Physical and chemical characteristics of after-reclamation dust from used sand moulds

Abstract

The paper presents the results of investigations of physical and chemical properties of after reclamation dust that is generated in the foundry industry. Universally applied mechanical reclamation processes of spent moulding sands generate large amounts of after-reclamation dusts containing mainly rubbed spent binding agents and quartz dusts. An amount of after-reclamation dusts-in dependence of the reclamation system efficiency and the reclaim dedusting system-can reach 5-10 % in relation to the total reclaimed spent moulding sand. After-reclamation dusts originated from spent moulding sands with different kinds of resins mostly belong to dangerous wastes, since they contain chemo-setting binders with dangerous substances removed in the reclamation process. None of the companies producing mechanical reclamation systems offers presently the complex technology and equipment for utilisation of after reclamation dusts, which would meet technical and economic expectations of foundry plants. The paper presents the results of research carried out at the Faculty of Foundry Engineering AGH UST in Cracow which aims on the determination of possibilities of using the post-reclamation dust generated during mechanical reclamation of used moulding sands with organic resins as a source of energy. Different dusts generated in the mechanical reclamation process of used organic sands, delivered from foundries, were tested to determine their chemical composition, granular characterisation and physicochemical properties. As a result of the investigations, possible ways to utilise the dusts are presented.

Evaluation of Sand Quality in Thermal Sand Reclamation System

“…(3) The diagnosis for ADV represents, the ADV of reclaimed sand is about 6-7, which helps to achieve better casting quality [12] .…”

“…Minimum value of ADV means minimum reactivity with acid and it is suitable for molding sand. Greater than 6-10 mL acid demand is not acceptable ADV for acid catalyzed binder system [12] . The mean effect plot of acid demand value is presented in Figure 10.…”

Mechanical Reclamation of Spent Moulding Sand on Chromite Sand Matrix; Removal of Alkali-Phenolic Binder

“…This article presents the changes that occur on the surface of the grains in the relationship between these two materials as a result of mechanical reclamation and the supplementary effect of the temperature that is applied in assessing the quality of the regenerate (ignition losses). The process of reclaiming spent moulding sand was described in [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. The mechanical reclamation of used grain matrix was addressed in [ 32 , 33 , 34 ].…”

Comparison of the Properties of Alkali-Phenolic Binder in Terms of Selection of Molding Sand for Steel Castings

“…However, it is important to use special additives (0.6–1.0%) to the shakeout sand just prior to its entry into a thermal reclaimer, in order to make this possible [1]. Another important issue is the utilization of the after-reclamation dust, which was already discussed by the authors in [13]. They analyzed several molding sand compositions, using different binding reagents, including the ones used in the Alphaset process.…”