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Number of results: 121
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Abstract

The goal of this article is to application of non-silica sands based on alumininosilicates as an alternative of traditionally used chromite sand for alloyed steel and iron castings. Basic parameters as bulk density, pH value of water suspension, refractoriness, grain shape of the testing sands were evaluated. Also mechanical properties of furan no-bake moulding mixtures with testing sand were determined. Finally, the influence of non-silica sand on casting quality was evaluated via semi-scale under normal casting production for sand characterization Optimization of production process and production costs were described.

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Authors and Affiliations

J. Beňo
M. Poręba
ORCID: ORCID
T. Bajer
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Abstract

The paper presents the test results of molding compounds, sand casting molds and their analysis. The subject of testing was compound containing furan resins prepared according to the following recipe: matrix – regenerate 90% + fresh sand – 10%, furan resin – 1.10% by weight, hardener – 0.40% by weight. The impact of adhesive type and its quantity (Quan = 0.90, 1.1 and 1.5%) on the strength indexes of molding compound subject to densification was analyzed. The publication presents the test results: tensile strength Rm, compressive strength Rc and flexural strength Rg, as well as compound permeability as function of its density. The analysis also covers the impact of density level on mold strength and the distribution of density level along the mold height.

Based on the test results, it was found that the best method to obtain high strength molds made from compounds with chemical adhesives was to densify it by vibrating the system: match plate – molding flask – compound filling the mold. The effectiveness of this densification method depends on the amplitude and frequency of vibrations.

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Authors and Affiliations

Ł. Petrus
A. Bulanowski
J. Kołakowski
ORCID: ORCID
M. Urbanowicz
J. Sobieraj
M. Jelonek
M. Brzeżański
ORCID: ORCID
J.S. Zych
K. Janerka
ORCID: ORCID
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Abstract

In this work, an assessment and comparison of the quality of selected bentonites and bentonite mixtures was made. The samples consisted of available foundry materials used for bonding green sands. Determining the homogeneity degree and specific surface area of the grains allowed us to compare the examined materials and determine their influence on other parameters. On the basis of a thermal analysis of the bentonites or bentonite mixtures, the changes occurring in the sample during its heating were determined. Determining the potential for ion exchange and montmorillonite content enabled us to assess the binding properties of the materials. The preparation of six green sands with different bentonites or bentonite mixtures gave us the opportunity to assess the changes in apparent density, permeability, compressive strength and friability as a function of humidity, and the impact of different materials on the mentioned parameters. Their charts were analyzed, and the molding sand with the addition of bentonite or a bentonite mixture was selected for which these parameters are favorable. On this basis, the best-presented binding material was assessed and selected.

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Authors and Affiliations

S. Paź
D. Drożyński
M. Górny
S. Cukrowicz
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Abstract

This article investigates the possibilities of the recovery of raw materials at the Kraków–Płaszów municipal wastewater treatment plant (WWTP). The materials include sand coming with raw sewage and delivered by septic tankers, after cleaning sewage systems. Following the Regulation of the Minister of Climate (January 2020), sand from grit chambers is classified in the waste catalog as waste, with the code of 19 08 02. (Journal of Laws of 2020, item 10). The purchase of very efficient units has optimized the grit chamber operation and minimized the amount of waste generated as well as being an odor nuisance. The paper presents a mass balance for sand collected at the WWTP. Due to the use of new sand separators, the amount of this waste has been reduced by 28%. The paper presents the sieve curves of sand collected at the wastewater treatment plant and during the cleaning of sewage wells, as well as for sand mixtures. The sand mixture was prepared to allow some variations in the grain size characteristics of the sand. The graining differentiation indexes and curvature indexes were calculated. In addition, in laboratory tests, the leachability of heavy metals and the content of dry matter (DM) and dry mineral matter (DMM) were determined. The laboratory tests confirmed the reduction of organic solids to a level below 3% of dry weight; the content of heavy metals remained below the level of detection. The experiments confirmed that sand from the WWTP can be used as fine-grained aggregate in the production of concrete.
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Authors and Affiliations

