(12) STANDARD PATENT APPLICATION (11) Application No. AU 2008221580 Al (19) AUSTRALIAN PATENT OFFICE

(54) Title The technology of producing ferrotitanium

(51) International Patent Classification(s) C22B 5/04 (2006.01) C22B 5/10 (2006.01)

(21) Application No: 2008221580 (22) Date of Filing: 2008.09.25

Priority Data

(31) Number (32) Date (33) Country 2007905269 2007.09.26 AU

(43) Publication Date: 2009.04.09 (43) Publication Journal Date: 2009.04.09

(71) Applicant(s) Alexey Nosenkov;Nosenkova Margarita

(72) Inventor(s) Nosenkov, Alexey;Nosenkova, Margarita

(74) Agent Attorney Alexey Nosenkov, 50 Mundy Street, Mentone, VIC, 3194 THE TECHNOLOGY OF PRODUCING FERROTITANIUM 00 O Abstract. (N Method of alumothermal and carbothermal production of ferrotitanium has been offered. Charge consisting of oxides of , iron, calcium and metallic aluminum is being heated to V) the temperature of 800-1000OC and set on fire with ignition mixture. Carbon can be used instead of aluminum. As the second option the following process is offered: titanium oxide is being mixed with any source of carbon (soot, coal etc.), heated and soaked at temperatures up to 1000 0C-25000 C. Then in the process of melting oxides of titanium, iron and/or metallic iron are being added. 00

00

(N, THE TECHNOLOGY OF PRODUCING FERROTITANIUM 00 0 Ferrotitanium is a metallic alloy of titanium and iron and it is widely used as an active alloying Cq addition in the production of stainless and interstitial free steels. Traditionally ferrotitanium is produced by using metallic scrap. However production of ferrotitanium by reduction of titanium V oxides did not find wide application due to the absence of robust technology that would allow to produce ferrotitanium with 70% titanium contents. The invention consists in aluminothermic and carbothermic production of ferrotitanium, 00 including out-of-furnace reduction of charge comprising oxides of titanium, oxides of iron, Saluminum, carbon and oxide of calcium. Titanium concentrates (, leucoxene, Cq , ) are being used as source of titanium component of the charge. Sources of 00 Scarbon are being used as soot,coal, charcoal (including activated coals), graphite .The charge N components are being mixed until the ratio of oxides of iron mass to titanium mass equals 1:(1,0 oxide of calcium equals 0,2-0,5 of the total mass of oxides of titanium and iron and aluminum 1:(1,8-2.2),carbon equals 0-30% of aluminium content. Before reduction the charge is being heated to the temperature of 800-1000C 0 in inert atmosphere and then kept until the temperature is even across the charge. The reduction process is started by igniting the charge with consequent switching off the heat. Before feeding of the charge its components are being crushed. First oxides of titanium and aluminum are being crushed and mixed and then the rest of the charge components are added and mixed one more time. Feeding of the charge into the crucible is done in portions with consequent compression. Rutile, ilmenite, leucoxene, perovskite or their mixture are being used as source of titanium and iron. The charge is ignited to start the reduction process by using thermal mixture of iron oxide and aluminium. Mixing and crushing of charge components takes place in vacuum or inert atmosphere. Unlike any other known methods of production of ferrotitanium the invented method uses only the energy of reduction reaction without external heating and the aluminothermic and carbothermic reduction of titanium and iron oxides is performed out of furnace. This method permits to melt the ferrotitanium containing up to 70% of titanium and no more then 4% of aluminium. The necessary condition of out-of -furnace method of reduction is the stated ratio of the oxides of titanium, iron, calcium and aluminum. Another distinctive feature of the method is also the use of containing oxides of titanium and iron as the only raw material components. 2 Various sources of raw material containing titanium can be used for that method such as rutile 0(90-98% TiO2), ilmenite (35-50% TiO2; 50-65% FexOx). This factor determines the possibility of industrial implementation of the invented method. The invented method will ensure energy savings as for the initiation of the reduction process, metal melting (at 1600C is not required. The charge is simply being heated through evenly to C, 800-1000C and ignited with power switched off To ensure even distribution of the reaction throughout the whole volume of the material and to 0stop aluminum discharge even distribution of reaction components is required. This is achieved 00 by prior crushing and mixing of the charge components. Besides even distribution of the charge components preliminary crushing also increases the contact surface of oxides of titanium and 000aluminum and increases inner energy of particles due to deformation.

Establishing parameters.

