Feedstock composites of carbonaceous materials with tailored density

Abstract

The invention relates to a feedstock composite comprising a metal oxide fraction and a carbonaceous fraction, to a binder composition and to the use thereof for obtaining a feedstock composite. The invention further relates to a method for obtaining a raw material composite.

Description

Technical Field

[0001] The invention relates to a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, a binder composition and the use thereof for obtaining the raw material composite. Furthermore, the invention relates to a method for obtaining the raw material composite. Background Art

[0002] The carbochlorination process is a process in which a metal oxide is converted to its corresponding metal chloride in the presence of chlorine and a carbonaceous material. The most common carbochlorination process involves the processing of feedstocks, such as ores and slags, containing oxides of refractory metals (among which are niobium, tantalum, tungsten, molybdenum and rhenium), or oxides of rare earth metals (such as cerium, neodymium, samarium), or oxides of light metals (such as aluminum, silicon, vanadium or titanium), or oxides of other metals (such as zirconium). Metal chlorides generally exhibit relatively low vapor pressures and can be removed from the original solid matrix by sublimation, or can be purified by fractional sublimation or distillation, taking advantage of their different boiling points, with or without the use of solvents. In addition, metal chlorides can also be purified by extraction or other separation methods.

[0003] Typically, metal chlorides are further processed into metals, metal alloys or purified oxides or hydroxides, all of which are economically attractive. One of the most important carbochlorination processes is the carbochlorination process for the production of titanium dioxide.

[0004] Titanium dioxide is produced by either the well-established sulfate process or the chloride process. The chloride process uses a titanium-containing raw material that has been subjected to a carbochlorination process. The chloride thus obtained is subsequently separated by re-evaporation or distillation. Titanium tetrachloride is ultimately converted into titanium dioxide and the chlorine released from the above reaction is separated and reused in the reaction with the titanium-containing raw material. Among other reasons, the reuse of chlorine makes the chloride process economically more attractive than the sulfate process.

[0005] The coke of choice in the process is petroleum coke with a specific particle size. Fine petroleum coke is discharged from the reactor due to its small particle size and low weight and is therefore not suitable for the carbochlorination reaction itself. The same applies to green and sustainable coke extracted from renewable raw materials such as coking coal and biochar due to its low particle density and low poured bulk density. Moreover, the demand for petroleum coke is increasing due to the attractiveness of the chlorination process compared to the sulfate process. The growing demand has led to an increase in the price of petroleum coke. Alternative cokes are less expensive but are not suitable for the carbochlorination process due to the above-mentioned facts.

[0006]

[0006] Therefore, there is a need in the art for a feedstock for a carbochlorination process, particularly for a titanium dioxide chlorination process, wherein the coke, other than petroleum coke, has specific physical properties that qualify the material. Summary of the invention

[0007] The present invention aims to use carbonaceous materials which are not suitable for use as feedstocks in carbochlorination processes because of their castable bulk density and particle density.

[0008] This object is achieved by a raw material composite, an adhesive composition, the use thereof and a method for obtaining the raw material composite.

[0009] The present invention provides a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, wherein the carbonaceous fraction has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density and 0.85 g / cm 3 Up to 1.15 g / cm 3 The carbonaceous material can be selected from a variety of cokes, which can be, for example, biochar or pyrolysis coke and peat from carbon chlorination reactions that are not suitable. Therefore, expensive petroleum coke with specific physical properties, especially at least 0.8 g / cm 3 Petroleum coke, with its cast bulk density, is not the only acceptable source of carbonaceous feedstock for carbochlorination reactions.

[0010] Therefore, in a first aspect, the present invention relates to a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, characterized in that the carbonaceous fraction has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density and 0.85 g / cm 3 Up to 1.15 g / cm 3 of particle density.

[0011] In a second aspect, the present invention relates to an adhesive composition comprising lignin sulfonate, carboxymethyl cellulose and water glass.

[0012] In another aspect, the present invention relates to the use of a binder composition as disclosed herein for obtaining a feedstock composite comprising a metal oxide fraction and a carbonaceous fraction.

