Die Technologie des Pelletierens von Eisenerzen wird seit Jahrzehnten angewendet. Die Grundprinzipien sind die Gleichen, aber es gibt noch Raum für Verbesserungen.
Die Experten der HAVER NIAGARA GmbH: Der Vertriebsleiter Dr. Metodi Zlatev und der Pelletierexperte Dr. Jan Lampke erläuterten diese Verbesserungen im exklusiven Experteninterview.
Wie populär ist das Pelletieren in der Eisenerzindustrie?
Der beständige Bedarf an Eisenerz führt zu der Notwendigkeit, auch minderwertige Lagerstätten abzubauen. Der verminderten Qualität der natürlichen Ressourcen stehen wirtschaftliche, ökologische und technologische Restriktionen gegenüber, die eine Aufbereitung des gewonnenen Eisenerzes erfordern. Eine Anreicherung des Eisenerzes kann durch die Abtrennung unerwünschter Bestandteile erreicht werden. Diese Anreicherung von Eisenerz stellt in der Stahlproduktion einen signifikanten Verfahrensschritt dar. Bei der Anreicherung wird der größte Teil der Nebengesteine abgetrennt. Dadurch werden Transportkosten reduziert und die Produktionsrate von Hochofen und Direktreduktionsanlage gesteigert. Da das bis zur Aufschlusskorngröße zerkleinerte und aufkonzentrierte Eisenerzkonzentrat weder transport- noch gebrauchsfähig ist, muss es agglomeriert werden. Die Aufbauagglomeration von Eisenerzkonzentrat im Pelletierteller ist daher ein unverzichtbarer Bestandteil der Aufbereitung von Eisenerz.
Wird diese Methode immer bekannter/beliebter? Und warum?
Die weltweite Roheisenproduktion entwickelte sich in den Jahren 2007 bis 2015 mit einer jährlichen Steigerung von ca. 3,5%. Die Eisenerzfördermenge im Jahr 2019 wird mit 2,850 Mrd. t angegeben, bis 2028 soll laut konservativen Prognosen eine globale Eisenerzfördermenge von 3,119 Mrd. t erreicht werden, was einem jährlichen Anstieg von nur noch 0,9 % entspricht. Demgegenüber steht eine bis 2025 erwartete Steigerung der globalen Pelletierkapazitäten von 5.5 % per annum. Diese Zahlen verdeutlichen eindrucksvoll, dass die Aufbauagglomeration im Pelletierteller nicht nur bekannter, sondern auch beliebter wird.
In den Jahren von 2005 bis 2015 konnte eine stabile weltweite Produktion von nur 56 Mio. t Eisenschwamm (DRI) beobachtet werden. Trotz vielfältiger Entwicklungen und moderner Technologien der Direktreduktionsverfahren zeigte sich noch immer eine deutliche Branchenfokussierung auf die konventionelle Hochofen-Konverter-Route. Neuste Bestrebungen zur Verringerung des weltweiten CO2-Ausstoßes zeigen jedoch eine Trendwende auf. Alleine von 2017 bis 2018 ist die globale DRI-Produktion um 11.6 % gestiegen, im Folgejahr nochmals um 7%. Moderne Direktreduktionsanlagen verwenden designte Eisenerzpellets, mit ganz speziellen Pelletgrößenverteilungen und Basizitäten. Diese können nur mit modernen Pelletiertellern wirtschaftlich sinnvoll produziert werden.
Welche Ausrüstung braucht man für die Vorbereitung des Materials für den Pelletierprozess?
Zur Anreicherung des Eisenerzes ist es notwendig, das Erz bis zur Aufschlusskorngröße zu zerkleinern und Sortierprozessen wie Magnetscheidung und Flotation zuzuführen. Das dadurch produzierte Eisenerzkonzentrat wird anschließend mit Bindemittel, z.B. Bentonit oder organischen Bindemitteln, wie Carboxymethylcellulose und Polyacrylamid vermengt.
