Feasible Environmental Solutions for Small Scale Secondary Lead Smelting Industry Sector

1. Dr. AmitavaBandopadhyay, Chief Scientist CSIR-National Metallurgical Laboratory Jamshedpur - 831 007 Feasible Environmental Solutions forSmall Scale Secondary Lead Smelting Industry Sector Workshop on Sustainable Environment Management Practices in Small Scale Secondary Lead Smelting Industry Sector Kolkata : November 6, 2012

2. The Facts

3. World's Worst Pollution Problems : 2012[Source : Blacksmith Institute, New York and Green Cross, Switzerland – October 23, 2012] Industrial pollution is a critical public health threat on a par with malaria and tuberculosis. While 125 million people around the world are at risk from toxic pollutants, these causes of illness and death are underestimated. The lack of investigation and quantification of the human health impacts of contaminated site have left an often marginalized population with few resources to address this growing problem. Sadly, health impacts from environmental pollution often affect the most vulnerable, especially children, within these already neglected populations. The Blacksmith Institute – Green Cross Report recentlyidentified the 10 most toxic industries responsible for the number of illnesses and deaths – number one on the list is lead-acid battery recycling. The world’s second most toxic industry is lead smelting, with mining and ore processing ranked third.

4. Health Impacts of Lead Poisoning Based on methods detailed by the World Health Organization (WHO), it has been concluded that : Lead impairs the neurological development of children Lead also causes cardiovascular disease in adults A Typical Lead Recycling Unit • Pollution from Small Scale Lead Smelting Causes Health Problems for Workers as Well as Nearby Residents • Often lead recycling occurs at uncontrolled or poorly controlled facilities in the informal economic sector, even at home, making lead reprocessing itself a major problem in many countries

5. The Technological Options, Practices and Possible Solutions

6. Technological Development andEnvironmental Implications 1850s Onwards - [Abundant Resources, Diverse Market, Unrestricted Development & No Concern for Environment] DRIVER : Concern for Health & Safety 1970-1990 - [Industry & Government Focused on Managing Pollutants] DRIVER : Concern for High Cost 1990 Onwards - [Prevent or reduce pollution by providing help to industry outside the enforcement realm – Era of Green Design]

7. Advantages of Secondary Processing Conservation of ore resources and fuels Lower energy consumption – 5% for Al, 6-10% for lead, 2-5% for Mg, 20-25% for zinc and 30% for Cu Solution to waste disposal problem Lower emission of noxious and green house gases The outlook for recycling various from country to country but each nation benefits in the long run.

8. Production and Uses of Lead Principal application area of lead is Pb-acid batteries – accounts for 60% of total consumption. Other uses are – corrosion resistance surfacing, radiation shielding, cable sheathing, sound proofing, damp proofing, ornamental work etc. Total production in India : ~100000 tons [~40,000 tons from secondary sector]

9. Sources of Lead Waste Generation Sources of lead bearing wastes are : Used lead acid batteries, rejected materials from battery manufacturing industries, slag from smelters and other lead bearing scrap materials such as bottom dross from galvanizing units, used lead anode sheets from primary and secondary zinc producing units using electrolytic methods, lead scrap from printing press and lead pipes etc.

10. BASIC ISSUES Pollution from metallurgical sectors create significant health hazards Industrial processes are not designed keeping pollution prevention and control as priority Cost effective pollution control technologies are mostly not available Pollution prevention require substantial discipline from industries –However, benefits are significant Psychological obstacles for pollution prevention and control

11. What is Recycling? • Recycling involves processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower green house gas emissions as compared to virgin production. • Recycling is a key component of modern waste reduction and is the third component of the “Reduce, Reuse, Recycle" strategy.