Justyna Górka
1
ORCID: ORCID
Dominika Poproch
2 3
ORCID: ORCID
Małgorzata Cimochowicz-Rybicka
1
ORCID: ORCID
Bartosz Łuszczek
4
ORCID: ORCID

  1. Faculty of Environmental Engineering and Energy, Cracow University of Technology, Kraków, Poland
  2. Doctoral School, Cracow University of Technology, Kraków, Poland
  3. Krakow Water, Kraków, Poland
  4. Kraków Water, Kraków, Poland
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Abstract

The quality of the castings depends, among other influences, on the quality of the moulding mixture used. The silica sands used are characterized by high thermal expansion compared to other sands. The tendency to dilatation of the moulding mixture can be influenced by the choice of the granulometric composition of the basic sand and the grain size. The aim of this work is to present the influence of grain distribution of foundry silica sand BG 21 from Biala Góra (Poland) and the degree of sorting (unsorted, monofraction, polyfraction) on the degree of thermal dilatation of the sand and thus on the resulting quality of the casting and susceptibility to foundry defects. For the purpose of measuring thermal dilatation, clay wash analysis was performed, sieve analysis of the sand was carried out, and individual sand fractions were carefully sorted. The measurements confirmed a higher thermal expansion in the case of monofractional sand grading, up to 51.8 %. Therefore, a higher risk of foundry stress-strain defects, such as veining, can be assumed.
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Bibliography

[1] Czerwinski, F. (2017). Modern aspects of liquid metal engineering. Metallurgical and Materials Transactions B. 48(1), 367-393. DOI: 10.1007/s11663-016-0807-6.
[2] Brůna, M. & Galčík, M. (2021). Casting quality improvement by gating system optimization. Archives of Foundry Engineering. 21(1), 132-136. https://doi.org/10.24425/afe.2021.136089.
[3] Monroe, R. (2005). Porosity in castings. AFS Transactions. 113, 519-546.
[4] Kowalski, J.S. (2010). Thermal aspects of temperature transformation in silica sand. Archives of Foundry Engineering. 10(3), 111-114. ISSN (1897-3310).
[5] Jelínek, P. (2004). Binder systems of foundry moulding mixtures – chemistry of foundry binders. (1st ed.). Ostrava. ISBN: 80-239-2188-6. (in Czech).
[6] Svidró, J., Svidró J. T., & Diószegi, A. (2020). The role of purity level in foundry silica sand on its thermal properties. Journal of Physics: Conference Series. 1527(1), 012039, 1-8. DOI 10.1088/1742-6596/1527/1/012039.
[7] Chao, Ch. & Lu, H. (2002). Stress-induced β→ α-cristobalite phase transformation in (Na2O+Al2O3)-codoped silica. Materials Science and Engineering: A. 328(1-2), 267-276. DOI: 10.1016/S0921-5093(01)01703-8.
[8] Hrubovčáková, M., Vasková, I., Benková, M. & Conev, M. (2016). Opening material as the possibility of elimination veining in foundries. Archives of Foundry Engineering. 16(3), 157-161. DOI: 10.1515/afe-2016-0070.
[9] Beňo, J., Adamusová, K., Merta, V., Bajer, T. (2019). Influence of silica sand on surface casting quality. Archives of Foundry Engineering. 19(2), 5-8. DOI: 10.24425/afe.2019.127107.
[10] Thiel, J., Ziegler, M., Dziekonski, P., Joyce, S. (2007). Investigation into the technical limitations of silica sand due to thermal expansion. Transactions of the American Foundry Society. 115, 383-400.

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Authors and Affiliations

M. Bašistová
1
ORCID: ORCID
P. Lichý
1
ORCID: ORCID

  1. VSB-Technical University of Ostrava, Faculty of Materials Science and Technology, Department of Metallurgical Technologies, Czech Republic
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Abstract

