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1

Studies of mechanical and technological parameters and evaluation of the role of lustrous carbon carriers in green moulding sands with hybrid bentonite

Kamińska Jadwiga, Stachowicz Mateusz, Puzio Sabina, Angrecki Michał

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e11, 2023

EN

Green moulding sands containing special carbonaceous additives, which are the source of lustrous carbon (LC), are discussed in this paper. Five potential lustrous carbon carriers, i.e., two types of hard coal dust (No.1 and No.2), amorphous graphite (No.3) and two hydrocarbon resins (No.4 and No.5), were selected for tests as carbonaceous additives to conventional moulding sands. To better emphasize the differences in the additives used, reference green moulding sand (GMS1) was prepared and subjected to a wide range of basic tests focussed on technological parameters, such as permeability (Pw), friability (Fw), Dietert mouldability test (PD) and compactability (Z) and mechanical parameters, such as compressive strength (Rcw), tensile strength (Rmw), strength in the transformation zone (Rkw). The proposed comprehensive spectrum of tests was repeated on sands with five carbonaceous additives. The most important for the use of additives as carbon carriers was to interrelate the content of lustrous carbon (LC), loss on ignition (LOI) and the obtained results of mechanical and technological tests carried out on conventional moulding sands with the surface quality of iron castings. For this purpose, a series of iron castings was made in the prepared moulding sands and used for the assessment of surface quality based on a number of roughness parameters (Ra, Rz, Rp, Rq, Rv, Rlr, RSm). As a result of the studies it was found that the carbonaceous additives proposed for use help to obtain high-quality surfaces in iron castings.

2

Research on Selected Types of Lustrous Carbon Carriers After the High - Temperature Pyrolysis

Kamińska Jadwiga, Stachowicz M., Kubecki M.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 1

56--62

EN

For research purposes and to demonstrate the differences between materials obtained from the carbonaceous additives to classic green moulding sands, five lustrous carbon carriers available on the market were selected. The following carbonaceous additives were tested: two coal dusts (CD1 and CD2), two hydrocarbon resins (HR1 and HR2) and amorphous graphite (AG1). The studies of products and material effects resulting from the high-temperature pyrolysis of lustrous carbon carriers were focused on determining the tendency to gas evolution, including harmful compounds from the BTEX group (benzene, toluene, ethylbenzene and xylene). Moreover, the content of lustrous carbon (LC), the content of volatile matter and loss on ignition (LOI) of the carbonaceous additives were tested. The solid products formed during high-temperature pyrolysis were used for the quantitative and qualitative evaluation of elemental composition after the exposure to temperatures of 875oC in a protective atmosphere and 950oC in an oxidizing atmosphere. The conducted studies have indicated the necessity to examine the additives to classic green moulding sands, which is of particular importance for the processing, rebonding and storage of waste sand. The studies have also revealed some differences in the quantitative and qualitative composition of elements introduced to classic moulding sands together with the carbonaceous additives that are lustrous carbon carriers. It was also considered necessary to conduct a research on lustrous carbon carriers for their proper and environmentally friendly use in the widely propagated technology of classic green sand system.

3

Studies of Poly(Acrylic Acid-co-Maleic Acid) Sodium Salt Intercalated Montmorillonite

Grabowska B., Cukrowicz S., Kurleto-Kozioł Ż., Kaczmarska K., Drożyński D., Sitarz M., Bobrowski A.

