Flotation Process Intensification Study of Carbon-ash Separation of Gasification Fine Slag Based on Mechanical Dissociation Activation
As a typical solid waste in the coal chemical industry,the high unburned carbon content of gasification fine slag restricts the utilization of resource.Flotation is an effective method for the separation of carbon and ash from gasification fine slag,but the pores of unburned carbon particles are developed,and the carbon ash components are mixed with each other,resulting in large consumption and low efficiency of traditional flotation reagents.In order to reduce the adverse effect of pores on the flotation of gasification fine slag,two mechanical dissociation activation methods of rod mill and stirring mill were used to grind gasification fine slag of Shaanxi Province,and the mechanism of the effect of mechanical activation on the flotation process was investigated by scanning electron microscopy,BET,mercury porosimeter and total organic carbon analyzer.The re-sults show that when the dosage of collector kerosene is 11 kg/t and the dosage of foaming agent MIBC is 6 kg/t,the flotation index of tailings ash content of 64.82%and combustible recovery of 59.92%can be obtained by direct flotation,and the sepa-ration effect of carbon ash is poor.On this basis,the mechanical dissociation activation is carried out by the rod mill,the flota-tion test can increase the ash content of the best tailings by about 15 percentage points to 80.09%,and the combustible recov-ery rate reaches 79.95%,and the flotation index is significantly optimized.Using stirring mill for mechanical dissociation and activation,the flotation test can obtain excellent indexes of 87.48%ash content and 90.93%combustible recovery rate.In comparison,using stirring mill for mechanical dissociation and activation,the flotation test is not only better than the rod mill in the separation of carbon and ash,but also better than the rod mill in reducing the particle size,destroying the pores,and reduc-ing the adsorption effect of the agent.Therefore,mechanical activation can significantly improve the combustible recovery rate and tailing ash content of gasification fine slag flotation,and the activation effect of stirring mill is better than that of rod mill.More than 90%combustible recovery rate can be obtained after 10 min grinding.On the one hand,the mechanical activation re-alizes the effective dissociation of carbonaceous components and ash components,on the other hand,it destroys the larger pore structure above 1000 nm,avoids the ineffective adsorption and penetration of flotation reagents in the particle pores,increases the hydrophobicity of the unburned carbon surface and reduces the consumption of reagents.
gasification fine slagflotationcarbon ash separationmechanical activationpore structure
万方数据
维普
