Evaluation of waste minimization alternatives for the galvanizing production process: A case study of Uganda Baati Limited

Abstract

Uganda Baati Limited is one of the largest manufacturers of metal roofing products in Eastern and Central Africa. The company is faced with waste from the production process of the galvanizing line in terms of defects and scrap which amounts to approximately 646 metric tons a year out of 50,544 metric tons of prime sheets. The aim of the study was to investigate the possibility of minimizing waste generation in the production process in order to propose technically feasible and economically practical alternatives to be employed by Uganda Baati Ltd. The study focused on analyzing the production processes of the galvanizing plant with an interest of identifying waste produced, its amount and the causes which lead to its production. Measurements of various parameters such as temperature, running current and voltage were also taken and compared with the standard operating parameters. From the data that was gathered, the identified major factors leading to waste production included: frequent stoppages, poor storage of Cold Rolled (CR) coils and use of operating parameters which are not within the recommended standard. The stoppages are caused by various factors such as: the sheet getting broken at various points, electrical faults, sheet getting damaged and stuck at various points on the production line. These stoppages lead to increased white rust, lead lines and black marks on the sheet hence formation of rejects. Poor storage of CR coils in un-sheltered bond causes rusting of this raw material when it rains leading to scrap production. This study has observed that the company uses more casual workers of low education levels whose technical know-how is minimal as far as the operation of the galvanizing plant is concerned. The study concluded from the measurements taken at various points on the production line and statistical analysis, that waste (rejects and scrap) at the continuous galvanizing line (CGL) is due to inexact operating parameters, human factors, frequent stoppages, improper materials handling and storage. As such, a Manual Guideline containing some Cleaner Production (CP) options has been developed which will help to address how to minimize these wastes and improve on the efficiency of machines and equipments.