Recycling of foundry sands
Disposal of Waste Foundry Sand (WFS) remains to be one of the significant challenges faced by the foundry industry nowadays. Because they are using large quantities of sand, foundries implementing sand-based molding and core-making processes should consider its recycling as a strategic industrial issue. The distances and transportation costs to landfills are increasing for foundry companies, which is why alternatives to the environmentally friendly treatment of this waste became a key issue for foundries. Approximately 100 million tons of waste foundry sands (WFS) are generated annually worldwide by the foundry industry and around 70% of recycling sand cans could be use as new sand (source: Climaxion). This recycling approach is even more important as foundries deal with an increasing demand of this natural resource while volumes extracted from deposits are continuously reduced. Reclamation of waste foundry sand can be done 2 ways namely, mechanical, and thermal reclamation (as JML Industrie operates). This treatment is particularly efficient for chemical sand as it allows us to recover up to 95% of the sand used within the foundry. In addition, thermal sand reclamation appears to be a great solution face to environmental issues: low energy consumption (gas) and limited pollutants discharges into the air. Even if it could be considered as expansive and quite difficult to implement, a thermal reclamation plant should be considered as a long-term and suitable investment. Our team at JML Industrie, helps foundries, depending on their needs and market, to select the most appropriate equipment for their business. More information: https://www.jml-industrie.com/environmental-solutions/
In progress Operations
JML is currently manufacturing a cooling drum at his headquater and main production site located in France, Vrigne-au-bois (Grand Est). This equipment is built to shake-out and to cool the sand and will be used by a foundry based in the East of France which produces ductile iron with vertical molding line to optimize their road plate production JML has already installed 6 of them in the last 2 decades Around 6 months are necessary to deliver this equipment as we are now at step 1 (workshop test to ensure all mechanical parts are well assembled). Then step 2 will focus on commissioning on customer site empty test in line with the sand shop test with cold sand during 3 days after 2 weeks of production, optimisation with hot sand We will be proud to share the second step with you next time ! We help your foundry stay ahead by helping you optimise your operations through the right machinery that gives you better results, reduced maintenance and reliable run times.
In progress Operations
JML is currently manufacturing a cooling drum at his headquater and main production site located in France, Vrigne-au-bois (Grand Est). This equipment is built to shake-out and to cool the sand and will be used by a foundry based in the East of France which produces ductile iron with vertical molding line to optimize their road plate production JML has already installed 6 of them in the last 2 decades Around 6 months are necessary to deliver this equipment as we are now at step 1 (workshop test to ensure all mechanical parts are well assembled). Then step 2 will focus on commissioning on customer site empty test in line with the sand shop test with cold sand during 3 days after 2 weeks of production, optimisation with hot sand We will be proud to share the second step with you next time ! We help your foundry stay ahead by helping you optimise your operations through the right machinery that gives you better results, reduced maintenance and reliable run times.
Dust silos delivered
Environmental requirements require the proper treatment of the dust generated during the foundry manufacturing process. JML offers many technical solutions meeting both the CE and ATEX standards. The images shown below are of a 60m3 stainless steel dust silo to centralize the dust coming from the mechanical regeneration filter and from the mechanical regeneration filter. In this example, the discharge rate is one tanker truck per week. This assembly has eliminated all bigbag handling and protected the operators from diffuse dust during these handlings, in particular thanks to the telescopic sleeve for the transfer of dust from the silo to the tanker trucks.
Three 60m3 silos delivered
We have recently completed a project for a French foundry and have delivered 2 new sand silos and 1 black/bentonite premix silo. Each silo has a capacity of 60m3 and allows the unloading of delivery trucks. The sand and the premix are dosed by a weighing hopper. The entire contents is then sent by pneumatic transport into the sand mixer. We have been working on projects of this type since the decision 4 years ago to further invest in our equipment range. This was a key step and has allowed us to produce silos, chimneys and discharge drums at highly competitive prices without compromising on quality.