Durch Wasseraufgabe im Pelletierteller wird ein Aufquellen des Bentonits erreicht. Dabei zerfällt das Bentonit in kleine Plättchen, welche sich mit den Eisenerzkonzentrat-Partikeln wie auch untereinander verbinden. Während des Trocknungsvorgangs der Pellets entstehen dadurch stoffliche Brücken zwischen den Eisenerzkonzentrat-Partikeln, welche die Trockenfestigkeit der Agglomerate deutlich steigern. Beim anschließenden Brennen bzw. Härten der Pellets wirken die Sodium- bzw. Kalzium-Komponenten als Fließmittel, wodurch die Schmelztemperatur der Grundsubstanz verringert und somit lokale Schmelzbrücken bei Temperaturen unterhalb der eigentlichen Schmelztemperatur des Eisenerzkonzentrates erzeugt werden. Da der Bentonit während des Agglomerationsprozesses einen Teil der Pelletierflüssigkeit bindet, stellt er ein robustes Bindemittel mit einem breiten Bereich der Einsatzgrenzen dar.
Problematisch stellt sich allerdings der Eintrag der Mineralkomponenten dar, wobei im Speziellen durch den erhöhten SiO2-Gehalt der Eisenerzkonzentrat-Pellets der Energiebedarf zur Reduktion und Schmelzung derer gesteigert wird. Zudem steigt der Anteil an auszutragender Schlacke bzw. Verunreinigung im DRI. Daher gibt es, speziell im Bereich der DR-Pellets immer intensivere Bestrebungen, dieses Bindemittel weitgehend durch organische Bindemittel zu ersetzten.
Wie entwickelt sich die Pelletiertechnologie allgemein?
Zur ressourcenschonenden Erzeugung von Roheisen und Eisenschwamm sind geeignete Pellets notwendig. Diese zeichnen sich neben metallurgischen Zielgrößen im Speziellen durch eine enge Partikelgrößenverteilung und ein hohes Rundheitsmaß aus. In der Praxis hat sich herausgestellt, dass die Betriebsbedingungen des Pelletiertellers die Pelletqualität stark beeinflussen. Daher sind Pelletierteller notwendig, mit denen unsere Kunden sowohl auf sich ändernde Materialeigenschaften wie auch auf geänderte Zielgrößen des Produktes reagieren können.
Gibt es regionale Unterschiede?
Wir verzeichnen ein globales Interesse an der multidimensionalen Automatisierung unserer Pelletierteller. Der osteuropäische Markt erscheint besonders interessiert an der HAVER SCARABAEUS-Technologie.
Welche Firmen sind bereits mit Pelletiertellern ausgestattet und warum hat sich der Kunde gezielt für dem HAVER SCARABAEUS entschieden?
Metinvest und Ferrexpo sind bereits mit dem HAVER SCARABAEUS ausgestattet. Beide Unternehmen haben festgestellt, dass zur Produktion enger Partikelgrößenverteilungen für Direktreduktionsprozesse innovative Technik notwendig ist, die den Anlagenbedienern vielfältige Möglichkeiten gibt, den Pelletierprozess zu stabilisieren und ein optimales Ausbringen zu erreichen. Die moderne SCARABAEUS-Technologie, bestehend aus dem Pelletierteller HAVER SCARABAEUS, einer Partikelgrößenanalyse der Pellets mit der HAVER Momentum und das HAVER Process Management System bietet die Möglichkeit, die Erfahrung der Anlagenbediener für die Zukunft zu konservieren und mit innovativer Technologie zu optimieren. Nur so können ideale DR-Pellets produziert werden.
Welchen Service / Unterstützung bietet HAVER NIAGARA dem Kunden beim Entscheidungs- / Ausarbeitungsprozess?
HAVER & BOECKER Niagara unterstützt Sie bei der Entwicklung und Optimierung Ihrer Prozesse, Maschinen und Anlagen. In unserem Technikum stehen verschiedene Prüfgeräte zur Pelletierung zur Verfügung. Das Ziel des HAVER Process Engineering ist es, Ihre technischen Anforderungen und wirtschaftlichen Ansprüche zu erfüllen. Um dies zu erreichen, ist es notwendig, sich auf den gesamten Pelletierprozess zu konzentrieren, beginnend mit der Rohstoffaufbereitung, Dosier-, Misch- und Bindemittelbehandlung. Die Kernkomponenten der Pelletierung werden im Detail fokussiert, um den notwendigen Aufwand der Endproduktklassierung, des Materialumlaufes sowie der Entstaubung zu minimieren und dabei höchsten Standards der Prozess- und Mitarbeitersicherheit sowie des Umweltschutzes zu erfüllen.
