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1
Content available Curing Properties of Furotec 132 Resin- Bonded Foundry Sand
Mashingaidze M. M.
Archives of Foundry Engineering
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2019
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iss. 4
117--123
EN
The study evaluated the curing properties of natural silica sand moulded with 1% by weight Furotec 132 resin binder catalysed by Furocure CH Fast acid and Furocure CH Slow acid. Physical properties of this sand included an AFS number of 47.35, 4.40 % clay, 0 % magnetic components, 0.13 % moisture, and 64.5 % of the size distribution spread over three consecutive sieves (150 – 600 μm). The sand was washed repeatedly to remove all the clay and oven dried. 2 kg washed sand samples were mulled with pre-determined weights of either catalyst to give 30 %, 50 % and 70 % by weight of 20 g Furotec 132 resin which was added last. Furotec 132 resin + Furocure CH Slow acid catalyst system gives longer bench lives and strip times but the maximum compressive strength in excess of 5000 N/cm2 is attained after more than 8.5 hours curing time irrespective of the weight % of catalyst added relative to the resin. On that basis, exceeding 30 weight % Furocure CH Slow acid catalyst when sand moulding with Furotec 132 resin has neither technical nor economic justification. In comparison, the Furotec 132 resin + Furocure CH Fast acid catalyst system was only capable of producing mould specimens with maximum compressive strength above 5000 N/cm2 at 30 weight % catalyst addition rate. At 50 and 70 weight % catalyst addition rates, the mulled sand rapidly turned dark green then bluish with a significant spike in temperature to about 40 oC, far exceeding the optimum curing temperature of Furotec 132. This high temperature accelerates the curing rate but with a very low degree of resin curing which explains the low compressive strength. In fact the sand grains fail to bond and have a dry, crumbly texture implying dehydration. Thus, not more than 30 weight % Furocure CH Fast acid catalyst should be used in sand moulding.
2
Content available Effect of foundry sand and mineral admixtures on mechanical properties of concrete
Sastry G. K., Ravitheja A., Reddy C. S.
Archives of Civil Engineering
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2018
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Vol. 64, nr 1
117--131
EN
Foundry sand waste can be utilized for the preparation of concrete as a partial replacement of sand. The strength properties of M25 grade concrete are studied with different percentages of replacement of fine aggregates by foundry sand at 0%, 10%, 20%, 30%, 40%, and 50%. The optimum percentage of foundry sand replacement in the concrete corresponding to maximum strength will be identified. Keeping this optimum percentage of foundry sand replacement as a constant, a cement replacement study with mineral admixtures such as silica fume (5%, 7.5%, 10%) and fly ash (10%, 15%, 20%,) is carried out separately. The maximum increase in strength properties as compared to conventional concrete was achieved at 40% foundry sand replacement. Test results indicated that a 40% replacement of foundry sand with silica fume showed better performance than that of fly ash. The maximum increase in strengths was observed in a mix consisting of 40% foundry sand and 10% silica fume. SEM analysis of the concrete specimens also reveals that a mix with 40% foundry sand and 10% silica fume obtained the highest strength properties compared to all other mixes due to the creation of more C-H-S gel formations and fewer pores.
PL
Ze względu na swoją przewodność cieplną, piasek jest używany od wieków jako materiał formierski w przemyśle odlewniczym wykorzystującym metale żelazne i nie żelazne. Odlewnie z powodzeniem wielokrotnie przetwarzają i ponownie wykorzystują piasek. Jeśli piasek nie może być ponownie użyty w odlewni, wówczas jest on usuwany z odlewni i określany jako ZUŻYTY PIASEK ODLEWNICZY (UFS) lub ODPADOWY PIASEK ODLEWNICZY (WFS). Takie odpady zużytego piasku odlewniczego mogą być wykorzystywane w procesie przygotowywania betonu w ramach częściowej wymiany piasku. W celu zbadania możliwości wykorzystania zużytego piasku odlewniczego jako częciowego zamiennika dla drobnego kruszywa, przeprowadzono badanie eksperymentalne. Właściwości wytrzymałościowe, takie jak wytrzymałość na ściskanie, wytrzymałość na rozciąganie i wytrzymałość na zginanie betonu klasy M25 są badane z zastosowaniem różnego procentowego zastąpienia drobnego kruszywa zużytym piaskiem odlewniczym, przy wartościach 0%, 10%, 20%, 30%, 40% i 50%. Określona zostanie optymalna zawartość procentowa zużytego piasku odlewniczego w betonie, odpowiadająca maksymalnej wytrzymałości. W celu utrzymania takiej optymalnej zawartości procentowej w odniesieniu do takiej wymiany zużytego piasku odlewniczego przeprowadzane są badania wymiany cementu z domieszkami, takimi jak popiół lotny (10%, 15%, 20%) oraz pył krzemionkowy (5%, 7,5%, 10%), oddzielnie dla właściwości wytrzymałościowych betonu. W ramach powyższych badań, określono maksymalną wytrzymałość betonu odpowiadającą wymianie pyłu krzemionkowego i popiołu lotnego. Zaobserwowano, że maksymalny wzrost właściwości wytrzymałościowych w porównaniu do konwencjonalnego betonu został osignity przy 40% zastpieniu zuytego piasku odlewniczego. Maksymalny wzrost wytrzymałości zaobserwowano w mieszaninie składającej się z 40% piasku odlewniczego z 10% zawartością pyłu krzemionkowego. Analiza SEM próbek betonu pokazuje również, że mieszanina z 40% zawartością piasku odlewniczego oraz 10% zawartością pyłu krzemionkowego uzyskała najwyższe właściwości wytrzymałościowe w porównaniu do wszystkich innych mieszanin, ze względu na tworzenie większej ilości form żelowych C-H-S i mniejszej ilości porów.
