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.
Sand samples with furan binder were prepared using Sand, Furfuryl Alcohol and Toluene Sulfonic Acid with ratio 100:0.85:0.30. To
identify and quantify gases releasing from furan binder various studies like FTIR, TGA and GC-MS were carried out. After analyzing our
materials using above mentioned characterizations the chemical formula of the Resin and Binder and amount of gases releasing from
composition were confirmed. After studying various reports on pyrolysis process of furan binder calculation of the % of various gases
emitting during pyrolysis process of furan was carried out. Sample of gas collected from mold was analyzed using GC-MS. Based on GCMS
measurement various gases emitting from furan sand mold were identified and their amount were calculate and compared with the
international standers of permissible gas emission limits in a foundry. The purpose of this paper is to assist foundries in pollution
prevention by devising clean technologies which maintain or improve the quality of ambient surrounding. This paper aimed at
minimization of pollution of air by using various techniques.
The paper focuses on investigation of properties of two most widely used self-set sand binder systems APNB and FNB across the Globe, for making molds and cores in foundries to produce castings of different sizes involving wide range of metals and alloys, ferrous and nonferrous. This includes study of compression strength values of samples made out of molding sand at different binder addition level using new, mechanically reclaimed (MR) and thermally reclaimed (TR) sand. Strength values studied include dry strength (at room temperature) at specified intervals simulating different stages of mold handling, namely stripping and pre heating, followed by degraded strength after application of thinner based zircon wash by brush, subsequent lighting of, then checking strength both in warm (degraded strength) & cold (recovered strength) conditions. Throughout the cycle of mold movement from stripping to knock out, strength requirements can be divided into two broad classifications, one from stripping to closing (dry strength) and another from pouring to knock out (hot & retained strength). Although the process for checking of dry strength are well documented, no method using simple equipments for checking hot & retained strength are documented in literature. Attempts have been made in this paper to use some simple methods to standardize process for checking high strength properties using ordinary laboratory equipments. Temperature of 450°C has been chosen by trial & error method to study high temperature properties to get consistent & amplified values. Volume of gases generated for both binders in laboratory at 850°C have also been measured. Nature of gases including harmful BTEX and PAH generated on pyrolysis of FNB and APNB bonded sands are already documented in a publication [1]. This exercise has once again been repeated in same laboratory, AGH University, Poland with latest binder formulations in use in two foundries in India.
Mechanical reclamation process of spent moulding sands generate large amounts dusts containing mainly rubbed spent binding agents and quartz dust. The amounts of post-reclamation dusts, depending of the reclamation system efficiency and reclaim dedusting system, can reach 5 -10% in relation to the total reclaimed moulding sand. This dust due to the high content of the organic substances is a threat to the environment and therefore requires the storage on landfills specially adapted for this type of waste. On the other hand, the presence of organic substances causes that these dusts have relatively high energy values that could be used. However, at present there is no coherent, environmentally friendly concept for the management of this type of dust. The paper presents the results of tests of thermal utilization the dusts (as a source of energy) were carried out at AGH University of Science and Technology. Thermal utilization of dusts was carried out in the co-burning with carbon carriers process or in individual burning (Patent PL 227878 B1 and patent application PL - 411 902).
Casting covers major area of production all over the world. Resin bonded casting is widely used in today’s manufacturing industries. Furan
No bake casting is most widely accepted in indian foundries due to its excellent surface finish and dimensional stability. It is a self-setting
binder and it has a lower work and strip times. Though the casting process is also known as process of uncertainty, in the present study, an
attempt has been made to investigate the effect of Grain Fineness Number, Loss of Ignition, Potential of Hydrogen, % of Resin with
respect to sand, Sand Temperature and Compressive strength of the mould on Sand Inclusion defect – one of the most dominating defect in
the Krislur Castomech Pvt. Ltd. Industry situated at Bhavnagar, Gujarat, India. The experiments were conducted based on response surface
methodology (RSM) and sequential approach using face centered central composite design. The results show that quadratic model with
removal of some insignificant term is comparatively best fits for Sand Inclusion Defect.
The results of researches of sorption processes of surface layers of components of sand moulds covered by protective coatings are
presented in the hereby paper. Investigations comprised various types of sand grains of moulding sands with furan resin: silica sand,
reclaimed sand and calcined in temperature of 700oC silica sand. Two kinds of alcoholic protective coatings were used – zirconium and
zirconium – graphite. Tests were performed under condition of a constant temperature within the range 30 – 35oC and high relative air
humidity 75 - 80%. To analyze the role of sand grains in sorption processes quantitavie moisture sorption with use of gravimetric method
and ultrasonic method were used in measurements. The tendency to moisture sorption of surface layers of sand moulds according to the
different kinds of sand grains was specified. The effectiveness of protective action of coatings from moisture sorption was analyzed as
well.
Knowledge of the role of sand grains from the viewpoint of capacity for moisture sorption is important due to the surface casting defects
occurrence. In particular, that are defects of a gaseous origin caused by too high moisture content of moulds, especially in surface layers.
The furan resin offers advantages such as high intensity, low viscosity, good humidity resistance and is suitable for cast different casting
alloys: steel, cast iron and non-ferrous metal casting. For hardening furan resins are used different hardeners (acid catalysts). The acid
catalysts have significant effects on the properties of the cured binder (e,g. binding strength and thermal stability) [1 - 3]. Investigations of
the gases emission in the test foundry plant were performed according to the original method developed in the Faculty of Foundry
Engineering, AGH UST. The analysis is carried out by the gas chromatography method with the application of the flame-ionising detector
(FID) (TRACE GC Ultra THERMO SCIENTIFIC).
The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of
material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the
construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding
sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in
mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations
equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand
allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of
determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid.
It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium).
The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.