Research Of Ultrafine Coal In Blend Coal Coking Technology

In the coal blending for coking, the coke quality can be improved by grinding theweak caking coal, which has high content of the inert component, but the relatedresearches didn’t provide the grinding particle size of the weak caking coal. In order torealize the purpose of adjusting the optimum size, this paper based on the advantage ofcoal preliminary grinding technology, combined with DAPS and SCOPE21of coal fineparticle size application thought, through adding the weak caking coal which has beensuperfine grinded for coking, was studied the optimal grinding particle size of the weakcaking coal.We use single coal for production and coal blending ratio of a coking plant for40kgsmall coke oven test. The high rank coal and low rank coal have a low cost and cakingproperty. We have studied on changing the weakly caking coal particle size for coking onthe influence of coke quality by adjusting the weakly caking coal particle size. The resultsshow that, on the condition that other types of coal particle size not change, changing theparticle size of lean coal, meager lean coal, anthracite has an obvious influence on thecoke quality. It was found that when the lean coal particle size <0.2mm, anthracite <0.5mm and meager lean coal <1mm, the coke quality can be significantly improved. Andwhen weakly caking coal and gas coal particle size <1mm, the coke crushing strengthcan be improved too. In this paper image analysis method was used to determine the cokeporosity, which characterizes the CRI, at the same time, SEM was used to observe cokemicrostructure, which showed the micro interpretation on the influence of the coke porestructure from various coal particle size, and further proved the effect on the properties ofcoke. Besides, polarizing microscope and laser particle sizes were used for thedetermination of the content of coke optical organization and the specific surface area ofdifferent coal particle sizes respespectively, which analyses coke macroscopic structurewith the change of particle sizes on microscopic theory.The results show that the coke quality can be improved by changing the weaklycaking coal particle size, especially for the anthracite and meager lean coal, which haverich resources and low cost. In this way, it not only can improve the coke quality, but alsoexpand the coking coal resources, and reduce the coking operation cost. What’s more，itprovides a new strategy of sustainable development for the coking industry and the ironand steel industry.