The experts from HAVER & BOECKER NIAGARA: Project & Sales Manager Dr. Metodi Zlatev and pelletizing expert Dr. Jan Lampke about recycling of steelworks remnants by the SCARABAEUS®
Most metallurgical processes are characterized by a gas flow through the material bed. Thus fine particles are carried away and have to been filtert after the metallurgical devise. Every modern metallurgical plant, no matter if based on blast furnace process, oxygen steelmaking process, electric arc furnace or direct reduction process consists of filters and wet separation for the exhaust gases. In the past these dusts and sludges had been landfilled. Since several decades different extraction processes for special reasons are in industrial use and only little amounts of the remains were discarded as dumps. Most recycling-processes are faced with very small particle sizes of the steel work remnants. Thus agglomeration is necessary in order to improve transport, storage and utilisation properties, especially the reintroduce into the metallurgical process.
The pelletizing disc SCARABAEUS® is perfectly suitable and in multible use for the transmission of fine-grained particles into larger agglomerates with defined particle size distribution with smooth surface. [1]
As an example of the use of the SCARABAEUS® in the recycling of steelworks remnants, such as blast furnace dust and sludge, converter dust and sludge, electric arc furnace dust, metallurgical debris, mill scale, mill scale sludge and various slags will be focused in the following. Since these metallurgical waste materials contain impurities such as zinc and lead, the reuse of these residual materials in the blast furnace or direct reduction plant may be problematic. Some of these materials are landfilled, anyhow the very most proportion is recycled to zinc, nickel, molybdenum or chromium.
Worldwide approximately 6,750,000 t of electrical arc furnace dust are produced annually. These dusts contain 1.600.000 tpy of zinc. About 35 Waelz kilns with an average capacity of 75,000 tpy are installed worldwide. They process every year 3.400.000 tons of electric arc furnace dust [2].
In zinc recycling, zinc-containing residues are reduced by carbon carriers in rotary kilns. Zinc and lead sublimate and are re-oxidized in the air flow in counterflow and are transported and separated in downstream waste gas purification plants. In the production of Waelz oxide, lime is used for slag formation. Prior to the Waelz process, the zinc-containing components dust and sludge (approx. 74 wt.%), coal (approx. 19 wt.%) and lime (approx. 7 wt.%) are homogenized and pelletized. In opposite to the dust, the pellets have got improved transport and storage properties and most important significantly enhanced utilisation properties.
As the Waelz kiln works in counterflow, the risk of discharging unprocessed materials and contamination of the product is high. Defined particle sizes of the steelworks remants pellets are a pre-requisite for Waelz kiln optimization. Typically the pellets have a moisture content of approx. 14 wt.%. The target size of the pellets is mostly approx. 4 to 8 mm. The capacity of the SCARABAEUS® in the recycling sector is approx. 50,000 to 150,000 t/a.
Scheme of Waelz kiln [3]
As early as 2010 HAVER ENGINEERING GmbH developed a pelletizing prozess, wich was attapted to the individual particle size requirements of the Waelz kiln process [4]. One year later HAVER NIAGARA GmbH delivered a SCARABAEUS SC 4200 for this process optimizing project in Germany. The plant was running with a vertical intensive mixer to blend the feed materials and charge them directly into the rotary kiln. To optimize the kiln capacity and the Waelz oxide output, the customer decided to produce agglomerates in the SCARABAEUS (better reaction with the process gas in the kiln due to higher permeability of the pellets). It was possible to increase the zinc output significant using the combination of a mixer and a pelletizing disc with a capacity of approx. 17 tph instead of only using the vertical intensive mixer as they done before.
The target of the project was to increase the total throughput and optimize the Zinc recovery. Due to the pellet production the customer could not only achive the set targets they exceed them.
The basic idea of the customer was using an agglomerate with high porosity to have a fast gas diffusion through the agglomerates into the inner core. Comparing the nature of agglomerates generated in a mixer and in a disc a general difference is the density of the agglomerates. Usually pellets produced in a mixing process have a higher density due to relative high energy input into the material by the agitators and a more coarse particle size distribuion compared to the roll agglomeration in a SCARABAEUS® which is characterized by its segreation effect.
