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 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.

This paper deals with the complete technology of inorganic geopolymer binder system GEOPOL® which is a result of long term research and development. The objective of this paper is to provide a theoretical and practical overview of the GEOPOL® binder system and introduce possible ways of moulds and cores production in foundries. GEOPOL® is a unique inorganic binder system, which is needed and welcomed in terms of the environment, the work environment, and the sustainable resources. The GEOPOL® technology is currently used in the foundries for three basic production processes/technologies: (1) for self-hardening moulding mixtures, (2) sand mixtures hardened by gaseous carbon dioxide and (3) the hot box technology with hot air hardening. The GEOPOL® technology not only solves the binder system and the ways of hardening, but also deals with the entire foundry production process. Low emissions produced during mixing of sand, moulding, handling, and pouring bring a relatively significant improvement of work conditions in foundries (no VOCs). A high percentage of the reclaim sand can be used again for the preparation of the moulding mixture.

It was found that the addition of carbon fibers (CFs) does not affect the crosslinking process in the microwave radiation (800 W, 2.45

GHz) of the BioCo2 binder, which is a water solution of poly(acrylic acid) and dextrin (PAA/D). It has influence on BioCo2 thermal

properties. The CFs addition improves the thermostability of a binder and leads to the reduction of gas products quantity generated in the

temperature range of 300-1100°C (TG-DTG, Py-GC/MS). Moreover, it causes the emission of harmful decomposition products such as

benzene, toluene, xylene and styrene to be registered in a higher temperatures (above 700°C). BioCo2 binder without CFs addition is

characterized by the emission of these substances in the lower temperature range. This indicates the positive effect of carbon fibers

presence on the amount of released harmful products.

The selected technological tests (permeability, friability, bending strength, tensile strength) have shown that the moulding sand with the

0.3 parts by weight carbon fibers addition displays the worst properties. The addition of 0.1 parts by weight of CFs is sufficient to obtain a

beneficial effect on the analyzed moulding sands properties. The reduction of harmful substances at the higher temperatures can also be

observed.

The article deals with the gas development of the geopolymer binder system hardened by heat and provides the comparison with organic binder systems. The GEOPOL® W technology is completely inorganic binder system, based on water. This fact allow that the gas generated during pouring is based on water vapour only. No dangerous emissions, fumes or unpleasant odours are developed. The calculated amount of water vapour generated from GEOPOL® W sand mixture is 1.9 cm3/g. The measured volume of gas for GEOPOL® W is 4.3 cm3/g. The measurement of gas evolution proves that the inorganic binder system GEOPOL® W generates very low volume of gas (water vapour) in comparison with PUR cold box amine and Croning. The amount of gas is several times lower than PUR cold box amine (3.7x) and Croning (4.2x). The experiment results are consistent with the literature sources. The difference between the calculated and the measured gas volume is justified by the reverse moisture absorption from the air after dehydration during storing and preparing the sand samples. Minimal generated volumes of gas/water vapour brings, mainly as was stated no dangerous emissions, also the following advantages: minimal risk of bubble defects creation, the good castings without defects, reduced costs for exhaust air treatment, no condensates on dies, reduced costs for cleaning.

The influence of the refractory coating which is a mixture of silica flour and kaolin on the surface roughness of the plate castings produced

using evaporative patterns had been considered in this work. The kaolin was used as a binder and ratio method was employed to form basis

for the factorial design of experiment which led to nine runs of experiments. Methyl alcohol at 99% concentration was used as the carrier

for the transfer of the coating to the surface of the patterns. Pouring temperature was observed as a process parameter alongside the mix

ratios of the coating. Attempts were made to characterize the refractory coating by using two methods; differential thermal analysis (DTA)

and X-ray diffraction. Attempt was also made to characterize the casting material. Gating system design was done for the plate casting to

determine the correct proportions of the gating parameters in order to construct the gating system properly to avoid turbulence during

pouring of liquid metal. A digital profilometer was used to take the measurements of the surface roughness. It was observed that the mix

ratio 90% silica flour-10% kaolin produced the lowest value of the surface roughness of the plate castings and had the lowest material loss

in the DTA test. The pouring temperature of 650o

C produced best casting.