[0013] In another aspect, the present invention relates to a method for obtaining a raw material composite disclosed herein, comprising the steps of: a) providing a raw material mixture of a titanium-containing material and a carbon-containing material, wherein the carbon-containing material has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm3 or lower casting bulk density, and b) agglomerating the raw material mixture to obtain a raw material composite.

[0014] Further advantageous embodiments of the invention are stated in the dependent claims. DETAILED DESCRIPTION

[0015] These and other aspects, features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description and study of the claims. Each feature of one aspect of the present invention may be used in any other aspect of the present invention. Numerical ranges stated in the format "from x to y" include the values ​​mentioned and values ​​known to those skilled in the art within the respective measurement accuracy. If several preferred numerical ranges are stated in this format, all ranges formed by combinations of the various endpoints are of course also included.

[0016] In a first aspect, the present invention relates to a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, wherein the carbonaceous fraction has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density and 0.85 g / cm 3 Up to 1.15 g / cm 3 The casting volume density of the carbon-containing fraction is preferably not less than 0.3 g / cm 3 or less, more preferably 0.2 g / cm 3 The raw material preferably has a carbon content of 0.7 g / cm 3 Up to 2.0 g / cm 3 , more preferably 0.9 g / cm 3 Up to 1.7 g / cm 3 and even more preferably 1.2 g / cm 3 Up to 1.5 g / cm 3 In a preferred embodiment, the raw material composite has a casting volume density of 0.7 g / cm 3 Up to 2.0 g / cm 3 , preferably 0.9 g / cm 3 Up to 1.7 g / cm 3 and more preferably 1.2 g / cm 3 Up to 1.5 g / cm 3 In yet another preferred embodiment, the raw material composite has the form of particles, and preferably the size of the particles is 0.1 mm to 6.0 mm, preferably 0.3 mm to 4.0 mm, and more preferably 0.5 mm to 3.0 mm, making the composite highly suitable for carbochlorination process.

[0017] As used herein, "cast bulk density" refers to the mass per unit volume of the composite raw material and the continuous fluid that fills the gaps between the composite raw materials, wherein the fluid is air and the individual components of the raw material materials must not dissolve in each other. The cast bulk density is determined using the procedure described in DIN53468. "Particle density" as used herein refers to the mass per unit volume of the solid. The cast bulk density is determined using the procedure described in ISO 12154.

[0018] The carbonaceous fraction is preferably selected from the group consisting of fine petroleum coke, recycled petroleum coke, biochar, coking coal, pyrolysis lignite, pyrolysis peat and pyrolysis coke. In addition, materials produced from organic recycled materials or secondary or tertiary raw materials for producing coke by, for example, pyrolysis and similar processes, hydrothermally produced coke (HTC) produced from sewage sludge, manure, wood, straw or other agricultural residues, and appropriate parts of municipal waste. "Fine petroleum coke" as used herein refers to a carbonaceous fraction having a carbon content of 0.5 g / cm 3 or lower, preferably 0.4 g / cm 3 or lower pouring bulk density of petroleum coke.

[0019] The metal oxide fraction may be any metal oxide used as a starting material for the carbochlorination process, including any metal of interest, for example, refractory metals (among which niobium, tantalum, tungsten, molybdenum and rhenium, rare earth metals such as cerium, neodymium, samarium or light metals such as aluminum, silicon, vanadium or titanium) or other metals such as zirconium. Preferably, ores and slags containing the above substances may be used. Preferably, the metal oxide fraction is a titanium-containing fraction, and the titanium-containing fraction is selected from the group consisting of natural rutile, synthetic rutile, titanium-containing slag, recycled titanium-containing slag, residue and ilmenite. The residue may originate from the steel industry.