Green sand molding challenges and best practice
How have green sand molding requirements changed over the years? Over the past 20 years, the requirement of quality, in particular but not only, by users in the automotive sector, are the source of modernizing the structures of technological readiness of existing green sand plants. The quality and characteristics of molding sand as it was conceived in the recent past, now is not acceptable. The cadences of the installations of green sand molding, both type flaskless vertical and/or horizontal separation, as well as those using the flask molding, can be managed only if the technical characteristics of the green sand are kept in accordance with the programmed values within limits very tight.In short, it must always comply with the necessary values in the green sand used for the molding, even in the presence of a great variability of the different characteristics in the return sand from the shakeout.At the same time, one of the consequences of the recent crisis was that, to alleviate the drastic reduction in the value of sales, general business and foundries in particular, have devoted their efforts, with a production substantially reduced in order to maintain where possible, the necessary margin of profit by reducing production costs.Said target can be achieved mainly by reducing the consumption of raw materials and minimizing the number of defective castings or scrap.Space, in response to these needs, collaborating with some of its traditional customers, has developed an important research work on the optimization of equipment and controls achieving, without large investments, very positive results. Optimal molding sand preparation A good molding sand, where it is intended to feed a vertical flaskless molding line, in our experience should appear with the following values: Compressive strength gr/cm2 2,300 ± 50 Shear strength gr/cm2 550 ± 25 Moisture % 3.2 ± 0.1 Compatibility % 40 ± 2 Permeability gr/cm2/m 100 ± 5 The data above shows the behaviour of the temperature of the green sand before and after treatment with an installation of MU + TVR Space 120 T/h, installed in a foundry which produces exclusively for an important automotive industry.It is obvious the excessively uneven temperature behaviour at the inlet with values varying between 65÷125 ° C while the output values found are stable between 25÷35 ° C. A document, prepared by one of our customers, from which we have the consent and permission for its disclosure, provides information of a confidential nature relating to the production and confirms the remarkable economy seen after the investment made with the installation of the system Space, as well as the improved quality of castings and reduced casting scrap. Effective treatment of return sand Regardless of the type of the installation of molding, the return sand will always suffer for substantial changes in the values of flow rate, temperature and residual moisture.For years, the continuing need to improve the quality of green molding sand, always in coincidence with the increase of the production of the plant, it is taken for granted the need to optimize both equipment and facilities for the correct preparation of molding green sand. In the market appeared coolers, pre-coolers, mixers, vibrating fluid bed coolers, cooling mixers … etc. all controlled by more or less complex control equipment.You could say that to the market appeared more manufacturers than ideas.So you could say in a more direct way and, as always happens in all areas, that from an idea many copies were created. Introduction of additives in the pre-mixer The technical department of studies and projects Space, with more than 49 years of experience in the preparation of the green molding sand, but above all, thanks to the collaboration of our most demanding customers, has developed an innovative technological process. A process started and already experienced for years in many installations. This process ensures the management and control best suited to the regeneration and development of for green molding sand. Below we provide a summary of the experience gained through innovation and checked step by step in the practical exercise of the treatment of the molding sand. Managing hot and dry return sand It is desirable to reduce the temperature at least to 34÷38 °C and humidity values about 2÷2,3%. The temperature and humidity of the return sand can vary within a wide range of values, as well as the flow rate or capacity of the preparation plant. In order to decide, for the most accurate corrective actions, it is essential to obtain the instantaneous values of temperature, humidity and flow rate of the system. A temperature probe PT 100, located and protected in a very thin support, not to suffering from excessive thermal inertia, measures the temperature of the return sand. A capacitive radiofrequency probe SPACE “PGF” provide a continuous measurement of moisture in the return sand. A system of continuous weighing, applied on the conveyor belt, grant a continuous measurement of the return sand weight. A set of temperature sensors and moisture, installed at the outlet of the cooler, ensure the measuring of the sand temperature and the humidity. All probes, through an analogue to digital conversion circuit, are connected to a PLC. A program developed and adapted specifically for each application ensures a fully automatic operation of plants. A feedback system, based on a PID algorithm, ensures the constant maintenance of the characteristics of programmed values within narrow limits of variability. The above graphs display the parameters before and after (see blue arrow indicates the date before / after) of an installation System Space: The evolution of the temperature of the sand at the beginning of the mixing cycle. The amount of water added in each cycle. The required mixing time after introducing water into the mixer The data correspond to a foundry, equipped with a green sand molding plant with two mixers, which was originally not equipped with premixing and cooling system. It is evident that the lowering of the temperature from 55/65 ° C at levels of 25/30 ° C, together with further optimization of the moisture
How can green sand preparation be improved?