The manuscript presents the research results concerning the properties of concrete with non-clinker, low-emission binder composed of by-products from metallurgy and power industry: ground granulated blast furnace slag and fly ash from circular fluidized-bed combustion of brown coal. The binder was added in five proportions. The consistency and air content of the concrete mix were measured, as well as the temperature of the concrete mix during hardening. The compressive strength of the hardened concrete was investigated in three periods of samples’ curing: after 28, 90 and 360 days. Also the penetration depth of water under pressure and freeze and thaw resistance of concrete samples were investigated. The results confirm the possibility of application of slag-CFBC fly ash binder for mass concrete due to low temperature during hardening. The obtained results of the compressive strength and penetration depth of water under pressure reveal the influence of changing the proportion of the binder ingredients, as well as the sample damage during testing the freeze/thaw resistance. The CFBC fly ash-slag binder can be used for mass concrete, hydrotechnical concretes in particular, but excluding the zones exposed to frost.

Fly-ash is a form of production waste produced as a result of the burning of coal for energy production. Millions of tonnes of this waste are produced worldwide every year; hence it is extremely important to dispose of it in a useful way, including through treating the initial raw material to obtain a material of higher quality. The aim of the present work is to determine the suitability of processed fly-ash from lignite for reinforcing (stabilizing) soils used in the building of road foundations and embankments. The results provide a method of recycling this waste while at the same time obtaining new materials and technologies for use in road building. This is an important issue both environmentally and in terms of the positive effect that processed fly-ash can have on the stability of road structures.

This article presents the results of experiments carried out using fly-ash produced from lignite at the P¹tnów Power Plant. This ash was first modified (activated) using a Wapeco magnetic activator, and then used to produce hydraulic binders (with the addition of cement) and soil-binder mixtures. These mixtures were made using natural soils from seven different deposits in the Lubuskie region (western Poland). They were stabilized using two hydraulic binders (strength ratings 3 MPa and 9 MPa) added in different amounts (6% and 8% relative to the mass of the soil). During the experiment, a determination was made of the increase in the strength of the analysed samples (after 14, 28, and 42 days) and the increase in the bearing ratio (immediately after consolidation and after 7 days).

Interpretation of the results of the experiment made it possible to assess the dynamics of the increase in compression strength and load-bearing capacity of various soils stabilized with hydraulic binders produced from lignite ash, and to indicate possibilities for the use of these materials.

The analysis showed that it is possible to use these binders for the stabilisation of soils, enabling soils formerly considered to have weak load-bearing capacity (clayey sand; clayey, sandy gravel; clays) to be classified as fully usable in road construction.

Each year, mine and mill operations generate enormousamounts of two waste types – fine-grained tailings andcoarse-grained waste rocks. Fine-grained tailings are either discharged in slurry form to surface tailings dams ordelivered in cementitious form to underground mine stopes as backfilling, while coarse-grained rocks are typicallystored by depositing as a dry material in large dumps. The engineering design of surface tailings dams orunderground mine stopes is often controlled by the high compressibility and low shear strength characteristics offine-grained tailings. Cemented paste backfill CPB indicating saturated, fine-grained backfills can undergo majorconsolidation settlement during early curing stages. Thus, a better understanding of the rate and magnitude of bothdifferential and total settlement of CPB cured under stressis essential for a proper backfill geotechnical design. Theconsolidation parameters of CPB can be determined from an improved lab setup called CUAPS (curing underapplied pressure system). This setup is capable of simulating the CPB placement and curing conditions, andmeasuring the consolidation parameters of CPB cured under effective stresses ranging between 0.5 and 400 kPa.In this study, a series of one-dimensional consolidation tests were conducted on CPB samples allowing forexamination of the effects of binder type and rate as well as curing time on the compression properties (e.g.,coefficient of consolidationcv, compression indexCc, and recompression indexCr) and the final geotechnicalindex properties (e.g., void ratioef, water contentwf, and degree of saturationSf). Results showed that as the bindercontent increases, the initial resistance to consolidation increases. Thecvvalue decreases over the course of timedue to evolution of the CPB microstructure generated by the hydration process.

