WO2008068350A1

WO2008068350A1 - Molded body containing titanium

Info

Publication number: WO2008068350A1
Application number: PCT/EP2007/063635
Authority: WO
Inventors: Djamschid Amirzadeh-Asl; Dieter FÜNDERS
Original assignee: Sachtleben Chemie Gmbh
Priority date: 2006-12-08
Filing date: 2007-12-10
Publication date: 2008-06-12
Also published as: TW200844389A; KR20090110832A; AR064219A1; US20130305882A1; CA2671706A1; BRPI0720000A2; US20100031772A1; EP2099947A1

Abstract

The subject matter of the invention is a molded body containing titanium, a method for the production thereof, and the use thereof.

Description

Titanium-containing moldings

The invention relates to a titanium-containing molded body, a process for its preparation and its use.

In particular, the invention relates to a titanium-containing molded body, for example in the form of a briquette, pellets or crushed stone, a process for producing the shaped body and its use in metallurgical processes, in particular for introduction into melting vessels or vessels of primary, secondary and tertiary metallurgy.

The invention also describes a method for increasing the durability of the refractory linings, for reducing the nitrogen oxides and the sulfur content, in particular in the iron analysis and in the exhaust gas, and for reducing the harmful recycling substances in the furnace or shaft furnace, in particular cupola, by using synthetic and / or natural titanium supports.

Furthermore, a method is described to use titanium-containing moldings as slag formers, slag protection agents and alloying agents.

Due to the increasing requirements of environmental protection in the smelting of metals, the manufacturer must resort to increasingly costly methods for the reduction of polluting substances. This increases the manufacturing costs and thus burdens the economic efficiency of a process. Numerous companies have therefore developed methods to solve this complicated task as economically as possible. Among other things, the smelting of metals for the reduction of polluting substances is being exploited by existing processes such as the gassing of waste. The gassing of waste is based on the application of metallurgical process techniques. This will have the following benefits: a) High temperatures ensure that mineral and metallic waste components are converted into a molten phase and organic and inorganic pollutants are destroyed. The resulting products are - unless they escape gas or vapor - bound in the liquid slag and / or liquid metal is not elutable. Act

Slag and metals as process-integrated pollutants.

b) The reducing atmosphere ensures that metal oxides are reduced. This is a prerequisite for the formation of liquid metal alloys.

c) An above-average material use of waste is caused by unusually low residual waste (dusts, sludges, salts from the

Crude gas cleaning) guaranteed. In addition, the production of a liquid slag that can be dry or wet granulated produces a recognized and globally used building material. Such as the production or production of a metal alloy, which can be sold in scrap metal trading or directly in metallurgical plants or foundries.

In secondary metallurgy, ferrotitanium, ferrocarbotitanium and titanium aluminum from aluminothermic production are also used as alloying agents. These alloying agents, especially the ferrotitanium, are very expensive. An analysis of the ferrotitanium shows that it is mainly composed of 20 to 75% by weight or more of Ti, from 2 to 10% by weight or more of Al + Al ₂ O ₃ , from 0.2 to 8% by weight or more Si and from 20 to 65 wt .-% or more Fe. A ferrocarbotitanium may, for example, have the following composition of the main constituents: Ti: 30 to 40%; C: 5 to 8%; Si: 3 to 4%; AI: 1 to 2%; Mn: 0.5%. Titanium-aluminum may have, for example, the following composition of the main components: Ti: 5 to 10% and 50 to 63%, respectively; AI: rest.

Substitution of these alloying agents by cheaper materials would significantly improve the economics of steelmaking. The main reason for the use of titanium in modern steels or cast iron is the stabilization of austenitic chromium / nickel / steel against cracking and for refining graphite inclusions in cast iron.

Due to the often very long-lasting processes in secondary metallurgy (up to more than 2 hours), the slag zones of the pans or vessels are heavily stressed by slag thermodynamics or kinetics

Early shutdowns and costly repairs of pans are required.

The cupola is a shaft furnace in which metals can be melted. As a rule, the cupola furnace is used for the production of metals. Here, the shaft furnace is charged from the top with coke as an energy source, the feedstock and the additives. The starting materials are solid pig iron, recycling materials, laminated cores and selected metal scrap, depending on the production target. To adjust the Si content in the iron analysis and to form favorable flow properties of the slag moldings of silicon carbide, gravel and limestone are used as additives. To remove the metal, the oven must be slightly pierced above its bottom. The tapping is followed by a siphon, which has two outlets. In this case, the liquid slag is discharged through the upper in a collecting container. By the other, the iron is forced through the slag and can be passed, for example, in a Vorhalteofen. The function of the siphon is only possible due to a slight overpressure in the shaft furnace.

