Study On Mechanism Of Waste Rubber As Additive For Coking With Coal Blending

Waste rubber is one of the common "black pollution" at present.The increasing waste rubber has a more and more serious impact on the environment.Scientific and reasonable treatment and utilization of waste rubber has become an urgent problem in energy and environment.Using waste rubber as additive in coal blending coking can not only solve the problem of recycling waste rubber,but also achieve the purpose of improving coke quality and reducing cost.Different rubber products come from different raw materials and proportions in production.For example,natural rubber(NR),styrene butadiene rubber(SBR)and cis-1,4-polybutadiene rubber(BR)are mainly used for various automobile tires,but natural rubber and cis-1-butadiene rubber are mainly used for truck,natural rubber and styrene butadiene rubber are mainly used for tractor and agricultural three-wheel,and cis-1-butadiene rubber is mainly used for household car tires.The rubber composition of the conveyor belt is different from that of the tire.The main components of the conveyor belt are chloroprene rubber(CR),ethylene propylene rubber(EPR)and cis-1,4-polybutadiene rubber.In order to clarify the process conditions and mechanism of waste rubber as additive for coal blending and coking,this study focused on 7 kinds of waste rubber,including 6kinds of tires and mineral transmission belt,which accounted for a large proportion of trucks,family cars,tractors,electric vehicles,off-road vehicles,agricultural tricycles and so on The pyrolysis characteristics during carbonization were analyzed.The results showed that the adhesive properties of coal samples were studied by adding the same amount of different rubber powder on the condition that the original coal blending raw materials were unchanged.It was found that the adhesive index of coal samples increased the most with the rubber powder of household car waste tire.When the ratio of waste rubber to coal was 1:100,the caking index of coal samples increased by31.5% when the ratio of waste rubber to coal was 1:100,followed by tractor,agricultural tricycle,conveyor belt,truck,electric vehicle and so on.However,the addition of off-road vehicle waste rubber powder has no effect on coal sample adhesion index;truck tire waste rubber powder can increase the maximum thickness of coal colloid layer by 2.30%,and reduce the final shrinkage rate by 1.85%.The maximum thickness of resin layer increased by 1.54%,and the final shrinkage rate decreased by 0.62%.The rubber powder from truck and electric vehicle tire reduced the maximum shrinkage of coal samples3.85%.Combined with small coke oven experiment,the influence law and mechanism of waste rubber on the performance index were studied.The results showed that the cold strength of coke increased with the addition of waste tire rubber powder,M40 increased by 2.55%,and M10 decreased by 17.50%.At the same time,the true relative density of coke increases by 1.38%,the porosity decreases by 4.45%,and the moisture content decreases by 18.42%.Secondly,the rubber powder of waste tire of electric vehicle can reduce the porosity of coke,reduce the true and apparent relative density,but at the same time,the addition of rubber powder can reduce the coke M40.At the same time,it was found that the addition of waste rubber powder reduced the thermal strength of coke and enhanced the reactivity.Among them,the largest decrease in thermal strength was found in waste tire powder of electric vehicle,and the smallest decrease was in waste tire powder of truck,with the decrease rates of 5.66% and 0.70% respectively.Without considering the influence of waste rubber on the thermal strength of coke or no obvious requirements for the change of thermal strength,the purpose of improving the quality and reducing the cost of coal blending coking can be achieved by adding waste rubber powder of truck tires mainly composed of natural rubber and cis-1-polybutadiene rubber.In addition,through the study on the coal sample cohesiveness with the addition of the same amount of rubber powder,it is found that with the increase of the rubber powder dosage,the coal sample caking index first increases rapidly,and then decreases when the rubber powder: coal sample(mass ratio)= 1:100,and the adhesive index begins to decrease to 4:100 and then increases slowly.The best ratio of rubber powder to coal sample is 1:100(mass ratio).There are 24 pictures,8 tables and 60 references.