This paper focuses on the thermal behavior of the starch-based binder (Albertine F/1 by Hüttenes-Albertus) used in foundry technology of molding sand. The analysis of the course of decomposition of the starch material under controlled heating in the temperature range of 25-1100°C was conducted. Thermal analysis methods (TG-DTG-DSC), pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS) and diffuse reflectance spectroscopy (DRIFT) were used. The application of various methods of thermal analysis and spectroscopic methods allows to verify the binder decomposition process in relation to conditions in the form in both inert and oxidizing atmosphere. It was confirmed that the binder decomposition is a complex multistage process. The identification of CO2 formation at set temperature range indicated the progressive process of decomposition. A qualitative evaluation of pyrolysis products was carried out and the course of structural changes occurring in the presence of oxygen was determined based on thermo-analytical investigations the temperature of the beginning of binder degradation in set condition was determined. It was noticed that, significant intensification of Albertine F/1 sample decomposition with formation of more degradation products took place at temperatures above 550ºC. Aromatic hydrocarbons were identified at 1100ºC.

The paper presents the results of an investigation of the gases emission of moulding sands with an inorganic (geopolymer) binder with a relaxation additive, whose main task is to reduce the final (residual) strength and improves knocking-out properties of moulding sand. The moulding sand without a relaxation additive was the reference point. The research was carried out using in accordance with the procedure developed at the Faculty of Foundry Engineering of AGH - University of Science and Technology, on the patented stand for determining gas emissions. Quantification of BTEX compounds was performed involving gas chromatography method (GC).The study showed that the introduction of relaxation additive has no negative impact on gas emissions - both in terms of the total amount of gases generated, as well as emissions of BTEX compounds. Among the BTEX compounds, only benzene is emitted from the tested moulding sands. Its emission is associated with the introduction a small amount of an organic hardener from the group of esters.

The investigation results of the influence of the reclaim additions on the properties of moulding sands with the GEOPOL geopolymer

binder developed by the SAND TEAM Company were presented. Two brands of hardeners were applied in the tested compositions, the

first one was developed by the SAND TEAM Company, marked SA72 and the new hardener offered by the KRATOS Company, marked

KR72. The main purpose of investigations was to determine the influence of reclaim fractions and the applied hardener on the basic

moulding sands properties, such as: bending and tensile strength, permeability and grindability. The unfavourable influence of the reclaim

additions into moulding sands on the tested properties as well as an increased hardening rate, were found. Moulding sands, in which the

hardener KR72 of the KRATOS Company was used, were less sensitive to the reclaim additions.

In this paper the results of studies of polymeric binders on the example of the new BioCo2 binder, including the problem of its renewability, are presented. The results of structural studies (FT-IR) for the BioCo2 binder before and after crosslinking, and bending strength tests Rg u fresh and renewed cured molding sands with BioCo2 binder are discussed. The cross-linking binder and curring of moulding sand was carried out by physical agents (microwave radiation, temperature). On the basis of obtained results was shown that it is possible to restore the initial properties of the adhesive of BioCo2 binder. The initial properties of moulding sand can be achieved, after the cross-linking binders and after curing in the moulding sands with bioCo2 binder , by supplementing the moulding sand composition by the appropriate amount of water.

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.

No-bake process refers to the use of chemical binders to bond the moulding sand. Sand is moved to the mould fill station in preparation for

filling of the mould. A mixer is used to blend the sand with the chemical binder and activator. As the sand exits the mixer, the binder

begins the chemical process of hardening. This paper presents the results of decomposition of the moulding sands with modified ureafurfuryl

resin (with the low content of furfuryl alcohol below 25 % and different activators: organic and inorganic) on a quartz matrix,

under semi-industrial conditions. Investigations of the gases emission in the test foundry plant were executed according to the method

extended in the Faculty of Foundry Engineering (AGH University of Science and Technology). Article presents the results of the emitted

chosen aromatic hydrocarbons and loss on ignition compared with the different activators used to harden this resin. On the bases of the

data, it is possible to determine the content of the emitted dangerous substances from the moulding sand according to the content of loss on

ignition.

The study investigates the effect of the organic compound representing the cellulose derivative - sodium salt of carboxymethyl cellulose (CMC/Na) on the structure of the main component of bentonite (B) - montmorillonite (MMT). Structural analysis revealed that the CMC/Na of different viscosity interacts with the mineral only via surface adsorption, causing at the same time partial or full delamination of its layered structure. This was confirmed by the XRD diffraction tests. Such polymer destructive influence on the structure of the modified main component of the bentonite limits the use of its composites as an independent binder in moulding sand technology, but does not exclude it from acting as an additive being a lustrous carbon carrier. According to the IR spectra of the B/CMC/Na materials, it can be stated that the interaction between the organic and inorganic parts is based on the formation of hydrogen bonds. That kind of the interpretation applies especially to the MMT modified in the bentonite with a lower viscosity polymer. The characteristics of the main IR absorption bands for composites with a higher viscosity polymer indicates the formation of less stable structures suggesting the random nature of the hydrogen bonds formation.

