Party B's Environmental Protection 3 Is the oil-free phosphating liquid ring environmentally friendly? Can it be directly discharged for use by the powder spraying plant?

First, don't think about it. Can't be discharged directly.

Regardless of the composition in the phosphating solution, the oil you remove needs to be treated separately. Generally, phosphating solution will have certain acidity and alkalinity and high total phosphorus and phosphate, not to mention the metal ions contained in it. Don't keep the mentality of direct discharge without treatment. The pollutant concentration of environmental protection phosphating solution is at most lower than that of traditional phosphating solution, but it is still many times higher than the environmental protection discharge standard.