oxygen, and Lead. FTIR gives us information about the presence of many organic groups in the examined samples. The complexity of the FTIR spectrum is typical of most infrared spectra and illustrates their use of identifying materials through functional groups. the gap in the spectrum of between (1048 and 3618) cm-1. An unambiguous analysis of the IR spectra of rocks was difficult to clarify due to the presence of many ingredients. The bands in this region originate in interacting vibrational modes resulting in a complex absorption pattern. Usually, this region is quite complex and often difficult to interpret. Diffuse Reflectance Spectroscopy has been used as property prediction models to study the physical, optical and electrical properties. KM function, extinction, absorption, refractive index, optical band gap, electrical and optical conductivity, and many of properties have calculated and discussed in detail based on DRS provided background through related equations. overall, results have given different values two mineral categories of corundum and silica group with the preference of corundum specimen from silica group optical and electrical properties in most results obtained. The DRS results provide reliable information and new insights into the structural characteristics of the surface metal oxide species on different environmental conditions. Analyses and studies for selected rock samples were carried out to identify mineral type through physical and chemical characteristics and discrimination of basic contents as well as impurities the possibility to determine of chemical and concentration of specific mineral depends on the backbone of the basic body composition, available of chemical data always important to observe the behavior rock samples. In general, according to the analyzing outcome, optical and electrical the research can consider the rock samples as semi-conductors due to silicon contents were represented as greats of all rock samples until they were treated and extracted using the scientific methods which used for mineral treatment .The Sudanese corundum less quality than other countries corundum but quartz is nearly the same characteristics to the other countries due to SiO2 content more than (98%)