Extending the coking time helps improve coke particle size
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Extending the coking time helps improve coke particle size
Extending the coking time can easily lead to overheating if the temperature control is not proper, and it also doesn’t help much with the particle size of the coke. Speaking only of coke ovens, one method involves high temperatures, that is, increasing the heating rate as it approaches semi-coke.
Relatively low temperature retarding slows down the thermal polycondensation reaction in the coking zone, resulting in larger coke particles and improved mechanical strength. Slightly extending the furnace holding time not only improves strength but also reduces the pusher current, facilitating coke pushing.
Extending the coking time can increase the degree of thermal polycondensation reaction, which is beneficial for improving the CSR of coke. At the same time, the small temperature gradient in the coke cake is conducive to improving the size of the coke pieces, but the effect is not significant.
Increasing the coking time can improve the crush strength of coke, reduce its wear resistance, and enhance its hot-property characteristics
Not necessarily; extending the coking time requires adjustments to the coal blending ratio and furnace temperature as well. It mainly depends on the properties of the blended coal
I agree with the opinion above; we have conducted experiments, and reducing the coking time for 6.25-meter coke ovens helps to improve the particle size of the coke
Firstly, in my opinion, the main factor affecting coke particle size is the composition of the coal used. Secondly, the idea that extending the coking time can improve the size of coke particles is based on certain adjustments to the furnace temperature; generally, it is advisable to start with rapid heating, then slow down the increase in furnace temperature, or even reduce it. Only by doing so and extending the coking time can the quality of coke in various aspects be improved. A practical example of this is dry quenching of coke, which essentially also involves extending the coking time to enhance coke quality.
It is undisputed that extending the coking time increases the coke particle size, but it is difficult to say by how much. Our plant produces 900,000 tons per year of compacted coke, accompanied by a dry quenching system with a capacity of 125 T/h. Previously, the coking time was 24 hours, and the particle size of the coke was relatively small – none of the particles were larger than 80 mesh. Now, the coking time is 43 hours, and the particle size of the coke has increased significantly; after passing through the coke cutter, 13% of the particles are still larger than 80 mesh. The price of coke cutters can even exceed 200. Now, large coke pieces are also a problem; I’m frustrated. PS: The usage of lean coal is 13%.
Increasing the coking time can improve the heat strength of coke, especially for coal types with lower heat strength.
As long as the coking time is longer, the size of the coke particles will be larger; however, increasing the coking time alone cannot increase the size of the coke particles. There are many ways to change the size of coke particles.