Green coke calcining method

In the proprietary rotary hearth method of calcining coke, green coke is fed to the perimeter of the rotating circular table and gently moved toward the center of the hearth in a circular path by stationary rabbles. A combustion zone above the coke bed, formed by liberated volatiles, supplies the heat necessary for calcination. A rotating hearth furnace can also be equipped with energy efficient features, such as steam generation and air preheat. 

Properties of Calcined Coke. Table II shows the properties of calcined cokes A, B, C, D and F by the new and traditional methods. Regardless of the green coke type, the thermal expansion coefficient of calcined coke by the new method was lower than that of traditional calcination method. Porosity values for calcined cokes by the new method have a higher value, regardless of the coke type, than... 

We found the latter factor-voids to be important. Experimental results showed that when green coke was calcined under the new methods, and the derived calcined coke was observed by scanning electron microscopy (Figure 2) and its pore size distribution was measured by mercury porosimetry (Figure 3), microcracks of significant sizes (1 to 60 microns) were developed. This was an important contribution to the reduction of the thermal expansion coefficients of the calcined coke processed under the new method. 

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