Post on 08-Apr-2015
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Red Mud, & other industrial waste products
Industrial wastes – Group I
Properties – soundness, strength, shape, abrasion resistance and gradation
Blast furnace slagBottom ashFlyashBoiler slagAnthracite coal residueScrap iron
Scrap aluminiumStone waste Felspar wasteChina Clay wasteBurnt tile wastePhospho gypsumFluorogypsumBorogypsum
Industrial wastes – Group II
Require some processing
Steel Slag
Bituminous coal waste
Phosphate slag
Slate mining waste
Laterite waste
Foundry waste sand
Incinerator residue
Waste glass
Zinc smelter slag
Building rubble
Alumina red mud
Acetylene lime sludge
Lime sludge from fertilizer
Industrial wastes – Group III
No standard specifications yet for their proposed uses.
Sugar lime sludgePaper lime sludgeTannery lime sludgeGold ore tailingCopper ore tailingZinc ore tailingIron ore tailingFluorspar tailingMarble dressing waste
Occupational Hazards in Handling waste
Wastes and by products are many times categorized hazardous.
They produce dust, heat, and have pollutantsThey cause silicosis, asbestosis and
pneumoconiosis.Thus need very careful handling, up gradation
and detoxificationAn industrial or mining waste only in perfectly
upgraded form becomes a low cost but high value material
Major wastes produced in IndiaWaste Annual
Production (MT)
Uses Materials saved
Metal Scraps In metal products
Blast furnace slag 25 PSC, SSC, oil well, Cement masonry, Cement aggregate, Concrete blocks
Limestone, clay, shale stone aggregate & coal
Flyash PFA 12 PPC, concrete, Masonry block, Calcium silicate Brick & cellular concrete
Limestone, clay stone aggregate, Sand, Coal & water
Mine tailings 95 Fine aggregate, Concrete additive, in calcium Silicate brick
Sand, clay
Byproducts gypsum 6.5 Cement, plaster boards Natural gypsum
Other Wastes
Waste Source Quantity Use Cinder Thermal Power
plants 1 MT/yr Lime Cinder Morttar, Conc
blocks, bricks from black cotton soil
Gypsum mine 1.5 Gypsum building plaster, ready made plaster with lime
Limestone waste Quarry 17.8 Masonry cement, activated lime pozzonlana mixture
Paper waste City garbage Pitch Fibre pipes, asphaltic corrugated roofing sheets. Fruit pack trays, pulp moulded packaging materials.
Characterization of the Wastes
Mining and mineral waste must be fully characterized for potential application
Granulated blast furnace slag must be free of MnO2 like oxides.
FLyash with CaO<5% - BPCFlyash with CaO>10% - Bricks, mortar,
plaster
Red Mud
Red Mud is produced during the Bayer process for alumina production
We can extract the aluminum (oxy)hydroxides from bauxites and get alumina, which eventually can be smelted and give aluminum.
It is a mixture of compounds originally present in the parent mineral, bauxite, and of compounds formed or introduced during the Bayer cycle.
Red Mud - Disposal
Production – 4 MT/yr. It is disposed as a
slurry having a solid concentration in the range of 10-30%, pH in the range of 13 and high ionic strength.
Red Mud - Composition
A chemical analysis would reveal that RM contains silica, aluminum, iron, calcium, titanium, as well as an array of minor constituents, namely: Na, K, Cr, V, Ni, Ba, Cu, Mn, Pb, Zn etc.
Fe2O3 30-60wt% Al2O3 10-20wt%
SiO2 3-50wt%
Na2O 2-10wt% CaO 2-8wt% TiO2 trace-25wt%
Red Mud uses
Conventionally – construction of clay-lined dams or dykes, sea disposal
New Uses-Building Bricks and TilesLightweight structural blocksRoofing sheetsAdditive to Concrete, Paint, wood Substitute, Glass
CeramicFlyash/ Redmud Polymer Door Shutter
Uses of Red Mud
Red Mud Jute Fibre Polymer
Composite (RFPC) – ferric oxide, alumina and
titanium oxide from red-mud, 82.5% cellulose and 11.3% lignin from its jute component (jute is 15% of the total volume of the shutter).
product uses zero energy aided raw materials
conserves energy by room-temperature processing.
Suitable for Door Shutters, Furniture, flooring and panelling work, electrical switch boxed and insulating sheets
Phospho Gypsum
Source by-product of the
phosphoric acid based fertiliser industry
interaction of ground phosphate rock with sulphuric acid produces 10-40% free moisture along with phosphogypsym
For every ton of phosphoric acid made,, some four to five tons of phosphogypsum are created.
Phospho Gypsum
4.5 million tonnes is generated per year in India. Over 10 million tonnes has accumulated at plant
sites. The fluoride content of phosphogypsum causes
land and water pollution
Uses of Phospho Gypsum
Gypsum plaster, boards, tiles.As set controller in the manufacture of Portland
cement.Non-shrinking cement, super
sulphated/anhydride cement.As a hydraulic binder.As mineraliser.Simultaneous manufacture of cement and
sulphuric acid.Artificial marble, fibre boards.