1.Technological process
Pickling——Rinsing——Fluxing——Dring——Galvanizing——Cooling——Passivation
Fluxing is a process before galvanizing.
After rinsing, putting the black workpieces into the fluxing tank, keeping them in ZnCI2—NH4CL double salt aqueous solution about 0.5～1min, heating to keep the temperature during 50～70℃.
Zinc ash is mainly composed of ZnO, Zn and metal chloride etc..
Per 1kg zinc ash contains Zinc >800g .
Zinc consumption that caused by ash occupied 20〜30% of total amount of zinc
If the flux not treated before hot galvanizing , the Fe2+ and HCl solution will attached to the workpiece surface, and then put into zinc tank with workpiece together, it will not only affect the galvanizing quality but also increase the zinc consumption, produce a large number of zinc slag(zincilate), zinc ash and zinc powder, this result in the galvanizing quality declined.so it is necessary to remove Fe2+ and HCl from the flux.
At initial status, both of the the and ‚ are full, and tƒ is empty, after sometime for using of fluxing solution and it needs treatment, open “pump 2”, at this time the fluxing solution in ƒis pumped into , when it is full, the fluxing solution overflow into ‚through overflow pipe, when the ‚is full, “pump 2 “can be closed, then blow the fluxing solution in ‚, add air and chemicals, leave it calm for sometime, open “pump 1”, fluxing solution in treating tank ‚is pumped into pressure filter by “pump 1”, after filter it flows into transition tankƒ, the precipitation is carried out of factory, this process is repeated, which can achieve fluxing recycling and regeneration .
