Title of Invention

A PROCESS FOR PRODUCING WEAR RESISTENT CAST IRON BY SMELTING REDUCTION OF WASTE PRODUCTS LIKE RED MUD AND DESILICATED SAND

Abstract This invention relates to a process for producing wear cast iron by smelting reduction of a flux cover of a waste material like red mud of desilicated sand over a metallic charge of cast iron or steel scrap + carbon + ferrosilicon.
Full Text -2-
FIELD OF INVENTION
This invention relates to a process for producing wear resistant cast irons by smelting reduction of waste products like red mud and desilicated sand,
BACKGROUND OF INVENTION
Huge quantities of red mud and desilicated sand are produced during refining of bauxite (ore of Aluminium) in aluminium extraction plants, which hitherto has been considered as a waste. The average composition of red mud and desilicated sand are given below.
Table l(b) chemical composition of Sand (dry)
Table l(a) chemical composition of red mud (dry)



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Titanium microalloyed cast irons have been previously produced by
a) addition of ferrotitanium to cast iron melts.
b) Plasma smelting of ilmenite ore.
Various publications have disclosed the utilization of red-mud evidence However, no such publications disclose the smelting reduction of red mud for the preparation of wear resistant cast irons. A process has been described for producing wear resistant cast irons by the plasma smelting of ilmenite ore Such a process employs the use of a plasma furnace, and a rich grade ore like ilmenite.
OBJECTS OF THE INVENTION
An object of this invention is to propose a process for producing wear resistant cast iron
using a waste material such as red mud and desilicated sand.
Another object of this invention is to propose a process for producing wear resistant cast iron using a waste material such as red mud and desilicated sand in an induction or electric ore fumace.
Still another object of this invention is 10 propose a process for producing wear resistant cast iron using a waste material such as red mud and desilicated sand, which is economical

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Yet another object of this invention is to propose a process for producing wear resistant cast iron using a waste material such as red mud and desilicated sand and wherein the cast iron has suitable hardness properties.
A further object of this invention is to propose a process for producing wear resistant cast iron using a waste material such as red mud and desilicated sand and wherein the cast iron has suitable lubrication properties.
DESCRIPTION OF INVENTION
According to this invention there is provided a process for producing wear resistant cast iron by subjecting a metallic charge to the step of smelting reduction in the presence of a flux, said flux is selected from red mud or desilicated sand as a source of titanium.
In the process, cast iron scrap or mixtures of steel scrap + carbon + ferrosilicon are melted under a flux cover of red mud + CaF2 and/or CaO or desilicated sand + 5-25% CaO. The weight of flux may vary from 1.0-5.0% of the metallic change. The melting can be carried out in a basic lined induction or electric are furnace. During melting, the constituents in the metallic charge react with the various oxides in the flux. As a result,

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the final metal melt is depleted in carbon and silicon, but it picks up detectable quantities of titanium, chromium and nickel from the flux through the reduction of the oxides present in it Since the process of melting also involves flux-melt reduction reactions, it is termed smelting reduction The resultant cast iron, when cast in said moulds, solidifies with a motted or white cast iron microstructure depending on the final carbon and silicon contents Fine cuboidal partices of TiC are embedded in the matrix However, if late inoculatin of the cast iron melt with FeSi is carried out just before casting, it may as well solidify as grey iron Of course, TiC particles are finely distributed in the cast iron matrix.
The chilled iron may be further converted into malleable iron by a malleatising treatment at 900-950°C. Thus there is a feasibility of producing TiC impregnated (a) motted or chilled iron, (b) grey iron, (c) Malleable iron.
Because of the presence of finely distributed TiC particles, this type of cast iron develops very good wear resistance The TiC particles impregnated matrix bears the wear toad while lubrication is provided by smeared graphite particles.

The hardness of these wear resistant of cast irons may vary between 140-300 BHN depending upon the matrix structure and the titanium content in the alloy.
Smelting reduction of red mud/desilicated sand has not been tried before. In the present process red mud/desilicated sand has been used as a flux cover over a metallic charge of cast iron or steel scrap + carbon + ferrocilicon. Titanium microalloyed cast
iron is produced by reduction of the TiO2 in the flux by
reduc t ion like carbon and sillicon present in meta11ic charge
itself.
The cast iron produced by the method has been tested for its properties where Table 1 shows cast irons produced with different charge mix in induction furnace using NALCO red mud- Table 2 shows cast irons produced with different charge mix in induction furnace. Table 3 shows cast iron produced in electric furnace using NALCO sand.



Table 1





Table.2
Table 3

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-9-WE CLAIM:
1. A process for producing wear resistant cast iron by subjecting a titanium bearing flux cover of red mud or desilicated sand such as herein described to the step of smelting reduction in presence of an underlying metallic charge.
2. A process as claimed in claim 1I whrerein the weight of said
flux is from 1-0 to 5.0% of the metallic charge.
3. A process as claimed in claim 1 wherein the step of
smelting reduction is carried out in an induction or electric arc
furnace.
4. A process as claimed in claim 1 wherein the metallic
charge is selected from cast iron or steel scrap, carbon and
ferrosilicon.
5. A process for producing wear resistant cast i ron substantially as herein described.

This invention relates to a process for producing wear cast iron by smelting reduction of a flux cover of a waste material like red mud of desilicated sand over a metallic charge of cast
iron or steel scrap + carbon + ferrosilicon.

Documents:

00405-kol-2003-abstract.pdf

00405-kol-2003-claims.pdf

00405-kol-2003-correspondence.pdf

00405-kol-2003-description(complete).pdf

00405-kol-2003-form-1.pdf

00405-kol-2003-form-18.pdf

00405-kol-2003-form-2.pdf

00405-kol-2003-form-3.pdf

00405-kol-2003-g.p.a.pdf

00405-kol-2003-letters patent.pdf

405-kol-2003-granted-abstract.pdf

405-kol-2003-granted-claims.pdf

405-kol-2003-granted-correspondence.pdf

405-kol-2003-granted-description (complete).pdf

405-kol-2003-granted-examination report.pdf

405-kol-2003-granted-form 1.pdf

405-kol-2003-granted-form 18.pdf

405-kol-2003-granted-form 2.pdf

405-kol-2003-granted-form 3.pdf

405-kol-2003-granted-gpa.pdf

405-kol-2003-granted-letter patent.pdf

405-kol-2003-granted-reply to examination report.pdf

405-kol-2003-granted-specification.pdf


Patent Number 203340
Indian Patent Application Number 405/KOL/2003
PG Journal Number 10/2007
Publication Date 09-Mar-2007
Grant Date 09-Mar-2007
Date of Filing 25-Jul-2003
Name of Patentee INDIAN INSTITUTE OF TECHNOLOGY
Applicant Address KHARAGPUR 721302
Inventors:
# Inventor's Name Inventor's Address
1 CHAKRABORTY A.K INDIAN INSTITUTE OF TECHNOLOGY KHARAGPUR 721302
2 CHATTERJEE U K INDIAN INSTITUTE OF TECHNOLOGY KHARAGPUR 721302
3 SUBBA REDDY N. INDIAN INSTITUTE OF TECHNOLOGY OF KHARAGPUR 721302 WEST BENGAL
4 MISHRA C.R INDIAN INSTITUTE OF TECHNOLOGY OF KHARAGPUR 721302 WEST BENGAL
5 SETH M M INDIAN INSTITUTE OF TECHNOLOGY OF KHARAGPUR 721302 WEST BENGAL
PCT International Classification Number C 22 C 37/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA