The liquid steel is processed into coils in a single plant, without interruption, without intermediate products (slabs), without handling of the material, in 15 minutes for ISP and 7 minutes for ESP and in a space only 180 metres long. Conventional techniques, on the other hand, operate in distinct phases, through intermediate products, at different times and at times in different works, with a linear plant development in the order of a thousand or more metres.
Arvedi technology maximizes the exploitation of the heat contained in the liquid steel (along the whole cycle the temperature never drops below 950°C); this leads to considerable energy saving, calculable in a saving of about 22 TOE (ton oil equivalent) every thousand tonnes of steel produced; consequently there is a considerable beneficial effect on the environment, since the lower demand for electrical power from power stations leads to a corresponding reduction of about 50% in CO2 emissions (greenhouse gas), well beyond the objectives of the Kyoto protocol.
The invested capital, per product unit, of a production works based on Arvedi technology (with the associated melt shop for the production of liquid steel), is from two to three times lower than that required for a conventional-type steel works, the minimum size of which, to be economically efficient, is over 4 million tonnes. With Arvedi technology break-even points can be reached of less than one million tonnes.
Energy saving, associated with the (from 2 to 3 times) higher per capita productivity, leads to a reduction in operating costs of between 30 and 50% compared with conventional cycles.
The particular and innovative solidification processes realised by the process allow excellent internal steel structures to be obtained and a high quality end product, such as high strength and multi-phase steels which represent the new frontier in automotive applications.
The plant also directly produces hot rolled thin gauges (0.8 – 1.2 mm) which can be obtained on conventional plants only after a subsequent processing phase – cold rolling – and therefore with higher costs and energy requirements.
The shortening of the production cycle, the sequencing of the production cycle and control in real of the various processing phases, in virtue of the high degree of automation and computerised process control, allow an end product to be obtained in only 90 minutes starting the raw material (including melting of the scrap to produce liquid steel).
Moreover, the plant using Arvedi technology allows variation of speed from coil to coil, without losing productivity, providing a service in terms of speed of response (just-in-time service feasible) and variety of offer that the extremely rigid traditional systems, represented by the major steelmaking centres, are unable to provide.
The combination of the strong points mentioned above, briefly summed up as low capital expenditure for the investment, low production costs, highly flexible production and high added value of the product mix lead to high profitability and a rapid return on the investment.
|Most noteworthy points|
|Relative to “size” reduction||ISP (1992)||ESP (2009)||CONVENTIONAL CYCLE |
(Casting, slab yard, rolling)
|Annual production per square metre used (casting and rolling)||≅16 m2/KTpy||≅9 m2/KTpy||≅30 m2/KTpy|
|Productivity per head (hot rolled coil)||3000 tonnes||6000 tonnes||2000 tonnes|
|Investment per tonne of annual capacity||300 Euro/tonne||150+200 Euro/tonne||400 Euro/tonne|
|Relative to times|
|From raw materials to coil||90 minutes||80 minutes||The conventional cycle proceeds by distinct phases. Times are calculated in days.|
|Casting and rolling cycle||15 minutes||5 minutes||From 2 hours (direct charging) to several days|
|Just in time||Yes||Yes||Very problematic|
|Product warehouse||10 + 15 days||10 + 15 days||Against 1 - 2 months of stock products and semi-finished products for conventional ones|