Assessment Criteria of Bentonite Binding Properties

The criteria, with which one should be guided at the assessment of the binding properties of bentonites used for moulding sands, areproposed in the paper. Apart from the standard parameter which is the active bentonite content, the unrestrained growth indicator should be taken into account since it seems to be more adequate in the estimation of the sand compression strength. The investigations performed for three kinds of bentonites, applied in the Polish foundry plants, subjected to a high temperature influences indicate, that the pathway of changes of the unrestrained growth indicator is very similar to the pathway of changes of the sand compression strength. Instead, the character of changes of the montmorillonite content in the sand in dependence of the temperature is quite different. The sand exhibits the significant active bentonite content, and the sand compression strength decreases rapidly. The montmorillonite content in bentonite samples was determined by the modern copper complex method of triethylenetetraamine (Cu(II)-TET). Tests were performed for bentonites and for sands with those bentonites subjected to high temperatures influences in a range: 100-700ºC

The BTEX emission from moulding sands with furan resin dependence on the VOC content and loss on ignition

The article contains the results of emission BTEX (benzene, toluene, ethylobenzene and xylenes) during thermal destruction (500 – 1 300 °C) of moulding sand with furan resin. This furan resin is with a high content of free furfuryl alcohol (about 80 %). Knowledge of emissions of these compounds allows the assessment the harmfulness of a given moulding sand. Quantitative analysis of BTEX is highly complex and requires using of modern equipment (e.g. gas chromatography – mass spectrometry). Therefore, an attempt to assess potential emissions of BTEX compounds from a given moulding sand based on measurements of total volatile organic compounds (VOC) emission and loss on ignition (LOI). These measurements are less time-consuming and do not require expensive equipment

Investigations of the Temperature Influence on Formation of Compounds from the BTEX Group During the Thermal Decomposition of Furan Resin / Badania wpływu temperatury na powstawanie związków z grupy BTEX podczas termicznego rozkładu żywicy furanowej

Spoiwa organiczne stosowane w odlewnictwie bazujące na żywicach syntetycznych, z jednej strony wpływają na uzyskanie przez masę formierską odpowiednich właściwości technologicznych a w konsekwencji tego otrzymania dobrych odlewów, a z drugiej w procesach odlewniczych stanowią źródło lotnych związków organicznych (LZO). Wraz z żywicami syntetycznymi stosowane są również ich utwardzacze, których dodatek stanowi wprawdzie niewielki procent w stosunku do masy żywicy, ale związki uwalniane w trakcie ich termicznego rozkładu mogą negatywnie oddziaływać na środowisko naturalne. Zarówno żywice jak i utwardzacze dopiero pod wpływem temperatury towarzyszącej zalewaniu formy ciekłym metalem generują szkodliwe lotne związki organiczne, w tym związki z grupy BTEX. Badania wpływu temperatury na rodzaj oraz ilość związków organicznych powstających podczas termicznego rozkładu wybranych spoiw i utwardzaczy oraz ich mieszanin, pozwalają określić zarówno zakres temperatur najbardziej charakterystycznych dla uwalniania szkodliwych związków, jak również dokonać porównania ich emisji z wybranych materiałów

Ljevačka industrija – sadašnje stanje i budući razvitak

The casting production is considered as one of the main factors influencing the development of world economy. The state of art and foresight of world’s casting production is discussed in the paper on the basis of the latest statistical data. The progress gained during the last few years in foundry engineering is shown as a way to further development of foundry technology. The last decade brought significant changes in the world map of the greatest casting producers. Globalization and transformation of economic systems is reflected by variations of foundry production in different countries, more over the globalization of economy is regarded not only as a chance but also as a menace for the European foundries.Ljevačka proizvodnja se smatra jednom od glavnih utjecajnih faktora u svjetskom gospodarstvu. Stanje postignuća i predmnijevanje ljevačke proizvodnje na temelju posljednjih statističkih podataka daje se u ovom članku. Polučeni napredak tijekom nekoliko posljednjih godina u ljevačkoj tehnici je prikazan kao putokaz budućeg razvitka ljevačke tehnologije. Posljednja dekada donosi značajne izmjene na svjetskoj karti najvećih proizvođača odljevaka. Globalizacija i tansformacija ekonomskog sustava održavanja se raznolikošću u ljevačkoj proizvodnji različitih država, što više globalizacije gospodarstvo se motri ne samo kao šansa nego i kao ugroz europskih ljevaonica

The state of art and foresight of world’s casting production

The casting production is considered of the main factors influencing the development of World economy. Actual capacity of the world’s casting production, which is about 101 mln metric ton per year (2012), is strongly diversified. The last decade brought significant changes in the World map of the greatest casting producers. Globalization and transformation of economic systems is reflected by variations of foundry production in different countries, moreover the globalization of economy is regarded not only as a chance but also as a menace for European foundries

Emission of polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX) from the furan moulding sands with addition of the reclaim

In this paper, the results of decomposition of a moulding sand with furfuryl resin also on a quartz matrix and with additions of a reclaimed material, under industrial conditions, are presented. 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 dependence of the emitted PAHs and BTEX group substances and ignition losses on the reclaim fraction in a moulding sand are of a linear character of a very high correlation coefficient R2. On the bases of the derived equations, it is possible to determine the amount of the emitted hazardous substances from the moulding sand containing the known fraction of the reclaim

