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.