REFRACTORY CERAMIC BATCH COMPOSITION, USE OF A BATCH COMPOSITION OF THIS TYPE, AND METALLURGICAL MELTING VESSEL

Abstract

The invention relates to a refractory ceramic batch for the production of an unformed refractory ceramic batch, the use of a batch of this kind for lining metallurgical melting vessels and also a metallurgical melting vessel which is lined with an unformed refractory ceramic product based on a batch of this kind.

Claims

1. A refractory ceramic batch for the production of an unformed refractory ceramic product which comprises the following raw materials: 1.1 one or a plurality of magnesia-based raw materials low in iron with a fraction in the region of 66 to 94% by mass; 1.2 one or a plurality of calcium carbonate-based raw materials with a fraction in the region of 5 to 30% by mass; and 1.3 iron powder with a fraction in the region of 1 to 6% by mass.

2. The batch according to claim 1, wherein the fraction of iron in the magnesia-based raw materials low in iron, calculated as Fe.sub.2O.sub.3 and relative to the total mass of the raw materials low in iron, is below 1.5% by mass.

3. The batch according to claim 1, wherein the fraction of calcium in the magnesia-based raw materials low in iron, calculated as CaO and relative to the total mass of the raw materials low in iron, is below 5% by mass.

4. The batch according to claim 1, wherein the fraction of magnesia in the magnesia-based raw materials low in iron, relative to the total mass of raw materials low in iron, is above 90% by mass.

5. The batch according to claim 1 with magnesia-based raw materials low in iron in the form of at least one of the following raw materials: fused magnesia or sintered magnesia.

6. The batch according to claim 5, wherein the magnesia-based raw materials low in iron have a grain size of maximum 10 mm.

7. The batch according to claim 1, wherein the fraction of calcium carbonate in the calcium carbonate-based materials, relative to the total mass of the calcium carbonate-based raw materials, is above 90% by mass.

8. The batch according to claim 1 with calcium carbonate-based raw materials in the form of at least one of the following raw materials: limestone or dolomite.

9. The batch according to claim 1, wherein the calcium carbonate-based raw materials have a grain size of maximum 8 mm.

10. The batch according to claim 1, wherein the iron powder has a grain size of maximum 0.3 mm.

11-13. (canceled)

14. A method comprising: lining metallurgical melting vessels with unformed refractory ceramic product, wherein the unformed refractory ceramic product comprises: 1.1 one or a plurality of magnesia-based raw materials low in iron with a fraction in the region of 66 to 94% by mass; 1.2 one or a plurality of calcium carbonate-based raw materials with a fraction in the region of 5 to 30% by mass; and 1.3 iron powder with a fraction in the region of 1 to 6% by mass.

15. The method of claim 14, wherein a batch of the unformed refractory ceramic product is prepared using at least one plasticizer.

16. A metallurgical melting vessel which is lined with an unformed refractory ceramic product, wherein the unformed refractory ceramic product is produced by a batch which comprises the following raw materials: 1.1 one or a plurality of magnesia-based raw materials low in iron with a fraction in the region of 66 to 94% by mass; 1.2 one or a plurality of calcium carbonate-based raw materials with a fraction in the region of 5 to 30% by mass; and 1.3 iron powder with a fraction in the region of 1 to 6% by mass.

Description

[0047] The invention is explained in greater detail with the help of the following exemplary embodiments.

[0048] The subject matter of the exemplary embodiments are batches based on sintered magnesia low in iron which were obtained from a magnesite low in iron and chalk.

[0049] The sintered magnesia used in the exemplary embodiments has the following composition according to Table 1, wherein the figures shown in the right-hand columns are each in % by mass relative to the fraction of the oxide in each case relative to the total mass of the sintered magnesia.

TABLE-US-00001 TABLE 1 Oxide Fraction MgO 94.4 Fe.sub.2O.sub.3 0.6 SiO.sub.2 2.2 Al.sub.2O.sub.3 0.1 CaO 2.7

[0050] In the following Table 2, three sample batches A, B and C are specified for batches according to the invention based on the sintered magnesia according to Table 1, wherein the figures in the batch columns are each in % by mass relative to the fraction of the respective components of the total mass of the respective batch.

TABLE-US-00002 TABLE 2 Raw material Grain size Batch A Batch B Batch C Sintered magnesia >5-8 mm 15 Sintered magnesia >3-5 mm 15 12 10 Sintered magnesia >1-3 mm 17 13 11 Sintered magnesia >0.3-1 mm 10 7 12 Sintered magnesia >0.1-0.3 mm 40 40 10 Sintered magnesia >0-0.1 mm 5 5 20 Chalk 1-5 mm 10 20 20 Iron powder >0-0.3 mm 3 3 2

[0051] The batches according to A and B are used as a hearth-repair mass (hot-repair mass) and the batch according to exemplary embodiment C as a hearth-construction mass (cold lining) for the lining of a metallurgical melting vessel.

[0052] For this purpose, the batches according to A and B were each additionally prepared with a plasticizer in a fraction of 0.5% by mass sunflower oil relative to the total mass of the respective batches without sunflower oil into a mass and the metallurgical melting vessel was then lined with the mass prepared in this manner.

[0053] The batch according to exemplary embodiment C was used directly as a mass without a plasticizer and the metallurgical melting vessel lined with the batch.

[0054] Further features of the invention emerge from the claims.

[0055] All of the features described in relation to the invention may be randomly combined with one another, individually or in combination.