The process chamber of the SCARABAEUS® is made by an inclined, rotating, flat cylindrical pan. Due to rotation of the pan, the fine material is pulled along to the disc uppermost point and then rolling down onto a material bed. Caused by the special movement of the material itself and the addition of water onto the material, nucleation and growing occurs as a result of the settings of the pelletizing disc. Typically, final pellets with a very tight particle size distribution are discharged continuously over the board of the SCARABAEUS®.
Due to the good porosity of the pellets and the teight particle size distribution what leads to a high pellet bed / bulk permeabilty the capacity of the kiln and the Zinc recovery increase.
In the following years that process was adapted on similar or compareble processes. Pelletizing disc with diameters from 2.2 m to 5.2 m are to be found nowadays in recycling of steelworks remnants.
HAVER & BOECKER NIAGARA supports the customers to develop and optimize their processes, machines and plants. In the test facility of HAVER ENGINEERING are various tests equipment for pelletizing available. The objective of HAVER Process Engineering is to meet customers technical requirements and economic benefits. To achieve this, it is necessary to concentrate on the whole pelletizing process, starting with raw materials preparation, dosing and mixing and binder treatment. The core-components of pelletizing are focused in detail to minimize the efforts of final product classification, material circulation as well as de-dusting, safety and environmental protection. Applying recognized technical norms and standards with tailor-made processing leads to a production process that saves energy and resources.
How HAVER & BOECKER NIAGARA is handling the Covid-19 pandemic?
Dear colleagues, customers, business partners, dear friends,
The Corona virus is spreading worldwide: As an international company, we have already taken all the recommended precautions set out by the World Health Organization and we comply with all the government regulations to ensure the smooth running of our business. Our main priority is the safety of our employees and communities during this unprecedented time and we are doing everything we can to protect them. We created Corona Preventive Task Forces at the end of February 2020 and built Corona prevention teams, thus being updated in a very fast and regular way. Based on this, we have taken a large number of precautionary measures ranging from digital meetings to avoiding travel to increased information about hygiene to keeping daily contact logs. Thanks to the efforts of our IT team and our crisis management, we are still available for you.
You can contact us
We are open and operational. Part of our colleagues are working mobile. To enable face-to-face meetings without travel, we use modern chat and video conferencing tools.
Service
With the increasing number of travel restrictions, we are offering remote service tools as a way to access the expertise of our service technicians. Our goal is to help keep your machines in production. We have increased our capacities accordingly. Installations and commissioning of new machines will be arranged in close cooperation with our respective customers.
Contact
HAVER NIAGARA GmbH: +49 (0) 251 9793 0
info(at)haverniagara(dot)com
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In addition, we are supporting DR-Process with Haver & Boecker pelletizing disc THE SCARABAEUS 7500. Find out more on our new landing page: haverniagara.de/pelletizing/
Supporting our customers’ ability to remain in production is our top priority. Our spare parts department is prepared. Most of our original spare parts are available as inventory. Due to closed border and longer waiting times, in some cases we will coordinate with our customers to determine the quickest way for ordered parts to reach them.
Thank you for your continued trust in us! Together we will cope with this challenge and we will get stronger! We wish you and your families all the health, patience and strength! We will see us in person again! Take care of yourself!
Peter Grotjohann
CEO of Haver Niagara GmbH
When thinking about developing new technologies, universities bring valuable resources to the table and HAVER NIAGARA GmbH always uses every chance to strengthen the link between industry and university. Last week our expert in fine screening Markus Löher gave an interesting lecture to the students at TU Bergakademie Freiberg. He shared with them insights and trends in the industry, answered question about our innovation in fine screening – the ultrasonic technology U-Class, supported the students by bridging the gap between theory and practice and gave them a look behind the scenes of his work life.
After the lecture, Prof. Holger Lieberwirt expressed his impressions: “The lecture was a perfect mix of revisions of different basics in mineral processing for our students shortly before the exam. You imparted exciting information about the latest developments in the magnificent field of fine screening and you have managed to show our students once again that Haver Niagara is a significant lead, when it comes to innovation in mechanical engineering. Thank you, Mr. Löher! You’ve made a great job!”.
Appreciating these kind words, we are sure that these students will be the experts of tomorrow and we have to support them. We can hardly wait to welcome one of them to our staff! Good luck!
