Why is slag green sometimes?
Thread Content
In practical operation, it has been observed that whenever the pressure difference in the gasification furnace increases, and the oxygen-to-coal ratio is raised to increase the furnace temperature and melt the slag, the slag turns green. As the furnace temperature rises, green slag containing a large amount of glass fibers may also appear. Someone on the forum explained the issue with glass fibers, but why does a high furnace temperature cause the slag to turn green? At first, I thought it was the color resulting from the increased wear of the furnace bricks, which led to the release of chromium oxides, but this analysis doesn’t seem to be correct; I’d like the members of the forum to discuss this.
We are sometimes red and sometimes white; a red color indicates a high iron content, while a white color suggests a high level of ash elements such as calcium and aluminum
No way. I ask, do you people on the first floor have Texaco gasification? I’m talking about Texaco gasification
I still think it’s related to fire-resistant bricks; greening shouldn’t happen
It may be related to the furnace temperature and slag composition. The color of the glass produced at high furnace temperatures should be related to its composition; why not conduct an elemental analysis? I also miss the operating conditions when the slag was greenish-yellow back then.
Could it be the refractory mortar used when building the brick walls of the furnace that’s coming out? Hehe, logically, after being exposed to such high temperatures, it shouldn’t happen
It’s mainly because the furnace temperature is too high.
It’s a Texaco gasifier, right? It is very likely that the excessively high furnace temperature accelerated the erosion of the refractory materials, causing some of the high-chromium refractory slurry to be washed away and dissolved into the slag; the green color is probably due to Cr3+. It is recommended to conduct a chemical analysis to determine it.
May I ask the original poster: What you mentioned – at first I thought it was the color resulting from increased abrasion of the furnace bricks, which led to the release of chromium oxides, but this analysis doesn’t seem to be correct. Could you explain why? Also, some people have guessed that the green color might be related to copper elements in the slag; as the experts said, a comprehensive analysis of the slag should be conducted
It is mainly because the furnace temperature is too high, which causes excessive ablation of the refractory mortar and bricks. Since the refractory materials contain large amounts of chromium (as well as other elements; the bricks produced in different locations vary), the slag turns green. Of course, to determine the exact cause, element analysis is necessary; a spectroscopic analysis provides the most accurate results.