ROMELT TECHNOLOGY

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BACKGROUNDER

For long there was no answer to the problem of disposal of Municipal Solid Wastes (MSW) in an environmental friendly manner. Now, thanks to the Romelt technology developed by Moscow Institute for Steel and Alloys (MISA), primarily for extraction of iron from any iron bearing wastes from mines, there is an answer to the vexing problem of MSW treatment.

Based on the experience gained, after successful installation of a 300,000 tonnes per annum capacity Romelt Plant at Novolipetsk Iron & Steel Works (NLSW) at Russia and the technical, technological and techno-economic indices as emerged at NLSW, two major entrepreneurs National Mineral Development Corporation Ltd. (NMDC) and National Aluminium Company Ltd. (NALCO) is 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 it. Because of very high temperature oxidation of MSW in a liquid slag bath with oxygen enriched air along with coal and limestone for converting the non-combustible part of MSW 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.