The iron and steel industries are indispensable components of economy. Our world is built by using steel. We need even more steel for the improvement of infrastructure of our cities. Owing to this increasing steel demands we consider significantly growth of the iron ore production in recent years.
On the other hand, there are many environmental effects from the iron industry. Iron ore and steelmaking are the largest energy consumer of electricity and fossil fuels, being responsible for over 25% of hazardous atmospheric emissions and over 30% of carbon dioxide emissions. That’s why we need to think about sustainable solutions that minimize the CO2 emissions and energy use by iron ore production; solutions that deliver higher performance in terms of energy efficiency, resource efficiency and better process and product performance. We need CO2-efficient ironmaking processes.
One of the possible solutions could be direct reduction process like Midrex- or HYL, Corex process. 1
In this light, the transformation of iron ore into steel requires several process stages. First at all, we need to become H2 and iron ore pellets. Iron ore pellets produced from the iron ore concentrate by pelletizing and sintering. At the same time, the quality requirements of pellets, such as size distribution, physical, chemical and metallurgical specifications are higher and should be guaranteed by very innovative pelletizing technology that is able to ensure the perfect flow for our blue planet.
As a world’s leading supplier for customized screening, washing, pelletizing machines and plants solutions, we are feeling responsible to take actions into the protection of our environment by developing systems, which use fewer resources, fulfill the needed higher quality of the pellets and care for the health of the mother Earth.
Тhe result of our efforts we developed the SCARABAEUS pelletizing disc. The pelletizing disc fulfills the specification deeds for the processes of direct reduction and saves up to 5% energy by reduced recycling rate. The production capacity can be up to 150 t/h.
Those characteristics convinced experts from Eastern Europe in the potential of our innovative pelletizing technology for the production of iron ore pellets with a very narrow particle size distribution (10 to 12,5 mm) and high product rate (up to 70 %). Subsequently we got the great opportunity to work with one of the international steal and mining groups in east Europe: Metinvest. Аfter conducting iron ore tests in Haver Engineering in Freiburg and proving the possibility of achieving the desired parameters, a contract for the supply of the necessary equipment was signed. The pelletizing disc SCARABAEUS 7500 was delivered in combination with completely automatic control system.
In order to satisfy the higher needs of the pellets, an automatic pelletizing disc control system was introduced for the first time, incorporating three machine parameters: rotation speed, tilt angle, and board height.
In the end of July the CEOs of Haver Niagara GmbH (Peter Grotjohann) and Metinvest (Yuriy Ryzhenkov) have met in the manufactory of Metinvest in Ukraine. They inspected our powerful and reliable pelletizing technology and discussed the future course of our business relationship. The managers have dealt with all the advantages that our technology ensures to Metinvest and put heads together into developing the best strategy that is able to become fully aware of their common vision for the future: to live in a stronger, lighter and more sustainable world, where technology guarantees the care for the health of the mother Earth using highest environmental protection standards.
We are very happy that starting working together with Metinvest opened new doors to more CO2-efficient ironmaking processes and we have the unique opportunity to lay the first foundation stone of the future to green iron ore processing.
Metinvest, we would like to express our huge thanks for the trust, which you have placed in us. It is such a pleasure working together!
Die Hydro-Clean Waschanlage HC aus dem Programm von Haver & Boecker Niagara befreit in effektiver Weise Nutzkorn von Schad- und Störstoffen. Dabei soll der Wasserbedarf im Vergleich zu traditionellen Waschsystemen um bis zu 75 % niedriger liegen bei ebenfalls um bis zu 15 % geringeren Energiekosten. Dieser Spareffekt ist der kompakten Baugröße und dem geringeren Gewicht gegenüber traditionellen Waschsystemen, die zudem eine größere Aufstellfläche haben und mehr Ausrüstung benötigen, zu verdanken. Das wartungsfreundliche Design ermöglicht im Bedarfsfall den einfachen Austausch der wenigen Standardkomponenten, wobei der HC laut Hersteller wenig verschleißanfällig sein soll.