The aim of this study was to assess sand accumulation in the gastrointestinal tract and fecal sand excretion in Silesian foals using three diagnostic methods and taking into account the sex and age of the animals. Another aim of the study was to compare the three diagnostic methods. The study was carried out on 21 clinically healthy Silesian foals (10 females and 11 males) from 9-28 weeks old grazed on permanent pasture. The sand intake was assessed using a sedimentation test, abdominal ultrasonography and a quantitative evaluation of sand per 100 g of stool. In the sedimentation test, the sand was palpable in the stool of 57.1% of the horses, and clearly visible in 42.9% of the animals. The ultrasound examination revealed the presence of sand in the gastrointestinal tract in 66.7% of the horses. It was limited to a single location in 60% of the horses, while it was present in several regions in 40% of the horses. The mean amount of sand was 0.14 ± 0.33 g per 100 g of stool. It did not exceed 0.1g in 71.4% foals, while it ranged from 0.1-0.5 g in 23.8% foals. In 4.8% of the animals, it amounted to 1.6 g per 100 g of stool. There was no correlation between age and gender and the results. There was a positive correlation between the ultrasound examination and the sedimentation test.

Sand may be accumulated in the gastrointestinal tract of foals without any clinical signs. The amount of sand excreted in the stool is not an indicator of the amount of sand accumulated in the gastrointestinal tract. An abdominal ultrasound examination should be combined with a sedimentation test for more specific results.

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Authors and Affiliations

N. Siwińska
A. Łuczka
A. Żak
M. Słowikowska
A. Niedźwiedź
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Abstract

The paper refers to earlier publications of the author, on identification of properties of thermomechanical, chemically hardened core/mold sands. In that earlier period, first version of the original DMA apparatus, produced by a Polish company Multiserw-Morek, was used. The Hot Distortion (HD) study results, published by the author in 2008, referred to phenomena accompanying a thermal shock in real conditions of thermal interaction of a liquid alloy on a mold, in reference to a shock possible to obtain in laboratory conditions, without use of liquid alloy as a heat source, with analysis of solutions applied in the DMA apparatus. This paper presents author’s observations on testing a new, innovative version of the LRu-DMA apparatus, containing a module allowing the Hot Distortion (HD) study. Temperature of specimens achieved in the case of the gas burner heating reaches values definitely above 800°C on the heated side and 610°C on the other side. Using an electric radiator, with maximal temperature of 900°C allows obtaining temperatures in between 225-300°C.
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Authors and Affiliations

Z. Ignaszak
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Abstract

The goal of this contribution is summary of physical – chemistry properties of usually used foundry silica and no – silica sands in Czech foundries. With the help of dilatometry analysis theoretical assumptions of influence of grain shape and size on dilatation value of sands were confirmed. Determined was the possibility of dilatometry analysis employment for preparing special (hybrid) sands with lower and/or more linear character of dilatation.

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Authors and Affiliations

M. Břuska
J. Beňo
M. Cagala
V. Jasinková
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Abstract

Casting industry has been enriched with the processes of mechanization and automation in production. They offer both better working standards, faster and more accurate production, but also have begun to generate new opportunities for new foundry defects. This work discusses the disadvantages of processes that can occur, to a limited extend, in the technologies associated with mould assembly and during the initial stages of pouring. These defects will be described in detail in the further part of the paper and are mainly related to the quality of foundry cores, therefore the discussion of these issues will mainly concern core moulding sands. Four different types of moulding mixtures were used in the research, representing the most popular chemically bonded moulding sands used in foundry practise. The main focus of this article is the analysis of the influence of the binder type on mechanical and thermal deformation in moulding sands.
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Authors and Affiliations

A. Grabarczyk
1
ORCID: ORCID
K. Major-Gabryś
1
ORCID: ORCID
J. Jakubski
1
ORCID: ORCID
St.M. Dobosz
1
ORCID: ORCID
D. Bolibruchová
2
ORCID: ORCID
R. Pastirčák
2
ORCID: ORCID

  1. AGH University of Science and Technology, Faculty of Foundry Engineering, Department of Moulding Materials, Mould Technology and Foundry of Non-ferrous Metals, Al. Mickiewicza 30, 30-059 Krakow, Poland
  2. University of Zilina, Žilinská Univerzita v Žiline, Faculty of Mechanical Engineering, Žilina, Slovak Republic
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Abstract

