This article discusses critical issues in regard to recycling of lead.There is a need to develop a systematic ,well-implemented, carefully controlled and monitored approach to recycling of lead battery scrap and other lead containing waste materials.It gives us information about the current demand for lead and lead batteries.
Lead finds applications in storage batteries, cable sheathing, pipes, pigments and many other sectors. It is an essential component in the industrial sector, for which there is no substitute at present. In the case of batteries, it must be emphasised that it is not a question of finding replacement for the entire quantity of lead in a used battery, but with proper recycling, only to find the "top-up" quantity (which is very smalt and corresponds to the losses). There are primarily four critical issues in regard to recycling of lead. These are: a Unsafe collection and recycling of lead battery scrap by unorganised units and the trade. The trade dominates the collection and handling of lead battery scrap, particularly the auctions from public sector organisations with large quantities of waste batteries to sell.Lack of understanding about the nature of hazards by those connected with handling lead scrap/wastes. Absence of compatible and cost effective technology with in-built pollution control system, particularly for the small scale and medium enterprises sector.
In relation to current practices in the country, the causes for high levels of lead in the environment are the following:
Generation of dust during manual breaking, crushing and preparation of charge for smelting. During its visits to secondary lead processing units, the HPC found such activity conducted in the open environment. Workers were found to have frequent contact will lead in the workplace. Most such units had poor housekeeping practices,
Drainage of spent sulphuric acid from lead acid batteries into streams, rivers and other waterbodies. Emission of lead, S02 fumes and suspended particlilate matter (SPM) into the atmosphere during smelting. Some units have sought to control air pollution with standard air pollution control devices including cyclones, scrubbers and bag filters. The cost of such pollution control equipment ranges from Rs.5 lakhs to 12 lakhs, whereas the cost of the production unit including the furnace is around Rs.l lakh. Such proposals are, therefore, not found to be viable. Unauthorized disposal of the smelted slag containing high amount of lead. Non-compliance of proper safety measures by the workers in these units. In none of the small units were workers aware of the dangers of lead exposure and poisoning. Medical records, of course, were never maintained.Lead introduced into the atmosphere through the use of lead-containing autofuel, now under substantial reduction with the introduction/use of unleaded auto fuel.
The current demand for lead in India is about 1,61,000 TPA, of which about 50% is met through imports.5 Spent battery scraps are the source of 80% lead that is recycled in the country. It may be noted here that most of the lead recyclers are small-scale enterprises or tiny industries where lead recovery potential is less. Infact, due to the nature of technology used by them, the pollution potential is much higher than the recovery aspect. Many backyard smelters are not registered and operate on fly-by-night basis: when action is taken for their closure, they merely shift their activities to other places. Used batteries auctioned through disposal programmes of large scale users like the railways often go to traders/backyard (cottage) type of industries who cannot afford suitable facilities, and hence do not have pollution control facilities and even consent or authorisation from the.SPCBs. Being small units they escape the legal net. As a result, recycling of hazardous lead takes place openly and without safeguards, thus causing much harm to the environment rather than contributing positively to the national economy. Therefore, suitable legal action in this context is necessary to effectively ban the handling of hazardous lead wastes by such units who obtain their wastes through auctions and traders.
The HPC was seriously concerned about the situation arising out of the processing of lead in the country and had meetings with associations/major authorised lead reprocessors, besides visiting various lead handling units, large and small, and having several discussions in HPC meetings themselves. In one of its earliest meetings, the HPC had already advised the Ministry of Environment & Forests to write to other Ministries to stop the auction of used lead acid batteries. However, inspite of a public notice issued by the MoEF/CPCB, the auctioning of hazardous lead waste batteries through traders has continued, as is evident from the auction notices appearing in the newspapers.
In the meanwhile, the MoEF set up a separate group to go into the problems associated with this area of lead waste handling and reprocessing. The HPC was not formally informed of the constitution or kept abreast of its proceedings. The work of the group has resulted in a draft notification on battery collection, handling and reprocessing which was notified on 25.5.2000 for inviting suggestions/objections from those concerned with the trade.
The HPC is firmly of the view that a system needs to be developed to curb such practices described above. Improper collection of battery scrap and its reprocessing by the unorganised sector-which observes little or no precautions that are needed for the handling of a toxic threat to the environment in general and to the work force which is associated with the reprocessing of lead scrap in particular.In view of-the above, it is necessary to develop a systematic, well-implemented, carefully controlled and monitored approach to recycling of lead battery scrap and other lead containing waste materials. It is also necessary to develop a compact and cost effective technology for small scale authorised recycling units,with in-built pollution control systems. The world over, 99% of recycling of lead is done through the thermal treatment process, i.e. the Cleaner technologies have been developed which are mostly hydrometallurgical,However, most of the hydrometallurgical routes are still under development on a pilot scale. A major promotional effort for their adoption is called for.
There are large-scale users of lead batteries e.g., Defence, Railways, State Transport Corporations, government vehicles, etc. There should be no difficulty in ensuring that batteries from these go only to large-scale authorised reprocessors. As a matter of practice, as in several other countries, new batteries should only be supplied after surrender of the one being discarded.
|Posted : 10/26/2005|