Zur Reinigung von Aufgabematerialien bis zu einer Größe von 150 mm in einer vertikalen Trommel sprühen Hydro-Clean-Hochdruckdüsen Wasser mit Drücken bis zu 140 bar bei einer Drehzahl von 90 UpM auf das Material. Das Waschsystem entfernt auf diese Weise Schlamm- und Lehmpartikel bis zu 63 Mikron aus Mineralgemischen.
Die Waschanlage ist in vier Modellgrößen erhältlich, die 18 bis 400 t Material pro Stunde aufbereiten, je nach Typ und Anwendung. Der Wasserverbrauch reicht dabei je nach Anwendung und Modellgröße von 102 bis 798 l/min.
Das System funktioniert folgendermaßen: Verunreinigtes Material wird über einen Trichter in die vertikale Trommel des Hydro-Clean aufgegeben, woraufhin die oben montierten Hochdruckdüsen rotieren und das Material mit Wasser besprühen. Die Turbulenzen in der Trommel erzeugen zusätzliche Scheuer- und Schleifkräfte, die den Reinigungsprozess verstärken, während das Material den Trommelzylinder passiert. Am Ende des Reinigungsprozesses wird die Aufgabe über einen Abzugsförderer ausgeleitet, der zu einem Waschsieb führt. Dieses ist für eine Nachwäsche zuständig, während es gleichzeitig das Material fraktioniert.
Lesen Sie den Beitrag in Ausgabe 4/2019 von Gesteinsperspektiven
The customer Steinbruch Schelmberg GmbH & Co. KG is completely satisfied with the perfect flow of our screening machines
We are always pleased, when our products provide added value for our customers. We developed this amazing gravel and split plant for medium-hard and hard rock for Steinbruch Schelmberg in Oelsnitz/Vogtland. There we implemented three of our free-vibrating screening machines type T-Class in heavy duty design for regular and high loads, one Fine-Line especially for fine particle natural moisture screening and two Haver Niagara Feeder. They support our customer to classify his material of the secondary crushing stage by specific sizes, to re-crush the coarse excess material to a minimum size and finally to transport the classified material to the heap.
A modern robust built of this installation allows the processing of more than 200 t/h and crushes the feed material up to 90 mm. The processed material is used to satisfy the needs of asphalt and concrete industry whereby we also could contribute to the development of sustainable infrastructure for our cities.
Few months after processing start we visited our customer ‘‘Steinbruch Schelmberg GmbH & Co. KG” ones again. He is completely satisfied with the perfect flow of our screening machines, feeder, fine line and the whole process as well. He is impressed how fluently works the classifying of fillers from fine material and he find out that with our innovative processing technology he spares resources, increases his productivity and reduces his costs.
We highly appreciate hearing such fantastic impressions from our customers.
Reduced water and energy use
Haver & Boecker Niagara advanced Hydro-Clean® washing technology is helping a gold producer looking to expand its operation in eastern Russia increase production, reduce water consumption and minimize wear. The producer currently uses a test washing drum and two bearing screen to separate the sand and clay from its mined gold ore. This method provides inadequate washing results, causes excessive equipment wear and consumes high volumes of water and energy. Working closely with the customer, the HSG set up the Hydro-Clean 700 unit (Fig. 1) and rinse screen as a separate test operation to prove it could successfully wash the operation’s three distinct products better than the current test equipment. Each product has varying degrees of impurities, ranging from easy-to-wash to sticky material that is nearly impossible to clean with the current washing system. Since installing this combination, the operation has increased production from 5 t/h to 25 t/h, reduced its water consumption by up to 70 % and saved up to 30 % energy for every ton of material.
In preparation for a large mine upgrade project, these positive results have led the operation to put the Hydro-Clean in its plans for all future mineral washing.
The Russian gold producer, who asked to remain unnamed due to the competitive advantage this equipment provides, first contacted the HSG about the Hydro-Clean in 2009 after seeing impressive results at a different gold operation using HSG equipment. The Hydro-Clean appealed to the producer because its current washing system, a traditional washing drum, was not removing enough sand and clay content to produce the required 2 mm to 120 mm gold product with clay content less than 2 %.