It is an established fact that when roads are planned and constructed, consideration needs to be given to ensuring the strength of the road surface. It is, however, also the case that when an existing road is being rebuilt or is under maintenance, its base may need to be fortified to increase the road’s vehicle-carrying capacity. The base may, for example, contain a high proportion of weak soil that would be difficult, time-consuming, and costly to remove. This paper aims to investigate the efficacy of using sand-filled piles to reduce road deformation. Experiments conducted on sponge samples confirm that there is a relationship between the total area of sand-filled piles and relative reduction in deformation. It finds that the relationship is non-linear, but that the relationship can be made linear by adjusting the area of sand-filled piles. When the area of sand-filled piles increases from 7.8% to 19.4%, the deformation module can change by up to 100%. Relative reduction in deformation can change from 14% to 45.5% when the area of sand-filled piles increases from 7.8% to 11.7%. The maximum reduction in deformation – 92.4% - occurs when the area of sand-filled piles exceeds 19.5%. Changing the loads borne also affects the deformation module. This paper found that when there was a 10 to 15kg load, and the number of sandfilled piles was increased, there was a change in the deformation module by 380-470%. When there was only a 5kg load on the sample, and the number of sand-filled piles was increased, there was a change in the deformation module by up to 1217%.
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Authors and Affiliations

Sami Mohammed Ayyad
1
Omar Asad Ahmad
1
ORCID: ORCID

  1. Amman Arab University, Faculty of Civil Engineering, Civil Engineering Department; Amman, Jordan Street–Mubis, 11953, Jordan,
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Abstract

The vegetation of the Chernihiv city sands (natural and technogenic origin) has rather high syntaxonomic diversity (17 associations and 5 initial communities) and the ruderal phytocoenoses prevail. Natural phytocenoses are represented to a small extent (Cyperetum flavescentis Koch 1926, Dichostylidi–Helochloetum alopecuroidis (Timar 1950) Pietsch 1973, Artemisia scoparia–Dianthus borbasii community, Kochietum arenariae Fijalk 1978). Synanthropic psammophytes species communities that are more resistant to anthropogenic influence, are formed under urban conditions. The ecological range of vegetation of sandy alluvia varies from xerophytic phytocoenoses in mineral-poor sand (Kochietum arenariae) to the communities, which indicate waterlogged areas with increased mineralization of water and saline bottom sediments (Typhetum laxmannii Nedulcu 1968). Itispossibletoobserve the adventization and apophization of sand vegetation, one of the indicators of which is the rupture of coenotic connections between the species of the community. These phenomena indicate that the process of synanthropization of the vegetation cover of the city keeps intensifying, and first of all, occurs in places of newly formed technogenic ecotopes.

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Authors and Affiliations

Oleksandr Lukash
Hanna Danko
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Abstract

This paper studies the assessment of sensitivity to land degradation of Deliblato sands (the northern part of Serbia), as a special nature reserve. Sandy soils of Deliblato sands are highly sensitive to degradation (given their fragility), while the system of land use is regulated according to the law, consisting of three zones under protection. Based on the MEDALUS approach and the characteristics of the study area, four main factors were considered for evaluation: soil, climate, vegetation and management. Several indicators affecting the quality of each factor were identified. Each indicator was quantified according to its quality and given a weighting of between 1.0 and 2.0. ArcGIS 9 was utilized to analyze and prepare the layers of quality maps, using the geometric mean to integrate the individual indicator map. In turn, the geometric mean of all four quality indices was used to generate sensitivity of land degradation status map. Results showed that 56.26% of the area is classified as critical; 43.18% as fragile; 0.55% as potentially affected and 0.01% as not affected by degradation. The values of vegetation quality index, expressed as coverage, diversity of vegetation functions and management policy during the protection regime are clearly represented through correlation coefficient (0.87 and 0.47).

