AGGLO COLUMN FLOTATION OF TURKISH LIGNITE SLIME AND ŞIRNAK ASPHALTITE BY MICRO SELECTIVE COAGULATION IN MODIFIED COLUMN FLOTATION SEPARATOR

Abstract

The asphaltite reserves and current coal mining in Şırnak, were 83% of total Turkey's asphaltite reserves. This type of asphaltite should be washed with a washing plant to operate in areas where sulfur content and ash content of asphaltite were removed. Tunçbilek, Bolu Mengen and Kütahya Gediz lignite were tested in selective agglomeration by asphaltite together. The ash and sulfur contents in coal washing provided great issue due to hard washability of Şırnak asphaltite. This evaluation gave great benefits in terms of reduced costs as well as transport and environmental protection. The coal slime recovery ranged from a 20-120 mg/l fuel oil solution through with mechanical agitation of fuel oil micro coagulation followed by modified centrifuge baffle was researched. Micrographs and particle size measurements indicated that coagulates were the fine agglomerate of fuel oil micro coagulation and slime, with size ranging from 70 to 100 μm. Micro column flotation proved much as other mechanical techniques such as inclined lamella plates in column and coagulation effect was managed in agitation conditioner by fuel oil. Modified column flotation cell used to recover coagulates on the lamella bafflers temporarily. The fuel oil and surfactant adsorption was evaluated through control measurements. The influence of collector fuel oil concentration, pH and bubble size on slimes recovery was investigated. In the absence of collector, a combustible recovery of 45% was achieved, while in the presence of 20 mg/L of fuel oil it was increased to 80%, at pH 8. The slime recovery also increased with fuel oil micro coagulation increase to 30gr/l slurry and bubble size decrease, reaching 50-150 micron coagulates and bubble size around 60 µm.