Seeking advice on controlling coke moisture

Controlling the moisture content of coke can be approached from the following aspects: 1. Check whether the samples taken for testing are representative, as the coke quenching process carried out by the coke quenching vehicle is not uniform; if the samples are not representative, the aforementioned problems are likely to occur. 2. Check whether the quenching time is set reasonably; here it is 120 seconds, but this amount may change depending on the weather – for example, it might be reduced on rainy days. Managers need to pay close attention to this. I am in charge of coking production management, so I pay special attention to this issue. 3. The drying time must be ensured; ensuring this drying time is closely related to how well the driver of the coke quenching vehicle performs his job. 4. The secondary quenching on the drying platform leads to excessive moisture; I’m not sure if this is a problem in the owner’s case. If the coking car does not extinguish the coke evenly, and red coke may still be present, water is sprayed to put out the fire on the coke cooling platform; improper control of the water volume can result in excessive moisture.

Reply to Yan Xiangsi: I’m glad to see you online. I work for Shandong Shenglong Company. I wonder where you are? I also hope to learn more from you*. The coking shutdown control here is quite good; the residence time on the coking cooling platform is about 15 minutes, and there is basically no secondary coking shutdown. However, the moisture content of the coke remains unsatisfactory. I’m not sure what the reason for this is

Please pay attention to the following issues: 1. What method do you use for wet quenching of coke? Is it conventional wet quenching or low-moisture quenching (Nucor technology)? 2. What is the water consumption per ton of coke? Under normal circumstances, as long as the coking process is carried out in a way that ensures even and thorough cooling, with no red coke forming, the goal of coking is achieved. Different coking methods lead to varying levels of moisture during this process; you can start by controlling the coking time and gradually reducing it. Additionally, by studying the areas where red coke appears, it is possible to increase the amount of water used for cooling in those areas. Furthermore, it is necessary to ensure that the temperature of the coke after coking does not drop too low; this can be checked to ensure that a temperature of around 150 degrees is appropriate.

The spray quenching method can reduce coke moisture, but equipment modifications are required.

What moderator Yan said earlier makes a lot of sense. I also think that the quality of the water used for quenching coke has an impact on the moisture content of the coke; for example, the quenching water in my plant contains a high level of oil, which results in a higher moisture content compared to when the water quality is better. At the same time, the driver of the coking quenching vehicle should allow a slightly longer drainage time after quenching, of course, as long as it does not affect production operations. After improving the control of water injection time, it is also necessary to gain a better understanding of the condition of equipment such as pumps (under conditions other than quenching with low water levels).

The poster is asking whether the moisture content of coke refers to that of coke on the cooling rack or to that of coke ready for shipment and sale – there is a big difference between the two. Cooling coke with a high moisture content is not representative; exported coke also has a high moisture level, probably because the cooling time is too short, preventing adequate water removal, and the moisture ends up in the storage area. Additionally, the coke stays in storage for a short period of time, so the moisture does not have time to evaporate fully. Today’s data from our company: For the cooling platform, the moisture content of the conveyor belt is 13.13–13.18%. In the coke storage area, the moisture content of the coke before it is loaded onto vehicles is 5.6–5.8%. The coke stays in the storage area for 10 days, and the total storage capacity is 100,000 tons.

Two approaches should be taken: 1. Without changing the existing equipment and process conditions, efforts should be focused on aspects such as the quality of the quenching water, the quenching time, and the cooling time. 2. To bring about fundamental changes, low-water-content quenching should be considered; domestic companies such as Jinan Iron and Steel and Handan Iron and Steel are already using this method, with satisfactory results. They employ different technologies, which you can use as a reference for making corresponding modifications

I’m glad to meet you too. I’ve been on business trips lately and just saw your reply; my apologies for the delay. If the coking quenching operation is working fine, the causes can be sought from two aspects: 1. Establish a reasonable coking quenching time, and this requires some experimentation. In simple terms, during the coking shutdown process, a timer is used to keep track of the time; by gradually reducing the number of seconds and measuring the moisture content of the coke, the optimal shutdown time corresponding to that moisture level is determined. I did it 8 times here before I was sure. Since we sell all our coke to large steel mills and the transportation costs are high, the requirements for the moisture content of the coke are extremely strict. We generally require it to be around 3. 2. Another very important reason is that I’m not sure what the content of coke dust in your product is; if the amount of coke dust in the coke is high, it’s easy for water to be absorbed by this coke dust, which in turn leads to an increase in the moisture content of the coke. I’m not sure if this is correct; please forgive me!

One more thing: the operator of the coking quench vehicle also plays a crucial role; it is essential to ensure even coking.

The moderator from Yan Xi Si Xiang has covered this quite comprehensively. Apart from normal production operations and process control, the level of M10 in coke does indeed have a significant impact on its moisture content; as M10 increases, the moisture content of coke also increases； Conversely, as M10 decreases, the water content decreases. In actual production, when the process conditions of the production machinery remain unchanged, adjustments to the coal blending formula result in changes in the M25 and M10 values of the coke; as a consequence, the moisture content of the coke also changes significantly.