Grinder mill: the best way to obtain a high quality scrap

Iron and steel industry looks for more and more metal products coming from the recovery of scrap. It considers that part of this collected matter must be of an optimal quality for better controlling the steel manufacturing process. A kind of scrap, called “cooling scrap” is often used in this process.
Grinder mills
How is this kind of scrap characterized?
How does DANIELI HENSCHEL grinder mill allows to obtain the “cooling scrap”?

For some time, we noted that more and more scrap merchants were looking for a compact shredding installation to be able to meet the needs of the iron and steel industry. These latter express a need in obtaining a specific kind of shredding scrap: the cooling scrap. These industrialists make use of this product to cool their molten steel baths. In the cast iron from the blast furnace, one inject oxygen into a converter (batch treatment used for steel producing) in order to burn the carbon contained in the cast iron. At this stage, steel is in a liquid state, its temperature strongly increases and largely exceeds its melting point (iron melting point: 1535°C). The cooling scrap is added at this time to stabilize the temperature of the liquid which can exceed 2500 even 3000°C.

Cooling scrap must have certain characteristics to satisfy the need of steelmakers:

– The material, of steel or iron, with an extremely high rate of purity (more than iron 98% of iron) not to pollute molten steel
– A raised density, more than 2 t/m3
– A regular geometrical form: pellets-shaped, with a diameter not exceeding 50 mm and a thickness lower than 2 mm. This particularly fine and homogeneous granulometry facilitates proportioning in the crucible and allows the scrap to melt quickly in the molten steel bath and thus to guarantee its homogeneity.

The cooling scrap is currently not referenced by the European standards. It is an E40 scrap of very top quality which has characteristics more difficult to obtain during the treatment phase of metal waste. Once recovered, it is indeed considered as a qualified new “secondary raw material” product because most waste and impurities have been withdrawn.

DANIELI HENSCHEL developed the grinder mill in order to enable its customers to obtain an output product of an incomparable quality, something impossible with all the other types of machines present on the market: shears, presses, and hammer mills. The treated product can reach a very fine granulometry with a density higher than 2 t/m3. Since the launching of this machine, we have counted about 50 references worldide.

In order to obtain a top quality “cooling scrap”, the grinder mill treats mainly new metal process scraps, from automotive industry for instance. It is also able to recover scrap coming from a hammer mill by a secondary shredding.

Video BMH_Grindermills

The grinder mills process is very efficient. The machine is fed from the top by a hopper. This routing is carried out by the means of a conveyor. Scrap runs down by gravity around the rotor. The grinding stars assembled on the latter come to hammer-harden the scrap against the side of the grinder mill.
The gap is reduced as scrap goes down into the mill. The smaller the gap is between these stars and its casing, the more refined is the granulometry. Today DANIELI HENSCHEL is able to offer two different versions of grinder mills according to the granulometry wanted by the customer. Depending on the matter refining, the output production lies between 6 and 20 t/h, for a density going from 1 t/m3 to more than 2 t/m3. Shredded scrap is evacuated by an exit door. The treated matter is generally collected by a vibrating table or a conveyor placed below the exit door. If ever scrap could not be shredded passes through the machine, it is then possible to eject it by an escape hatch located on its side.

BMH Cooling scrap Danieli Henschel grinder mills    BMH grinder mill rotor   BMH trufer grinder mills









DANIELI HENSCHEL considers its grinder mill the best way to treat scrap efficiently and make it possible for its customer to obtain a top quality product with strong added value. This recovered product is sold today significantly at a higher rate than traditional E40 resulting from a hammer mill, for weaker costs of exploitation.


Danieli. Plants and equipment for the steel industry

Danieli Team mission is to serve Customers with competitive plant and process technology/automation to produce quality at the lowest depreciation and production cash costs and offer efficient after-sale service. The technology spectrum and relevant process know-how provided by our Product Lines, the well-known tendency towards innovation and high reliability are the best guarantees in reaching this target.

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