12. Critical Issues in Recycling of Lead Bearing Wastes The recycling of wastes is one of the most important components of the sustainable development process Wastes are now regarded as unutilized resources Significant efforts are required to recycle wastes irrespective of their type and the source of generation Recycling takes a greater dimension as treatment and disposal of hazardous wastes take significant investment. Recycling of lead bearing hazardous wastes results in conservation of mineral resources and lesser mining resulting in lower environmental pollution. The recycling must be done using Environmentally Sound Technologies (EST) A large gap exists between actual generation and the amount that is being recycled through EST

13. Developments in Traditional Lead Waste Processing Use of non metallic constituents as fuel is discouraged Primary issue in cleaner technology is separation of all components and subsequent processing A sequence of crushing, screening/washing, heavy media separation and flotation processes are used for separation of components Pretreatment of battery paste to lead carbonate is used now to avoid sulphur problems during smelting Level of sophistication varies from place to place

14. Recycling of Lead Bearing Wastes The lead bearing wastes as specified in Schedule - 4 are used in the production of lead ingots and lead alloy ingots The main steps involved are : smelting of the lead bearing wastes after addition of fuel and flux, cooling and casting of the molten lead into lead ingots. Alloys are produced by melting and refining of the lead ingots after mixing with alloying elements. Smelting is a thermal metallurgical processing operation in which the metal or matte is separated in fused form from non-metallic materials or other undesired metals with which it is associated.

15. Non-ferrous Wastes Covered Under HWM Rules, 2008

16. Technological Options in Lead Recycling • Traditional Mandir Bhatti Furnaces • Blast Furnaces • Rotary Furnaces • Lead Sweat Furnaces • Reverberatory furnaces [More suitable for fine particles]

17. Typical Flowsheet of Lead Batteries Scrap Processing Plant Figure : 1

18. Features Typical Mini Blast Furnace for Secondary Processing of Lead A Mini Blast Furnace (Commonly know as mandir bhatti or shahi bhatti) is a simple time tested and widely used system to produce secondary lead in India and many other countries. It is the most basic of all furnaces and production system based on this technology has certain distinct characteristics such as: Low project capital cost Low energy cost Easy to install Easy to operate and maintain

19. Features Typical Rotary Furnace for Secondary Processing of Lead The Rotary Melting Furnace is a very flexible and universal equipment used for recycling many non-ferrous metals. It is the major lead production technology used in India and many other countries for Secondary Lead Production. A lead production system based on this technology has certain distinct characteristics such as: Equipment scalable for installing higher capacities Recovers all lead in one production cycle Plates & powder from scrap battery as well as slag from Mini Blast Furnace can be used as raw material Requires addition of certain consumables Can be fired with various fuels Generates high pollution both as flue gases & fugitive emissions

20. Typical Material Balance for Secondary Processing of Lead Scrap Source : APPCB Information Bulletin, March 2001 (Publication 111)

21. Emissions and Waste Generation in Secondary Lead Recycling Source : APPCB Information Bulletin, March 2001 (Publication 111)

22. Typical Values of Pollutant Emissions from Secondary Lead Smelters ConstituentsConcentration (mg/Nm3) • Suspended 250 • Particulate Matters • SOx 60 • NOx 30 • Lead in Work Area : 0.15 mg/Nm3

23. Steps to Minimize Fugitive Emissions in Secondary Lead Processing The design of the hood/fume collection system from the smelting/refining operations should be capable of collecting the lead emissions and their transfer to the control system(s) The storage of all the raw materials, intermediates and products should be in covered area/shed having concrete floors and mechanized equipment should be used to handle these materials as far as possible. The floors in the loading area should be kept wet through sprinklers to reduce the chances of lead particles/dust getting airborne. The movement of vehicles to the administrative/working/production areas should ensure that only the trucks/vehicles involved in the material handling / transportation reach the work areas, and their tyres are washed before they leave these areas.

24. Pollution Prevention & Control in Lead Recycling Use doghouse enclosures where appropriate; use hoods to collect fugitive emissions. Mix strong acidic gases with weak ones to facilitate production of sulfuric acid from sulfur oxides, thereby avoiding the release of weak acidic gases. Maximize the recovery of sulfur by operating the furnaces to increase the SO2 content of the flue gas and by providing efficient sulfur conversion. Use a double-contact, double-absorption process. Desulfurize paste with caustic soda or soda ash to reduce SO2 emissions. Use energy-efficient measures such as waste heat recovery from process gases to reduce fuel usage and associated emissions.

25. Pollution Prevention & Control in Lead Recycling Recover acid, plastics, and other materials when handling battery scrap in secondary lead production. Recycle condensates, rainwater, and excess process water for washing, for dust control, for gas scrubbing, and for other process applications where water quality is not of particular concern. Give preference to natural gas over heavy fuel oil for use as fuel and to coke with lower sulfur content. Use low-NOx burners. Give preference to fabric filters over wet scrubbers or wet electrostatic precipitators (ESPs) for dust control. This reduces secondary pollution.