Im HAVER INSTITUT, einem An-Institut der TU BERGAKADEMIE FREIBERG werden maßgeschneiderte Aufbereitungsprozesse unter Anwendung anerkannter technischer Normen und Standards erarbeitet, um Einsparungen im gesamten Ressourceneinsatz unserer Kunden zu erzielen.
MÜNSTER, Germany (June 5, 2019) — Haver & Boecker Niagara offers rugged primary crushing plants in a wide variety of configurations for pre-crushing, secondary and tertiary crushing in the mining and aggregates industries. From design to installation, the manufacturer uses its extensive industry experience and knowledge to provide turnkey systems engineered and built to individual specifications. Haver & Boecker Niagara will work with any crusher and peripheral component manufacturers to ensure customers receive the best plant matched to their requirements.
“We’re entrenched in the mining and aggregates industries and are dedicated to each customer’s profitability and success,” said Peter Grotjohann, managing director of the German facility. “We use our industry experience and work closely with each operation to design comprehensive primary crushing plant systems with the highest level of durability, service and flexible design so each customer can find the best plant for their operation.”
Haver & Boecker Niagara offers turnkey primary crushing plant solutions through customer-oriented project support, from initial concept to the production phase. In addition to coordinating the physical plant, Haver & Boecker Niagara offers structural building engineering at the start, including verifiable statics calculation. The company features transportation management, supervision or the complete package: from assembly and electrical installation to plant start-up and optimization. Haver & Boecker Niagara also offers project management, on-site services, operating supplies, components or plant control. Operations also benefit from service and spare parts planning and service contracts.
Haver & Boecker Niagara provides crushing plant systems with a variety of components, including impact, jaw, cone or roller crushers, Haver screens or rolling screens, push feeders, apron conveyors and Haver vibrating feeders. The plant systems work with all peripheral components such as maintenance cranes, de-dusting systems, compressed air systems, hydraulics and hammers.
Customers choose from two types of systems, basic or master. Basic is the classic pre-crushing plant that uses a Haver & Boecker Niagara N-Class eccentric screening machine to relieve the primary crusher. It includes a feeder, vibrating screen, crusher and several conveyors. If needed, an additional screen deck screens stony earth either to be screened away or to be fed to production.
The master system allows customers to get the most production and profitability out of their natural mineral deposit. The system provides increased flexibility for primary crushing stages, especially with non-homogeneous natural deposits. For high quality natural deposits, the operations can use the master system to feed extracted material completely to the production. The system can screen stony soil off to a second vibrating screen for moderate natural material deposits. The system can be configured to completely remove stony soil from difficult natural material deposits.
Both systems work with the Haver & Boecker Niagara N-Class vibrating screen. The screen is perfect for scalping thanks to its smooth operation and heavy-duty design making it capable of screening as much as 5,000 tons per hour. Haver & Boecker Niagara builds the equipment with an advanced four-bearing design that minimizes structural vibration and maintains constant g-force even through fluctuating material feed rates.
Haver & Boecker Niagara primary crushing plant systems feature rugged steel construction and a robust design incorporating a durable, optimum flow, low wear and maintenance friendly chute system and integrated custom conveyor technology. Accessibility is easy thanks to engineered work platforms, walkways and stairway systems. Integrated plant control systems and data management ensure intuitive operation.
Also included is comprehensive plant documentation on CE requirements and beyond and declaration of conforming with EC directives for machines 2006/42/EG (CE). Haver & Boecker Niagara gives extensive consideration of requirements for personal safety and the environment.
About Haver & Boecker Niagara
Haver & Boecker Niagara is a leading provider in screening, washing, pelletizing and primary crushing systems. The company’s mission is to deliver the best of these technologies to customers in the aggregates, mining, mineral processing, chemical and food industries. With deep roots and years of experience in these industries, Haver & Boecker Niagara uses its innovative and shared technologies to effectively meet the needs of customers around the world.
Haver & Boecker Niagara features its Pulse vibration analysis service program. This innovation in vibration analysis gives mining and aggregate customers a means to optimum vibrating screen performance.
Haver & Boecker will feature Pulse in Hall B2, Booth 149 at bauma 2019 in Munich.
