Determination of optimal conditions for the galvanisation process at Luwero industries

Abstract

In Electro galvanization, one metal (steel fragments) is coated with another metal, for many reasons such as increasing corrosion resistance and improving the appearance of the fragments. The objective of this project was to determine the optimal conditions for the zinc plating process by running the galvanisation line various times while varying different parameters (like concentration of zinc chloride, voltage, time and temperature) in the galvanization. Investigation of process parameters for the electro-deposition of zinc was carried out using direct current. Fragments were first pre cleaned using gasoline to remove oils and grease, sodium hydroxide solution to remove any remaining dirt and dipped in hydrochloric acid solution for thorough cleaning after which they were galvanized, bright dipped & passivated and the dried using low temperature warm air (60°C). Extreme conditions yielded poor results, that is, high zinc chloride concentration, high voltage, high temperature and much time gave thick and dull deposits while low zinc chloride concentration, low voltage, low temperature and little time gave faint deposits. The optimum parameters were therefore moderate, which are; a concentration of 130.5g/l, voltage of 11.5V, temperature of 40°C and 30 minutes since they gave desired and bright deposits. Fragments electrodeposited using moderate conditions were also able to withstand harsh conditions. Therefore, moderate conditions as stated should be maintained and critically monitored for quality zinc deposits onto the steel fragments.