May I ask: What type of plate and frame filter press is used in phosphate production?
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In phosphate production, plate and frame filter presses are used to filter gypsum – are these ordinary plate filter presses or diaphragm filter presses? Or a closed-filter press? Thanks for the advice from a familiar friend
In phosphate production, diaphragm filter presses are primarily used for pressing gypsum, as they offer high dehydration efficiency and produce compact filter cakes, making them suitable for handling materials with a high solid content. Ordinary plate filter presses are used less these days. Although closed-type filter presses offer good corrosion resistance and environmental benefits, they are expensive and are generally used in situations with special requirements. So diaphragm type is more common, and it also offers good cost-performance. .
Since phosphoric acid contains a small amount of HF, when using a diaphragm filter press, it is inevitable that a small amount of HF will leak out from between the filter plates； Furthermore, when the plate is opened, a small amount of HF can also leak out from the acid solution entrained in the filter cake. How are the above issues addressed during production?