Extraction of Tin (Sn) from Solder Dross by using Citric Acid Leaching Treatment Syarifah Aminah Ismail 1,a , Noorina Hidayu Jamil 2,b ,H.Kamarudin 1 and Mohd Arif Anuar Mohd Salleh 1 1. Centre of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis, Jejawi, Malaysia. 2. Faculty of Engineering Technology, Universiti Malaysia Perlis, Perlis P.O Box 77, D/A PejabatPosBesar, 01007Kangar, Perlis, Malaysia a amyna89@gmail.com, b noorinahidayu@unimap.edu.my, c vc@unimap.edu.my, d arifanuar@unimap.edu.my Keywords : Tin, Solder Dross, Citric Acid,Leaching Abstract. Solder dross containing Sn, Ni, Cu, Zn, Fe and other impurities was leached with 0.1-1.0 M citric acid at 60 °C for 24 hours stirring times. Parameter affecting the tin recovery of suggested method such as acid concentration, stirring time and temperature were investigated. Results obtained revealed that the optimum leaching parameter were achieved using 250ml of citric acid (C 6 H 8 O 7 )and 10 acid/g drossfor 24 hours at 60°Cof solution temperature. Recovery of tin from solder dross was 99.0%. Introduction Solder dross was formed during melting process and handling of tin alloys, it floats on the molten bath around 98 % of metallic tin and skimmed manually. The waste of materials contains toxic heavy metal such as Zn and Pb, where it isgenerally treated by pyrometallurgical process[1]. However, the main disadvantages of pyrometallurgical treatments includes having a multi stage process, low efficiency and high primary cost[2]. Leaching of Sn with hydrochloric acid from waste PCBs due to the removal of varnish and the increase in reaction interface [3]. Previous researchers have studied the bio-processing of metal from secondary electronic wastes/solid waste using microbes such as bacteria, fungiand archaea[4]. Although this process was successfully applied for the leaching of metals from ores but it has notbeen commercially applied yet to recover metals from PCBs. The use of organic acids for the extraction of metals has been studied by many researchers where citric acid was found to be the most effective solvent for nickel recovery[5]. Organic acid like citric acid is a naturally occurring fruit acid, produced by microbial fermentation. It is one of the world's largest-tonnage fermentation products. Recovery of metals or metal oxides in hydrometallurgical method isdepend on their chemical reactivity. When the metal treated is known to be easily dissolved the use of citric acid is appropriate economically and is categorized as abiodegradable leachant [6]. Since the leaching processof Sn oxide using citric acid have not been reported yet, therefore the main aim of this research is to study the new method to recover high percentage of Sn which is economical in waste treatments. Applied Mechanics and Materials Vols. 754-755 (2015) pp 571-575 Submitted: 06.01.2015 © (2015) Trans Tech Publications, Switzerland Accepted: 06.01.2015 doi:10.4028/www.scientific.net/AMM.754-755.571 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP, www.ttp.net. (ID: 58.27.57.126-10/02/15,02:54:32)