The moulding system, based on green sand technology remains the most widely employed process for foundries around the world. As is well known, the basic components used are easily available. These are, silica sand, clay and water. Today these are available in consistent quality with a narrow tolerance range of variability. Coal dust, and other additives are casting finish enhancers and these are added to the basic components to the individual foundry requirements. Over the years foundry professionals have developed the best individual characteristics of each element to obtain optimal sand mixture for their foundry. The uninterrupted customer demand for continuous improvement in casting quality, along with casting price control, created a permanent research and development process. This continues today and involves close partnerships between foundries, raw material producers and equipment manufacturers. Modern infrastructure has reduced the influence of the material source location relative to the foundry market. In general, most foundries have no problems selecting the most suitable components for their needs. The continued challenge with green sand The instability of green sand characteristics unless handled by a well conceived processing plant and a reliable in line control instruments will produce ongoing problems in the foundry. The moulding sand quality must be adapted to the moulding equipment in use. But, once this has been established, it will be the consistency within a close range of variability that allows for a reduced level of sand quality-related scrap. It is well known that a good moulding sand should never be subject to temperatures above 40 or less than 25°C. This is fundamental but not the only consideration. It should also offer no free moisture, at all, and the compactability has to be maintained ± 2 % with a compressive strength ± 50 2gr/cm, on the target values. These are the most important parameters. Achieving consistency The big question is how is consistency possible when shake-out sand conditions, depending on the sand/metal ratio and core sand pollution, could vary so far as temperature from 70 to 160°C, moisture from 0 to 1,8 %. There is a range of green sand solutions available, at least in as many as the foundry equipment manufacturers available in the market. An ideal system brought to practice SPACE’s return sand processing philosophy was conceived in the ’70s, encompassing all that has been done and developed by other foundry equipment manufacturers. Paying close attention to our customer’s suggestions, learning also from our past mistakes, we now believe that SPACE’s green sand processing equipment, is the most advanced and reliable available anywhere SPACE SPR polygonal screen The dedusting system is designed to cooperate with an adjustable extra ambient air intake, installed all along the enclosing hood underside. This allows the sand falling through the rotating basket to be “counter washed” by the air stream directed up-wards. This feature provides a primary temperature reduction, combined with the possibility to adjust fines removal and keep the screening basket dry for a more efficient operation with reduced maintenance. SPACE MU Pre-mixer Cooling and tempering water is then added, and efficiently mixed, into the return sand in a continuous pre-mixer. The twin horizontal shaft, multi-paddles mixer, provide an intensive action and produces a very consistent and homogeneous sand mixture. As an option, the possibility of introducing additives at this stage, is available. Additions are made on a programmable percentage based on the true weight of processed sand. A notable first cooling effect is also obtained in the MU pre-mixer. SPACE TCR fluid bed cooler The Space TCR is the equipment designed for the processing and management of the final cooling stage. It is based on a vibrating conveyor fitted with micro-perforated stainless steel plates on the top surface of which flows the