ROMELT TECHNOLOGY FOR
DISPOSAL OF MUNICIPAL SOLID WASTES
The disposal of Municipal Solid Wastes
(MSW) is a universal problem. In India the problem is alarming.
It is reported that Delhi, Capital of India is sitting on a garbage
bomb. The municipal corporations in India are unable to manage
the quantities of wastes generated every day. This has been increasing
in geometric proportions year after year. Many methods have been
tried without much success.
MAJOR TECHNOLOGY OPTIONS
Generally MSW is disposed off by dumping in low-lying grounds
as solid land filling .This is the cheapest and easy form of disposal,
but requires huge area of low lying, preferably fallow lands,
around the city, which is increasingly becoming scarce. Besides,
this method leads to various types of communicable diseases &
ground water contamination in the vicinity of the dumping area.
Segregating biodegradable wastes
and using them for biodegradation to produce Compost, which can
be used as manure is a viable method, but has not achieved the
desired results. Huge quantities of compost are lying unsold at
the processing areas for disposal. Low temperature incineration
produces toxic gases and the ashes so produced need environment
friendly disposal.
Another tried technology is to manufacture Refuse Derived Fuel
(RDF) from the MSW which can be used as domestic fuel and in the
industrial ovens. This method also could not become useful because
the RDF does not have a market in the cities.
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ROMELT
TECHNOLOGY FOR DISPOSAL OF SOLID WASTES
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ROMELT TECHNOLOGY FOR DISPOSAL OF
SOLID WASTES
There was not any answer to the problem
of disposal of MSW in an environment friendly manner. Now thanks
to the Romelt technology developed by Moscow Institute for Steel
and Alloys (MISA), there is an answer to the vexing problems of
MSW treatment.
Successful installation of a three
lakh tone per annum capacity Romelt Plant at Novolipetsk Iron
& Steel Works (NLSW) at Russia brought out new technical,
technological and techno-economic indices. National Mineral Development
Corporation Ltd. (NMDC) and National Aluminium Company Ltd. (NALCO)
are in the process of setting up commercial plants of the same
capacity at Nagarnar (Jagdalpur), Chhattisgarh State and Damanjodi,
Orissa State to mitigate the problem of solid waste generation
in the form of iron ore slimes and red mud respectively.
THE ROMELT FURNACE FOR TREATING MSW
The high temperature Romelt Furnace operation has been tried for
pyrolysis of MSW, and the results obtained make it a breakthrough
in treating the MSW. Because of very high temperature, oxidation
of MSW converts the non-combustible part into slag instead of
toxic ashes. The combustible part of the MSW produces rich gases,
which is partly post combusted within the furnace to supply heat
for sustenance of the process.
The high temperature attained by
the post combustion, disassociates the toxic gases like dioxins
into harmless compounds, which settles back into the furnace and
are discharged through the slag. The uncombusted gases in the
exit gases within the furnace are burnt during the passage of
the gases through a waste heat boiler, and the heat so generated
along with the sensible heat of the gas itself produces supersaturated
steam. This supersaturated steam, in turn is used to generate
electric power. Thus, the process ensures the generation of extra
revenue through sale of this electric power apart from the production
of slag.
The slag converted into slag ballast
can be sold for use in place of stone ballast for roads and construction
purposes. The electric power so generated has ready use in the
city corporation. The exhaust gases are process for removing all
dusts. The coarse dusts are recycled back and the fine dust are
further processed for extraction of different precious metals.
ENVIRONMENTAL ADVANTAGES
Besides operational advantage it has a lot of environmental advantages.
Generation of nitrogen oxides and other impurities in the exhaust
gases is low. Due to high temperature, incineration fumes contain
very less organic compounds and in particular, dioxides. Transfer
of alkaline and alkaline-earth metals into steam gas phase promote
binding of chlorine, fluorine, sulfur oxides into safe compounds
trapped by gas cleaning as solid particles of dust.
Instead of large amount of ecologically dangerous ash residue,
containing heavy non-ferrous metals and dioxin, inert slag is
produced which is a valuable raw material for the production of
construction materials. The dust discharged from the furnace with
fumes is trapped selectively at different stages of cleaning.
Coarse dust is recycled into the furnace. Fine dust, which is
in the concentrate of heavy non- ferrous metals (zinc, lead, cadmium,
tin etc.), is suitable for extraction in non-ferrous metal.
