Technology Research Of Graphite Extracted From Stone Coal

As an important nonmetal material, graphite has attracted huge scientific interest and has been used in numerous technological fields such as modern astronavigation, aviation, electronics and mechanics due to its exceptional electrical, mechanical, and thermal properties. In this thesis, to efficient the exploitation of graphite resource, research aiming to extract graphite from stone coal mined in Zhuxi county, Shiyan city, Hubei Province have been carried out, which has a carbon content of 74.02%. The main contents are as follows:A detailed description is given on various methods for graphite purification mainly including flotation, alkali-acid method, hydrofluoric acid washing approach, chloridizing roasting and purification in high temperature. Based on the systematic exposition of their basic principles, progress conditions, research progresses and practical applications, the comparison of the merits and demerits of these methods, the conclusion can be drawn that the alkali-acid method could still be considered as the best way in graphite purification. From the chemical reaction principle, as well as the perspective of thermodynamics and kinetics of alkali fusion roasting process, the reaction of NaOH and impurities is exothermic; the roasting temperature is a key factor to determine the effect of roasting in graphite purification, and the optimal temperature must be confirmed to balance reaction rate and extent of reaction.Experiment based on acid alkali method, chose fixed carbon content as a parameter and analyzed the influence of sieve mesh number, NaOH dosage, roasting temperature, roasting time, concentration of hydrochloric acid, hydrochloric acid dosage and acid leaching time to graphite extraction effect.By single factor experiment come to the optimum technology condition of mine ore from 150 mesh to 200 mesh, alkali fusion condition is the quality of NaOH/C is 3.8 g / 10 g, roasting temperature is 600 ℃, roasting time is 90 min, acid leaching condition is concentration of hydrochloric acid is 8%, the dosage of HCl/C ratio is 20 ml / 5 g, pickling temperature is 80 ℃, pickling time is 150 min. Under the condition process, fixed carbon content of the sample can increase from 74.02% to 90.43%.By four kinds of detection methods such as Scanning Electron Microscope(SEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy and Raman spectrum analysis, analysis the crystal structure and element composition of the purified sample, the results show that extraction of graphite by alkaline acid method has good effect to miscellaneous, it can improve the fixed carbon content and confirmed that the extraction of graphite from the stone coal is feasible. Based on the actual situation of stone coal ore enterprises, combined with the cost of extract graphite by alkaline acid method, estimate the implementation of the process can bring 3.276 million yuan every year for the enterprise economic benefits and achieve the efficient use of resources.