[0020] In order to improve the adhesion of the fractions of the raw material composite, at least one adhesive can be used, which is selected from the group consisting of sodium chloride, sodium carbonate, bentonite, water glass, carbon black, soth, polyvinyl alcohol, plasticizer, lignin sulfonate, carboxymethyl cellulose, starch, starch ether, tar, bituminous coal, molasse, natural resin, asphalt, gelatin and tannin. Starch ether can be obtained from Agrana Beteilungs-AG in Vienna, Austria. Preferably, an adhesive composition comprising lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is used, preferably lignin sulfonate, carboxymethyl cellulose, water glass and bentonite The ratio is 1:2:2:2 to 1:3:4:4, which is advantageous in the carbon chlorination process. Preferably, the raw material composite also contains 1 wt.% to 20 wt.%, preferably 3 wt.% to 17.5 wt.% and more preferably 7.5 wt.% to 13 wt.% of at least one adhesive or adhesive composition relative to the total weight of the raw material composite.

[0021] In another aspect, the present invention relates to an adhesive composition comprising lignin sulfonate, carboxymethyl cellulose, water glass and bentonite. Preferably, the ratio of lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is 1:2:2:2 to 1:3:4:4.

[0022] In yet another aspect, the present invention relates to a binder composition as disclosed herein for obtaining a feedstock composite comprising a metal oxide fraction and a carbonaceous fraction, preferably for obtaining a feedstock composite as described herein. Even more preferably, the binder composition according to the present invention is used to obtain a feedstock composition for a titanium dioxide chlorination process.

[0023] In another aspect, the present invention relates to a method for obtaining a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, comprising the following steps: a) providing a raw material mixture of a metal oxide material and a carbonaceous material, wherein the carbonaceous material has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density, and b) agglomerating the feedstock mixture to obtain a feedstock composite.

[0024] Agglomeration in step b) can be achieved by compaction and / or extrusion and / or wet extrusion, preferably extrusion. In addition, pressure agglomeration, dry agglomeration, tumble growth agglomeration, heating or sintering can also be used.

[0025] Preferably, in a step after step a) and before step b), the raw material mixture is prepared by drying, wetting and / or pre-agglomeration. This step is performed to prepare the raw material mixture for step b). Equipment and techniques are known in the art, such as a pan granulator. The particle size of the raw material can also be adjusted by common reduction techniques.

[0026] The metal oxide fraction may be any metal oxide used as a starting material for the carbochlorination process, including any metal of interest, such as refractory metals (among which niobium, tantalum, tungsten, molybdenum and rhenium), rare earth metals (such as cerium, neodymium, samarium) or light metals (such as aluminum, silicon, vanadium or titanium) or other metals (such as zirconium). Preferably, ores and slags containing the above substances may be used. Preferably, the metal oxide fraction is a titanium-containing fraction, and the titanium-containing fraction is selected from the group consisting of natural rutile, synthetic rutile, titanium-containing slag, recycled titanium-containing slag, residue and ilmenite. The residue may be derived from the steel industry.

[0027] In order to improve the adhesion of the fractions of the raw material composite, at least one binder selected from the group consisting of sodium chloride, sodium carbonate, bentonite, water glass, carbon black, soth, polyvinyl alcohol, plasticizer, lignin sulfonate, carboxymethyl cellulose, starch, starch ether, tar, bituminous, molasse, natural resin, pitch, gelatin and tannin can be added in step a). Starch ether can be obtained from Agrana Beteilungs-AG in Vienna, Austria. Preferably, a binder composition comprising lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is used, preferably in a ratio of lignin sulfonate, carboxymethyl cellulose, water glass to bentonite of 1:2:2:2 to 1:3:4:4, which is advantageous in the carbon chlorination process. Preferably, the raw material composite also contains 1 wt.% to 20 wt.%, preferably 3 wt.% to 17.5 wt.%, and more preferably 7.5 wt.% to 13 wt.% of at least one binder or binder composition relative to the total weight of the raw material composite.

Claims

1. A raw material composite comprising a metal oxide fraction and a carbonaceous fraction, characterized in that: The carbon-containing fraction has a mass of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density, and The particle density is 0.85 g / cm 3 Up to 1.15 g / cm 3 .

2. The raw material composite according to claim 1, characterized in that The raw material composite has a thickness of 0.7 g / cm 3 Up to 2.0 g / cm 3 , preferably 0.9 g / cm 3 Up to 1.7 g / cm 3 and more preferably 1.2 g / cm 3 Up to 1.5 g / cm 3 The casting volume density.