The use ofFeO2, TiO2 at the ratio of 1 0-3, 0) in mass as the components of the charge after reduction allows to produce ferrotitanium with 35 to 70% titanium content. Addition of oxide of calcium at the ratio of 0,2-0,5 of the oxide of iron and titanium mass increases the extraction of titanium into metal. It also increases the fusibility of aluminothermic slag due to formation of compounds CaO.(A1203)x during the fusion (fusion temperature does not increase 1700C°). Heating of the charge to 800-1000C in inert atmosphere allows achieving reduction out of furnace. Final product depends on the ratio of the charge components FeO2:TiO2 equal to as follows: The lower border results in production of ferrotitanium with titanium contents of less than 35% mass. The components ratio of 1: 3 results in production of ferrotitanium with titanium contents of not less than 70%. Depending on the required contents of titanium in the final alloy different ratio ofrutile and ilmenite is used in the charge. Addition of oxide of calcium into the charge at the ratio of to the total mass of oxides of titanium and iron allows to produce ferrotitanium out-of-furnace with extraction of titanium into metal equal to 80-85%. It also helps the formation of clear border between metal and slag during reduction. The upper border corresponds to the maximum possible contents of oxide of calcium in the charge which allows to carry out reduction without damping and to ensure the necessary speed of reaction distribution. Higher than stated quantity of CaO in the charge slows down the reaction distribution which causes early slag hardening and formation of slag crust with metallic insertions into the walls of the crucible. The lower border of the ratio equals the minimum quantity of oxide of calcium in the charge which is required to achieve high extraction of titanium Decreasing that quantity of CaO will cause excessive decrease of titanium extraction into metal (60% and less). In that case reduced titanium is caught in the slag and is not

0 transformed into ingot. Addition of peroxide of barium (BaO2) into the charge at 5-20% of the total mass of oxide of calcium increases the extraction of titanium up to 87-95%. Peroxide of barium could be replaced by sodium chlorate (NaC103) or potassium chlorate (KC103).Addition of chlorites into the

C, charge at 5-15% of the total mass of oxide of calcium increases the extraction of titanium up to 90-97%. OThe quantity of aluminum added to the charge is determined by its acceptable contents in the 00 final product. Using the ratio of total contents of oxides of titanium and iron to aluminum as 1:(0,45-0,55) allows to produce ferrotitanium with aluminum contents of4-15% depending on its 00 O titanium contents. The lower ratio border is the minimum quantity of aluminum in the charge required for the reduction process. Increasing aluminum contents in the charge above the stated upper border of the ratio results in higher contents of aluminum in ferrotitanium while the degree of reduction of metals into ferrotitanium remains the same. The temperature interval for preliminary charge heating is determined by the following: At temperature below 800C0 reduction process goes at low speed with slag crust forming on the wall of the crucible with metal insertions, i.e. metal and slag are not being separated. Heating of the charge to temperatures higher than 1000C0 causes spontaneous ignition of the charge and uncontrolled reduction process that may cause the charge to leak from the crucible. Distinctive feature of the invented method is preliminary crushing of separate components of the charge of aluminothermic reduction, i.e. of oxide of titanium and aluminum taken at the ratio of The crushing increases the contact surface of oxide of titanium and aluminum particles and increases the inner energy of the particles. As an option ferrotitanium can be produced by reduction of titanium slag, rutile and ilmenite with aluminium, silicon and (or) carbon soot, coal, charcoal (including activated coals), graphite or other sources of carbon. The process can take place in a vacuum induction furnace, arc, plasma arc or electrical resistance furnace. If melting takes place in an induction or arc furnace then a mixture of slag and ilmenite with a source of carbon (with or without rutile additives) is being loaded first and melting is carried on at the temperature of 1000C-2500C for 5-180 min depending on the mixture composition. If melting takes place in a plasma arc furnace or a resistance furnace then rutile or its mixture with other titanium or titanium slag can be used as raw material. As a result of the first stage titanium carbide (TIC), its derivatives and free carbon are produced. The second stage involves addition of iron oxide and/or ilmenite, rutile (and also other possible titanium minerals as the source of titanium oxide) and /or metallic iron and smelting at the 4 highest possible temperature. Ready made titanium carbide which is commercially available can 00 be used as raw material at the second stage. At the second stage the added oxides are being reduced by the carbon produced at the first stage. The third stage, which is not always used, involves addition of silicon, calcium or their alloys (silicocalcium, ferrosilicon, ferroaluminium etc.) to decrease contents of oxygen in the melt. C, The described method allows to produce ferrotitanium with carbon contents of 0,1% 2% and with different contents of titanium (Ti iron, oxygen, aluminium and silicon.