Archives of Foundry Engineering

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2019

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iss. 4

67--75

EN

The intercalation into interlayer spaces of montmorillonite (MMT), obtained from natural calcium bentonite, was investigated. Modification of MMT was performed by the poly(acrylic acid-co-maleic acid) sodium salt (co-MA/AA). Efficiency of modification of MMT by sodium salt co-MA/AA was assessed by the infrared spectroscopic methods (FTIR), X-ray diffraction method (XRD) and spectrophotometry UV-Vis. It was found, that MMT can be relatively simply modified with omitting the preliminary organofilisation – by introducing hydrogel chains of maleic acid-acrylic acid copolymer in a form of sodium salt into interlayer galleries. A successful intercalation by sodium salt of the above mentioned copolymer was confirmed by the powder X-ray diffraction (shifting the reflex (001) originated from the montmorillonite phase indicating an increase of interlayer distances) as well as by the infrared spectroscopy (occurring of vibrations characteristic for the introduced organic macromolecules). The performed modification causes an increase of the ion exchange ability which allows to assume that the developed hybrid composite: MMT-/maleic acid-acrylic acid copolymer (MMT-co- MA/AA) can find the application as a binding material in the moulding sands technology. In addition, modified montmorillonites indicate an increased ability for ion exchanges at higher temperatures (TG-DTG, UV-Vis). MMT modified by sodium salt of maleic acid-acrylic acid copolymer indicates a significant shifting of the loss of the ion exchange ability in the direction of the higher temperature range (500–700°C).

4

Procesy pirolizy i ich wpływ na jakość odlewów oraz na warunki pracy

Holtzer M., Kmita A., Roczniak A.

Prace Instytutu Odlewnictwa

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2016

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Vol. 56, no. 3

175--192

PL

W artykule omówiono procesy termiczne, jakim jest poddawana masa formierska w kontakcie z ciekłym stopem odlewniczym. W zależności od charakteru atmosfery w formie może to być proces spalania lub pirolizy (przy braku tlenu). Procesy te, szczególnie gdy w skład masy wchodzą związki zawierające węgiel (np. masy z żywicami lub z bentonitem i nośnikiem węgla błyszczącego (NWB)), generując odpowiednią atmosferę wewnątrz formy, mają duży wpływ na występowanie takich wad w odlewach, jak: żyłki, przypalenia czy penetracja ciekłego metalu. Aby uniknąć tych wad, należy wytworzyć we wnęce formy atmosferę redukującą. W artykule dokonano obszernego przeglądu prac, w tym również prac własnych autorów, w zakresie procesów pirolizy zachodzących w masach z dodatkiem substancji zawierających węgiel. Przedstawiono schematy mechanizmów rozpadu termicznego żywic oraz NWB podawane przez różnych autorów. Procesy pirolizy generują wiele szkodliwych związków z grupy tzw. Niebezpiecznych Zanieczyszczeń Powietrza (HAPs – Hazardous Air Pollutants), w tym z grupy BTEX (benzen, toluen, etylobenzen i ksyleny) oraz z grupy WWA (wielopierścieniowe węglowodory aromatyczne), co zagraża zdrowiu pracowników odlewni.

EN

The article discusses the thermal processes undergone by the sand mould in contact with the liquid casting alloy. Depending on the character of the atmosphere in the mould, this can be the process of combustion or pyrolysis (when there is no oxygen). These processes, especially when the sand mould contains compounds with carbon, (e.g. sand moulds with resins or bentonite and lustrous carbon formers (LCF)), generating the proper atmosphere inside the mould, have a significant effect on the presence of such casting defects as: veinings, burn-ons and liquid metal penetration. In order to avoid these defects, a reducing atmosphere should be formed inside the mould cavity. The article provides a comprehensive review of the studies, including the authors’ own works, in the scope of the pyrolysis process taking place in sand moulds with the addition of a carbon-containing substance. Diagrams of the mechanisms of the thermal decomposition of resins and lustrous carbon formers (LCF) given by various authors are presented. The pyrolysis processes generate many hazardous compounds from the group of the so-called Hazardous Air Pollutants (HAPs), including those from the BTEX group (benzene, toluene, ethylbenzene and xylenes) as well as from the PAH group (polycyclic aromatic hydrocarbons), which create risks for the health of the foundry workers.

