Corrosion issue with the coal grinder steel plates!
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The inlet drum of our coal grinder is severely corroded; we only add water, coal, limestone, and additives to the coal grinder. There’s nothing else; the pH value of water is also neutral! What caused the steel plate to corrode?
Is the chloride ion content high? Chloride ions are corrosive to the alloy, and their effect is quite strong
Is raw water being used? If wastewater from other processes is used, corrosion is likely to occur
I don’t know what kind of water the person who posted this is using as a water source; if it’s recycled water, then it’s really hard to say
It’s likely caused by wear and tear; we’ve encountered similar situations before
It mainly depends on water quality. First, test for Cl ions in the water; second, if the water source contains graywater, be cautious of its pH value: D
Chloride ions are highly corrosive to austenitic materials, but have little effect on carbon steel; drum feeders are mostly made of carbon steel. The additive makes the wall alkaline; the pH value of water-coal slurry is generally above 7, so there is no risk of acidic corrosion. The water used for pulping is certainly very complex; it’s not possible to use raw water for this purpose. Our factory uses water from gasification filter presses as well as wastewater from the sewage treatment plant. In addition, there is also waste ammonia water. Our drum feeders have not only remained free from corrosion but have also developed a thick layer of scale (mainly ammonium salts).