Often, however, melting or shaft furnaces reach their limits, so that there is still the compulsion to develop new, special technologies enriched with the use of metallurgical waste.

In all previously known methods for the treatment of waste materials but the burden of metallurgical cycle substances, such as zinc, sodium, potassium, lead, copper, vanadium, etc., remain. The more waste to be disposed of, ever greater is the content of these unwanted substances. This leads in particular to the fact that the durability of the refractory linings and aggregates is significantly reduced.

Thus, for example, in a shaft furnace, which operates according to the Oxi Cup method, finished compacts are used whose composition consists of various waste materials, such as iron-containing dusts, reducing agents, slag formers and binders. The purpose of this technology is to allow the smelting process, which normally takes place in the blast furnace process, to take place in the individual pressed moldings themselves. Thus, dust-like iron oxide, which occur repeatedly in all smelting processes, be better processed. Without these technologies, the proportion of dusts to be reused would be relatively low, so that another environmentally harmful disposal would be necessary.

All previously used compacts contain the above-mentioned harmful metallic recycling substances. In the thermal treatment of such waste also creates an exhaust gas, which still contains NO _x (nitrogen oxides) and SO ₂ (sulfur dioxide). The harmful circulating substances to be highlighted in particular in the Oxi Cup process are zinc, lead, sodium and potassium.

Due to its low melting point and vapor point, zinc has the negative property that it accumulates in the gout dust and is recycled again and again during the recycling process. Those zinc particles that come into contact with the refractory lining reduce their durability. So far, there is no fundamental way to neutralize the negative effects of zinc, except to remove zinc from the siphon.

Lead, due to its high specific gravity, acts on the bottom of a shaft furnace, penetrates into the porosities of the lining and destroys it there. Alkalis such as sodium and potassium hinder the desulfurization of the pig iron due to the need for an acidic slag for the discharge from the furnace, which in turn requires as basic as possible slag. The contrary requirements hinder the blast furnace process very much. Furthermore, alkalis act as fluxes for any refractory lining, which in turn has a negative impact on economy.

The elements copper, chromium, nickel and vanadium dissolve almost completely in molten pig iron so that they can not be removed in the downstream steelmaking process. Again, the proviso is to reduce the contents as far as possible in advance as possible.

Coke is used as an energy source in all shaft furnaces. In this case, coke contains as an impurity, among other unwanted sulfur. As a result of the combustion of the coke, the liquid iron assumes a sulfur content which interferes with further processing. The iron must therefore be desulfurized very costly and expensive in special systems of primary and / or secondary metallurgy.

The object of the invention is to overcome the disadvantages of the prior art and in particular by using synthetic and / or natural titanium support to reduce the contents of the above-described negative circulating or accompanying substances, optionally the content of nitrogen and sulfur in the iron Reduce formation of NO _x , thereby improving the quality of the exhaust gas and thus to protect the environment.

A further object of the invention is, if appropriate, at the same time to increase the durability of refractory linings and aggregates.

A further object of the invention is to provide titanium-containing shaped bodies as alloying agents in primary, secondary and tertiary metallurgy. Surprisingly, these objects have been solved by the features of the main claim.

According to the invention, the titanium-containing shaped bodies contain synthetic and / or natural titanium supports. Under titanium substrate are understood to mean substances containing the element titanium, for example as an element, as a compound and / or as part of a salt. The synthetic and / or natural titanium carriers are mixed homogeneously with the other substances, if appropriate with the addition of a binder, and then by way of a shaping process, for example, into agglomerate stones,

Processed briquettes, pellets or briquettes. If necessary, the titanium-containing shaped bodies are then subjected to a temperature treatment. The

Treatment temperature is up to 1500 ⁰ C, preferably at 80 ⁰ C to 1400 ⁰ C.

According to the invention, it is also possible to use titanium-containing shaped bodies consisting mainly of titanium dioxide or its compounds.

The titanium-containing shaped body according to the invention contains 0.5 to 100, preferably 1 to 90, particularly preferably 1 to 80, very particularly preferably 3 to 70, particularly preferably 4 to 65, preferably 4 to 50, in particular preferably 5 to 30 wt .-% TiO ₂ (calculated from the total titer content). According to the invention, this shaped article is particularly suitable for use in melting and shaft furnaces in the field of primary, secondary and tertiary metallurgy.

Synthetic raw materials from the chemical industry are pelletized by means of various chemical binders, or converted into chargeable titanium carriers in sintering processes and charged to the liquid media such as metals or slags in the respective processes of the secondary metallurgy.