5

Analizatory do oznaczania frakcji węgla wielopostaciowego w materiałach węglopochodnych, w tym kompozytowych

Witowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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Vol. 50, nr 7

154-157

PL

W artykule omówiono aktualnie prowadzone w Instytucie Tele- i Radiotechnicznym prace nad opracowaniem rodziny analizatorów do oznaczania frakcji węgla wielopostaciowego w materiałach węglopochodnych. Omawiane analizatory są nowymi rozwiązaniami technicznymi wykorzystującymi unikalną metodę pomiarową, polegającą na selektywnym utlenianiu zawartego w badanym materiale węgla wielopostaciowego i określaniu zawartości jego poszczególnych frakcji za pomocą modułów detekcyjnych NDIR. Proces oznaczania wielopostaciowych odmian węgla jest w pełni zautomatyzowany i sterowany komputerowo.

EN

Current work, carried out in the Tele & Radio Research Institute, on the elaboration of the analysers for determination of polymorphic carbon fractions in carbonic materials has been described. In the presented analysers new design solutions, based on an unique method of measurements, have been used. The method consists in selective oxidation of a polymorphic carbon included in the investigated material to determine a content of various kinds of carbon by NDIR detecting modules. The process of determination of various forms of carbon is fully automatized and computer controlled.

6

Effect of additives promoting the formation of lustrous carbon on the knocking out properties of foundry sands with new inorganic binders

Izdebska-Szanda I., Stefański Z., Pezarski F., Szolc M.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 1

17-20

EN

The article presents the results of investigations, which make a fragment of the broad-scale studies carried out as a part of the statutory activity on optimising the foundry sand technology using new, modified, inorganic binders. The results of investigations regarding the effect of lustrous carbon carriers on the technological properties of foundry sands with inorganic binders were presented in a concise manner. The selected additives were introduced to moulding sands prepared with the new, modified, inorganic binders bonded by the chemical reaction or by blowing with gaseous CO2. Attention was focussed on the effect of selected additives promoting the formation of lustrous carbon on the knocking out properties of moulds and cores prepared from sands with the new types of inorganic binders. The quality of the test castings was also evaluated along with the tendency to the formation of lustrous carbon at the metal - mould interface, basing on the results of microscopic examinations and analysis of the chemical composition using an X-ray microanalyser.

7

Morphological forms of carbon and their utilizations at formation of iron casting surfaces

Jelinek P., Beňo J.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 2

67-70

EN

Model pyrolysis made possible to identify three solid products of carbonaceous additives. Lustrous carbon is the most important form of the pyrolysis carbon. With its structure and physical and chemical properties it comes near to graphite. Amorphous carbon with turbo-stratic lattice, higher oxireactivity, and lower protective function against liquid metal comes near to carbon black. Semicoke also plays a non-negligible role. All forms of carbon have an important representation in oolitized quartz grain also during forming the casting surface. While amorphous carbon is formed directly from the gaseous phase by homogeneous nucleation, lustrous carbon, with regard to similarity of lattices with quartz, is formed by heterogeneous nucleation on grains. High covering power and low oxireactivity give its highest protecting power of the mould face. New experimental equipment made possible to check a possibility of use of new composite bentonite binders containing "process carbon" (graphite, anthracite, amorphous carbon). The BTEX content in exhalations and in waste sands too was considerably decreased with high smoothness of castings.

8

Pomiar zawartości węgla błyszczącego w materiałach stosowanych jako zamienniki pyłu węglowego w masach formierskich

Witowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 7

66-68

PL

Omówiono wpływ węgla błyszczącego na jakość odlewów, metody jego oznaczania, w tym opracowany w PIE model analizatora do oznaczania węgla błyszczącego w zamiennikach pyłu węglowego oraz w masach formierskich.

EN

In this paper, the importance of the pyrolytical carbon in the foundry process as well as the review of the analitycal methods for determination of the lustrous carbon are presented. The new methodology as well as equipment enables the direct determination of lustrous carbon in coal carriers is also presented.The analyzer is suitable for controlling the quality of carriers of lustrous carbon.

9

Wykorzystanie odpadowego polistyrenu do wytwarzania ekologicznie akceptowalnych nośników węgla błyszczącego dla odlewnictwa

Zieliński J., Polaczek J., Dobrzyńska D., Kordas T., Stefański Z., Machowska Z., Dubrawski S., Zieliński T.