pre-mixed and extra-moistened sand. Under the sand conveying and fluidising steel plates there is a multi-chamber air plenum system. An adjustable quantity of air is then blown through each chamber, this feature allows for adjusting the air volume as a function of the sand conditions. Where the sand is hot and very wet, a high volume of air is blown, but as the sand moves towards the cooler discharge the temperature and the moisture are reduced proportionally and the air volume is then adapted in order to reduce energy used and fines removal. Since the quantity of sand may vary according to the moulding line output, sometimes ± 30% or more of the air blowing system is automatically adjusted to obtain the target value of moisture and temperature at discharge. SPACE PGF- Control equipment This is a very sophisticated and efficient component of our system. It provide for the full automatic control of many functions that all together combine for compensating the wide fluctuations of the return sand physical characteristics. The return sand, before entering the pre-mixer, is subject to the following parameters control: Continuous weighing, by means of load cell system installed on the feeding belt conveyor Temperature and moisture, by means of self cleaning probes installed in the sand stream. The processed sand, after the fluidised bed cooler, is subject to the following parameters control: Temperature and moisture by means of self-cleaning probes installed in the sand stream. The quantity of water to be added is calculated using the inlet readings, but the outlet readings produce a feedback adjustment factor, through a ‘p.i.d.’ function. We can confirm that the required target moisture and temperature level are easily achieved and maintained within a very close range in spite of wide property fluctuation at the shake out. Therefore, we are in a position to guarantee very consistent physical characteristics of the sand in the storage bins ahead of the mixer or muller. Pre-conditioned sand at 2% to 2.2% moisture and at 30 to 35 °C, after about one hour of resting, is in ideal condition for preparing the optimum moulding mixture to guarantee the lowest sand related scrap. Today, a modern, well maintained muller-mixer equipped with an efficient control system is the way to produce high quality repeatable mixes, and
How to achieve significant economies in the consumption of additives and reduce the level of casting scraps
How the SPACE concept for the treatment of return sand in green sand moulding plants delivers the best characteristics of sand with the least consumptions. SPACE, now part of JML Industrie, is specialized in the treatment of moulding green sand and has built its excellent reputation thanks to the innovative SPACE SYSTEM. How does the SPACE system work for treatment of return sand? Step One Premixer to homogenize the return sand, by batching water and additions. Step Two Fluid bed cooler, where the values of moisture and temperature are brought to the required parameters, in very strict limits. Step Three The treated return sand is introduced into the storage silos. Here the bentonite is activated slowly and in a natural way. Step Four Intensive mixer where it takes place the final adjustment of the moulding sand, also by mean of an accurate automatic management system. Advantages of the SPACE system The latest studies on SPACE installations at some of our most important customers have shown: Reduced consumption of additives between 10% and 16% Increase in the efficiency of the mixer between 65% and 85% Reduction of defective/broken moulds between 5% and 10% Improvement of the green sand properties, reduction of the scraps and lower costs for shot blasting and casting fettling. Why choose the SPACE system? Because the equipment proposed provides the most innovative and competitive solution in the world market. The SPACE system has the following benefits: High quality instruments of measuring and control Constructive quality of the machine Low maintenance requirements Negligible consumption of space parts