Pulse is designed specifically to monitor the health of vibrating screens to ensure optimum screening performance and equipment durability. Understanding that small imbalances can lead to substantial and expensive problems, the program detects irregularities that could translate into diminished performance, decreased efficiency and increased operating costs for the vibrating screen. The reporting and historical tracking of the machine’s performance gives customers the information needed to minimize downtime and maximize productivity and profits.
The program was developed to be easy to operate. Components were specifically chosen and engineered for the harsh environments where screening takes place.
“Pulse has the potential to significantly impact our mineral processing customers as well as others in the processing chain,” said Florian Festge, Haver & Boecker managing director. “Customers that utilize the Pulse system have the tools they need to optimize screening efficiency on a daily basis. This helps improve their operation’s profitability through minimized downtime and lower maintenance costs.”
Pulse gives customers the hardware and software required to instantly record vibrations on their machine. That data is then transmitted to Haver & Boecker where the engineering team analyzes it. The team then issues a report back to the customer including an analysis of the machine’s performance and recommendations for improvement.
If the results are good, the customer has reassurance that the machine is healthy. If the results require a Haver technician to examine the machine in person, a service call is scheduled.
The Pulse system uses an industrial-grade tablet computer that connects wirelessly with eight tri-axial sensors. The sensors attach to key places on the equipment and send up to 24 channels of data to the tablet, which displays a real-time view of the machine’s orbit, acceleration, deviations and more.
Beyond the real-time view on the screen, all of the information from the sensors is electronically stored in the database for an easily-accessible historical overview of the machine. The information can be downloaded online in two report formats. The Orbit Report provides a visual of orbit and wave form, as well as data about acceleration, stroke, speed and phase angle. Fast Fourier transformation, or FFT, plots are processed by the software for values for three channels of data for each measuring point. The Tuning Report extrapolates deviations between measurement points while providing recommendations on balance, acceleration, stroke and speed. It provides feed and discharge analysis as well as diagonal measurements.
About Haver & Boecker
Haver & Boecker, is a leading provider in processing, storage, mixing, packing, filling, palletizing and loading systems. The company’s mission is to deliver the best of these technologies to the marketplace. With deep roots and years of experience in these industries, Haver & Boecker uses its innovative and shared technologies to effectively meets the needs of customers around the world.
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 %.
Haver & Boecker offers NIAflow plant simulation software. NIAflow helps producers optimize quarry and mine operations by diagramming plant flow, machine placement, product pre-calculations and more.
Haver & Boecker will feature NIAflow in Hall B2, Booth 149 at bauma 2019 in Munich.
Developed by Haver & Boecker engineers, NIAflow instantly analyzes existing or proposed processes, records plant statuses, and recognizes potential for plant optimization. The software is available for download on Windows-based systems. NIAflow supports the user in every engineering phase, from drafting flow diagrams for product pre-calculation to plant start-up and simulating parameter changes. Its intuitive menu control makes it easy for all levels of experience, and Haver & Boecker provides several levels of training, if needed. These can be group, company or even individual training sessions.
“We are constantly developing innovative machines, programs and software to help optimize plant efficiency,”
said Florian Festge, Haver & Boecker managing director.
“NIAflow will serve as a cornerstone in the development of process engineering projects. When paired with other Haver & Boecker technology, such as Pulse vibration analysis software, our customers will hold all of the tools they need to optimize process flow and increase productivity and profits.”
NIAflow allows users to analyze more than 90 different process equipment pieces, from crushers and vibrating screens to material washers and conveyers. Beyond equipment, the system uses scientific-based methods to monitor the operation’s input, output and waste piles. The program calculates the mass and volumetric flow rates as well as the valuable content with machine-specific operating parameters to prevent plant bottlenecks before equipment is in place.
“NIAflow will significantly impact the efficiency and profitability of our mineral processing customers,”
said Joachim Hoppe, Haver & Boecker Mining general manager. “The thought process behind this software development was to give our partners tools to closely monitor their plant setup as a whole, allowing them to identify problems and plant bottlenecks. NIAflow helps producers discover the most efficient set up for existing equipment as well as determine equipment needed to enhance productivity and increase production.”
NIAflow is available for purchase for aggregates and mining. The NIAflow Aggregates version is the extensive, full version of the NIAflow simulation software that allows unlimited machine input. NIAflow Mining complements the Aggregates full version, but offers additional equipment options, such as classifying and sorting equipment.
A basic, complementary version of NIAflow is available for download at www.niaflow.com.
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.