Przemysł Chemiczny

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2005

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T. 84, nr 3

184-187

PL

Mieszanki polimerowo-bitumiczne, otrzymywane z odpadowego spienionego polistyrenu oraz bitumów, pochodzących z wtórnego przerobu ropy naftowej (ciężki „olej sklarowany” z krakingu katalitycznego i ekstrakt furfurolowy średnich destylatów) poddawano termolizie, prowadzonej w obecności poli(chlorku winylu) w 150–200°C przez 1–3 h. W otrzymanych termolizatach oznaczano temperatury mięknienia (odpowiednio 110–145°C i 95–120°C), wydajność węgla błyszczącego (odpowiednio 57–60% i 50–55%) oraz emisję węglowodorów aromatycznych w warunkach eksploatacji form odlewniczych (1200°C). Najkorzystniejsze właściwości wykazał termolizat otrzymany z „oleju sklarowanego” i spienionego polistyrenu, wytworzony poprzez wygrzewanie mieszanki w 150°C przez 1 h przy użyciu dodatku 1% poli(chlorku winylu). Termolizat ten miał temperaturę mięknienia 118,9°C, wydajność węgla błyszczącego 57,7% oraz emisję węglowodorów aromatycznych ok. 60 ppm (w odniesieniu do benzo[a]pirenu 2 ppm), co odpowiada wymaganiom stawianym przez przemysł odlewniczy.

EN

Polymer-bitumen (1:1) blends prepared from expanded polystyrene wastes and secondary petroleum bitumens (heavy „clarified oil” from catalytic cracking or furfural extract of middle distillates) were thermally treated in the presence of small amounts of poly(vinyl chloride) at 150–200°C for 1–3 h. The resulting thermolyzates were analyzed for softening points (110–145°C or 95–120°C, respectively), lustrous carbon yield (57–60% or 50–55%, respectively) and emission of aromatic hydrocarbons under conditions of founding (1200°C). The best properties were found in the thermolyzate made of the ”clarified oil” and expanded polystyrene waste at 150°C for 1 h after addition of 1% poly(vinyl chloride). The thermolyzate showed a softening point of 118.9°C, lustrous carbon yield 57.7% and emission of aromatic hydrocarbons about 60 ppm (emission of benzo[a]pyrene, 2 ppm) and met the quality requirements of the foundry industry.

10

Zastosowanie środowiska LabVIEW przy tworzeniu oprogramowania pomiarowo-kontrolnego

Czerwiński M.

Prace Przemysłowego Instytutu Elektroniki

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2005

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nr 152

78--93

PL

W nowoczesnych urządzeniach pomiarowych konieczne jest często zapewnienie współpracy aparatury pomiarowo - kontrolnej z komputerem PC. Rodzi to potrzebę stworzenia aplikacji realizującej odpowiednie funkcje. W poniższej pracy przestawiono proces tworzenia takiego oprogramowania na potrzeby analizatora do wyodrębniania węgla błyszczącego z węgla pirolitycznego oraz oznaczania jego zawartości. Aplikacja ta była realizowana w środowisku LabVIEW.

EN

Communication with PC is for modern monitoring and measuring device frequently required. Therefor creation of software, that realizes given functions is needed. In this article a process of creation of such program for lustrous carbon analyzer is shown. This software was realized in Lab VIEW environment.

11

Rozwój metod oznaczania zawartości węgla błyszczącego do celów odlewniczych

Witowski A., Jasek K., Dubrawski S.

Prace Przemysłowego Instytutu Elektroniki

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2005

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nr 152

40--50

PL

W artykule omówiono rolę jaką odgrywa stosowanie węgla błyszczącego w procesach odlewniczych oraz zaprezentowano metody jego oznaczania.

