Process and device for calcinating desulfurization of green cokes with high sulfur content by the preparation of high quality and density desulfurized cokes

A process of producing electrode-grade carbon from green coke having a sulfur content higher than 3% by weight, said process comprising subjecting said coke to a desulfurizing calcination treatment under a reducing atmosphere at a temperature of 1,400.degree. - 1,700.degree. C. and within the temperature range at which the density of the coke decreases as the temperature increases, said treatment being conducted at least until the content of sulfur in the coke is reduced to 1.2% by weight, but at a sufficiently slow rate of coke crystallization to form open pores in the coke, thereby permitting sulfurized compounds to escape from the coke, controlling said process during said treatment by continuously sampling and measuring the following parameters:

• a. coke sulfur content
• b. coke graphitization
• c. coke pore structure
• d. coke density, and
• adjusting operation conditions in response to said parameters to yield the desired properties of the resultant coke.