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Authors and Affiliations

Ratko Kadović
Yousef Ali Mansour Bohajar
Veljko Perović
Snežana Belanović Simić
Mirjana Todosijević
Sonja Tošić
Milosav Anđelić
Dragan Mlađan
Una Dovezenski
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Abstract

The main subject of research in this paper is glauconite with its useful parameters, which is the object of exploitation in the “Górka Lubartowska-Niedźwiada” deposit. The main glauconitic horizon (lower Eocene) is built by loamy fine-grained and medium greenish sands with marine fauna and fragments of amber (ca. 7 m thick). Thin lamins and pockets of silts containing phosphorites and also glauconitic sands with underlaying very thin quartz-glauconitic sands are found at the bottom of this layer. The glauconite deposit in “Górka Lubartowska-Niedźwiada” is an amount of ca. 30% by volume of the main glauconitic horizon. Glauconite of the 1M polytype (XRD) shows large granulometric and morphological differentiation (SEM-EDS). It frequently contains aggregations of euhedral or framboidal pyrite grains (RS), which is indicative of the euxinic nature of the formation environment of the rocks under study. The individual glauconite grains show distinct chemical variability, manifested in a lower share of Al2O3 and an increased content of MgO and CaO (EPMA, XRF). At the same time, a large share of K2O (above 8% by weight) allows it to be included in highly matured glauconite, thus it can be considered as a potential raw material for the production of mineral fertilizers. The association of glauconite with phosphates (SEM-EDS) and anatase inclusions in the grains of glauconite (RS) indirectly point to the contribution of the decomposing organic matter to the formation of grains of this mineral. The xylite fragments preserved in the sediment show a low degree of coalification, which is typical of soft lignite. This also shows that the transformation process was taking place under a relatively small overburden.

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Authors and Affiliations

Lucyna Natkaniec-Nowak
Adam Piestrzyński
Marian Wagner
Wiesław Heflik
ORCID: ORCID
Beata Naglik
Jan Paluch
Krzysztof Pałasz
Stanislava Milovská
Paweł Stach
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Abstract

The results of investigations of spent moulding sands taken from the mould in which the metal core cooling system - to increase the

cooling rate of the ladle casting - was applied, are presented in the hereby paper. The changes of the spent moulding sand at the casting

external side being the result of degradation and destruction processes of organic binder, were analysed in this publication. Since the

reclaimed material, obtained as a result of the mechanical reclamation of spent sands of the same type, is used as a grain matrix of the

moulding sand, the amount of a binder left from the previous technological cycle is essential for the sound castings production. On the

bases of investigations of the thermal analysis, ignition losses, dusts contents and pH values of the samples taken from the spent sand the

conditions under which the process of gases displacing in the casting mould was realised as well as factors limiting the efficient mould

degassing - were considered in this study. The possible reason of a periodical occurrence of an increased number of casting defects due to

changing gas volume emission, being the reason of the realised technological process, was indicated.

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Authors and Affiliations

M. Łucarz
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Abstract

The results of investigations of the granulation process of foundry dusts generated in the dry mechanical reclamation process of used sands, where furan resins were binders are presented in the paper. Investigations concerned producing of granules of the determined dimensions and strength parameters. Granules were formed from the dusts mixture consisting in 50 mass% of dusts obtained after the reclamation of the furane sands and in 50 mass % of dusts from sands with bentonite. Dusts from the bentonite sands with water were used as a binder allowing the granulation of after reclamation dusts from the furane sands. The following parameters of the ready final product were determined: moisture content (W), shatter test of granules (Wz) performed directly after the granulation process and after 1, 3, 5, 10 days and nights of seasoning, water-resistance of granules after 24 hours of being immersed in water, surface porosity ep and volumetric porosity ev. In addition the shatter test and water-resistance of granulate dried at a temperature of 105oC were determined. Investigations were performed at the bowl angle of inclination 45o, for three rotational speeds of the bowl being: 10, 15, 20 rpm. For the speed of 10 rpm the granulation tests of dusts mixture after the preliminary mixing in the roller mixer and with the addition of water-glass in the amount of 2% in relation to the amount of dust were carried out. The obtained results indicate that the granulator allows to obtain granules from dusts originated from the reclamations of moulding sands with the furane resin with an addition of dusts from the bentonite sands processing plants.

