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Abstract

The cumulative results of investigations of the possibility of using the reclaimed materials after the mechanical, thermal or mechanical-thermal reclamation for making cores by means of the blowing method in the alkaline CO2 technology, are presented in the paper. Three kinds of spent sands: with furfuryl resin, bentonite and alkaline phenolic resin, obtained from the foundry, were subjected to three kinds of reclamation: mechanical, thermal and combined mechanical-thermal, applying for this aim adequate experimental devices. The obtained reclaims were assessed with regard to the degree of the matrix liberation from the determined binding material. Reclaims of moulding sands with binders of the form of resin were assessed with regard to ignition loss values and pH reaction, while reclaims of moulding sands with bentonite with regard to the residual clay content and pH value. In all cases the results of the performed sieve analyses were estimated and the average characteristic diameter dl was determined. The reclaimed matrix was applied as a full substitute of the fresh high-silica sand in typical procedures of preparing core sands used for making shaped samples for bending strength investigations, Rg u .
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Abstract

The paper, especially dealt with problems of reclamation of used furan sand, carried out in new, vibratory sand reclamation unit REGMAS developed by researches from AGH-University of Science and Technology, Faculty of Foundry Engineering in Cracow (Poland). Functional characteristics of reclamation unit as well as the results of reclamation of used sand with furfuryl resin are discussed in the paper. The quality of reclaim was tested by means of the LOI and pH value, dust content in the reclaim and at least by the the quality of the castings produced in moulds prepared with the use of reclaimed matrix.
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Abstract

The problem related to the management of post reclamation dusts generated in the reclamation process of waste moulding sands with organic binders is presented in the hereby paper. Waste materials generated in this process are products hazardous for the environment and should be utilised. The prototype stand for the utilisation of this dangerous material in its co-burning with coal was developed and patented in AGH in Krakow. The stand was installed in one of the domestic casting houses. As the utilisation result the transformed waste product is obtained and its management in the production of ceramic materials constitutes the subject of the presented publication.
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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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Abstract

The investigation results of the reclamation of spent moulding sands with furfuryl resin are presented in this paper. The reclamation process was performed in the secondary reclamation chamber of the REGMAS 1.5 vibratory reclaimer. 70 kg portions of moulding sands, previously subjected to the primary reclamation and dedusting, were used. The secondary reclamation was performed in two stages: the first consisted of determining the reclaimer intensity at various reclamation times (5 min, 10 min and 15 min) and various electrovibrator frequencies (40 Hz, 50 Hz and 60 Hz), the second consisted of determining the influence of additional crushing elements on the intensity of processes.
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Abstract

A technology of sands with water glass hardened by liquid esters is a cheap and ecologic method of producing moulding sands. Due to these advantages, this technology is still very important in several foundry plants for production of heavy iron and steel castings. Reclamation of the mixed moulding and core sands generates significant amounts of dusts, which require further treatments for their reuse. The results of investigations of a pressureless granulation of dusts generated in the dry mechanical reclamation process of the mixture consisting in app. 90 % of moulding sands from the Floster S technology and in 10 % of core sands with phenolic resin resol type, are presented in the hereby paper. Investigations were aimed at obtaining granulates of the determined dimensional and strength parameters. Granules were formed from the mixture of dusts consisting of 75 mass% of dusts after the reclamation of sands mixture and of 25 mass% of dusts from bentonite sands processing plant. Wetted dusts from bentonite sands were used as a binding agent allowing the granulation of after reclamation dusts originated from the mixed sands technology.
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