Processing technology with a proven worldwide track record for the carbon industry
Geplaatst op 07-09-2017
Carbon materials are used in many sectors of industry. Along with raw material selection, the production technology has a crucial influence on the properties of the carbon which is embedded in a pitch or synthetic resin binder matrix. Mixing in the high-viscosity binder presents a major challenge. That is the reason why EIRICH mixing systems are used worldwide in these applications.
Around 40 years ago, the carbon materials industry discovered the advantages of EIRICH processing technology, initially as a replacement for mixers running at low speeds and as mixer-coolers installed downstream of kneaders. Producers quickly recognized the opportunities offered by the new technology. The EMC© process (Eirich Mixing Cascade), with a hot-mixer and a remixer-cooler with throughput rates of 15 - 60 t/h backed up by 20 references worldwide, is available for anode fabrication. Due to the excellent cost/benefit ratio, EIRICH technology became the industry standard. More than half of the anode manufacturers worldwide use at least one EIRICH mixer, predominantly in continuous operating, for hot mixing as well as for subsequent cooling to pressing temperature which can be pre-selected with ± 3 K precision. Several hundred machines are currently in operation at well-known producers around the world which enabled them to substantially enhance the properties of the materials. The fact that a single EMC© mixer line is able to support production of 600,000 tons p.a. of aluminum demonstrates the performance capabilities of EIRICH processing technology.
EIRICH has also simplified the production of cathodes for the aluminum industry. As is the case for graphite electrodes, a special electrical heating technique is available which heats up the coke up to mixing temperature. Typical throughput rates for batch processing of graphite electrodes and cathodes are 4 -12 t/h. The EIRICH product portfolio for these applications ranges from single machines to complete plants including raw material dosing and weighing as well as mixing and filling of the correct quantities into the press. Of course, the whole process is operated fully automatically.
Inductive mixers with capacities between 5 liters and 400 liters which can be used to produce special products have been available for several years. Due to the inherent system design, they are capable of handling any consistency including extremely viscoplastic consistencies. Inductive heating of the mixing pan directly generates heat in the walls of the mixing pan. Fast heat transfer between the material which is being intensively mixed and the rotating walls of the mixing pan produces a high surface specific energy transfer. Dynamic regulation inherent for inductive heating systems makes it possible to select the exact temperature with high reproducibility. The chemical-thermal reaction in the mixture, called defuming, can be started quickly and stopped at exactly the right time when the mass is dry enough for further processing or forming. Heating capacities of 5 kW - 250 kW make it possible to process mixtures containing materials with high melting points such as solid resins rather than resin solutions. Solid resins introduce less volatiles, reducing process times and lowering porosity. This provides a basis for development of new materials, and that includes other industries which use synthetic resin bonding as well.
Producers who have chosen EIRICH mixing systems confirm that investment costs are up to 50% lower and operating and maintenance costs are up to 30% less. This is the reason why EIRICH has recently acquired a number of new orders, e.g. for Aluminium Bahrain (ALBA) PL6, Bahrain. The order includes an EMC© system for anode paste for the aluminum industry with a hot-mixer and a remixer-cooler. The system has a throughput rate of 55 t/h. The equipment is being supplied by the French engineering group Fives Solios.