Research On Flotation Upgrading Of Steam Coal Slime Of Hulusu Coal Preparation Plant

In this paper,the quality improvement of coal slime with three different particle sizes in Hulusu Coal Preparation Plant was studied.Due to the large consumption of conventional flotation reagents for power coal slime,three reagent combinations are used to explore the effect of new reagents.The three reagent combinations are FDJ + Q1,EKOF +sec-octanol,kerosene + sec-octanol.Through the comparison of conventional flotation,high shear slurry adjustment and flotation tailings settlement test,the reagent combination,process parameters and quality improvement mechanism suitable for flotation are explored.The main conclusions are as follows :FDJ + Q1 reagent combination at the similar combustible recovery level,the reagent dosage is less,the flotation rate is high,and the results are consistent with the moisturizing test.Process test can reduce the ash content of clean coal by 1?5 percentage points and increase the ash content of tail coal by 1 ? 14 percentage points.Compared with conventional flotation,the combustible recovery can be increased by about 2?6 % when the dosage of reagent is constant in high shear slurry flotation,and the collector dosage can be saved by 30?50 % under the premise of similar combustible recovery.The flotation kinetic test results show that after high shear slurry adjustment,the kinetic constants of primary slime,underground slime and cyclone overflow slime increase by 1.15,1.01 and0.28 respectively under FDJ + Q1 combination,and the theoretical maximum combustible recovery increases by 5,7 and 3 percentage points.Under kerosene + sec-octanol combination,the kinetic constants increase by 0.85,0.95 and 0.52 respectively,and the theoretical maximum combustible recovery increases by 12,6 and 3 percentage points.As the particle size becomes finer,the rate increases slowly.In general,the high shear slurry flotation shows fast flotation rate,especially in the early stage of flotation.Three kinds of slime in FDJ + Q1 and kerosene + sec-octanol reagent combination,showed that the combustible recovery rate increased with the increase of slurry speed and slurry time,and the trend gradually slowed down.When the stirring speed is 1500 r / min and the stirring time is 2min,EKOF tends to be saturated,while EKOF is a compound reagent.The foaming agent plays a role in the high shear pulping stage,showing poor selectivity,low separation efficiency,and the recovery rate of combustible is lower than that of conventional flotation.Comprehensive image analysis test shows that high shear sizing can inject energy into the system to break through the energy barrier between coal particles and form flocs,but the speed and time of sizing are not simple positive correlation with the size of flocs.The optimal process parameters of three kinds of coal slime obtained from the settlement test of tail coal are PAM(polyacrylamide)cation 300 w : 1000 g / t,PAC(polyaluminum chloride): 5000 g / t.Under the condition of cationic 300 w,the initial settling velocity increased first and then decreased with the increase of PAC proportion,and the turbidity of supernatant decreased gradually with the addition of PAC.Under the condition of anionic medication,it was found that the increase in the molecular weight of PAC and polyacrylamide would increase the viscosity of the sedimentation system,thereby affecting the sedimentation rate and the clarity of the supernatant.