We Claim:
1. A desulphurization reagent comprising about 12-18% w/w of CaSi, about
4-8% w/w of a slag conditioner and about 1-5% w/w of a melt agitator or
gassifying agent.
2. The desulphurization reagent as claimed in claim 1, further comprising an
10 additional component selected from a group comprising a calcium bearing
compound, a flow aid or fluidizer and a deoxidizer or any combination
thereof.
3. The desulphurization reagent as claimed in claim 1, wherein the slag
conditioner is selected from a group comprising a sodium based compound,
15 an aluminium based compound and a fluorine-based compound or any
combination thereof.
4. The desulphurization reagent as claimed in claim 3, wherein the slag
conditioner is selected from a group comprising cryolite, alumina, fluorspar,
bauxite, soda ash and borax or any combination thereof.
20 5. The desulphurization reagent as claimed in claim 1, wherein the melt
agitator or gassifying agent is selected from a group comprising coal,
limestone, dolomite and gilsonite or any combination thereof.
6. The desulphurization reagent as claimed in claim 2, wherein the calcium
bearing compound is selected from a group comprising lime, calcined lime,
25 limestone and calcium chloride or any combination thereof, and/or wherein
the calcium bearing compound is present at a concentration ranging from
about 70-80% w/w.
7. The desulphurization reagent as claimed in claim 2, wherein the flow aid or
fluidizer is selected from silicone oil and coal or a combination thereof,
30 preferably silicone oil; and/or wherein the flow aid or fluidizer is present at
a concentration ranging from about 0.05-5% w/w.
8. The desulphurization reagent as claimed in claim 2, wherein the deoxidizer
is selected from a group comprising metallic aluminium, coal and coke or
any combination thereof, preferably metallic aluminium; and/or the
35 deoxidizer is present at a concentration ranging from about 1-10% w/w.
10. A method for preparing the desulphurization reagent as claimed in any one
of claims 1-9, the method comprising:
mixing about 12-18% w/w of the CaSi, about 4-8% w/w of the slag
conditioner, about 1-5% w/w of the melt agitator or gassifying agent and
optionally, the calcium bearing compound, the flow aid or fluidizer and/or
25 the deoxidizer to obtain the desulphurization reagent.
11. The method as claimed in claim 10, wherein the mixing step comprises
mixing the components, crushing, grinding, pulverising, or any combination
of said techniques; and wherein said mixing is carried out by employing a
rod mill, ball mill, blender, crusher, grinder, pulverizer, or any combination
30 thereof.
12. The method as claimed in claim 10, wherein the calcium bearing compound
is employed at a concentration of about 70-80% w/w, the flow aid or
fluidizer is employed at a concentration of about 0.05-5% w/w and the
deoxidizer is employed at a concentration of about 1-10% w/w.
13. A process of desulphurization of hot metal during production of steel, the
process comprising contacting the desulphurization reagent as claimed in
any one of claims 1-9 with the hot metal to obtain desulphurized hot metal
and sulfur rich slag.
14. The process as claimed in claim 13, wherein the process also results in the
10 simultaneous reduction of FeO content in the slag along with the removal
of sulphur from the hot metal.
15. The process as claimed in claim 13, wherein the desulphurization reagent is
contacted with the hot metal for desulphurization through one or more of
mono-injection process, co-injection process, multi-injection, pour-over
15 process, ladle top addition or ladle bottom addition.
16. The process as claimed in claim 15, wherein the desulphurization reagent is
contacted with the hot metal for desulphurization through mono-injection
process.
17. The process as claimed in claim 15, wherein the desulphurization reagent is
20 contacted with the hot metal for desulphurization through co-injection
process.
18. The process as claimed in claim 17, wherein the co-injection process
comprises co-injecting Reagent A comprising about 20% to about 25% w/w
of CaSi, about 1% to about 5% w/w of a melt agitator or gassifying agent
25 and about 4% to about 10 % w/w of a slag conditioner, and Reagent B
comprising about 90% to about 97% w/w of calcium bearing compound and
about 1% to about 10% w/w of slag conditioner, such that the final reagent
contacted with the hot metal is the desulphurization reagent as claimed in
any one of claims 1-9.
30 19. The process as claimed in claim 18, therein the Reagent A further comprises
about 60% to about 75% w/w of a calcium bearing compound and about
0.05% to about 0.5% w/w of a flow aid or fluidizer.
20. The process as claimed in claim 19, wherein the co-injection process
comprises co-injecting the Reagent A comprising about 24% w/w of the
35 CaSi, about 2% w/w of the melt agitator or gassifying agent, about 6% w/w
of the slag conditioner, about 67.9% w/w of the calcium bearing compound
and about 0.1% w/w of the flow aid or fluidizer, and the Reagent B
comprising about 96% w/w of the calcium bearing compound and about 4%
w/w of the slag conditioner, such that the final reagent contacted with the
hot metal is the desulphurization reagent as claimed in any one of claims 1-
10 9.
21. The process as claimed in any of claims 18-20, wherein the ratio between
the Reagent A and the Reagent B ranges from about 3:1 to about 10:1.
22. The process as claimed in any one of claims 13-21, wherein the
desulphurization reagent is contacted with the hot metal at a ratio of about
15 9:10000 to about 1:100 by weight; and/or wherein the desulphurization
reagent is contacted with the hot metal at a temperature ranging from about
1275°C to about 1450 °C.
23. The process as claimed in any one of claims 13-22, wherein the
desulphurization reagent is contacted with the hot metal at a flow rate of
20 about 10 kg/minute to about 80 kg/minute.
24. A kit comprising the desulphurization reagent as claimed in claim 1, or a
combination of about 12-18% w/w of CaSi, about 4-8% w/w of slag
conditioner and about 1-5% w/w of melt agitator or gassifying agent and
optionally about 70-80% w/w of a calcium bearing compound, about 0.05-
25 5% w/w of a flow aid or fluidizer and/or about 1-10% w/w of a
deoxidizer(s), or Reagent A and Reagent B as defined in claim 18 or 19,
along with an instruction manual.
25. The kit as claimed in claim 24, further comprising means for facilitating
introduction of the desulphurization reagent or the combination of
30 components constituting the desulphurization reagent or the reagents into
hot metal for desulphurization of the hot metal.
26. The process as claimed in any of claims 22-23, wherein said process yields
a desulphurization efficiency of about 30% to about 100 %; reduces hot
metal sulphur level after desulphurization to about <=0.008% sulphur;
and/or reduces FeO content in the process slag to about <=20%.