Global Journal of Engineering and Technology Advances, 2019, 01(01), 022–026 Global Journal of Engineering and Technology Advances Cross Ref DOI: 10.30574/gjeta Journal homepage: http://www.gjeta.com  Corresponding author E-mail address: smithonyekwere@gmail.com Copyright © 2019 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. (R ESEARCH A RTICLE ) Determination of percentage zinc loss during melting of zinc scrap in a crucible furnace Onyekwere, Okwuchi Smith 1, * Orji, Chiawolamoke Ihenwokeleme 2 and Uyanga, Kindness Alfred 3 1 Faculty of Engineering, Federal University Wukari Taraba State, Nigeria. 2 Department of Welding and Fabrication, Abia State Polytechnic Aba, Nigeria. 3 School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong. Publication history: Received on 15 October 2019; revised on 02 December 2019; accepted on 04 December 2019 Article DOI: https://doi.org/10.30574/gjeta.2019.1.1.0004 Abstract During the melting process of zinc scraps, not all the zinc metals in the scrap are recovered. This article evaluates the extent of zinc loss during melting of zinc scraps. Zinc scraps were melted in a charcoal-fired crucible furnace, and the percentage zinc loss was determined. Two modes of zinc loss were observed – zinc loss through evaporation and zinc loss through the dross. It was determined that 2.2 percentage of the total zinc was lost through evaporation while 10.8 percentage of the total weight was lost in the dross when zinc scrap was melted without fluxing. The total zinc loss when zinc scrap was melted without fluxing was found to be 13 percent. With fluxing, using chloride-salt based flux (17% KCl, 20% NaCl, 63% ZnCl2 salt system), 0.79weight percent and 1.74weight percent was lost through evaporation and dross respectively. The total zinc loss was reduced to 2.53weight percent with fluxing. This work will help foundrymen in method and economic decision making when working on zinc scraps. Keywords: Zinc Loss; Zinc Alloys; Dross; Zinc recovery; Zinc scrap 1. Introduction Zinc alloys have been used in the production of various parts such as car carburettors, door handles, etc. Based on historical consumption, it is estimated that currently, 30-40% of the cast zinc components used in manufacture are being recovered and recycled [1].Recycling zinc alloys from scraps has energy savings advantage over processing zinc composites. The ability to melt zinc scrap many times without losing its properties is of significant benefit to the zinc die caster. However, it is important to keep the material clean and free of unwanted substances [2]. Despite cleaning of the scraps, oxide films and some unwanted substances are also found in the zinc melt. When an alloy melt reacts with the atmosphere or moisture, it forms an amorphous continuous oxide film on the surface of the bath. These oxide films are an essential part of the melting process because they protect the metal underneath from further oxidation. Also, during the melting of the scraps, some have inserts that may not be very economical to remove before the melting operation. Some of the inserts made of iron and aluminium will dissolve in the zinc melt up to their respective solubility limits. Dissolution above their solubility limit will cause the formation of intermetallic compounds, in particular, the zinc-iron and zinc-iron-aluminium compounds with high proportions of entrained zinc [3]. In the process of removing these unwanted substances, zinc will be lost. Zinc dross is a mixture of metallic materials contained in a matrix of zinc. During melting of zinc scrap, the intermetallic compounds formed will adversely affect the wetting characteristics of the zinc slag, causing the dross to encapsulate free zinc metal; thus the resultant dross is rich in metallic zinc which cannot easily be mechanically separated. Skimming out the dross will mean substantial loss in the zinc metal. In foundry operations, the surface of the molten bath is always moving due to charging, skimming, cleaning, transferring, ladling, etc. Any of these melting practices causes the thin film