The Effect Of Plastics On The Properties Of Carbon-containing Pellets Under Micro-thermoforming Conditions

The increasingly severe environmental protection pressure requires metallurgical workers to actively explore new technologies that are efficient,low-energy,and lowpollution to directly reduce ironmaking.At the same time,as China's plastic production and consumption increase,a large amount of waste plastics are produced each year.The combination of waste plastic metallurgy raw material and CCB direct reduction technology promotes the development of direct reduction ironmaking process,reduces the burden of waste plastics processing,and achieves the goal of environmental protection.In view of the characteristics of raw materials of pulverized coal and plastics and the research status of CCB,this paper proposes a new process of carbon-containing pellets with plastics under the conditions of microthermoforming.Through the preparation of CCB with internal plastic,the influence of hot-pressing temperature and hot-pressing die temperature on the compressive strength of CCB with internal plastics was studied,and a reasonable internal-compressed plastic hot-pressing was determined.Carbon pellets were heated at a temperature of 150°C and mold temperature was 120°C.Based on the compressive strength of the three plastics(PS,SAN,and PP),the type of plastic for the later experiment was determined to be PS.This article through orthogonal experiment to study the temperature,the amount of plastic added,the ratio of C/O ratio of the internal plastic with hot pressing carboncontaining pellets direct reduction metallization of the order of the primary and secondary.The results of orthogonal experiments show that the primary and secondary factors affecting the metallization rate of CCB with internal plastics are the reduction temperature,the amount of plastics added,and C/O;the best reduction conditions obtained are the reduction temperature of 1200°C,the amount of plastic added 20%,C/O ratio 1.1,the highest metallization rate at this time,up to 64.55%.After the best reduction conditions were obtained,the effect of heating rate and the amount of plastics added on the single-factor variable method was used to study the effect of CCB with internal plastics on the direct reduction fraction.The single-factor experimental study shows that the slower the heating rate,the higher the metallization rate of pellets,the smaller the area of unreacted cores,and the faster the heating rate is,the reverse is true.The amount of plastic as a variable,the experimental reaction 0-10 min early reaction,the difference between the reduction score of the different plastic pellets is not large,the reaction mid 10-35 min,the hot carbon carbon pellet reduction score in order is the amount of plastic 40%,30%,20%.In the later 35-50 min of the reaction,the gap between the 30% and 40% plastic reduction pellets gradually decreased.Hot-pressing carbon-containing pellets can accelerate the reaction rate even though they are incorporated into plastic pellets.However,once too much plastic is added,the amount of reductant will be insufficient in the later period of the reaction to slow down the reaction rate and affect the reaction.The more plastics added,the lower the metallization rate after reduction is.