On the issue of coal blending for ramming coking

The ramming coking process allows the use of more low-cost coal with high volatility or weak cohesion compared to the top-charging coal coking process. It also enables an increase in the use of petroleum coke and coke dust, while reducing the amount of coking coal required. This results in significant savings in the costs associated with purchasing raw coal, thereby directly lowering the production cost of coke.

Reduces cracks, increases strength, and lowers costs.

The significance of ramming coking lies in: 1. Using more low-quality coal, thereby saving high-quality coking coal and reducing costs. 2. Improve coke quality. 3. It is more environmentally friendly compared to conventional coking. Whether to add retarding agents (such as coke dust) has no causal relationship with whether coking is done by ramming; it mainly depends on the coking property of the blend coal. If the coking property of the coal is not good enough, there are two scenarios: a) excessive cohesiveness, b) insufficient cohesiveness. To solve problem a, inert thinning agents (such as coke dust, low-grade coal, anthracite) need to be added ； For b, an active binder (such as asphalt or tar residue) needs to be added. Regarding the situation of coking coal resources in the country, most areas have abundant bituminous coal; using bituminous coal for ramming can achieve good results in reducing costs and improving quality. Generally, in coals with a high bituminous coal content, the coke cake may shrink too rapidly during the later stages of coking, resulting in numerous cracks, which directly leads to a decrease in the size and strength of the coke. To minimize cracks as much as possible, it is necessary to add crack-resistant agents such as coke powder. This post was last edited by xjqj70 on 2008-2-27 10:19.]

The main purpose of adding thinning agents during compacted coking is to increase the size of the coke pieces and reduce cracks, as more gas coal is used in this process of compacted coking； The main purpose of recycling coke dust is to replace the amount of lean coal used, thereby reducing production costs.

Adding coke powder is mainly to increase the fixed carbon content of coke.

The fineness of coal has a significant impact on the cold and hot strength of coke, and it should be kept within a certain range.

When the price of coke powder is lower than that of coal, adding a certain amount of coke powder can reduce the cost of coke.

It is mainly aimed at increasing the strength and bulk density of coke, reducing coke cracks, and lowering the cost of coal blending.

For the mixing ratio of coal used in our company’s ramming coking process, 25% is main coking coal, 13% is fat coal, 37% is gas coal, 14% is lean coal, and 11% is weak lean coal. The strength of the coke obtained is 90.4% at M25 level and 5.6% at M10 level. The fineness of the coal mixture can only be ensured to be >83%. To improve the strength and size of the coke, should we increase the amount of leaning agents or improve the fineness of the coal mixture? Is that method effective quickly?

The crusher is of the impact type. Since coal was previously fed from the top in the coke ovens, the requirement for coal fineness was not very high. Now, there is a desire to increase the fineness of the coal, but no new crusher wants to be installed; the hammer heads need to be replaced almost every two weeks. Overall, the fineness can only be maintained at around 83%.

The main objectives of the development of new modern coking technologies are as follows: 1. To expand the range of coal types used for coking. Due to the limited reserves of primary coking coal, it is necessary to expand the variety of coal used for sustainable development, while ensuring the quality of coke. 2. Reduce coking costs. 3. Improve coke quality. For example: coal preheating coking technology, shaped coke technology, selective crushing technology, and so on.