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1

Method of Selecting the Reclamation Temperature of Spent Moulding Sands with Organic Binders

Łucarz M.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

65--70

EN

The thermal reclamation process as a utilisation method of spent moulding and core sands is more costly than other reclamation methods, but in the majority of cases it simultaneously provides the best cleaning of mineral matrices from organic binders. Thus, the application of the thermal analysis methods (TG-DSC), by determining the temperature range within which a degradation followed by a destruction of bounded organic binders in moulding sands, can contribute to the optimisation of the thermal reclamation process and to the limiting its realisation costs. The thermal analysis results of furan resin, one of the most often applied binder in foundry practice, are presented in the hereby paper. The influence of the heating rate of the sample - placed in the thermal analyser - on its degradation and destruction process under oxygen-free (argon) and oxygen (air) conditions, were compared. The recorded TG and DSC curves were used for analysing these processes as the temperature as well as the time function. The obtained results were analysed with regard to determining the required temperature of the thermal reclamation of the investigated organic binder. The usefulness of the developed methodology was found out, however under conditions of meeting several essential requirements concerning the repeatability of performed analyses.

2

Influence of the reclamation method of spent moulding sands on the possibility of creating favourable conditions for gases flow in a mould

Łucarz M., Drożyński D.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

359--364

EN

The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim) on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles), are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions). It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.

3

Conditions of Thermal Reclamation Process Realization on a Sample of Spent Moulding Sand from an Aluminum Alloy Foundry Plant

Łucarz M., Dereń M.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 2

197--201

EN

The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of organic binders on grain surfaces). This process is spontaneously sustained and decreases the demand for gas. However, due to the significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

4

Ecological Aspects of the Performed Thermal Reclamation

Łucarz M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 1

329--333

EN

The thermal analysis results of the selected group of binders and the thermal reclamation of one spent moulding sand with organic binder, are presented in the paper. The reclaiming process of the quartz matrix was performed on the basis of the own method of selecting the reclamation temperature. Taking into account thermogravimetric (TG) analysis results of the binder, the temperature range - required for performing the efficient reclamation of spent moulding sand containing this binder - was indicated. In order to confirm the assumptions, the thermal reclamation operations were carried out at a temperature similar to the determined on the TG basis and - for comparisons - at lower and higher temperatures. During the reclamation operation the reclaim samples were taken for the loss on ignition testing, aimed at the determination of the process efficiency. Temperature in the reclaimer chamber and gas consumptions were also recorded. On the bases of the thermal analyses, loss on ignition, gas consumption and temperatures of the reclaimed moulding sand bed the recommendations for the realisation of the thermal reclamation were given. These recommendations will allow a better, than currently available, process control in an aspect of decreasing the pyrolysis effect and limiting the emission of substances harmful for the environment.

PL

W publikacji przedstawiono wyniki badań analizy termicznej wybranej grupy spoiw i regeneracji termicznej jednej zużytej masy ze spoiwem organicznym. Proces odzysku osnowy kwarcowej przeprowadzono w oparciu o sformułowany własny sposób doboru temperatury regeneracji. Na podstawie zrealizowanych badań analizy termograwimetrycznej (TG) spoiwa wskazano zakres temperatury, wymaganej do przeprowadzenia skutecznej regeneracji termicznej masy zużytej z jego udziałem. W celu potwierdzania przyjętych założeń wykonano zabiegi regeneracji termicznej w temperaturze zbliżonej do wyznaczonej na podstawie TG oraz dla porównania w niższej i wyższej temperaturze. W trakcie trwania zabiegu regeneracji pobierano próbki regeneratu do badania strat prażenia, w celu określenia skuteczności działania procesu. Podczas regeneracji rejestrowano temperaturę w komorze regeneratora oraz zużycie gazu. Na podstawie zestawienia analiz termicznych, strat prażenia, zużycia gazu oraz temperatury złoża regenerowanej masy podano wytyczne do realizacji regeneracji termicznej, w warunkach pełniejszej niż dotychczas kontroli procesu w aspekcie zmniejszenia zjawiska pirolizy i emisji związków szkodliwych do otoczenia.

5

Analiza termiczna a regeneracja termiczna zużytych mas formierskich - cz. II

Grabowska B., Łucarz M.

Laboratorium - Przegląd Ogólnopolski

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2014

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nr 3-4

44--48

PL

Zagospodarowanie zużytych mas formierskich i rdzeniowych wytwarzanych w przemyśle odlewniczym jest aktualnie coraz większym problemem, głównie ze względów ekologicznych. Dlatego celowe wydaje się poszukiwanie metod zmierzających do minimalizacji nakładów na jego realizację.