00

The method is illustrated by example. 000Aluminothermic reduction is being carried out in vacuum furnace with nickel-chromium heater. The basic elements of the unit are water-cooled body, lid, resistance electric furnace and crucible. The body of the furnace is connected to the lid through a vacuum rubber sealing. After crushing of rutile and aluminum the other components are added to the mixture in accordance with stated ratios. The charge is being mixed in a mixer in inert atmosphere until mass of even composition is produced. The prepared charge is poured into the crucible in portions and compressed. The crucible is placed into furnace. Before heating the unit is vacuumed until pressure of 0.03 atmosphere is achieved and filled with argon or other inert gas. Then heating is started. When desired maximum temperature is achieved it is held to heat the whole volume of the charge depending on the composition of the charge. Reduction process is initiated by top ignition of the charge by using thermal mixture based on aluminum powder. Then heating is stopped. After the reduction reaction and cooling of the crucible the mass is taken out and it consists of metal and slag parts that are clearly divided.

A closed furnace with crucible diameter of 0.2 meter was used for reduction process. Aluminum power was used as reducing agent (fraction 0-5mm). Rutile and ilmenite powder were used as titanium containing components. The ratio of the charge components was as follows: (TiO2+FeO2):CaO:AI=1:0,4:0,5 and (TiO2: FeO2)=3:1 The calculated composition of the charge: 3000 grams ilmenite concentrate 3000 grams- rutile 2400 grams- oxide of calcium 2800 grams- aluminum powder 0The charge was prepared by the method described above. Maximum temperature for heating the charge was 800C0 and that temperature was held for 30 minutes after which time the charge was ignited by thermal mixture based on aluminum powder. The mass of produced ferrotitanium CO ingot was 2900 gm, slag mass was 8100 gm and waste 200 gm. C Chemical composition of the alloy is presented in Table 1. Ferrotitanium yield equals 84%.

00 U- Table 1.

Chemical composition of ferrotitanium Fe Ti Al Ca Si S C 02 24 68,7 5,7 0,007 0,05 0,004 0,01

The invented method allows to achieve the following results:

1. Decrease energy consumption 2. No need to use metallic titanium 3. Higher extraction of titanium into final product

Besides high degree of extraction of metal, reliable technology that allows to automate the process and feasibility of industrial use of the tested equipment create positive perspective for wide industrial application of the method. Claims 00 o Claim 1

A new process of ferrotitanium production with various titanium contents has been offered. The method consists of preliminary heating of the charge consisting of titanium oxides, iron oxides, V) silicon, carbon and metallic aluminum to the temperature of 800'C -10000C in inert atmosphere. Vfl The charge components are being mixed until the ratio of oxides of iron mass to titanium mass N equals 1: oxide of calcium equals 0,2-0,5 of the total mass of oxides of titanium and iron and aluminum Carbon contents in the charge equals 0-10% of the mass of the o metallic aluminum in the charge. Silicon contents in the charge equals 0-5 of the mass of the 00 metallic aluminum in the charge The process consists of reduction of oxides by metallic aluminum at the temperature of 800-IOOC by setting fire to the charge by ignition mixture. N Heating of the charge stops before setting it on fire. (N o0 Claim 2 Same process as in Claim 1 but the charge continues to be heated afler being set on fire.

Claim 3

Same process as in Claim 1 and Claim 2 but with addition of barium peroxide (BaO2) into the charge at 5 o0of the total mass of calcium oxide. Barium peroxide can be replaced by sodium chlorate (NaCIO3) or potassium chlorate (KCIO3) (at 5-15% of the total mass of oxide of calcium in the charge).

Claim 4

Same process as in Claim 1 and Claim 2 but with preliminary grinding of the charge in a mill.

Claim

Same process as in Claim 1 and Claim 2 but between 10-100% of aluminum is substituted by silicon or (and) metallic calcium.

Claim 6 Same process as in Claim 1 and Claim 2 but with no addition of carbon, and silicon.

Claim 7 A three stage process of ferrotitanium production by carbothermal reduction of titanium minerals was offered.

First stage Minerals containing titanium (or any material containing oxides of titanium such as titanium slag, artificial rutile) are mixed with aluminium, silicon and carbon reductant at different ratios to produce titanium carbide, its derivatives and residual carbon. Also ready made titanium carbide can be used. Second stage Addition of titanium oxides and/or iron oxides to the material produced at the first stage.

Third stage Addition of silicon, aluminium, calcium (each separately or a combination) or their alloys (each separately or a combination) to the material produced at the second stage. 00 Claim 8 O Same process as in Claim 7 but the process starts from the second stage using titanium carbide.

Claim 9 SSame process as in Claim 7 but with addition of metallic iron at the third stage.

SClaim C, Same process as in Claim 7 but with addition of metallic iron and titanium oxides at the third stage.

00 Claim 11 Same process as in Claim 7 but with addition of metallic iron, titanium oxides and iron oxides at N, the third stage. (N 00 0Claim 12 Same process as Claim 7 but with no addition of aluminium at the first stage.

Claim 13 Same process as in Claim 7 but with no addition of silicon at the first stage.

Claim 14 Same process as in Claim 7 but with no addition of aluminium and silicon at the first stage.