Study Of Surface Modification And Flotation Improvement Of Contact Metamorphosed Coal

The coal is invaded by the magmatic intrusion,resulting in a large amount of contact metamorphosed coal.The samples in this paper come from Ningxia field.The alkyl side chain of the sample decreased,and formed a large number of honeycomb pore structures because of high temperature,causing the low floatability of the sample.The contact metamorphosed coal is difficult to float.When collector was not added,only 1 kg/t2-octanol was added as frother,the combustible matter recovery of contact metamorphosed coal was 9.81%,and a large amount of coal was lost in tailing.The samples were contacted with the modifying agents,kerosene and heavy oil,by grinding and conditioning.The effects of reagents dosage,grinding time,stirring strength and conditioning time on the modification were explored.The reasons of flotation improvement were explored by SEM,FTIR and induction time measurements.The experimental results show that the grinding and conditioning can promote the adsorption and filling of agent and fine particles in the surface and pores,increasing the effective adhesion area of the particle surface and the effective adhesion area between particles and bubbles,and strengthening the mineralization of contact metamorphosed coal.When the heavy oil content in the grinding is 10 kg/t,the combustible matter recovery of contact metamorphosed coal can reach 87.70 %.In order to explore the applicability of the modified measures to different quality contact metamorphosed coal,the low ash contact metamorphosed coal and high ash particles were mixed in different proportions.The results show that the presence of high ash particles does not affect the effect of modified agents and contact with coal.