DESC:PLEASE SEE THE ATTACHMENTS. ,CLAIMS:1. A desulphurization reagent comprising calcium carbide, aluminium and alumina.
2. The desulphurization reagent as claimed in claim 1, wherein calcium carbide is present
in a raw crushed form and aluminium and alumina are present in powdered form.
3. The desulphurization reagent as claimed in claim 2, wherein the raw 5 crushed form of
calcium carbide comprises at least about 75% calcium carbide.
4. The desulphurization reagent as claimed in any one of claims 1-3, wherein calcium
carbide is present at a concentration of about 45% w/w to about 65% w/w, aluminium
is present at a concentration of about 10% w/w to about 20% w/w and alumina is present
10 at a concentration of about 15% w/w to about 35% w/w.
5. The desulphurization reagent as claimed in any one of claims 1-4, wherein said
desulphurization reagent reduces sulphur content of steel from about 0.054-0.986%
w/w to about 0.038-0.011% w/w.
6. The desulphurization reagent as claimed in any one of claims 1-5, wherein said
15 desulphurization reagent provides a reduction in sulphur content of steel by about 25-
60 points.
7. A process for preparing the desulphurization reagent as claimed in any one of claims
1-6, comprising mixing calcium carbide, aluminium and alumina to obtain the
desulphurization reagent.
20 8. The process as claimed in claim 7, comprising mixing calcium carbide at a
concentration of about 45% w/w to about 65% w/w, aluminium at a concentration of
about 10% w/w to about 20% w/w and alumina at a concentration of about 15% w/w
to about 35% w/w.
9. The process as claimed in claim 7 or claim 8, wherein aluminium and alumina are mixed
25 to provide a pre-mix and calcium carbide is added to the pre-mix.
10. A process for desulphurization of steel, comprising contacting liquid steel with the
desulphurization reagent as claimed in any one of claims 1-6 to obtain desulphurized
steel.
11. The process as claimed in claim 10, wherein the liquid steel is contacted with the
30 desulphurization reagent at a temperature ranging from about 1575°C to about 1675 °C.
12. The process as claimed in claim 10 or 11, wherein said contacting comprises adding
the desulphurization reagent to the liquid steel at a concentration of about 2-3kg/ton of
liquid steel.
19
13. The process as claimed in claim 10 or 11, wherein the liquid steel is contacted with the
desulphurization reagent during and/or after tapping of the liquid steel.
14. The process as claimed in claim 13, wherein a portion of the desulphurization reagent
is added to a ladle before tapping of the liquid steel and the remaining portion of the
desulphurization reagent is added to the liquid steel 5 during tapping.
15. The process as claimed in claim 14, wherein about 40-60% of the desulphurization
reagent is added to the ladle before tapping of the liquid steel.
16. The process as claimed in claim 15, wherein about 60% of the desulphurization reagent
is added to the ladle before tapping of the liquid steel and about 40% of the
10 desulphurization agent is added during tapping of the liquid steel.
17. The process as claimed in claim 13, wherein a portion of the desulphurization reagent
is added to a ladle before tapping of the liquid steel, a portion of the desulphurization
reagent is added to the liquid steel during tapping, and the remaining portion of the
desulphurization reagent is added to the liquid steel after tapping.
15 18. The process as claimed in claim 17, wherein about 40-60% of the desulphurization
reagent is added to the ladle before tapping, about 10-20% of the desulphurization
reagent is added to the liquid steel during tapping and the remaining portion of the
desulphurization agent is added to the liquid steel after tapping.
19. The process as claimed in claim 17 or 18, wherein about 50% of the desulphurization
20 reagent is added to the ladle before tapping, about 15% of the desulphurization reagent
is added to the liquid steel during tapping and about 35% of the desulphurization agent
is added to the liquid steel after tapping.
20. The process as claimed in any one of claims 10-19, wherein the process desulphurizes
steel from about 0.054-0.986% w/w of sulphur to about 0.038-0.011% w/w of sulphur.
25 21. The process as claimed in any one of claims 10-20, wherein the process desulphurizes
steel by about 25-60 points.
22. The process as claimed in any one of claims 10-21, wherein the steel is aluminium
killed steel.