Study On Discarding Tailings By Gravity Separation And Floatation Combined Process Of High-ash Middlings

China's coal and coking coal resources is extremely scarce,scarce coal resources in the context of extreme shortage,each year there are still a large number of scarcity of coking coal as a driving force for coal,resulting in a waste of resources.Therefore,the study of scarcity of coal flotation coal re-election,whether from the perspective of national resource reserves or the economic point of view of enterprises are of great significance.In this paper,the tailing-pulverized coal-ultrasonic flotation process suitable for flotation coal sorting is proposed in the Qianjiaying ore flotation.The aim is to provide a new process for coal sorting in flotation.The idea.The coal content of flotation coal in Qianjiaying Coal Preparation Plant was studied.The conclusions were as follows: the ash content in the flotation was 49.30%,the main grain size was +0.5 mm,the yield was 32.32%,the yield was 0.0.50 mm The rate of 80.77%,ash 47.66%,the overall size of coarse.The leaching content of coal in the flotation was higher,the yield of the density was + 48 kg / L,the yield was 48.62% and the ash was 71.88%.Through the analysis of the composition of the coal in the flotation,the flotation coal contained kaolinite-based clay Minerals.The results show that the grain size of-0.045 mm increases with the increase of grinding time,and the ash content increases first and then decreases,but the ash content is more than 60%.The results show that with the increase of the processing capacity of the screw separator,the recovery rate of the combustible body is gradually decreasing and the ash content is gradually increasing.The results show that the higher the concentration of the screw feed is,the lower the recovery rate of the combustible body is,and the ash content decreases first and then increases.When the concentration of the screw separator was 0.25 t / h and the feed concentration was 20%,the yield was 49.76% and the ash content was 69.21%.The ash content in the flotation decreased from 49.30% to 31.24%.The grinding time of the spiral coal was explored,and the grinding time was set at 2 min,3.5 min,5 min,10 min and 15 min.The results showed that with the increase of the grinding time,The content of grain content was more than 30.18% when the coal grinding time was 2 min,and the grain size of-0.045 mm was 71.46% when the grinding time was 15 min.The results show that the longer the grinding time is,the more the dissolution of the product is,and the cumulative yield of the refined coal ash is 12.50% at the site.The cumulative yield is R15 min(60%)> R10 min(57%)> R5 min(53%)> R3.5 min(50%)> R2 min(24%);After the step-by-step release of the product after the test,the site requirements of coal ash is 12.50%,the average yield was R3.5 min(50%)>R5 min(40%)>R2 min(33%)>R10 min(16%)>R15 min(12%)has been able to meet the dissolution requirements.The conventional flotation of flotation coal was studied.Under the conditions of single factor optimization,the conditions of the slurry concentration,the amount of collector,the amount of foaming agent and the speed of impeller were selected.The results show that under the condition of better roughing test,The yield was 65.68% and the ash content was 18.18%.The results showed that the yield of clean coal was 60.62% and the ash content was 15.63%,which was selected as the collector and foaming agent.Conventional a rough one fine flotation process is difficult to achieve qualified clean coal ash,add a selection(a rough two fine)can be sorted out the ash for 12.48% qualified coal,the yield of 50.14%.The results show that the whole process of ultrasonic treatment of 40 KHz is better when the ultrasonic wave is used for different frequency,ultrasonic join mode and processing time.The whole process of ultrasonic treatment for a coarse one fine flotation process,the final available for the 12.49% ash,the yield of 61.75% qualified coal.The scanning electron microscopy(SEM)of the coal samples after ultrasonic treatment shows that the ultrasonic cleaning effect on the coal particles is significant.A new process of flotation and refueling combined with tail gas dissolution-ultrasonic action was proposed.The quality of the process is calculated and compared with the conventional sorting process.The yield of refined coal is increased by about 9 percentage points.This new process can not only save a selection,but also the preliminary economic results show that the process can be Enterprise income 27 million yuan / year sales profit.The proposed process provides a new idea for high ash flotation coal sorting process.There are 40 figures,31 tables and 130 references in this thesis.