Blue-coke production technology and the current state-of-the-art in China

Blue-coke is a kind of char obtained by the low temperature pyrolysis of non-caking or weakly-caking coal with high volatile matter. It is generally granular with high reactivity, high electrical resistivity and high in fixed carbon but low in ash, sulfur, aluminum and phosphorus content. It has low price and extensive application decided by the raw coal and the production technology. This paper reviews pyrolysis reactor, process principle, technology characteristic and application state of blue-coke production technology in China. It includes vertical oven technology, rotary kiln technology and rotary-hearth furnace technology with external-heating, and vertical oven technology, rotary-disc furnace technology and conveyor-belt furnace technology with internal-heating. According to the existing problems in industrial blue-coke production technology, perspectives in terms of dust removal from volatiles, coke quenching and breakthrough of pyrolysis technology are given.