Can iron slag be mixed with coal powder to start a furnace?
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To save on electricity costs, startup time, and diesel consumption during furnace startup, our plant has decided to use iron calcine mixed with coal powder as the starting material for boiling furnaces. The coal powder usage is 20%–30%. Since coal dust has a low ignition point and can generate a large amount of heat during combustion, we believe it is possible to save on electricity costs, diesel, time, and so on. However, after mixing in coal powder, a large amount of organic gases are generated in the fluidized bed furnace. My greatest concerns have always been whether the flue gas can be discharged smoothly through the exhaust openings at the top, and whether high concentrations of flue gas inside the furnace could lead to an explosion. Due to this doubt, I was unable to determine the feasibility of this method in my mind. Experts, what do you think? Is there anything worth our attention?
Pay attention to the type of coal and its calorific value; while aiming to reduce costs, it is also important to consider safety and environmental protection. Personally, I think coke is a better option, although its cost might be about 4 times higher than that of coal powder
It is recommended that your company use solid particle sulfur for lighting the furnace; it is fast, pollution-free, and causes no losses. Generally, it takes no more than half an hour to get the furnace lit.
It is recommended that your company use solid particle sulfur for lighting the furnace; it is fast, pollution-free, and causes no losses. Generally, it takes no more than half an hour to get the furnace lit.
Starting the furnace by mixing iron slag with coal powder makes it difficult to control the temperature during operation. Since there is coal powder in the iron slag, it is hard for it to burn at first; however, when the temperature rises, the coal powder burns easily, causing the temperature to spike sharply. If not controlled properly, this can lead to scarring of the iron slag. Whether an explosion will occur depends on the amount of coal powder present and the level of carbon monoxide. If there is too much coal powder, and it rises to the top of the furnace as the bed boils, an explosion is more likely to happen. Moreover, if the coal does not burn completely during combustion, resulting in an excess of carbon monoxide gas, this also increases the risk of an explosion.
What I mean is that during the heating process of the fluidized bed furnace, coal powder is mixed in before gas is introduced; at this time, the flue gas is discharged directly from the outlet of the fluidized bed furnace, and the use of sulfur is not allowed due to environmental regulations. During the gas absorption process, our company also uses sulfur. When lighting the furnace, we use a diesel gun to ignite it and raise the temperature. The problem now is, as mentioned on the 5th floor, the concern that there might be an excessive amount of carbon monoxide or large quantities of flammable organic gases in the furnace, posing a risk of explosion. Then, during the heating process, I wonder how high the local temperature inside the furnace can reach, and whether slag will form scabs; I think the possibility of that is low.
When we use sulfur to ignite the furnace, the smoke goes directly into the conversion system, so there is no issue with emissions. Diesel is only used to light the cotton yarns, and 50 kilograms isn’t necessary at all; there are no environmental problems associated with this. Sometimes, simple issues shouldn’t be complicated – conducting experiments in such a way may involve too many risks.
Do you turn on the furnace only after the inlet temperature has risen enough for conversion? Our approach is to increase the temperature while simultaneously raising the temperature of the boiling furnace; therefore, before gas is introduced, the flue gas from the boiling furnace is exhausted. I have the following questions regarding your approach: 1. Diesel is used as an ignition source; 50 kilograms of diesel should not be sufficient to reach the ignition point of sulfur. 2. Do you use a boiling furnace? 3. How long does it take to ignite the boiling furnace and start supplying gas? What is the ratio of sulfur to the base material?
Start heating the furnace only after the transformation temperature reaches the required level； When starting the furnace, air is introduced directly, so there is no need to exhaust waste gas ； The answers to the questions are as follows: 1. It’s very easy to light sulfur; you can give it a try ； 2. It is to light the furnace in a boiling furnace ； 3. It generally takes 15 to 20 minutes from starting the furnace to adding ore; there is no such thing as introducing gas, as flue gas begins to undergo conversion right from the moment the furnace is started. The specific process of lighting the furnace requires some technical knowledge and experience, so it’s not appropriate to go into detail here. If necessary, contact via station messaging.
I am very interested in what you said about starting the furnace with sulfur. But I still think: Can starting the furnace with sulfur be successful? How much sulfur needs to be used? What should be the gas flow rate during startup? Is most of the material used as a base layer in the furnace burnings residue? What temperature can be reached in 15–20 minutes, according to you? How will the sublimation of sulfur within the system be handled? Most importantly: Are our two furnaces similar in design? Does your furnace have any special features?