Coking Coal Pyrolysis And Char Gasification Of Thermal Analysis Kinetics And Coking Index

Coke gasification by carbon dioxide is an important reaction in the metallurgicalprocess. Coke plays a mainly role as a heat source, a reducing agent, stock columnskeleton and carburizing source in the production of blast furnace, Coal cokingprocess plays an important role in the cold state and hot state index of the coke. In thelong way , the coal static index of G bond index was seem as a measure of carbonizedcoke quality.The process of the coal pyrolysis is a constantly changing complex physical andchemical process. In the actual productionof coke,the dynamics behavior of coalpyrolysis process maybe better to reflect the quality of carbonized coke. Therefore,investigating of the different coal in the pyrolysis process to get the carbonizationmechanism, and establish the relationship between the cold state / hot state index ofthe coke is very significant to measure the quality of coke.In this paper, the kinetic study on the pyrolysis of some kinds of coal is carriedout by thermogravimetric analysis technology under non-isothermal conditions. Therelationship between the cold state and hot state index of the coke obtained from 40kgcoke oven is established. Conclusions drawn from this paper is as followed:(1) From the pyrolysis kinetic aspects, the process of coal pyrolysis whichexhibits different mechanism-coal pyrolysis has staged characteristics. determined thedrying degassing stage mechanism function is f (α) = 1-α, severe decomposition anddepolymerization reaction stage (that is softening stage) mechanism functionis f (α) = (1-α)2 , condensation stage (that is curing stage) mechanism functionis f (α) = 2(1-α)1/2 .(2) The activation energy of LW (gas coal) obtained in step of the softening isless than the activation energy obtained in step of the curing. Others coal, theactivation energy obtained in step of the softening were greater than the activationenergy obtained in step of the curing. In curing and softening stage of the coal, andthe relationship between E with traditional G bond index has certain correlation.(3) The activation energys of coking coal in the softening and curing stage arevery good correlation with coke thermal properties. When the values of the activationenergy obtained from various coal in the curing stage are close to each other, theshrinkage rate of making coke in the curing stage reach consensus. Reduced the level of uneven contraction caused by slow speed of partial shrinkage can make coke blockincrease.(4) The mechanism function of coke gasification by CO2 is f (α) = 3(1-α)1/3 .The activation energys obtained from coke gasification with carbon dioxide and coalin the curing stage have a certain relevance. The slower the coal shrinkage rate is inthe curing stage, the faster rate of coke gasification by carbon dioxide is.