The purpose of iron removal

Thoroughly solve the proportional relationship between acid, iron, ammonia and zinc in the solvent bath
Achieve recycling of the plating stream to achieve zero emissions
Control iron content below 1g/L to reduce zinc consumption
Improves the fluidity of zinc liquid and the surface quality of plated parts
30,000 (ton/year)x3(kg/ton zinc savings)x50,000,000(VND/ton, zinc price) =4.5 billion VND

Feasibility of chemical iron removal techniques

– The pH value of the plating tank is usually controlled at 3-4.5. When the pH is lower than 2, the iron content increases exponentially;

– When pH > 2.8, Fe3+ begins to precipitate out of a small amount of water;

– When pH > 5.4, zinc begins to hydrolyze and precipitate

– When pH > 5.6, zinc precipitates and the plating line begins to gradually lose its surface cleaning function.

Tip: Chemical iron removal is more than just adding ammonia and hydrogen peroxide to the plating solution and filtering!