Translation of "Schlackenbildung" in English

The oxygen is charged with ground lime (CaO) for the formation of slag.

Dolime offers swift slag formation and protects the refractory.

These limits lead in each case to reduced formation of slag.

These limits also lead to reduced slag formation.

The basic considerations pointed out above with respect to the formation of slag also hold for the production of ferroalloys.

This requires an especially strong combustion process at the end of the grate, with the corresponding formation of coke and slag.

With larger diameters however the risk of non-metallic inclusions, slag formation, rolling flaws and forging flaws increases.

As additives for forming the flux, mostly mineral products (lime, dolomite) are used.

A reduction in accumulated slag appears to be possible in principle by providing a suction device below the stripper nozzle.

The reaction must be carried out within a narrow temperature range; at temperatures which are too low, the reaction is incomplete and at temperatures which are too high, the formation of slag and encrustations impedes continuous operation.

The amount of CaO for slag formation is adjusted in such a fashion that a slag basicity (CaO/SiO2) of about 2 is obtained from the lime and SiO2 content of the coal ash and the dross of the ore.

The pre-heated furnace burden falling into the melting receptacle consists of lime stone for slag formation, of non-gasified coal particles for carburizing purposes, of fly ash particles obtained by filtering and of the charge pre-reduced to a large extent, for example iron sponge.

The carrier gas can be an inert gas such as, for example, nitrogen or argon, and together with such carrier gases it is also possible to inject slagging agents in order to improve the slag formation and to increase the iron yield.

The process according to the invention enables the disposal of the noxious substances contained in the offgases at a simultaneously optimum thermal utilization of the same in combination with a plant component, i.e., a lime kiln, which is available at every steelworks anyway, since burnt lime is employed in metallurgical aggregates for the formation of slag.

The thus burnt lime, in principial, may be used with all metallurgical aggregates (e.g., in E-furnaces, KVA scrap smelting reactors, LD crucibles, EOF, etc.) for slag formation.

Furthermore, the described cooling of the grate bars by blowing air against the bottom of the bar grates effectively delays the formation of slag and thus clogging of the bar grates.

The resulting weld metal must have a good bead formation, low amounts of slag formed over the weld bead, and other physical characteristics, which decrease the amount of labor needed to clean the resulting welded joint after the welding process.

The resulting weld metal must have a good bead formation, low amounts of slag formed over the weld bead, and other physical characteristics, which decrease the amount of labor needed to clean the resulting welded joint after the welding process.

As a result, there will be only small temperature differences in the gas stream so that the formation of slag from ash and dust and the thermally inducted formation of NOx will be greatly decreased.

For the slag formation, the oxygen is charged with lime dust (CaO) in an amount of approximately 12 tons/h.

With the analogous performance of the process as in the first example, the following values of materials used and gas compositions have been obtained for the production of 1 ton of raw steel: 640 kg coal (including for the gas reduction) of the mentioned composition, 130 Nm3 oxygen, 1250 Nm3 hot wind with 1200° C. preheating temperature, 155 kg lime for the slag formation, 1560 kg ore which, after a partial reduction with a degree of metallization of 75%, is directly supplied to the melting crucible from the ore reduction vessel with a temperature of approximately 800° C.

It is also known for a molten metal to be subjected to the action for example of fine-grain carbon, for example for caburisation purposes or for supplying energy or for promoting the formation of a slag above the molten metal.

Now it was surprisingly found that blowing oxygen-free gases below the bath surface, where said gases are loaded part of the time with ground solids for the purpose of slag formation, and together with which pulverized fuels containing carbon, for instance coke, are also being introduced, represent adequate converter steelmaking steps with good results, such as are known from the oxygen blow-through process.

In addition, the region of the solid-liquid transition is the site of chemical-metallurgical conversion phenomena such as the formation of slag, carburisation, etc, which can be promoted by the controlled feed of oxygen, coal or additive materials.

This type of removal of the slag formation is not very effective, since only a few surface cracks are produced by the quenching effect, for which reason this operation has to be repeated frequently until flaking of the slag can be achieved.

The material to be sintered, which is also referred to as sinter material, is solidified in the sintering plant by sintering, i.e. by heating to a point close to the melting point with surface softening and partial melt and slag formation.

For the batchwise charging of casting machines, melt has so far been discharged from a melting furnace by means of gas pressure conveyance (EP-A 0,252,318) or by means of piston pumps or spiral pumps (DE-B 1,134,183) via pump components extending beyond the cover of the melting furnace, so that long conveying distances along with the difficulties of an undesired premature slag formation and solidification have to be accepted and expensive holding and conveying means are required.