EN

Management of spent moulding and core sands produced in the foundry industry becomes currently more and more difficult problem, mainly due to ecological reasons. Therefore searching for methods leading to the minimisation of expenditures for its realisation, seems appropriate.

6

Determination of Parameters of the Moulding Sand Reclamation Process, on the Thermal Analysis Bases

Łucarz M., Grabowska B., Grabowski G.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 3

1023--1027

EN

For the practical and functional reasons the investigation of the thermal decomposition process is of an essential meaning in relation to the thermal stabilisation of materials and obtaining for them the desired thermal properties. On the other side, thermal tests are carried out in order to identify degradation mechanisms, which is important in the environment protection context, including materials reuse. The cycle of investigations in which thermal TG-DTA methods were applied as supplementary ones for the works on the optimisation of the thermal reclamation process is presented in the hereby paper. The thermal reclamation process as a utilisation method of spent moulding and core sands is more costly than other reclamation methods, but in the majority of cases it simultaneously provides the best cleaning of mineral matrices from organic binders. Thus, the application of the thermal analysis methods (TG-DTA), by determining the temperature range within which a degradation followed by a destruction of bounded organic binders in moulding sands, can contribute to the optimisation of the thermal reclamation process and to the limiting its realisation costs.

PL

Ze względów praktycznych i użytkowych zbadanie procesu degradacji termicznej ma podstawowe znaczenie w odniesieniu do problemu procesu stabilizowania termicznego materiałów i otrzymywania dla nich pożądanych właściwości termicznych. Z drugiej strony badania termiczne prowadzi się w celu rozpoznania mechanizmów ich degradacji, co ma też znaczenie w kontekście ochrony środowiska, w tym ich powtórnego wykorzystania materiałowego. W publikacji przedstawiono cykl badań, w którym zastosowano metody termiczne (TG-DTA) w uzupełnieniu do prowadzonych prac nad optymalizacją procesu regeneracji termicznej. Proces regeneracji termicznej jako sposób utylizacji zużytych mas formierskich i rdzeniowych w stosunku do innych rodzajów regeneracji zużytych mas jest bardziej kosztowny, ale jednocześnie dający w większości przypadków najlepsze oczyszczenie osnowy mineralnej ze spoiw organicznych. Stąd zastosowanie metod analizy termicznej (TG-DTA), poprzez określenie zakresu temperatury, w którym dochodzi do degradacji, a następnie destrukcji związanych spoiw organicznych w masie, może przyczynić się do optymalizacji procesu regeneracji termicznej i zmniejszenia kosztów jego realizacji.

7

Analiza termiczna a regeneracja termiczna zużytych mas formierskich - cz. I

Łucarz M., Grabowski G., Grabowska B.

Laboratorium - Przegląd Ogólnopolski

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2013

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nr 11-12

43--45

PL

Proces regeneracji termicznej jest jednym ze sposobów utylizacji zużytych mas formierskich i rdzeniowych. W stosunku do innych rodzajów regeneracji zużytych mas jest to zabieg kosztowny, ale jednocześnie dający w większości przypadków najlepsze oczyszczenie osnowy (piasku kwarcowego) ze spoiw organicznych. Zastosowanie analizy termicznej w celu określenia zakresu temperatury, w którym dochodzi do degradacji, a następnie destrukcji związanych spoiw organicznych, może przyczynić się do optymalizacji procesu i zmniejszenia kosztów jego realizacji.

EN

The thermal reclamation process is one of the utilisation ways of spent moulding and core sands. This procedure, in relation to other kinds of reclamation, is rather costly, however simultaneously providing – in a majority of cases – the best purification of the matrix (high-silica sand) from organic binding materials. The application of the thermal analysis in order to determine the temperature range, within which a degradation followed by a decomposition of organic binders occurs, can contribute to the process optimisation and decreasing costs of its realisation.

8

Influence green sand system by core sand additions

Špirutová N., Beňo J., Bednářová V., Kříž J., Kandrnál M.

Archives of Foundry Engineering

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2012

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Vol. 12, iss. 1

105-110

EN

Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron) are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: 'How the green sand systems are influenced by core sands?" This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50%. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition). Ratio of active betonite by Methylene blue test was also determined.

9

Gas evolution rate from heated moulding sands bonded with organic binders

Siewiorek A., Nowak R., Chojecki A., Mocek J.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 1

87-92

EN

This study is continuation of research on gas evolution rate from heated moulding sands used in the manufacture of foundry moulds. The first stage of the study described in [1] included bentonite-bonded sands. At the second stage, sands bonded with organic binders were tested. The composition of gases, evolved at a given temperature using mould heating system that simulates the process of mould pouring with molten metal, was determined. Metal was not used in these studies to prevent its reaction with gases formed as a result of moulding sand heating, since this effect would significantly impede the gas identification or even make it totally impossible.