• Clay-heavy material on the conveyor
Ideal for use in clay-heavy material deposits (Figs. 2 and 3), the Hydro-Clean employs high-pressure nozzles, rotating at 90 rpm, to spray up to 90 % recycled water on the material with pressures up to 200 bars (2900 psi) to remove silt and clay particles as small as 63 μm from mineral mixtures. While the high-pressure nozzles mounted at the top rotate and spray the material with water, the turbulence in the drum creates additional scrubbing and abrasive forces that enhance the cleaning process to break up agglomerates and clean the particles of stubborn material. The Hydro-Clean also injects high-pressure streams of water into areas of the material (holes, cracks, etc.) that are difficult to reach with traditional cleaning methods. A UME 1200 x 4500 mm rinse screen follows and rinses away the loose sand and clay contaminants. The end result is a cleaner gold ore product with clay content less than 2 % (Fig. 4).
• Final product is a clean washed material
The Hydro-Clean consumes far less water and energy. The test washing drum and two bearing screen used by the Russian gold producer consumes up to 13 m3 (13 000 liters) of water to wash just one ton of material. With the Hydro- Clean and rinse screen, the producer only uses a maximum of 4 m3 (4000 liters) of water for each ton of material, reducing the operation’s water consumption by up to 70 %.
In addition to water savings, the Hydro-Clean 700 model used by the gold producer was able to save up to 1.8 kW of energy for every ton of cleaned material when compared to the washing drum system. The Hydro-Clean’s compact size and reduced weight keep overall operating and structural costs considerably lower than with traditional washing systems – which also require more equipment and a greater footprint. In addition, it experiences little wear with a low-maintenance design that allows for simple replacement of the few standard components that are subject to wear. This allows operations to save thousands of rubbles in yearly maintenance costs. Thanks to the success of the Hydro-Clean 700 test unit, the producer plans to authorize an investment program that will allow the installation of a larger washing operation with several HSG Hydro-Clean 1000 units.
This operation would be capable of washing up to 4 million t of auriferous ore a year. To make the adaption of this new, advanced washing technology easier, the HSG has provided easy-to-understand flow sheets on how the Hydro-Clean would fit into this new operation. If made part of the producer’s every day operation, the Hydro-Clean could reduce its total water usage by up to 70 % and energy costs by up to 30 %.
Fertilizer production with the HAVER pelletizing disc SCARABAEUS
In view of the increasing food requirements of the world’s population and the continuing eluviation of the soil due to intensive agriculture as well as the loss of arable land following sealing of surfaces in urban environments, the exploitation of raw materials and the contamination with pollutants, fertilizers are becoming more and more important in the production of foodstuff.
Plant growth and harvest quality generally depend on how much of the required nutrients there is in the soil. The nutrient of which there is least defines the success of the cultivation. It follows that fertilizers are needed to make up for any deficits. Today, great demands are made on the fertilizers used to increase the yield of crops, for example regarding the mineral combination which supplies the plants with nutrients, or regarding the structure and shape of the fertilizer pellets to improve the flight behaviour when the pellets are spread.
The company “Australian Mineral Fertilisers“ produces fertilizers under the brand name ‘GrowSafe®‘ in Tenterden, West Australia. The biological mineral fertilizer is a material mix. Every pellet contains all combinations of minerals. The pellets are suitable for spreading with standardized sowing and fertilizer distributors. They are sold in Big Bags, 25 kg bags, or as bulk material.
In recent years, the company was faced with the question whether a 10-year old pelletizing drum could be safely replaced by a pelletizing disc to increase production capacity and product quality.
Owing to the complexity of the processes, the production of mineral fertilizers by means of the pelletizing drum proved to be increasingly complicated and highly inefficient due to the high volume of undersized and oversized pellets beyond the specified product range. The requirements made on a pelletizing disc were very high: In addition to a significant capacity increase from 7 to 20 t/h, it was to improve product homogeneity as well as product quality.
Australian Mineral Fertilisers directly contacted HAVER NIAGARA in Münster. Both sides quickly agreed that test runs were required to provide a basis for further discussion and for dimensioning the system components. In cooperation with HAVER ENGINEERING, a test concept was generated to investigate the suitability for pelletizing, which drew the interest of the project owners at AMF’s.
