Material selection for fluoride-containing wastewater
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I often encounter projects involving wastewater concentration. The fluoride ion concentration in the incoming water is around 300 ppm, while the chloride ion concentration is 20,000 ppm. The goal is to concentrate the water such that the fluoride ion concentration reaches 2,700 ppm and the chloride ion concentration reaches 190,000 ppm, at a temperature of 110 degrees Celsius. I’m not sure which materials to choose. I’ve heard that titanium can resist fluoride ion corrosion up to a concentration of 300 ppm at 110 degrees Celsius, but I haven’t been able to find any relevant information. I hope experts can help me out
This temperature can be handled with PTFE-lined materials, right?
This is the operating condition applied to the evaporator; for equipment, pipes, and heat exchange tubes, using fluorinated coatings doesn’t seem to be a viable option
Due to the high fluoride ion concentration, titanium materials are not suitable as they are highly susceptible to corrosion. The evaporator can be made of HC-276 material; if the budget is limited, a graphite evaporator can be used.
Check the pH value of your solution; using liner F46 is no problem
In the acetic acid industry, zirconium materials can be used for iodide ions; I guess fluoride ions are not as problematic as iodide ions