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Authors and Affiliations

J. Dańko
J. Kamińska
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Abstract

Measurements of the hardening process of the selected self-setting sands are presented in the hereby paper. Moulding sands were prepared

on the matrix of „Szczakowa” sand of the Sibelco Company. Two resins: phenol-formaldehyde-furfuryl (FF/AF) and urea-formaldehydefurfuryl

(MF/AF) were used for making moulding sands. – Methylbenzene-sulphonic acid was applied as a hardener for the moulding sand

on FF/AF resin, while paratoluene-sulphonic acid for the moulding sand on MF/AF resin. Both hardeners were used in two concentrations:

low – the so-called ‘slow’ hardener and high - ‘fast’ hardener. During investigations, the courses of the hardening process were

determined, more accurately changes of the velocity of the ultrasound wave passage through the moulding sand cL = f(t) and changes of

the moulding sand hardening degree versus time, Sx = f(t). In addition, the kinetics of the hardening process was determined.

Measurements were performed on the research stand for ultrasound investigations.

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Authors and Affiliations

Ł. Jamrozowicz
J. Kolczyk
N. Kaźnica
Z. Pyziak
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Abstract

This publication describes research on the course of the process of cross-linking new BioCo polymer binders - in the form of water-based polymer compositions of poly(acrylic acid) or poly(sodium acrylate)/modified polysaccharide - using selected physical and chemical factors. It has been shown that the type of cross-linking factor used influences the strength parameters of the moulding sand. The crosslinking factors selected during basic research make it possible to obtain sand strengths similar to those of samples of sands bonded with commercial binders. Microwave radiation turned out to be the most effective cross-linking factor in a binder-matrix system. It was proven that adsorption in the microwave radiation field leads to the formation of polymer lattices with hydrogen bonds which play a major role in maintaining the formed cross-linked structures in the binder-matrix system. As a result, the process improves the strength parameters of the sand, whereas the hardening process in a microwave field significantly shortens the setting time.
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Authors and Affiliations

B. Grabowska
A. Bobrowski
K. Kaczmarska
E. Olejnik
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Abstract

In the paper presented are results of a research on influence of electrical and physico-chemical properties of materials being parts of

multicomponent and multimaterial systems used in foundry practice on efficiency and effectiveness of microwave heating. Effectiveness

of the process was evaluated on the grounds of analysis of interaction between selected parameters of permittivity and loss factor, as well

as collective index of energy absorbed, reflected and transmitted by these materials. In the examinations used was a stand of waveguide

resonance cavity for determining electrical properties and a stand of microwave slot line for determining balance of microwave power

emitted into selected materials. The examinations have brought closer the possibility of forecasting the behaviour of multimaterial systems

like e.g. model, moulding sand or moulding box in microwave field on the grounds of various electrical and physico-chemical properties.

On the grounds of analysis of the results, possible was selecting a group of materials designed for building foundry instrumentation to be

effectively used in electromagnetic field.

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Authors and Affiliations

M. Stachowicz
B. Opyd
K. Granat
K. Markuszewska
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Abstract

The results of the efficiency of the primary reclamation process as well as the influence of the used sand temperature and other process parameters on it are presented in this paper. A separate stand realized on a reduced scale was built, which is an analogous process of the primary reclamation treatment of spent foundry sands. The used sands were introduced to the crushing process in an agglomerated form in the way typically used in industrial devices. The primary reclamation process was realized on a set of four horizontal sieves with decreasing mesh clearances while maintaining their geometrical dimensions applied in the Regmas industrial device. The model system consists of a vibratory drive mounted on the table, allowing us to control the supply frequency of the vibratory motors within a range of 40-60 Hz as well as the computer system for measuring the vibration parameters and drive power. The used sand on the quartz matrix with the KALTHARZ U404 resin and 100T3 hardener was used in our investigations. The used sand was prepared under the following conditions: cubic-shaped elements made of the applied furan sand was compacted by vibrations then hardened and subjected to heating under controlled conditions (as a “simulation” of the overheating process taking place in the mold after pouring). Time functions of the crushing and sieving process in dependence of the overheating degree of the reference sand samples (100°, 200°, and 300°C) were investigated at various table vibration frequencies and feed loads of the sieve set. The relative index of the crushing ability was determined.