3
Content available The Research on Characterization of Crushability for Foundry Sand Particles
Dai Y., Ma Q. Y., Li X. H., Zhang X., Hu F. P., Zhang Y., Xie W. D.
Archives of Foundry Engineering
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2017
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Vol. 17, iss. 4
231--235
EN
In this paper, crushability of foundry sand particles was studied. Three kinds of in-service silica sands in foundry enterprises selected as the study object, and foundry sand particles were subjected to mechanical load and thermal load during service were analyzed. A set of methods for simulating mechanical load and thermal load by milling and thermal-cold cycling were designed and researched, which were used to characterize the crushability for silica sand particles, the microstructure was observed by SEM. According to the user’s experience in actual application, the crushability of Sand C was the best and then Sand B, the last Sand A. The results indicated that mechanical load, thermal load and thermal-mechanical load can all be used to characterize the crushability of foundry sand particles. Microscopic appearances can qualitatively characterize the crushability of foundry sand particles to a certain extent, combining with the additions and cracks which are observed on the surface.
4
Content available Cement bound mixtures with metallurgical slags for road constructions: mix design and mechanical characterization
Pasetto M., Baldo N.
Inżynieria Mineralna
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2013
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R. 14, nr 2
15--20
EN
Environmental, economical and technical problems have led to increasing attention towards the recycling of waste materials in the construction of road infrastructure. This paper reports the results of a study carried out at the Experimental Road Laboratory of the University of Padua, aimed at designing cement bound mixtures for road construction, characterized by a stone matrix made exclusively with electric arc furnace steel slag, waste foundry sand and ladle furnace slag, used in different proportions. The physical-geotechnical properties of the metallurgical slags have been evaluated by means of the most pertinent laboratory procedures of the road technical sector. Cement bound mixtures, characterized by five different proportions of artificial aggre¬gates, have been designed in terms of Proctor, compression and indirect tensile strength tests. The mechanical characterization of the hydraulic mixes has been completed with the elastic modulus evaluation, through ultrasonic tests. The excellent results (compression and indirect tensile strength at 7 days up to 7.23 MPa and 0.92 MPa respectively, depending on the mixture type), have met the main Italian Contract Specifications, demonstrating the possibility to successfully reuse different types of metallurgical slags, in the complete substitution of the natural aggregates, for the development of cement bound mixtures designed for road construction.
PL
Ograniczenia mieszanin cementu i żużli metalurgicznych do budownictwa drogowego – charakterystyka właściwości mechanicznych Problemy środowiskowe, ekonomiczne i techniczne doprowadziły do wzrostu zainteresowania recyklingiem materiałów odpadowych w celu konstrukcji infrastruktury drogowej. Referat przedstawia wyniki badań przeprowadzonych w Drogowym Laboratorium Eksperymentalnym Uniwersytetu w Padwie, które zajmuje się projektowaniem mieszanki cementu do budowy dróg charakteryzującej się macierzą skalną wykonaną wyłącznie z żużla z pieca łukowego, piasku formierskiego oraz żużla kadziowego użytych w różnych proporcjach. Fizyczno-geotechniczne właściwości metalurgicznych żużli zostały określone dzięki najbardziej stosownym procedurom laboratoryjnym technicznego sektora drogowego. Zaprojektowano charakteryzujące się pięcioma różnymi proporcjami sztucznych kruszyw mieszanki oraz poddano je testom na sprężanie oraz pośrednim testom na wytrzymałość na rozciąganie. Charakterystyka mechaniczna mieszanek hydraulicznych została uzupełniona o określenie współczynnika sprężystości wzdłużnej poprzez testy ultradźwiękowe. Znakomite wyniki (sprężania i wytrzymałość na rozciąganie w siódmym dniu wynosiły odpowiednio 7,23 MPa i 0,92 MPa w zależności od rodzaju mieszanki) spełniły wymogi prezentując jednocześnie możliwość pomyślnego ponownego użycia różnych rodzajów żużli metalurgicznych, będących zamiennikami naturalnych kruszyw, w celu rozwoju mieszanek do konstrukcji dróg.