In cases in which the user's system has an adequate blowing-in system, the synthetic titanium supports can also be injected as an alloying agent. The respective quantities are adjusted according to the requirements and the classification.

The synthetic titanium carriers dissolve in the liquid metals or slags and increase the respective titanium content as required.

According to the invention are synthetic titanium support at levels of 10 to 100 wt .-%, from 25 to 35 wt .-%, from 45 to 65 wt .-%, from 70 to 90 wt .-% and also of 100 wt .-%, calculated as TiO ₂ , available.

In cases in which the oxygen content of the TiO _{2 is} disadvantageous (eg outside of vacuum systems), synthetic titanium supports based on titanium carbonitride, titanium nitrides or titanium carbides can also be used. Flexibility is available as needed.

For the charging of the melting or shaft furnaces, it is advantageous if the raw materials are in the form of shaped bodies. For example, silicon carbide in the form of briquettes is used to feed the cupola. According to the prior art, such shaped bodies are also produced on the basis of feedstocks which are to be disposed of industrially. As industrial feedstocks, for example, coal and coal sludge, residues containing silicon carbide, gout and steel mill dusts and sludges, and other materials may be used.

The gout and steel mill dust and sludge are very ferrous, but they can only be economically extracted pig iron, if they are agglomerated

Solid can be filled in the shaft furnace. For this purpose, methods have been developed with which the so-called agglomerated stones are produced from the dusts with the aid of binders. Before the molding process, the respective starting materials to be disposed of and smelted are mixed with slag formers, binders and carbon-based reducing agents. Titanium-containing materials selected from natural titanium ores, titanium dioxide-rich slags and synthetic titanium-containing materials or mixtures of at least two of these materials are used for the production of the titanium-containing shaped bodies according to the invention.

The synthetic titanium dioxide-containing materials are selected according to the invention from the materials listed below or mixtures thereof:

Intermediate, domed and / or finished products from the production of titanium dioxide. The materials may originate from the production of titanium dioxide after the sulphate process as well as from the production of titanium dioxide by the chloride process. The intermediate and co-products can be extracted from the running TiO ₂ -

Production deducted.

Residues from the production of titanium dioxide. The materials can originate both from the production of titanium dioxide after the sulfate (digestion residues) and from the production of titanium dioxide by the chloride process; If necessary, the materials are pretreated prior to use as an aggregate, for example by neutralization, washing, and / or predrying.

Residues from the chemical industry, for example from TiO ₂ -containing catalysts, again for example from DEN OX catalysts.

- Residues from the production of sulfuric acid, the so-called burn-off, which occur during the splitting of the filter salt (iron sulphate) and titanium dioxide in addition to iron oxide.

The titanium-containing shaped bodies according to the invention are produced by mixing and / or adding the natural titanium ores, for example ilmenite sand and / or Sorell slag, titania-rich slags and / or synthetic titanium dioxide-containing materials. To these titanium-containing materials may optionally be added other materials, such as feedstock and / or reducing agents, for example based on coal, such as silicon carbide-containing residues, coal and coal sludge, gassy and steel mill dusts and sludges, and other materials.

To produce the titanium-containing shaped bodies according to the invention, one or more of the abovementioned fine-grained titanium-containing materials are added to the mixtures of the fine-grained starting materials by molding, briquetting or pelleting before molding. The mixture thus obtained is compressed by means of binders to form the shaped bodies according to the invention. If necessary, the titanium-containing shaped bodies are then subjected to a temperature treatment. The treatment temperature is up to 1500 ° C, preferably at 80 ⁰ C to 1400 ⁰ C.

The titanium ores and titanium dioxide-rich slags used for producing the titanium-containing shaped bodies according to the invention contain from 15 to 95, preferably from 25 to 90,% by weight of TiO ₂ (calculated from the total titanium content). The titanium ores can be used untreated or after separation of impurities and gait for the production of the aggregate.

The synthetic titanium-containing materials used for producing the titanium-containing moldings according to the invention contain from 5 to 100, preferably from 10 to 100, particularly preferably from 20 to 100,% by weight of TiO ₂ (calculated from the total titanium content).

The invention furthermore relates to:

The use of the titanium-containing shaped bodies according to the invention for increasing the durability of refractory systems,

The use of the inventive titanium-containing moldings for

Reduction of nitrogen oxides and sulfur as well The use of the titanium-containing shaped bodies according to the invention for reducing unwanted accompanying substances in the metallurgical process, for example in the melting furnace or shaft furnace in the field of primary metallurgy.

The use of the titanium-containing shaped bodies according to the invention as slag-protecting agents and alloying agents.