26. Key Issues for Compliance Give preference to the flash-smelting process where appropriate. Choose oxygen enrichment processes that allow higher SO2 concentrations in smelter gases to assist in sulfur recovery; use the double-contact, double-absorption process. Improve energy efficiency to reduce fuel usage and associated emissions; use low-NOx burners; give preference to natural gas/LPG as fuel. Reduce air emissions of toxic metals to acceptable levels. Maximize the recovery of dust and minimize fugitive emissions; use hoods and doghouse enclosures. Reduce effluent discharge by maximizing wastewater recycling. Avoid contamination of groundwater and surface waters by leaching of toxic metals from tailings, process residues, slag, and other wastes.

27. Looking Ahead : Does Cleaner Production Provides a Better Future for Lead Smelting & Recycling?

28. Cleaner Production (CP) in Metallurgical Sector Cleaner Production (CP) is the continuous application of a preventive environmental strategy applied to processes, products and services to increase efficiency and reduce the risks to humans and the environment. Cleaner Production is aimed at reducing consumption of raw materials, energy and pollution created during the production processes through process optimisation and development of newer technologies.

29. What Cleaner Technology Tries to Achieve? • Minimise amounts and hazards of gaseous, liquid and solid wastes • Minimise accidental risks from chemicals and processes • Minimise consumption of raw materials, water and energy, and • Substitute chemicals and processes less hazardous to human and ecological health.

30. Cleaner Production (CP) in Metallurgical Sector - Advantages • CP eliminates toxic raw materials • It reduces the quantity of toxicity of all emissions and wastes at source • It reduces negative impacts along the life cycle of a product, from design to ultimate disposal.

31. Barriers to Cleaner Technology Applications • Non-availability of Technology: An off-the-shelf cleaner technology which can be readily purchased and installed, is not available. • Incompatibility: The cleaner technology that is available may not be compatible in terms of existing scale of operation, raw materials, process, products, lay-out, legal requirements etc. • Economic Non-viability:There may be a technology that may not be economically viable for the industry. • Other Non-technical Barriers :These include problems arising out of socio-economic conditions, psychological factors, administrative and union problems, fixed mind-sets, lack of awareness, lack of competition, unethical and/or illegal escape routes, legal entanglements, lack of incentives as well as punitive measures.

32. Characteristics of CP Systems Each system focuses on continuous reduction in raw materials & energy consumption The use of each system results in a series of waste reduction measures : Minimization, reuse, recovery and disposal Each system calls for an integrated approach to design, manufacture, and use of product. In addition to inputs and waste materials, it looks into how products are produced, disposed of and accounted for Each system, over the long-term, is cheaper than conventional “End-of-pipe” technology

33. Technology Related Issues Process Development & Integration Economies of scale – Advantages & Disadvantages Can we break the general rule of economies of scale to make smaller operation economically viable? Feasibility of integrated waste processing from multiple companies Engineering Issues It is a combination of may techniques rather than use of one fundamental principle More we push technology to its limits, engineering issues become more complex Industrial waste and materials recycling Technology only creates a barrier in 10% cases Waste materials is used to reduce waste handling cost rather than saving in raw materials cost Economy of recycling would improve if design value is utilised

34. Cleaner Technologies for Secondary Lead Processing Alternative cleaner technologies couple environmental requirements to the energy savings with substantial reduction in cost compared to traditional processes More advanced processes e.g. USBM, RSR, EWS and Placid are based on same philosophy: Conversion of insoluble PbSO4 and PbO2 into leachable products Leaching by a suitable electrolyte to put lead (Pb) into solution Lead electro-winning with a insoluble anode with oxygen evolution

35. Concluding Remarks An attempt has been made to summarise environmentally sound technologies (EST) for recycling of hazardous wastes containing lead The scale of operation of recycling plants in India is small or tiny as compared to that in advanced nations. Hence implementation of sophisticated technology at small scale of operation is not easy. There is an urgent need to evaluate cleaner technology options in the Indian context and chalk out a plan for the recycling industry. The evaluation process needs to concentrate not only on the technical and environmental aspects but has to focus on scale of operation and economic as well as societal aspects.