FUZZY GREY RELATIONAL ANALYSIS FOR INFLUENCE FACTORS .
petroleum coke [1]. Figure 1 shows a typical shaft calciner that comprises 24 vertical refractory pots; each pot is surrounded by eight layers of horizontally oriented heating flues. The entire calcination process is carried out in closed pots, and the combustion of volatiles (V) in the flues is the main source of heat in the shaft calciner.