5
Content available remote Possibilities of utilizing used moulding and core sands by microwave treatment
Granat K., Nowak D., Stachowicz M., Pigiel M.
Archives of Foundry Engineering
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2011
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Vol. 11, iss. 1
35-38
EN
The paper presents a semi-industrial reactor designed for microwave utilization of waste moulds and cores made of moulding sands prepared in furane resin technology. It was found that a possibility exists of effective incinerating this way prepared residues of cores separated from moulding sands or waste moulds left after casting. The preliminary tests evidenced that microwave heating is an effective way of disposing waste moulding sands and the applied apparatus permits effective control of the microwave heating process. The special structure permitting rotations of charge material and proper selection of the generators working cycles guarantee significant speeding-up the process and its full stabilisation. Application of microwave heating for utilization of waste moulds and cores containing synthetic resins as binders ensures significant and measurable economical benefits resulting from shorter process time.
6
Content available remote Influence of moulding sands grain size on the effectiveness of quality control systems
Jakubski J., Dobosz S. M., Major-Gabryś K.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 2
47-50
EN
One of the modern methods of the production optimisation are artificial neural networks. Neural networks owe their popularity to the fact that they constitute convenient tools, which can be applied in an extremely broad research scope. This is caused by their ability to represent complex functions. Their non-linearity should be specially emphasised. Neural networks are gaining broader and broader application in the foundry industry, among others for controlling melting processes in cupolas and in arc furnaces, for designing castings and supply systems, for controlling moulding sand processing, for predicting properties of cast alloys or selecting parameters of pressure castings. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is the assessment method of sands suitability by means of detecting correlations between their individual parameters. The presented investigations were obtained by using the Statistica 9.0 program. The aim of the investigations was to select the neural network suitable for prediction the moulding sand moisture on the basis of the determined sand properties such as: permeability, compactibility, friability and compressive strength in dependence on the matrix grain size.
7
Content available remote Gas pressure in sand mould poured with cast iron
Chojecki A., Mocek J.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 1
9-14
EN
The results of measurements of gas pressure in foundry moulds made from sands bonded with bentonite, sodium silicate and furan resin were disclosed. It was found that the maximum pressure during pouring of mould with metal occurs in the case of bentonite sands, especially with the addition of coal dust. The effect of this pressure on the formation of surface defects in castings was examined.
8
Content available remote Efficiency of additives of the polysaccharide type on physical properties of bentonite mixtures
Beňo J., Jelínek P., Špirutová N., Mikšovský F.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 1
5-8
EN
The addition of polysaccharide additives generally aims at improving some important physical properties of bentonite mixtures, above all the stability of moulds against the water loss and prevention of surface defects of castings. Polysaccharide products of inland and foreign production were checked in mixtures of two bentonites of the Czech provenance with the same montmorillonite content. The attention was paid in particular to the abrasion resistance of mixtures during storing them under constant climatic conditions. Conclusions have shown the substantial influence of: the amount of the added additive, the kind and structural composition of the additive (pH of the water extract, electric conductance).
9
Content available remote The cross-linking influence of electromagnetic radiation on water-soluble polyacrylan compositions with biopolymers
Grabowska B.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 1
41-44
EN
The results of examinations of the cross-linking influence of electromagnetic radiation - in a microwave range - on polyacrylan compositions with biopolymers, are presented in the hereby paper. The cross-linking process of the tested compositions was determined on the basis of the FT-IR spectroscopic methods. It was shown that microwave operations can lead to the formation of new cross-linked structures with strong covalent bonds. The adsorption process and formation of active centres in polymer molecules as well as in highsilica sand were found due to microwave radiations. In this process hydroxyl groups (-OH) - present in a polymer - and silane groups (Si-O-H) - present in a matrix - are mainly taking part. Spectroscopic and strength tests performed for the system: biopolymer binding agent - matrix indicate that the microwave radiation can be applied for hardening moulding sands with biopolymer binders.