Gattermann
Specialising in the production of small and medium series for small and large castingsn, Gattermann is a reliable partner for grey and nodular cast iron. In 2017, they decided to modernise their green sand plant. JML Industrie were delighted to have been selected as the equipment provider for the project. The goal for Gattermann was to take advantage of this investment opportunity to increase the storage volume of the sand. There was also an additional automation upgrade project that was entrusted to JML Industrie. The start of this 80t / h sandblasting project began at the end of 2017. The sand bunker unit installed at the company Gattermann is ready for starting operation
Wir werden grün und schauen, wie sich die Gießereitechnik verändert
Neue Technologien bieten den Gießereien die Möglichkeit, ihre laufenden Betriebe zu ändern und ihren ökologischen Fußabdruck zu reduzieren. Im Vergleich zu anderen Industrien stand die Gießereiindustrie bei der Entwicklung umweltfreundlicher Verfahren und Maschinen immer vor erheblichen Herausforderungen. Es ist bekannt, dass die Gießereien einer besonderen Herausforderung gegenüberstehen. Ein beträchtlicher Energiebedarf wird im Allgemeinen durch Verbrennung fossiler Brennstoffe gedeckt. Dies hat es immer unwahrscheinlich gemacht, dass die Branche grüne Innovationen anführen würde! Eine zweite Herausforderung in der Branche war die Größe der Gießereien weltweit. Die Gießereiindustrie besteht traditionell aus kleinen Gießereien mit einzigartigen Verfahren und Produktkombinationen. Dies beschränkte die Entwicklung von Maschinen und Prozessen, von denen die gesamte Branche profitieren könnte. In Verbindung mit den kleinen Margen, die normalerweise mit dem Gießen verbunden sind, hat dies die Kapazität für erhebliche Investitionen in wesentliche Prozessänderungen verringert. Die Regulierung stellt eine letzte Herausforderung für die Entwicklung neuer Gießereitechnologien dar. Herkömmliche Verfahren wie das Gießen von Gussstücken und die Verwendung von Schmelzöfen unterliegen häufig einer strengen Regulierung, so dass Änderungen häufig langwierige Genehmigungsverfahren erfordern. Dies bedeutet, dass kleinere Gießereien nicht in neue Ausrüstungen investieren können und weiterhin die gleichen CO2- und SO2-Werte abgeben. Technologie als treibende Kraft Mit dem Aufkommen von Industrie 4.0 sehen wir bedeutende Entwicklungen bei Gießereimaschinen. Die Branche hat sich der Bedeutung und der finanziellen Auswirkungen bewusst, umweltfreundlicher zu sein. Wir müssen nur die EcoMetals-Tour auf der GIFA betrachten, um die veränderten Einstellungen zu sehen. Die drei Hauptprozesse, die den Energieverbrauch und die Umweltverschmutzung in Gießereien vorantreiben, sind im Allgemeinen: Formvorbereitung Rohstoffe schmelzen Sand-Guss-Trennung Energieeffizienz In der US-amerikanischen Energy Information Administration Environment wird die Erzeugung von Elektrizität als Hauptquelle für Treibhausgasemissionen der Gießerei identifiziert. Gießereien, die sich auf eine Verringerung ihres Energieverbrauchs konzentrieren, wirken sich nicht nur auf die Umwelt aus, sondern wirken sich auch positiv auf ihren Gewinn aus. Untersuchungen der Abteilung für Industrie- und Fertigungstechnik an der Pennsylvania State University haben gezeigt, dass beim Einsatz von Strategien zur Energieeinsparung in Verbindung mit Techniken zur Abfallreduzierung erhebliche Kostenverbesserungen festgestellt wurden. Sie empfehlen die Verwendung einer Green Value Stream Map, um die wichtigsten Bereiche für die Leistungsbewertung hervorzuheben. Unabhängig von der gewählten Methode sind die Ergebnisse eindeutig. Je weniger Sie verbrauchen, desto geringer sind Ihre Energiekosten. Abfallreduzierung Die Technologie spielt auch eine wichtige Rolle dabei, den Gießereien dabei zu helfen, ihre Abfallmenge zu reduzieren. Die Art der Abfälle, die