e-waste management
DESCRIPTION
This presentation describes the urgency of E-waste management and the technologies present right now to process the E-wasteTRANSCRIPT
E-Waste Management in India(E-Parisaara Pvt. Ltd)
Why worry about E-waste ??
E waste is a rapidly growing problem
Phenomenal growth in field of electronics leading to
more e-waste
E-waste do not decompose
Lack of technological advancement
Highly toxic elements are present
Content of WEEE
It contains more than 1000 components
Toxic substances :lead,mercury,arsenic,cadmium,selenium etc.
Precious metals such as gold, silver
Ordinary metal such as copper, zinc, aluminium
Fig: WEEE material composition(ETCRWM)
E-Parisaara
First govt. authorized eco-friendly recycling unit
First scientific e-waste recycling technologies used
Aim to reduce pollution, landfills and to recover valuable metals, plastic and glass from E-waste
Simple and low cost machines being used ex: shredder, crusher etc.
Process of converting waste to Raw material
Manual Dismantling
Hands on segregation
Shredding
Density separation
Other processes in E-Parisaara
Toner cartridge dismantling
Gold recovery from Printed Circuit board strips and components
Silver recovery from silver coated components
Shredding of printed circuit board
Note: First three are pending for patent so no exact information of process used
Recycling of E-Waste can be broadly divided into
• Disassembly: selectively disassembly,targeting on singling out hazardous or valuable components forspecial treatment
• Upgrading: using mechanical processing and/or metallurgical processing to up-grade desirable materials
• Refining: recovered materials are retreated or purified by using chemical (metallurgical) processing so as to be acceptable for theiroriginal using.
Fig: Block diagram for first step disassembly
Chemical processes in EEE recycling
Pyro metallurgical recovery
Hydro metallurgical recovery
Bio metallurgical recovery
Pyro metallurgical recovery
Includes smelting in blast furnace
Drossing
Sintering
Melting
Reaction in gas phase at high temperature
Existing technologies
Norlando process
Boliden Ronnsker smelter
Umicore’s precious metal recovery
Dunn’s patent for Gold refining
Fig: Offgas emission control instalments in smelters
Limitation of Pyro Metallurgical process
Cannot recover aluminium and iron
HFR might lead to dioxins formation
Large amount of ceramic and glass makes PM extraction difficult
Only partial separation possible
Hydrometallurgical process
Consists of series of acid or caustic leaches of solid material
The leached solution is subjected to following methods
1. Precipitation of impurities
2. Solvent extraction
3. Adsorption
4. Ion exchange
Gold Adsorption on Activated carbon
Ag complexes adsorption also done
Leached Ag/Au gets adsorbed on activated carbon surface
Mechanism and kinetics of adsorption
La Brooy Model
Advantages of Hydro Metallurgical process
More exact More predictable Easily controllable PM recovery efficiency is higher
Disadvantages of Hydro Metallurgical process
Choice of solution is difficult Solution required in large amount leading to extra expense
Future scopes
Lack of technologies available in India for E-waste management
Very promising field for innovations
Lack of efficiency of formal sector role gives way to new start up's
PM recovery is a open field for exploration in India as of now
Thank You !!!
References
• www.ewasteindia.com• Metallurgical recovery of metals from e-waste : Journal of
hazardous material 158(2008)228-256• E-waste management: A case study of Bangalore(Research
journal of environmental and earth science)• Global perspective on e-waste( EIA review 25(2005)436-458)• E-waste management: An emerging environmental and health
issue in India• Development of an integrated model to recover precious metal
from electronic scrap(science direct)