10
Content available remote Assessment of environmental influence of bentonite and lustrous carbon carrier - in an aspect of gases emission
Bobrowski A., Holtzer M.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 1
21-24
EN
The emission results of the selected gases from a bentonite-carbon mixture and from dusts originated from dry de-dusting of the green sand processing plant (at high temperatures) are presented in the paper. In order to check and compare samples of dusts and bentonite-carbon mixtures in respect of emission of gases the Evolved Gas Analysis (EGA) was performed by means of the mass spectrometry method. This method allows to determine emission conditions of the selected chemical compounds.
11
Content available remote Applications of the systems theory to the designing of the sand preparation sub-system in foundry plants
Wrona R., Stawowy A., Macioł A.
Archives of Foundry Engineering
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2009
|
Vol. 9, iss. 3
217-220
EN
This study provides the basic principles for designing the functional structure of manufacturing systems and their components. The analysis of functional values is applied to create the technological and manufacturing model underlying the design of the foundry equipment with machine units and materials handling systems. Quoted examples illustrate the approved procedure to be applied to control the sand preparation process in a foundry.
12
Content available remote Polysialates binders preparation and their influence to shear strength of foundry sand mixtures
Fridrich R., Jelinek P.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 2
37-40
EN
This paper deals with polysialates water-glasses preparation. There were used various procedures with the goal to create inorganic polymer on silicon and aluminum base. The one composed of SiO2 and AlO4 tetrahedron chains. For the preparation was concentrated NaOH solution used together with metakaolinite in a way low-temperature synthesis in the presence of alkaline silicate: higher pressure and temperature (autoclave) to direct making of alkaline silicate made of sand, NaOH with metakaolinite addition and by melting fritted glass together with metakaolinite and dissolution in autoclave. The dissolving effectivity was evaluated by the concentration of aluminum in alkaline silicate and by the influence to reduce strengths after heat exposition with this inorganic binder.
13
Content available remote Wpływ dodatku pyłu krzemionkowego na właściwości klasycznych mas formierskich
Holtzer M., Rygulski T., Wyrobek A., Drożyński D.
Archiwum Odlewnictwa
|
2003
|
R. 3, nr 9
197--202
PL
W artykule przedstawiono wyniki badań wpływu dodatku pyłu krzemionkowego, powstającego przy produkcji żelazostopów, do klasycznych mas formierskich na ich właściwości technologiczne. Badania te stanowią element szerszych badań dotyczących możliwości wykorzystania pyłu krzemionkowego w odlewnictwie. Przeprowadzono próby z dodatkiem 2,5 i 5% pyłu. Jako masę wyjściową zastosowano masę z bentonitem na osnowie piasku kwarcowego. Ogólnie dodatek pyłu krzemionkowego powoduje przesunięcie uzyskiwania maksymalnych wartości przepuszczalności i wytrzymałości masy na rozciąganie i ściskanie w kierunku większych zawartości wody w masie. Wprowadzenie pyłu krzemionkowego ma korzystny wpływ na osiągane wartości wytrzymałości masy, zwłaszcza w przypadku wytrzymałości na rozciąganie. Jako optymalny dodatek do masy klasycznej uznano 5% pyłu.
EN
This papers deals with laboratory tests carried out to determine influence of silica powder contents on selected properties of green sand. The additions of silica powder were 2,5% and 5% as a sand replacement. The advantageous influence of silica powder on green sand compression and tensile strength and permeability was found. The optimum addition of silica powder was 5%.
14
Content available remote Analiza eksploatacji systemu transportu pneumatycznego piasku w odlewni „Koluszki”
Cyprys A., Grzelka T., Jopkiewicz A.
Archiwum Odlewnictwa
|
2002
|
R. 2, nr 5
11--18
PL
W referacie przedstawiono system transportu pneumatycznego firmy „DYNAMIC AIR” użytkowanego w Odlewni Koluszki od chwili jej powstania w 1976 roku. Opracowanie zawiera opis systemu oraz ocenę jego eksploatacji z podkreśleniem zaistniałych problemów i sposobów ich rozwiązywania.
EN
The sand pneumatic conveying system of the DYNAMIC AIR firm, used in Koluszki Foundry since it’s coming into existence in 1976, is presented. Paper contains a system description and its exploitation assessment. The existed problems and ways of their solving are pointed out.
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