EN

Lustrous carbon, which is the form of pyrolytical carbon, is produced by thermal degradation of carbonaceous additives in foundry moulds. The quantitative determination of the lustrous carbon content in the foundry moulds as well as in the carbonaceous additives is dificult and not fully solved problem. In this paper, the importance of the pyrolytical carbon in the foundry process as well as the review of the analytical methods for determination of the lustrous carbon are presented. The preliminary results of investigation on differentiation of various forms of pyrolytical carbon are described.

12

Hydrocarbon resin/polymer blends as precursors of lustrous carbon - Rapid Communication

Zieliński J., Polaczek J., Dobrzyńska D., Zieliński T., Dubrawski S., Machowska Z.

Polimery

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2005

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T. 50, nr 3

216-218

EN

Ternary hydrocarbon resin/expanded polystyrene/poly(vinyl chloride) (HR/EPS/PVC) blends and hydrocarbon resin/expanded polystyrene/polycyclic aromatic hydrocarbons (HR/EPS/PAH) were prepared. Softening point and lustrous carbon yield of the blends were studied to evaluate their applicability as lustrous precursors for molding sands manufacturing. The softening points of the blends increased while the lustrous carbon yield showed a flat maximum with increasing of poly(vinyl chloride) content. Both softening point and lustrous carbon yield decreased with increasing temperature of the blending.

PL

Otrzymano trójskładnikowe mieszaniny żywica węglowodorowa/spieniony polistyren/poli(chlorek winylu) (HR/EPS/PVC) i żywica węglowodorowa/spieniony polistyren/policykliczne węglowodory aromatyczne (HR/EPS/PAH) (tabele 1-3). Badano wydajność węgla błyszczącego (LC) oraz temperaturę mięknienia mieszanin w celu określenia ich przydatności jako prekursorów LC do wytwarzania mas formierskich stosowanych w odlewnictwie. Temperatura mięknienia mieszanin rośnie wraz ze zwiększaniem zawartości PVC [do 20 cz. mas./100 cz. mas. (HR + EPS)], natomiast wydajność LC wykazuje płaskie maksimum w obszarze 2-3 cz. mas. PVC/100 cz. mas. (HR + EPS) (rys. 1-4). Ze wzrostem temperatury mieszania (150-200 stopni C) zmniejsza się zarówno temperatura mięknienia badanych mieszanin, jak i wydajność LC (rys. 5 i 6).

13

Odlewnicze masy z bentonitami- jakość a wymagania

Dobosz S. M., Asłanowicz M.

Krzepnięcie Metali i Stopów

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1998

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nr 35

83--91

PL

W artykule przeanalizowano wymagania stawiane odlewniczym masom z bentonitem pod względem jakości bentonitu, obejmujące : właściwości technologiczne mas w temperaturze otoczenia i temperaturze podwyższonej, cieplną i chemiczną deaktywację lepiszcza decydującą o trwałości mas, a także możliwość wprowadzania bentonitu do mas w postaci mieszanek z dodatkami wydzielającymi węgiel błyszczący.

EN

The article analyses the requirements, set to foundry sands with bentonite with regard to quality of bentonite, that includes: technological properties of sands in the surrounding's temperature and in the increased temperature, thermal and chemical clay's deactivation, deciding about mould's durability; and also a possibility of putting a bentonite into sands in the form of mixture with additions, that secrete a lustrous carbon.

14

Bentonit z nośnikiem węgla błyszczącego w wilgotnych masach formierskich

Szmigielski T.

Krzepnięcie Metali i Stopów

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1998

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nr 35

77--82

PL

Przedstawiono badania wpływu zawartości nośnika węgla błyszczącego w bentonicie na jakość powierzchni odlewów żeliwnych. Stwierdzono, że udział nośnika dozowanego w odpowiednich ilościach w stosunku do bentonitu, gwarantuje uzyskanie powierzchni odlewu czystych i bez wad powierzchniowych.

EN

The studies on the effect of lustrous carbon contents on the quality of surface of cast iron castings were presented. It was confirmed that lustrous carbon carrier being supplied in the proper in to bentonite ensures the obtaining o f castings with clean and defect free surfaces.