The present invention will be:

A titanium-containing shaped body for use in metallurgical processes, in particular for use in melting vessels or vessels of primary, secondary and tertiary metallurgy, provided;

«A titanium-containing molding for addition in shaft furnaces to increase the

Durability of Ofenausmauerungen provided;

A titanium-containing shaped body is provided for addition in shaft furnaces for reducing the circulation substances;

• a titanium-containing shaped body for addition to shaft furnaces for reducing nitrogen, sulfur and / or nitrogen reduction;

A titanium-containing shaped body for addition to shaft furnaces and in primary or secondary metallurgy vessels for increasing the durability of the respective refractory linings;

A titanium-containing shaped body is provided as alloying agent in primary, secondary and tertiary metallurgy. When these titanium-containing shaped bodies according to the invention are introduced into shaft furnaces, these shaped bodies are heated during the metallurgical smelting process. The reducing agents present in the moldings reduce the oxidic components of the shaft furnace. This applies to both the iron oxides and the titanium compounds that were previously mixed into the stone. The present in the moldings reducing agents in the presence of natural titan ores such as ilmenite (in ilmenite is titanium as iron titanate ago) reduced in the first step to reactive TiO ₂ , then the final reduction of TiO ₂ particles obtained to CO and metallic titanium.

This reaction occurs immediately in the case of the synthetic titanium carriers, since titanium predominantly exists as titanium dioxide. The thus reduced to metallic titanium elements react in the last step to extremely high-refractory titanium carbides, titanium nitrides and / or titanium carbonitrides. Furthermore, high refractory compounds are formed with aluminum, magnesium, calcium, for example aluminum titanate, magnesium titanate and calcium titanate. In addition, metal oxide spinels which contain titanium also form. Subsequently, the moldings react in the course of the smelting process and dissolve to form a fine iron slag mixture. The titanium carbides, titanium nitrides, titanium carbonitrides or metal titanates and spinels emulsified therein are deposited wherever the respective liquids come into contact with the refractory lining. The deposition of these ultrafine particles on the surfaces to be protected forms very refractory and relatively dense layers of titanium carbonitrides, metal titanates and spinels. These deposited layers can both repair defective areas and protect healthy areas against the penetration of liquids such as iron or slag, significantly increasing their durability. The protective effect also extends in particular in the interior of a shaft furnace, for example within the tapping channels or siphon constructions.

When using the titanium-containing molded body according to the invention as

Slag protection can be achieved by the addition of the titanium supports, preferably by the addition of synthetic titanium supports, to the various secondary / and Tertiary slag of the iron and steel industry the leading wear in the slag zone of the steel pans can be significantly reduced or completely prevented.

This process is made possible by the fact that the liquid system by blowing or by Zuchargieren coarse-grained containers of synthetic titanium carriers with the present in the slags compounds of barium and / or calcium and / or aluminum and / or magnesium form various highly refractory titanates.

As the slag and metals are in strong agitation due to the metallurgical rinsing process, the titanate-containing slags are permanently in contact with the zone of leading wear in the slag area of the pans. At the respective contact surfaces then deposit the highly refractory barium-calcium magnesium and / or aluminum titanates and reduce or prevent the wear of this critical zone of a steel pan.

The advantage of this variant of the protective function of the various titanium supports is that even with oxidizing systems, the fire resistance of the refractory linings of melting vessels to be protected is increased by the respective titanates or titanium compounds.

The unwanted accompanying substances, for example zinc, lead, sodium, potassium, etc., are bound by the use of titanium-containing carriers as metal titanates and can thus be removed from the shaft furnace as part of the slag.

Due to the catalytic activity of titanium dioxide and the tendency of titanium to form titanium carbonitrides with nitrogen, on the one hand the resulting nitrogen oxides are catalytically reduced to nitrogen and on the other hand the formation of high temperature resistant titanium nitride, titanium carbonitride and / or titanium oxynitride favors. This has the advantage that the harmful nitrogen oxides are removed from the exhaust gas. In addition, the sulfur present in the iron with titanium forms various titanium sulfides, which are then removed as part of the slag from the shaft furnace.

The natural titanium supports are preferably ilmenite and / or sorell slag and / or rutile sand. Titanium compounds, in particular titanium dioxide, are used as synthetic titania-containing carriers. In addition, it is possible according to the invention to use residues from titanium dioxide production, both after the sulphate and after the chloride process. According to the invention it is also possible to use titanium dioxide-containing waste materials such as catalysts from DENOX plants and from the chemical industry.