Gießereien produzieren, hängt von ihrem Ausstoß ab und die Gießereiindustrie ist so groß, um alle Abfälle aufzulisten. Wenn wir das klassische Beispiel von Sand nehmen, der häufig wiederverwendet und recycelt wird, wissen wir, dass eine Gießerei ihren Gesamtabfall erheblich reduzieren kann. Viele recyceln regelmäßig grünen Sand. Das recyclen von Grünsand ist aber begrenzt und kann ab einen bestimmten Punkt nicht mehr verwendet werden. Maschinen, die entwickelt wurden, um weniger Sand zu tragen, erhöhen die Lebensdauer des Sandes. Eine der innovativen Maschinen, die JML Industrie auf der GIFA 2019 präsentiert, reduziert den Sandverschleiß erheblich, da keine mechanischen Teile miteinander in Kontakt kommen. Der Sand kann nicht nur häufiger wiederverwendet werden, sondern auch der Verschleiß der Ausrüstungsteile, wodurch die Lebensdauer der Maschine erhöht wird. In den Nichteisen- und Stahlgießereien entstehen durch das Vorhandensein von Blei, Zink und Cadmium schädliche Abfälle. Ein Bericht von Ijsee schätzte, dass Form- und Kernsand 66% bis 88% des gesamten Abfalls aus Eisengießereien ausmachen. Chemisch gebundener Sand, der für Kerne und Schalenformen verwendet wird, ist schwieriger wiederzuverwenden und kann nach einmaligem Gebrauch zu Abfall werden. Wenn nach der Verwendung zusätzliche Materialien in Sanden identifiziert werden, kann vor der Entsorgung eine Behandlung erforderlich sein. Geräte und Prozesse, die die Toxizität reduzieren, verbessern die negativen Auswirkungen auf die Umwelt und die Entsorgungskosten. Die Industrie arbeitet insgesamt daran, die Menge an Abfall zu reduzieren. Dazu gehören Recyclinginitiativen und Richtlinien zur Verringerung der Toxizität. Bei fortschrittlichen Sandmischern ist es möglich, den Abfall zu reduzieren und die Gesamtqualität zu verbessern, indem das genaue Sandrezept und die Menge zusammen mit einer vollautomatischen Abfüllsequenz geliefert werden. Verringerung der Umweltverschmutzung Das Ergebnis einer effizienteren Abfallbewirtschaftung und der Kontrolle des Energieverbrauchs führt dazu, dass die Gießereien umweltfreundlicher werden. Interne Programme und Richtlinien helfen, Energie zu sparen, Abfälle zu reduzieren und die Effizienz zu steigern. Die Einführung der “Right-First-Time” -Produktion hat einen erheblichen Einfluss darauf. Reduzierung von Abfall und Qualitätsverbesserungen Durch die Überprüfung der Fortschritte bei umweltfreundlichen Technologien wird deutlich, dass diese Verbesserungen auch zu einer höheren Produktionsqualität für Gießereien führen. Durch die Fokussierung auf Qualität und die richtige Produktion beim ersten Mal werden Abfall und Energieverbrauch automatisch reduziert. Dies ist sowohl für die Umwelt als auch für die Produktionsgemeinkosten positiv. Mit der Entwicklung der Branche werden wir auch weiterhin Innovationen sehen, die die Umweltbelastung reduzieren. Industrie 4.0 gewinnt zunehmend an Bedeutung, insbesondere in Deutschland. Da die Technologie die Effizienz und den Output weiter verbessert, wird sich der ökologische Fußabdruck der Branche weiter verringern. Das Engagement von JML Industrie für die Umwelt Vor kurzem hat JML Industrie eine Reihe umweltfreundlicher Geräte auf den Markt gebracht. Ein neues Logo wurde entwickelt, damit die Kunden erkennen können, dass die Produkte von JML Industrie einen Schritt in Richtung einer umweltfreundlicheren Gießereiproduktion darstellt. Seit Anfang Januar haben JML Industrie und alle Unternehmen, die zur Gruppe gehören, Regeln für eine drastische Reduzierung von Kunststoffen verabschiedet. Das Ziel für 2020 ist eine Reduktion von mehr als 70% der Verwendung von Kunststoffen. Dies schließt unsere Lager und Fertigungswerkstätten ein. Wir haben auch unsere Hauptlieferanten gebeten, die Verwendung von Kunststoffen in Verpackungen einzuschränken. Eine der ersten Maßnahmen, die in diesem Zusammenhang ergriffen wurden, ist die Abschaffung von Kunststoffbechern, und wir verwenden jetzt sehr passende Metallbecher.