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Authors and Affiliations

M. Skrzyński
R. Dańko
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Abstract

The investigation results of the influence of the selected parameters of the thermal reclaimer operations on the temperature changes in the

combustion chamber and the process energy consumption, are presented in the hereby paper. The analysis of the heat treatment was

performed with the application of a fresh foundry sand, since it was assumed that the dominating energy part was used for the grain matrix

heating and due to that, the energy used for burning small amounts of organic binder remained on sand grains could be omitted. Thermal

treatment processes performed under various conditions were analysed from the point of view of a gas consumption and temperatures

obtained in the experimental reclaimer. The recorded data allowed to point out the parameters having essential influence on the process of

the quartz matrix heating in the combustion chamber as a gas consumption function.

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Authors and Affiliations

M. Łucarz
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Abstract

Organic binders applied in foundry plants based on synthetic resins, from the one side influence obtaining the required technological properties by the moulding sand and – in consequence – obtaining good quality castings, and on the other side are the source of volatile organic compounds (VOC). Together with synthetic resins their hardeners, which although added in very small amounts emit during their thermal decomposition substances negatively influencing the natural environment, are also used. Both, resins and hardeners only at the influence of high temperatures accompanying moulds pouring with liquid metal generate harmful volatile organic compounds including compounds from the BTEX group. Investigations of the temperature influence on the kind and amount of organic compounds formed during the thermal decomposition of selected binders and hardeners and their mixtures allow to determine temperature ranges the most favourable for emitting harmful substances as well as to compare their emission from the selected materials. The aim of this study was the determination the temperature influence on formation substances from the BTEX group, during thermal decomposition of the selected binder, its hardener and their mixture. The BTEX group emission constitutes one of the basic criteria in assessing the harmfulness of materials applied for moulding and core sands and it can undergo changes in dependence of the applied system resin-hardener. Investigations were carried out on the specially developed system for the thermal decomposition of organic substances in the temperature range: 5000 C – 13000 C, at the laboratory scale. The investigations subject was the furan resin, its hardener and hardened furan resin. The assessment of the emission degree of the BTEX group in dependence of the system subjected to the temperature influence was performed, within the studies. The temperature range, in which maximal amounts of benzene, toluene, ethylbenzene and xylenes were emitted from tested materials – was defined. The qualitative and quantitative analysis of the BTEX group were carried out with using the gas chromatography technique coupled with the mass spectrometry (GC/MS).
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Authors and Affiliations

M. Kubecki
M. Holtzer
S. Żymankowska-Kumon
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Abstract

Measurements of the hardening process course of the selected self-hardening moulding sands with the reclaimed material additions to the matrix, are presented in the hereby paper. Moulding sands were produced on the „Szczakowa” sand (of the Sibelco Company) as the matrix of the main fraction FG 0,40/0,32/0,20, while the reclaim was added to it in amounts of 20, 50 and 70%. Regeneration was performed with a horizontal mechanical regenerator capacity of 10 t/h. In addition, two moulding sands, one on the fresh sand matrix another on the reclaimed matrix, were prepared for comparison. Highly-fluid urea-furfuryl resin was used as a binder, while paratoluensulphonic acid as a hardener. During investigations the hardening process course was determined, it means the wave velocity change in time: cL = f(t). The hardening process kinetics was also assessed (dClx/dt = f(t)). Investigations were carried out on the research stand for ultrasound tests. In addition strength tests were performed.

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Authors and Affiliations

Ł. Jamrozowicz
J. Kolczyk
P. Wojtuń
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Abstract

The results of investigations of moulding sands with an inorganic binder called GEOPOL, developed by the SAND TEAM Company are

presented in the paper. Hardeners of various hardening rates are used for moulding sands with this binder. The main aim of investigations

was determination of the influence of the hardening rate of moulding sands with the GEOPOL binder on technological properties of these

sands (bending strength, tensile strength, permeability and grindability). In addition, the final strength of moulding sands of the selected

compositions was determined by two methods: by splitting strength and shear strength measurements. No essential influence of the

hardening rate on such parameters as: permeability, grindability and final strength was found. However, the sand in which the slowest

hardener (SA 72) were used, after 1 hour of holding, had the tensile and bending strength practically zero. Thus, the time needed for taking

to pieces the mould made of such moulding sand will be 1.5 - 2 hours.

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Authors and Affiliations

M. Holtzer
A. Bobrowski
D. Drożyński
W. Plaza

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