In many industries dust containing materials which can still be reused is generated along with the exhaust gases involved. In the metallurgical industry, for example, these can be metals and metal compounds. To recover these materials the dust has to be agglomerated. Depending on the specific application this is achieved by granulation, pelletization or even compaction/briquetting. The use of Eirich preparation technology offers advantages for all applications.
In virtually all cases the agglomeration process is preceded by a mixing process. This is because, first, the self-moisture of the dust alone does not provide sufficient compactability; second, other materials – e.g. carbon carriers – often have to be mixed in as well. This is why liquids and additives are also admixed in a mixer, often along with binders as well.
As a general rule the volumes of dust requiring processing are very large. It is therefore desirable to use as little binder as possible. In addition the moisture, additives and binders need to be evenly distributed in order to achieve a product with sufficient homogeneity. Here the advantages of the Eirich mixer are that it saves on additives and binders. The Eirich mixing system delivers better distribution compared to other mixing systems.
A customer in France that recycles stainless steel dust and had problems with insufficiently homogeneous mixing results and inconsistent briquette strength as a result, replaced its planetary mixer with an Eirich mixer. Afterwards the strength of the briquette was up to 20% higher than the target strength. This made it possible to reduce the amount of binder by 25% and the mixing time from 5 to 3 minutes. Although the customer only operates the plant with a single shift, the new mixing system will still pay itself off in just one year.
Eirich mixers are used in a great many recycling plants. Where the granules (diameters of up to 8 mm) are suitable for the follow-on process, mixing and granulating takes place in a single step, without transferring. Examples include the agglomeration of dust from steelworks for recirculation to the sintering belt or charging to reduction processes, or for the agglomeration of converter dusts containing zinc for charging to the Waelz process. Special-purpose versions are used for the processing of contaminated soil – in the form of so-called vacuum mixers – or with explosion protection for the drying of paint/enamel sludge (spray can recycling). References can be gladly provided. To give customers the opportunity to find out about expected benefits themselves, Eirich offers to have tests performed at the test center and to have suitable rental mixers provided.