3. The raw material composite according to claim 1 or 2, characterized in that: The carbon-containing fraction is selected from the group consisting of fine petroleum coke, recycled petroleum coke, biochar, coking coal, pyrolytic lignite, pyrolytic peat and pyrolytic coke.

4. The raw material composite according to any one of claims 1 to 3, characterized in that The composite has the form of particles, and preferably the size of the particles is 0.1 mm to 6.0 mm, preferably 0.3 mm to 4.0 mm, and more preferably 0.5 mm to 3.0 mm.

5. The raw material composite according to any one of claims 1 to 4, characterized in that The metal oxide fraction is a titanium-containing fraction, and the titanium-containing fraction is selected from the group consisting of natural rutile, synthetic rutile, titanium-containing slag, recycled titanium-containing slag, residue and ilmenite.

6. The raw material composite according to any one of claims 1 to 5, characterized in that The raw material composite further comprises at least one binder selected from the group consisting of sodium chloride, sodium carbonate, bentonite, water glass, carbon black, soth, polyvinyl alcohol, plasticizer, lignin sulfonate, carboxymethyl cellulose, starch, starch ether, tar, bituminous coal, molasse, natural resin, asphalt, gelatin and tannin.

7. The raw material composite according to claim 6, characterized in that The raw material composite further comprises a binder composition, which comprises lignin sulfonate, carboxymethyl cellulose, water glass and bentonite, preferably, the ratio of lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is 1:2:2:2 to 1:3:4:

4.

8. The raw material composite according to claim 6 or 7, characterized in that: The feedstock composite further comprises 1 to 20 wt.%, preferably 3 to 17.5 wt.% and more preferably 7.5 to 13 wt.% of at least one binder or binder combination, relative to the total weight of the feedstock composite.

9. An adhesive composition comprising lignin sulfonate, carboxymethyl cellulose, water glass and bentonite.

10. The adhesive composition according to claim 9, characterized in that The ratio of lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is 1:2:2:2 to 1:3:4:

4.

11. Use of the binder composition according to claim 9 or 10 for obtaining a raw material composite comprising a metal oxide fraction and a carbonaceous fraction.

12. Use of the adhesive composition according to claim 11 for obtaining a raw material composite according to claims 1 to 8.

13. Use of the binder composition according to claim 9 or 10 for obtaining a raw material composition for a titanium dioxide chlorination process.

14. A method for obtaining a raw material composite comprising a metal oxide fraction and a carbonaceous fraction, comprising the following steps: a) providing a raw material mixture of a metal oxide material and a carbonaceous material, wherein the carbonaceous material has a carbon content of 0.8 g / cm 3 or lower, preferably 0.7 g / cm 3 or less and more preferably 0.6 g / cm 3 or lower cast bulk density, and b) agglomerating the feedstock mixture to obtain the feedstock composite.

15. The method according to claim 14, characterized in that The metal oxide fraction is a titanium-containing fraction, and the titanium-containing fraction is selected from the group consisting of natural rutile, synthetic rutile, titanium-containing slag, recycled titanium-containing slag, residue and ilmenite.

16. The method according to claim 14 or 15, characterized in that In step a), at least one binder selected from the group consisting of sodium chloride, sodium carbonate, bentonite, water glass, carbon black, soth, polyvinyl alcohol, plasticizer, lignin sulfonate, carboxymethyl cellulose, starch, starch ether, tar, bituminous coal, molasse, natural resin, asphalt, gelatin and tannin is added to the raw material mixture.

17. The method according to claim 14, characterized in that In step a), or after step a) and before step b), a binder composition comprising lignin sulfonate, carboxymethyl cellulose, water glass and bentonite is added, preferably in a ratio of 1:2:2:2 to 1:3:4:

4.

18. The method according to any one of claims 13 to 15, characterized in that Agglomeration in step b) is achieved by compaction and / or extrusion and / or wet extrusion and / or pressure agglomeration and / or dry agglomeration and / or tumbling growth agglomeration and / or heating and / or sintering, preferably extrusion.

19. The method according to any one of claims 13 to 16, comprising the following steps after step a) and before step b): The raw material mixture is formulated by drying, wetting and / or pre-agglomeration.