Meeting highest demands
Tender specifications were very ambitious indeed. The company Wilhelm Büchel AG from Liechtenstein wanted to replace the 120 000 tons of raw gravel previously sourced elsewhere p.a. to produce construction concrete as completely as possible. Excavated soil and mixed rubble which are abundant during the construction activities of the company should be recycled and reused for the production process of new concrete instead. Thanks to its long experience in the construction of stationary processing plants, SBM Mineral Processing managed to master this challenging task. Due to their extensive core competences the SBM experts were able to combine the essential components from crushing and screening expertise to conveying and silo technology from one single supplier.
Complex technology in perfect harmony
Principally, the complete material flow is similar to classical gravel processing. Pre-crushed material is washed and classified in various steps. As usual in contemporary efficient gravel works, the purely physical process takes place from above to below following gravitation to keep the outside energy requirements to a minimum. The technological challenge lies in implementing the requirements of a future-oriented ecological sustainability in combination with the highest purity grade of the final mineral products. Washing and separation procedures as well as their position in the complete flow must fit in with each other seamlessly. Additionally, a largely automated process is desired to realise the economic demands of the client. This is valid for the separation of all ferrous and non-ferrous parts and also includes the separation of the lightweight fractions in a pulsating upwards flow where e.g. impurities such as plastics or wood are removed reliably. At certain key points flexible adaptation to various application scenarios allows for numerous options. Upon demand, individual processing steps can be connected or disconnected during the washing process resulting in additional efficiency. Since the feed material consists of recycling materials of varying quality, the plant is provided with two completely separated closed water circuits. Processing covers every single step to the final product and finishes with drained screening which is seamlessly followed by the recipe-based removal of the grain sizes required for the respective concrete production.
Fulfilling all requirements
Precision and highly-efficient implementation combined with a perfectly harmonised flow of operation make the difference. SBM fitted together the complete technological equipment of the plant with the precision of a clockwork, and the client gave this processing procedure a special name: BUREMA (BUechel-REcycling-MAchine). The name says it all, as the whole extremely complex plant works like a perfectly matched homogenous machine. The plant was an immediate success working extremely profitably for Wilhelm Büchel AG right from the start. The responsible persons of Wilhelm Büchel AG confirm: “Our objectives have been completely achieved, material re-integration into the concrete production cycle comes to almost 100 %.“ Everybody was very impressed by the top quality of the final products: “Today we can justifiably call the output of BUREMA secondary raw materials; previous definition restrictions of recycling materials are not valid any more,” says Mario Schweizer, Sales Expert at SBM. All relevant physical and chemical properties of the raw gravel coming from BUREMA correspond to appropriate products made of primary raw materials. The high and reliably consistent quality has also convinced the approval authorities.
Fit for the future
Harmonic matching of the individual plant components is an integral part of the successful overall concept. Thanks to the flexible design and the multitude of options the technology can easily be transferred to varying applications and markets. “We at SBM have also learned a lot during projecting and realising BUREMA. Now we know even better what is technically feasible and how it can be implemented,“ underlines Mario Schweizer the valuable experience. Based on the certainty to be able to reinforce the claim to technological leadership, the design engineers of SBM Mineral Processing are confident that the authorities in major European markets such as the Netherlands, Switzerland, Austria and South Tyrol are prepared to accept secondary raw materials in tenders. Highest quality is an absolute necessity for the constantly increasing level of regulations. And here SBM is a pioneer with its technological expertise – well-prepared to fulfil future demands.