Claims

Patentanspriiche

1. Titanhaitiger shaped body, characterized in that it contains synthetic and / or natural titanium carrier.

2. Titanhaitiger moldings according to claim 1, characterized in that it contains as titanium carrier, the element titanium, titanium compounds and / or titanium as a constituent of a salt.

3. Titanhaitiger moldings according to claim 1 or 2, characterized in that it contains titanium dioxide as titanium carrier or its compound.

4. Titanhaitiger moldings according to one or more of claims 1 to 3, characterized in that it contains as titanium support natural titanium support, preferably ilmenite, sorsel slag and / or rutile sand.

5. Titanhaitiger moldings according to one or more of claims 1 to 3, characterized in that it contains as titanium carrier synthetic titanium carrier.

6. Titanhaitiger molding, according to one or more of claims 1 to 5, characterized in that it is synthetic and / or natural titanium support with a TiO ₂ content (calculated from total Ti content) of 50 to 100 wt .-%, preferably from Contains 60 to 95 wt .-%.

7. Titanhaitiger moldings according to one or more of claims 1 to 6, characterized in that the natural titanium support preferably has a titanium dioxide content (calculated from total titanium content) of 15 to 95 wt .-% and particularly preferably 25 to 90 Gew, contains%.

8. Titanhaitiger molding according to one or more of claims 1 to 7, characterized in that it contains synthetic titanium support based on titanium carbonitride, titanium nitrides and / or titanium carbides.

9. Titanhaitiger molding according to one or more of claims 1 to 8, characterized in that it 0.5 to 100 wt .-%, preferably 1 to 90 wt .-%, particularly preferably 1 to 80 wt .-% of the titanium support ( calculated from the total titer content).

10. Titanhaitiger molding according to one or more of claims 1 to 9, characterized in that it 3 to 70 wt .-%, preferably 4 to 65 wt .-%, particularly preferably 4 to 50, in particular 5 to 30 wt .-% of the titanium support (calculated from the total titanium content).

11. Titanhaitiger molding according to one or more of claims 1 to 10, characterized in that it 45 to 55%, 80 to 90% or 100% of

Titanium carrier (calculated from the total titanium content) contains.

12. Titanhaitiger molding according to one or more of claims 1 to 11, characterized in that it comprises synthetic titanium support with titanium dioxide contents of 10 to 100 wt .-%, from 25 to 35 wt .-%, from 45 to 65 wt - %, from 70 to 90% by weight and also from 100% by weight (calculated from the total titanium content).

13. Titanhaitiger molding according to one or more of claims 1 to 12, characterized in that it is in the form of agglomerated bricks, briquettes, pellets or briquettes.

14. A method for producing a titanium-containing shaped body according to one or more of claims 1 to 13, characterized in that titanium-containing materials selected from natural titanium ores, titania-rich slags and synthetic titanium-containing materials or mixtures of at least two of these materials, with the aid of binders and optionally other feedstocks, for example slag formers, residues containing silicon carbide,

Gout and steelwork dusts and sludges and other substances and / or Reducing agents, for example based on coal, such as coal and coal sludge, are pressed into shaped bodies.

15. A process for producing a titanium-containing shaped body according to claim 14, characterized in that the titanium-containing shaped bodies are then subjected to a temperature treatment up to 1500 ° C.

16. A process for producing a titanium-containing shaped body according to claim 14 or 15, characterized in that the titanium ores and titania-rich slags used for the production of titanium-containing moldings 15 to 95 wt .-%, preferably 25 to 90 wt .-% TiO ₂ (calculated from the total titer content).

17. A process for producing a titanium-containing shaped body according to one or more of claims 14 to 16, characterized in that the synthetic titanium-containing materials used to prepare the titanium-containing moldings 5 to 100 wt .-%, preferably 10 to 100 wt .-% particularly preferred 20 to 100 wt .-% TiO ₂ (calculated from the total titanium content).

18. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 for increasing the durability of refractory systems.

19. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 for reducing the circulation substances.

20. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 for the reduction of nitrogen oxides and sulfur.

21. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 for the reduction of unwanted impurities in the metallurgical process, for example in the melting or shaft furnace in the field of primary metallurgy.

22. Use of a titanium-containing shaped article according to one or more of claims 1 to 13 as slag protection agent and alloying agent.

23. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 in metallurgical processes, in particular in vessels of primary, secondary and tertiary metallurgy.

24. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 in melting and / or shaft furnaces in the field of primary, secondary and tertiary metallurgy.

25. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 in melting and / or shaft furnaces to increase the

Durability of the furnace linings.

26. Use of a titanium-containing shaped body according to one or more of claims 1 to 13 as an alloying agent in the field of primary, secondary and tertiary metallurgy.