Production of acid from copper smelting flue gas: the diluted acid contains high levels of fluorine; methods for treating flue gas with high fluoride content.
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Dear experts, recent test results show that the purified dilute acid contains high levels of fluorine, as does the flue gas. We sincerely seek an explanation for these high fluoride levels in both substances, as well as appropriate treatment methods.
The reasons are high fluoride content in the smelting furnace gas and high fluoride content in the purification make-up water. The solution is to add sodium silicate to the dilute acid used in the first stage of washing, ensuring that this dilute acid is distributed evenly and in sufficient quantities.
Add water glass to the first-stage dynamic wave scrubber, and monitor the fluoride ion concentration daily
If the flue gas contains high levels of fluorine, only a two-stage dynamic wave purification process can be used to control the fluorine content in the flue gas at the outlet by adding water glass.
A high fluoride content is generally due to issues with the raw materials; it is necessary to control the fluoride level in these materials at ≤0.013% from the source. Measures to reduce fluoride include adding water glass to the power wave stream to fix fluoride, and installing ceramic rings on the fillers of the gas cooling towers as well as on the gas distribution plates for fluoride reduction. It is also possible to increase the amount of water used in the purification system and the amount of dilute acid used for replacement, as well as raising the current of the purification circulation pump. Dust removal and fluoride removal can be carried out simultaneously.