An AMF associate together with the Plant Manager came to the site of HAVER NIAGARA to gain a personal impression of the manufacturing capacities. They also visited the R&D Center of HAVER ENGINEERING in Freiberg, to learn more about the results of the research. A presentation of detailed results and the demonstration of agglomeration tests with AMF fertilizers convinced the customers of the capabilities of HAVER SCARABAEUS. With up to 80 M.-%, the share of usable fertilizer pellets, produced in the tests under laboratory conditions, exceeded the expectations.
Based on the results of the test runs, the decision was made to replace the pelletizing drum by a pelletizing disc of the HAVER SCARABAEUS® series.
The features that made AMF decide on the HAVER SCARABAEUS 4200 were the robust design, the energy-efficient and low-maintenance drive unit with two asynchronous motors, which allow for start-up even under full load and ensure continued operation if one of the motors fails, as well as the system’s high flexibility, such as the possibility to adjust inclination and speed during ongoing operation.
Around the time this decision was made, HAVER AUSTRALIA was established in Perth West Australia. This means that the parameters for designing and dimensioning the system could be coordinated quickly, reliably and at low costs between the customers and HAVER NIAGARA.
In addition to the pelletizing disc HAVER SCARABAEUS SC4200 complete with its control system, a HAVER NIAGARA T-Class 1500×5000 for product grading and a Computer Particle Analyzer CPA 2.1 of our wire weaving company for continuous determination of product quality was sold. Other machines from the extensive product portfolio of HAVER NIAGARA are already operating successfully in the chemical fertilizer industry (MAP, DAP, NPK).
With 61 M.-%, the share of usable pellets in the product was above the level of the previously used drum already during the commissioning phase of the pelletizing disc in autumn of 2013. Today, after completed commissioning and some months’ worth of experience, the rate of yield for AMF is up to 80 M.-%. Even the solidity and roundness of the pellets improved significantly. The Plant Manager confirmed that his customers had registered this distinct improvement in quality and said that they were very satisfied. Such success stories not only guarantee the good image of the HAVER group in the eyes of the customers but also provide for sustainable growth of the customer, who can continue to rely on the services of the HAVER Group as a technological partner.
After the completion of commissioning, HAVER Australia took over customer service. They will carry out the regular maintenance of the machines and support the customer in future process optimization.
HAVER NIAGARA GmbH: after one and a half year new operators came to a positive result
The quarry for greywacke “Kleinhammer” is situated among a wooded mountainous region in Sauerland, sixhundred meters in south-east direction to the town Werdohl-Kleinhammer. Since the change of ownership in January 2015, Holcim, a manufacturer of construction material, has operated the quarry. Ownership changes did not result in a change of personnel.
In close collaboration with the previous operator HAVER NIAGARA GmbH designed a new primary crushing plant with subsequent processing of riprap. Besides the primary crushing plant and processing of riprap the scope of supply also included the complete conveying system, the intermediate silo and the dust silo as well as the planning of concrete works and the overall assembly.
The main challenge in this project were great demands of the customer on quality specifications, emission and environmental standards as well as the tight schedule for finalization. Furthermore, the installation should secure a safe and flexible production for the next decades. By means of the designed concept HAVER NIAGARA provided an innovative solution for the fulfilment of these requirements.
An example of the flexible production is the processing plant for riprap. The weight classes 540 kg and 10-60 kg can be processed separately or simultaneously on request by means of two heavy duty screening machines. Soundproofed building facades, energy saving electrical components and the dedusting unit are the main objective with regard to emission and environmental protection.
The period for the realization from the start of project until commissioning took 12 months. Due to the onset of winter at the beginning of 2013 concrete works had to be stopped for several weeks. Therefore, the planned start of production was endangered. The specialist in from Münster took up that challenge and modified the assembly process, so that contrary to the initial plan the building for the processing of riprap was installed at first. The concrete works on the building for the primary crushing plant have been continued at the same time. As a result of the measures taken, the scheduled start of production was at the beginning of September 2013. On the occasion of the opening celebration on 27 September the installation was formally inaugurated with a spectacular firework.
The successful realization of the project has been achieved by long-term and close cooperation between the previous operator and the experts from HAVER NIAGARA. This is the pooling result of years of experience and the technical know-how of both companies.
The precise realization on the basis of prescriptions is an impressive example for the problem-solving expertise of HAVER NIAGARA – particularly with regard to an efficient conception of primary crushing plants and its precise implementation.