Relationship between microstructure characteristics for coal & coke and quality of coke

The coal petrography of 13 different rank single coals and the quality of cokes made on 40 kg pilot coke oven were measured and analyzed in the paper.The results indicated that the relationship between optical texture index of coke(OTI) and vitrinite mean maximum reflectance of single coal was positive linear correlation.By multiple linear regression analysis,the quantitative relationship between vitrinite reflectance distribution and the component of coke optical texture were determined;The influence of composition of coke optical tissue on crushing strength for coke(M_(40)) and coke reactivity index(CRI) can be summarized:the more mosaics texture proportion of the optical tissue,the better of crushing strength for coke(M_(40)) and its coke reactivity index(CRI).

Effect of coal moisture content on coke’s quality and yields of products during coal carbonization

The coal with low moisture during carbonization could not only increase the yield of coke,but also promote the coke quality and reduce the energy consumption.In this paper,the influence of the moisture in the blend coal(1.8%10.13%)on the product yields and coke quality during coal carbonization were investigated.The results show that the coke yield is increased from 75.90%to 77.16%,and the coke qualities such as coke strength after reaction with CO2(CSR),coke reactivity index(CRI),fragmentation index(M25)and abrasion index(M10))are also improved when the moisture of the blend coal decreases from 10.13%to 1.80%in a bench scale reactor.Due to the secondary reaction,tar become lighter when the moisture is decreased.In order to further prove the above results,the blend coal with 1.8%and 9%10%(common moisture used in coke plant)moisture is carbonized in a coke oven with 6 m height,the results show that CRI are 23.4%and 27.3%,CRS are 67.1%and 62.2%under 1.8%and 9%10%moisture of blend coal.Moreover,the variation of the moisture in blend coal has a limited influence on dust emission at the ascension pipe and the charging car.

RESEARCH ON THE QUALITY PRICE RATIO OF COKING COAL

If assortment priee parity of Clase coking coal and its qtalty price danrcnee is nonreasonable, it deren't gulde in Anprotrig tbe quallry metaliurgical coking coal and may be influence theeconomic benefit of metallurgical enterprises. This paper propose the principles and mathematicmodel for determination aseortment party of clean cokingcoal and its quality difference of ash content in clean coking coal in order to urge wasbenes into producing superior clean coking cleal whichis under condition of consideration both interest waskeries and interest metallurgicai industry. It canbe used as a method in theory to make price strategies under condition of socialism maket economicfor washeries of clean coking coal

Upgrading of Yi'an gas coal by low temperature pyrolysis under different atmospheres

The quality of Yi＇an gas coal before and after low temperature upgrading under either a N2 or H2 atmosphere was examined by thermogravimetric and infrared analyses. The effect of upgrading on the prepared coke quality was analyzed. The results show that the carboxyl and phenolic hydroxyls in the coal molecular structure are removed after upgrading by low temperature pyrolysis under either N2 or Hz atmospheres. This improves coal caking properties to a certain extent. The upgrading effect under a Hz atmosphere is remarkably better than the effect observed after upgrading under N2. Compared to coke obtained from raw coal, the compressiveand micro-strength of the cokes obtained from upgraded coal are greatly improved. The effect on coke reactivity with CO2 is not significant. The best upgrading temperature for Yi＇an gas coal under either a N2 or H2 atmosphere is 250 or 275 ℃ respectively.