New Developments on the Properzi method for producing primary or secondary aluminium ingots by C.M. Brocato

The Properzi-Ingot casting line, designed at the beginning of 90’s is based on the unique Continuus-Properzi technology of continuous closed mould with cooled casting wheel and belt.
The wheel diameter ranges from 1.4 to 4.2 meters according to the required production rate and liquid metal supply.
Referring to pure Aluminum, the production rates vary from 4 t/h to 20 t/h. As far as concerns Aluminum alloys it is expected a production rate 15-20% lower depending on the alloy being cast.
Remarkably higher quantities can be obtained with other nonferrous metals, such as Brass, Lead and Zinc.
This patented technology allows for increased productivity and highly improved ingot quality.
The final product is easy to pack and store due to its shape. Smaller space requirement between stacked ingots reduces transportation costs considerably.
The picture on the right shows the difference between bundles of the old type of ingots (right hand side) and new Properzi produced ingot bundles of the same weight (left).
The main advantages of this unique technology - compared with the open top moulds technology - are briefly:
• Stable and repeatable ingot dimensions
• No traces of oxide foam or heavy surface oxide
• Compact metallurgical structure with very fine grains
• Smooth and flat external surface, designed to avoid any possibility of collecting water and/or moisture with consequent risk of explosion inside the furnace
• Dross problem is practically not anymore existing
• Ingots are suitable for automatic stacking operations

New Developments on the Properzi method for producing primary or secondary aluminium ingots by C.M. Brocato

In the new casting machine referred to as the TRACK & BELT SYSTEM the casting wheel has been replaced by several segments placed in sequence, like a chain of the bicycle or like the caterpillar of any earthmover machine. Liquid metal enters the linear cavity (mould) defined by the rectilinear sequence of segments and the steel belt. This new configuration produces the same quality of ingots as the casting wheel and belt, and in addition, the cast bar is solidified into a rectilinear mould, therefore it does not need to be straightened. Furthermore, the length of the solidification arc does not have significant impact on the depth of the foundations.

The new process has been given the name of Track and Belt Caster.

The circular copper ring mould has been replaced by a plurality of blocks made by a copper alloys and arranged in succession on a chain.
As a consequence, the closed continuous mould is composed on the upper side by the continuous steel belt and on the other three sides by the three sides of a plurality of blocks.
The length of the mould is determined by the distance between the two pressing rolls. The tracking wheels move the caterpillar, like the chain of the bicycle. The steel belt is pushed against the active chain of blocks, to form the top part of the closed continuous mould, by a series of antifriction skids operated by pneumatic pistons. The steel belt is powered by wheel in a way that in any point of the closed mould the speed of the caterpillar and the speed of the steel belt are exactly the same. It is needless to say that the speed of the caterpillar is equal to the casting speed. It is quite evident that we can have very long mould, i.e. very high production rate, without having negative effect on the foundation and installation costs.