Development of Cryptocrystalline Graphite Desulfurization Methods

Abstract

Increasing demands on the quality of graphite cause carrying out detailed studies of its desulfurization. Combined sulfur present in natural graphite reduces the heat transfer coefficient, increases the heat energy consumption, pollutes the atmosphere with harmful emissions in the process of their application in various branches of industry. The technology and deepness of desulfurization is determined by the total content and ratio of various sulfur compounds in graphite. Previously, a number of technologies for cryptocrystalline graphite enrichment had been developed by the authors. However, the use of these technologies does not effectively reduce the sulfur content in the graphite composition. Therefore, the aim of this work is to develop activation methods that can reduce effectively the sulfur content in the composition of cryptocrystalline graphite. In order to reduce the total sulfur content, mechanical and electro-explosive-pulsing activation were tested. Mechanical activation of graphite was carried out in АGО-2, DCM, D-100 activator mills in different environments and at different activation time. To implement electric-explosive-pulsing activation, special equipment was used. In the process of the research it has been found that the use of mechanical activation and electric-explosive-pulsing activation does not reduce the sulfur content below 0.25 wt.%. Mechanical activation of graphite in different modes enables more intensive release of sulfide minerals from aggregate graphite formations and their intensive oxidation.