Refial, an european aluminium scrap recycling plant dedicated to the production of liquid aluminium and secondary ingots, has trusted again in GHI Smart Furnaces for the integration and supply of new key equipment of its expansion of the melting process area and the new salt-slag cooling system. Refial and GHI have been collaborating since 2010.
One of the main challenges of the companies focused on aluminium recycling is the characterization of the aluminium scrap that they intend to process, since depending on its composition the performance of the overall recycling process varies, and therefore the company incomes. In this regard, GHI Smart Furnaces, an European leader designing and providing integral solutions for the aluminium recycling market has designed different types of equipment that allow to recover the highest metal yield from any kind of aluminium scrap with the highest energy efficiency and performance.
Refials aluminium recycling plant is equipped with cutting edge technology, allowing the company to process a large range of aluminium scrap. Its productive means are made of two twin production lines in order to guarantee a “Just in time” aluminium delivery to its customers and to satisfy the high demand of aluminium of the market.
A long-term relationship
The relationship between GHI and Refial began in 2010 with the turnkey supply of five furnaces and its auxiliary equipment.
At that time GHI supplied two melting towers, each one with a capacity of 5 tons per hour, to process aluminium alloy ingots or medium size scrap with a high metal yield and high energy efficiency due to the optimal use of heat from fumes.
The scope also included two rectangular reverberatory holding furnaces of 25 tons, specifically designed for receiving, holding, alloying and preparing molten aluminium. The open front of the furnaces, allows access to the entire chamber for cleaning and de-drossing operations, thus optimising finished product quality. The furnaces are equipped with porous plugs that homogenize the temperature and the alloy resulting in high-quality metal.
Additionally, GHI delivered one 30 tons tilting rotary tilting furnace, for low-grade scrap recovery, with its auxiliary equipment. The careful and studied design carried out by GHI on this kind of furnace, provides exceptional performance and metal yields producing significantly lower rates of undesired contaminant salt slags than traditional models.
Production increase and Salt Slag cooling System
Due to the great results obtained for the last 8 years and the current market demand, Refial has opted for expanding its production facilities and optimizing the plant layout. To that end, Refial has trusted again in GHI agreeing a turnkey project that comprehends a second 30 tons tilting rotary furnace and a salt slag cooling system and their auxiliary equipment. The new equipment was started up in May 2019 having widely achieved all the requested performance parameters.
The rotary tilting furnace is a twin of the previously supplied one in 2015 with a capacity of 30 tons for processing low-grade scrap. The new supplied salt slag cooling system contains the fumes and prevent the oxidation of the returned aluminium, increasing the metal recovery and drastically reducing the space required for cooling the traditional salt slag baskets.
The principle of operation of the salt slag cooling system is based on the cooling down of the salt slag coming from the rotary furnaces, which is classified depending on the size and metal content. The cooling system is automatically fed by a fit for purpose conveyor that carries the salt slag from the rotary tilting furnaces, avoiding the use of traditional baskets.
The system triggers automatically when the emptying of salt slags of the rotary furnace stars. The salt slags are poured over the conveyor and are transported to the inlet of the cooler feeding a trommel where they start to cool down. The salt slag never comes in direct contact with the cooling water, which makes this system completely safe.
The trommel has two directions of rotation based on its operation mode: cooling-wise and emptying-wise. At the outlet of the trommel, the temperature of the salt slag is continuously measured to determine the proper operation mode, and hence the direction of rotation, upon reaching the target temperature. The internal side of the trommel is provided with several buckets positioned in such a way that depending on the direction of rotation allow to keep the salt slag inside the trommel, continuing their cooling down, or to discharge the salt slag emptying of the trommel once the target temperature is achieved.
Once the cooling cycle is completed, at the output of the trommel, the salt slags pass through a screen which based on their size are discharged on two different conveyors, one for dust and fines that transports them to the storage silos and other for coarse items which convey them for its final storage on baskets.
Finally, the storage silos are provided with a vibratory discharging system including a telescopic discharge protection sleeve with level sensors to minimize the formation of dust during the loading of the trucks for its further processing in the external salt slag processing plant.
In addition, in order to control the emission of dust, a complete air treatment system has been installed with several suction nozzles in critical points, such as cooling output and screening, conveyors and storage silo discharge.