|Title of Invention||
AN IMPROVED PROCESS FOR PREPARATION OF A SLAG ENRICHED IN VANADIUM AND TITANIUM FROM VANADIUM BEARING TITANIFERROUS MAGNETIC ORE
|Abstract||The present invention relates to an improved process for preparation of slag enriched in vanadium and titanium from vanadium bearing titaniferous magnetite ores. The process of the present invention uses thermal plasma technique. An important objective of the invention is to obtain metallic iron containing 96-99% iron which has got potential use in iron and steel industries|
|Full Text||This invention relates to an improved process for preparation of a slag enriched in vanadium and titanium from vanadium bearing titani ferrous magnetite ore
Vanadium bearing titaniferrous magnetite is found in various parts of India. A large reserve of this ore containing "0.8-1.8%
V 0 is also found in Mayurbhanj district of Orissa. Deposits of 2 5
such ore with varying minerological composition have also been found in Bandra( Maharastra), North Godavari(Andhra Pradesh) and Nilagiri region of Karnataka- Maharastra [K.K.Dwivedy, Reserve, Resources and Geology in India in "Titanium, Nov. 1995, pp 16-39]. The minerological characterisation on such type of ore has revealed that only one phase of mineral i.e, magnetite bearing titanium in association with vanadium is present in the rock. Since no separate phase of Ti, Fe and V exist in appreciable quantity, physical separation by conventional mineral processing techniques has been ruled out. Considering a large tonnage of iron ore and titanium associated with vanadium available in the remote local areas of our country, a suitable metallurgical process by which Ti and V can be concentrated simultaneously as a product for further processing will be the most rewarding in utilising the vast resources. Besides that the country is look-.j ing for a suitable procees for the production of vanadium com¬pounds either as V 0 or as Fe-V alloy since most of its require-
ment is met through imports. Recovery of metal values such as Fe
with TiO and V 0 enriched slag from vanadium bearing titanifer-2 25
rous magnetite deposit of Mayurbhanja, Orissa by thermal plasma technology is a successful development.
Generally the recovery of vanadium values from the vanadium ore is carried out either (i) roasting of the fine ground ore
with sodium salts followed by leaching and precipitaion as V 0
or (ii) Electric arc smelting of the ore to obtain vanadium bearing pig iron discarding the titanium into the slag. The vanadium bearing pig iron on subsequent controlled oxidation gives rise to V enriched slag and metallic iron. The first pro¬cess is totally dependent on reaction temperature, time, salt concentration, pH of the leaching media etc. to get the precipi¬tated V 0 . The second process involves two steps for the separa-2 5
tion of vanadium slag from the ore. References can be made to some of the work carried out elsewhere in India and abroad [A.K. Tripathy et. al; Trans IIM 38(3), 1985, pp263-265] along with some other references [I.N. Gubajdullin et al; Izobreteniya, vol 12,(1995),pp.253 (Russia) and (C.A. 124 (1996) 62716); A.J.Mer¬chant and N.A. Warner, Trans IMM Sect.C. Vol 101 (1992), pp 177-182; T.Bold and R.Kuziak, Pr. Inst. Metal. Zealza, Vol.37(1), (1985), pp8-14; M.C.L. Patterson and J. Cameron, Trans IMM. Sect. C. Vol. 94, (1985),pp. C215-C223; A.A.Ryumin et al, Izobrteniya, 15(1995), 254 (Russia) Chemical Abstract, 124 (1996), pr.P33963y]. However the present invention is based on a plasma process relating to a single stage process for the simultaneous separation of V and Ti from an unexploited deposit. The slag enriched in V and Ti can be suitably used futher in the prepara-
tion of various vanadium and titanium compounds or alloys. Be¬sides that the metallic iron phase obtained by the technique virtually contain no V and Ti and hence can be used for high quality steel making. Therefore, the present invention is a completely different process than the other methods cited else¬where in the literature.
The objective of the present invention is to provide a new
process using thermal plasma technique for production of V 0
-TiO (Total vanadium and titanium expressed as V 0 and
TiO )enriched slag containing 2-3% V 0 and 35-45% TiO from a
typical deposit of Kumardhubi, Mayurbhanja, Orissa. The other
objective of this invention is to obtain metallic iron containing
96-99% Pe which has got its own use in iron and steel industries. Accordingly, the present invention provides an improved process for
preparation of a slag enriched in vanadium and titanium from vanadium bearing titaniferrous magnetite ore which comprises mixing the ore with graphite/petroleum coke in the powder form (stoichiometric to 5-10% excess ) and processing in transferred arc thermal plasma reactor under the gas flow rate Ar (1.6-2.0 1pm), current (250-350 amp), voltage (30-40) and time (15-30minutes) to obtain a slag enriched in vanadium and titanium values and metallic iron as the byproduct, separating the iron
form the enriched slag by known methods.
