THE ROOTS OF ENGITEC
Our fascinating non-ferrous metal industry remember that Engitec was established in 1978 as spin-off from Tonolli Group; the Italian excellency that was active in the industry of non-ferrous metals since late 1920s. Such prestigious heritage has been capitalized and expanded by Engitec Group who has developed, engineered, manufactured, supplied and commissioned, during the past four decades, a very broad variety of innovative capital-intensive plants for the non-ferrous industry, based either on hydrometallurgical or pyrometallurgical processes.
Tonolli Foundry after the World War II
Such technologies ranges from the plants for the recovery of exhaust batteries and the SPL (Spent Pot Lines) recovery technology down to casting plants for billets and slabs or ingot casting lines. Incidentally, one of the oldest aluminium ingot casting lines (open top fashion) supplied by Engitec is still in operation, at one of the largest secondary aluminium refinery located in Italy, after more than 35 years from commissioning.
About the engineering capability of Engitec Group, we could observe that one middle size plant for recovering batteries is shipped using some 180÷200 containers and, once installed, has a footprint of 20,000 square meters approx.
A couple of years back, the attention of the Group has been addressed to the CTL Ingots (where CTL stands for cut-to-length) so to explore the opportunity of giving a contribution to the worldwide producers of aluminium foundry ingots. Among the companies of the Group, GMS (Global Metallurgical Solutions) has been deputed to take this challenge.
THE CTL ALUMINIUM INGOTS PRODUCTION
The CTL aluminium ingots production method is basically based on the production of one trapezoidal cast bar or multiple “simil” square cast bars, alloyed or not, that is/are then cut-to-length through a dedicated cutting station. The resulting ingots, characterized by consistent shape, repeatable dimensions and weight, are then in-line palletized, weighed, strapped and tagged. After this operation, the ingot bundles are ready for storage or shipment.
During the past 25 years, several papers and technical articles have been written by prominent Experts about the CTL production methods and machineries, analyzing in depth, capability of producing complex alloys, metallurgical and physical quality of the ingots, metal recovery yields, general OpEx, OEE, reliability, availability etc., therefore we prefer skipping to add, one more time, our contribution to this subject.
We just say, that we have focused our attention on aluminium CTL ingots based on single bar with trapezoidal shape and we have developed our ingot casting line, branded with the name Wet & Dry Ingot Casting Line.
Sketch of the Wet & Dry Ingot Caster (Patent Pending)
The Crystallizer Machine is the heart of the line being the place where takes place the solidification of the molten metal. The machine is based on the continuous closed mold formed by a succession of profiled alloyed copper blocksclosed on the top by a flexible band that can be made, for example in steel.
The resulting closed and continuous mold is cooled through the action of the wet & dry cooling system so that the molten aluminium is solidified in a shape of the continuous cast bar.
With reference to the sketch, the innovative technical solutions have been addressed to ensure, over the time, excellent hydraulic sealing between the band and the blocks and safe and reliable hydraulic sealing between contiguous blocks even in the most critical operating conditions.
For such reasons, the entire machine has been configurated to obtain the maximum elasticity of the coupling of the parts composing the continuous closed mold, i.e., blocks and band. Among the most significant innovations, therefore, the self-closing design of the blocks chain deserves a particular mention, since it guarantees not only constant and perfect closure among contiguous copper blocks but, more important, it allows the caterpillar structure to be dragged in traction thus obtaining perfect alignment of the plurality of active blocks, reducing the mechanical stress on moving components.