Assessment of harmfulness of phenolic resins hardened by CO2 in an aspect of emission of substances from BTEX and PAH groups

Abstract Out of moulding sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. If in the initial state these resins are not very dangerous for people and for the environment, thus under an influence of high temperatures they generate very harmful products, being the result of their thermal decomposition. Depending on the kind of the applied resin under an influence of a temperature such compounds as: furfuryl alcohol, formaldehyde, phenol, BTEX group (benzene, toluene, ethylobenzene, xylenes), and also polycyclic aromatic hydrocarbons (PAHs) can be formed and released

Neškodljivost kalupnih pjesaka sa bentonitom i svijetlećim nositeljima ugljika

Procedures have been developed to determine the volume, rate and composition (particularly BTEX: benzene, toluene, ethylbenzene and xylenes and PAHs (polycyclic aromatic hydrocarbons)) of gas evolution from moulds and cores prepared with various binders as a means of harmfulness of moulding sands. The rate of gas evolution from green sands with four different lustrous carbon carrier and BTEX content were determined. The gas evolution rates are highest in the range of about 20 to 30 s after contact with molten metal. In practice during the first 200-250 s the total emission of gases generated in investigated samples occurred. The main emitted component from the BTEX group was benzene.Postupci su razvijeni za određivanje volumena, brzine i sastava (posebice BTEX: benzen, toluen, etilbenzen, xilana) i PAH (policiklički automatski hidrokarbonati) plina koji nastaje iz kalupa i jezgri na različitim nosačima u težnji za neškodljivost kalupnih pijesaka. Brzine nastajanja plina iz pripravljenih pijesaka sa 4 različita svijetleća nositelja ugljika i sadržajem BTEX su određeni. Brzine nastajanja plina su najveće u razini 20 do 30 s poslije dodira sa rastopljenim metalom. Praktično, tijekom prvih 200-250 s ostvaruje se ukupna emisija stvorenih plinova u istraživanim uzorcima. Iz BTEX skupine, benzen je glavna emitirajuća komponenta

Determination of Content of Phenol in Foundry Resins by Pyrolysis Gas Chromatography-Mass Spectrometry Method

In the foundry industry, many harmful compounds can be found, which as a result of gradual but long-term exposure to employees bring negative results. One of such compounds is phenol (aromatic organic compound), which its vapours are corrosive to the eyes, the skin, and the respiratory tract. Exposition to this compound also may cause harmful effects on the central nervous system and heart, resulting in dysrhythmia, seizures, and coma. Phenol is a component of many foundry resins, especially used in shell moulds in the form of resin-coated sands. In order to identify it, the pyrolysis gas chromatography-mass spectrometry method (Py-GC/MS) was used. The tests were carried out in conditions close to real (shell mould process – temperature 300°C). During the measurement, attention was focused on the appropriate selection of chromatographic analysis conditions in order to best separate the compounds, as it is difficult to separate the phenol and its derivatives. The identification of compounds was based on own standards

Identification of Compounds from Thermal Decomposition of Furan Resin by Gas Chromatography Coupled with Mass Spectrometry (GC/MS)

W celu wykonywania form i rdzeni dla odlewów ciężkich i lekkich stosowane są głównie żywice syntetyczne. Proces wiązania sypkiej masy samoutwardzalnej (SMS) z żywicą furfurylową (furanową) jest najczęściej stosowanym sposobem produkowania różnorodnych form i rdzeni dla praktycznie wszystkich stopów odlewniczych. Wszystkie nowoczesne żywice furanowe pozwalają na używanie dużej ilości regeneratu (praktycznie do 100%). Jako utwardzacze stosuje się kwasy organiczne i mieszaniny kwasów organicznych i nieorganicznych. Celem przeprowadzonych badań była identyfikacja związków pochodzących z rozkładu termicznego popularnej żywicy furanowej stosowanej w wielu krajowych odlewniach. Dodatkowo badaniom poddano katalizator, służący do utwardzenia żywicy. Do analizy zastosowano metodę chromatografii gazowej w połączeniu ze spektrometrią masową (GC/MS). Rozkład badanych próbek przeprowadzono w pirolizerze, w temperaturze 1300 °C, podłączonym do układu pomiarowego. Uzyskane wyniki pozwoliły na ocenę szkodliwości danej żywicy w stosunku do środowiska i otoczenia.Synthetic resins are mainly used to produce moulds and cores for heavy and individual castings. These resins are recommended for the production of steel castings and are used in foundries. All modern furan resins allow the use of large quantities of reclaim (virtually 100%). As hardeners are used organic acids and mixtures of organic and inorganic acids. The aim of the study was to identify compounds from thermal decomposition of popular furan resin used in many foundries. In addition, the tests was a catalyst (hardener) used to cure the resin. Substances were identified by gas chromatography coupled with mass spectrometry (GC/MS) method, in the examined samples. The resin and hardener subjected to the high temperature (1300°C) in the pyrolyser. The results allowed the evaluation of harmfulness of resin with respect to the environment