In an embodiment of the present invention, the titaniferrous mag¬netite ore used has the following composition 55-65% Fe, 0.8-
1.35 % V 0 , 10-12 % TiO .
In another embodiment of the invention the carbon content of graphite/petroleum coke varies from stoichiometric range to 5-10% extra.
In another embodiment of the invention the reduction time varies from 15 to 30 minutes.
The uniqueness of the process is that it involves a thermal plasraa as a heat source unlikely in any other process. Unlikely in other processes, iron is separated as the major phase result¬ing a slag enriched with both vanadium and titanium. The metallic phase obtained by this technique contains only iron along with traces of vanadium, carbon and virtually no titanium, silicon and aluminium. This slag on further treatment by hydrometallurgical processing[ Crabtree, E.H and Padilla, V.E., J. less Common
Metals 3 (1961) 437-442] can give V 0 as the final product. The
process involves roasting , leaching followed by precipitation to
form V 0 . The following examples are given by way of illustra-2 5
tion and should not construced the limit of scope of the inven¬tion. Example 1
SOOgms of vanadium bearing titaniferrous magnetite ore of
Mayurbhanja, Orissa assaying V 0 -0.84%, TiO -10.85 % and Fe
-54.5% were mixed with 80 gms of graphite powder/petroleum coke (99% purity) and fed into a graphite crucible placed inside the plasma reactor made up of mild steel chamber. Two graphite electrodes (1" dia.) were placed along the axis of the crucible where the top one was having a provision to move up and down with a hole to feed the plasmagen gas and other is connected to the
crucible. Argon was used as the plasmagen gas. The experimental
condition: current-250 amp. Voltage- 35 V, argon flow rate 2 1pm
and time 15 minutes gives a metallic phase containing 98.85% Pe
with no vanadium and titanium in it. The slag enriched in vanadi¬
um (as V 0 -3.43% and titanium (as TiO -25.5%)values along with
PeO (45%) is obtained.
500 gm of the said ore was mixed with slight excess of graphite powder (95 gms) and fed into the above said reactor. Experimental conditions such as 250 amp.current, 40 V and 15 minutes of reduction time was employed. The product was obtained
as a metallic phase containing arround 98% of Fe and 0.05% V 0 .
The slag phase thus separated contains arround 45.4% TiO and
3.05% of V 0 and 35% of FeO. 2 5
The process involves a thermal plasma process which has got certain advantages. The technique offers advantages such as steady state conditions and uniform flow of ionized gas with very high bulk gas temperature; Ores in fine form can be used unlikely in other processes. The plasma arc permits one to use a no. of unique methods to interface the transfer of electrical energy from the power sources to meet the thermal energy requirements of the process. The plasma reactors reduces environmental pollution to a great extent. The process simutaneously separates the vanad¬ium and titanium values.
1. An improved process for preparation of a slag enriched in vanadium and
titanium from vanadium bearing titaniferrous magnetite ore which comprises
mixing the ore with graphite/petroleum coke in the powder form
(stoichiometnc to 5-10% excess ) and processing in transferred arc thermal
plasma reactor under the gas flow rate Ar (1.6-2.0 1pm), current (250-350
amp), voltage (30-40) and time (15-30minutes) to obtain a slag enriched in
vanadium and titanium values and metallic iron as the byproduct, separating
the iron from the enriched slag by known methods.
2. An improved process as claimed in claim 1, wherein the vanadium bearing
titaniferrous magnetite ore used has the following composition; 55-65% Fe,
0.8-1.35% V205 and 10-12% Ti02.
3. An improved process for preparation of a slag enriched in vanadium and
titanium from vanadium bearing titaniferrous magnetite ore substantially as
herein described with reference to examples 1&2.
|Indian Patent Application Number||2710/DEL/1998|
|PG Journal Number||10/2008|
|Date of Filing||11-Sep-1998|
|Name of Patentee||COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH|
|Applicant Address||RAFI MARG, NEW DELHI 110001, INDIA|
|PCT International Classification Number||C22C 14/00|
|PCT International Application Number||N/A|
|PCT International Filing date|