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 of 66 to 94% by mass; 1. 2 one or a plurality of calcium carbonate-based raw materials with a fraction of 5 to 30% by mass; and 1. 3 iron powder with a fraction 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 magnesia-based 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 magnesia-based 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 the magnesia-based 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 8, 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. 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 of 66 to 94% by mass; 1. 2 one or a plurality of calcium carbonate-based raw materials with a fraction of 5 to 30% by mass; and 1. 3 iron powder with a fraction of 1 to 6% by mass.

12. The method of claim 11, wherein a batch of the unformed refractory ceramic product is prepared using at least one plasticizer.

13. 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 of 66 to 94% by mass; 1. 2 one or a plurality of calcium carbonate-based raw materials with a fraction of 5 to 30% by mass; and 1. 3 iron powder with a fraction of 1 to 6% by mass.

Description

(1) The invention is explained in greater detail with the help of the following exemplary embodiments.

(2) 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.

(3) 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.

(4) 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

(5) 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.

(6) 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

(7) 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.

(8) 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.

(9) 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.

(10) Further features of the invention emerge from the claims.

(11) All of the features described in relation to the invention may be randomly combined with one another, individually or in combination.