Flue gas from gypsum slag production using anhydrous hydrofluoric acid
Thread Content
Dear teachers: The slag generated during the production of anhydrous hydrofluoric acid, namely fluoro gypsum, is often accompanied by large amounts of HF gas, resulting in a high fluoride content in the water washing and absorption tank at the end of the furnace – sometimes exceeding 20%, whereas under normal conditions this level is less than 1%. Worse situations occur during loading, as the amount of smoke is too high to allow for transportation outside. After investigating this situation for a long time, we still don’t know why it is happening I would appreciate some guidance from the teachers. Thank you.
The reaction in the rotary kiln is not effective; the reaction inside the furnace is incomplete, and hydrogen fluoride is still being produced as the material moves toward the spiral at the rear of the furnace
Thank you for the response. Based on the slag testing parameters, the conditions are acceptable: the calcium fluoride content in the slag is between 1.5% and 2.5%, while the sulfur content is below 1%.