The intercalation into interlayer spaces of montmorillonite (MMT), obtained from natural calcium bentonite, was investigated. Modification of MMT was performed by the poly(acrylic acid-co-maleic acid) sodium salt (co-MA/AA). Efficiency of modification of MMT by sodium salt co-MA/AA was assessed by the infrared spectroscopic methods (FTIR), X-ray diffraction method (XRD) and spectrophotometry UV-Vis. It was found, that MMT can be relatively simply modified with omitting the preliminary organofilisation – by introducing hydrogel chains of maleic acid-acrylic acid copolymer in a form of sodium salt into interlayer galleries. A successful intercalation by sodium salt of the above mentioned copolymer was confirmed by the powder X-ray diffraction (shifting the reflex(001) originated from the montmorillonite phase indicating an increase of interlayer distances) as well as by the infrared spectroscopy (occurring of vibrations characteristic for the introduced organic macromolecules). The performed modification causes an increase of the ion exchange ability which allows to assume that the developed hybrid composite: MMT-/maleic acid-acrylic acid copolymer (MMT-co- MA/AA) can find the application as a binding material in the moulding sands technology. In addition, modified montmorillonites indicate an increased ability for ion exchanges at higher temperatures (TG-DTG, UV-Vis). MMT modified by sodium salt of maleic acid-acrylic acid copolymer indicates a significant shifting of the loss of the ion exchange ability in the direction of the higher temperature range (500–700°C).

Emission of gases under high temperature after pouring molten metal into moulds, which contain the organic binder or other additives

(solvents or curing agent), may be an important factor influencing both on the quality of the produced castings, and on the state of

environment. Therefore, a comprehensive study of the emitted gases would allow to determine restrictions on the use of the moulding

sands in foundry technologies, eg. the probability of occurrence of casting defects, and identify the gaseous pollutants emitted to the

environment. The aim of the research presented in this paper was to determine the amount of gases that are released at high temperatures

from moulding sands bonded by biopolymer binder and the quantitative assessment of the emitted pollutants with particular emphasis on

chemical compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The water-soluble modified potato starch as a sodium

carboxymethyl starch with low (CMS-NaL) or high (CMS-NaH) degree of substitution was a binder in the tested moulding sands.

A tests of gases emission level were conducted per the procedure developed at the Faculty of Foundry Engineering (AGH University of

Science and Technology) involving gas chromatography method (GC). The obtained results of the determination of amount of BTEX

compounds generated during the decomposition process of starch binders showed lower emission of aromatic hydrocarbons in comparison

with binder based on resin Kaltharz U404 with the acidic curing agent commonly used in the foundries.

The article presents research results of physico-chemical and environmental issues for the dust generated during dedusting of the

installation for the processing and preparation of moulding sand with bentonite. Particular attention was paid to the content of heavy

metals and emission of gases from the BTEX group, which is one of the determinants of the moulding sands harmfulness for the

environment. The analysis of heavy metals in the test samples indicate that there is an increase of the content of all metals in the dust

compared to the initial mixture of bentonite. The most significant (almost double) increase observed for zinc is probably related to the

adsorption of this element on the dust surface by contact with the liquid metal. The study showed, that dust contained more than 20% of

the amount of montmorillonite and had a loss on ignition at a similar level. The addition of 1% of dust to the used moulding sand results in

almost 30% increase in the total volume of gases generated in casting processes and nearly 30% increase of the benzene emission.

The paper presents the results of thermoanalytical studies by TG/DTG/DTA, FTIR and GC/MS for the oil sand used in art and precision foundry. On the basis of course of DTG and DTA curves the characteristic temperature points for thermal effects accompanying the thermal decomposition reactions were determined. This results were linked with structural changes occurred in sample. It has been shown that the highest weight loss of the sample at temperatures of about 320°C is associated with destruction of C-H bonds (FTIR). In addition, a large volume of gases and high amounts of compounds from the BTEX group are generated when liquid metal interacts with oil sand. The results show, that compared to other molding sands used in foundry, this material is characterized by the highest gaseous emissions and the highest harmfulness, because benzene emissions per kilogram of oil sand are more than 7 times higher than molding sand with furan and phenolic binders and green sand with bentonite and lustrous carbon carrier.

The spectroscopic FT-IR and FT-Raman methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic

acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands (as a novel group binders BioCo). The

cross-linking was performed by physical agent, applying the UV-radiation. The results of structural studies (IR, Raman) confirm the

overlapping of the process of cross-linking polymer composition PAA/CMS-Na in UV radiation. Taking into account the ingredients and

structure of the polymeric composition can also refer to a curing process in a binder - mineral matrix mixture. In the system of bindermineral

matrix under the influence of ultraviolet radiation is also observed effect of binding. However, the bonding process does not occur

in the entire volume of the investigated system, but only on the surface, which gives some possibilities for application in the use of UV

curing surface of cores, and also to cure sand moulds in 3D printing technology

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).