Leaching studies for tin recovery from waste e-scrap
- Metal Extraction and Forming Division, National Metallurgical Laboratory (NML), Jamshedpur 831 007 (India)
- Mineral Resources Research Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of)
Printed circuit boards (PCBs) are the most essential components of all electrical and electronic equipments, which contain noteworthy quantity of metals, some of which are toxic to life and all of which are valuable resources. Therefore, recycling of PCBs is necessary for the safe disposal/utilization of these metals. Present paper is a part of developing Indo-Korean recycling technique consists of organic swelling pre-treatment technique for the liberation of thin layer of metallic sheet and the treatment of epoxy resin to remove/recover toxic soldering material. To optimize the parameters required for recovery of tin from waste PCBs, initially the bench scale studies were carried out using fresh solder (containing 52.6% Sn and 47.3% Pb) varying the acid concentration, temperature, mixing time and pulp density. The experimental data indicate that 95.79% of tin was leached out from solder material using 5.5 M HCl at fixed pulp density 50 g/L and temperature 90 Degree-Sign C in mixing time 165 min. Kinetic studies followed the chemical reaction controlled dense constant size cylindrical particles with activation energy of 117.68 kJ/mol. However, 97.79% of tin was found to be leached out from solder materials of liberated swelled epoxy resin using 4.5 M HCl at 90 Degree-Sign C, mixing time 60 min and pulp density 50 g/L. From the leach liquor of solder materials of epoxy resin, the precipitate of sodium stannate as value added product was obtained at pH 1.9. The Pb from the leach residue was removed by using 0.1 M nitric acid at 90 Degree-Sign C in mixing time 45 min and pulp density 10 g/L. The metal free epoxy resin could be disposed-of safely/used as filling material without affecting the environment.
- OSTI ID:
- 22089891
- Journal Information:
- Waste Management, Vol. 32, Issue 10; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0956-053X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTIVATION ENERGY
CHEMICAL REACTIONS
CYLINDRICAL CONFIGURATION
ELECTRONIC EQUIPMENT
ENVIRONMENTAL EFFECTS
EPOXIDES
EXPERIMENTAL DATA
HYDROCHLORIC ACID
LEACHING
NITRIC ACID
PH VALUE
PRECIPITATION
PRINTED CIRCUITS
RECYCLING
RESIDUES
RESINS
SCRAP
SHEETS
SLURRIES
SODIUM
SOLDERING
SWELLING
THIN FILMS
TIN
TOXICITY