A thermo-insulating moulding sand with a binder made of aluminosilicate microspheres with organic binder was subjected to testing. The aim of the analysis was to determine selected technological properties of the developed compounds. Compressive strength, friability and gas permeability were determined. The binder content was changed within a range of 5÷20 wt% with a 5% step. The applied matrix is characterized by good thermo-insulating properties and a small size of grains, while synthetic organic binder has favourable functional properties, among which the most noteworthy are the extended life and setting time, good rheological properties as well as high resistance to chemical agents. The intended use of the compound is the casting of 3D CRS (Composite Reinforced Skeletons), which are characterized by a well-developed heat transfer surface area, good absorption of impact energy, low mass and a target thickness of connectors within a range of 1.5÷3 mm. The construction of 3D CRS castings is an original concept developed by the employees of the Department of Foundry Engineering at the Silesian University of Technology.

The research paper presents the results of testing the strength and technological properties of molding sand with gypsum binder, the bonding process proceeded: naturally or conventionally. The tests included mass containing (parts by weight): 78 pbw. Grudzeń-Las quartz sand, 22 pbw. plaster gypsum "Dolina Nidy” and 9 pbw. water. Measurements of compressive strength, shear, tensile and bending as well as permeability and looseness were carried out on standard cylindrical samples kept in the air for 1 - 96 hours or dried at 110 oC for 1 - 8 hours. The results of the analysis were analyzed in connection with the mass structure and construction binding bridges warp grains observed with a scanning microscope (SEM). The influence of drying intensity on the bonding process and related mass properties has been demonstrated, especially from the point of view of the possibility of selection and / or intensification of a specific curing method for use in the production of gypsum binger molds and cores.

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 use of environmentally friendly inorganic binders and new technologies for cores production is widely discussed topic in recent years. This paper contains information about new hot curing process for core making with alumina-silicate based inorganic binders – geopolymers. Main differences between hot cured geopolymers and hot cured alkali silicate based inorganic binders are discussed. The main objective of this research paper was to investigate basic technological properties of geopolymer binder system such as strength, compaction, storage ability and knock-out properties. For this purpose, three mixtures with different powder additives were prepared and tested in laboratory conditions using specific methods. Strength properties evaluation showed sufficient levels as well as knock-out properties measurement, even with additives B and C originally designed for the use with alkali silicate based two component binder systems. Additives B and C were considered compatible with geopolymer binders after casting production trial results. Storage ability of geopolymers seems to be more sensitive than of alkali silicate based binders in the same tested conditions. Mixtures with geopolymer binder showed 20% more decrease of strength compared to alkali silicate binders after 24 hours in conditions of 25 °C and 65 %RH.

The effects of silica additive (Poraver) on selected properties of BioCo3 binder in form of an aqueous poly(sodium acrylate) and dextrin (PAANa/D) binder were determined. Based on the results of the thermoanalytical studies (TG-DTG, FTIR, Py-GC/MS), it was found that the silica additive results in the increase of the thermostability of the BioCo3 binder and its contribution does not affect the increase in the level of emissions of organic destruction products. Compounds from group of aromatic hydrocarbons are only generated in the third set temperature range (420-838°C). The addition of silicate into the moulding sand with BioCo3 causes also the formation of a hydrogen bonds network with its share in the microwave radiation field and they are mainly responsible for maintaining the cross-linked structures in the mineral matrix system. As a consequence, the microwave curing process in the presence of Poraver leads to improved strength properties of the moulding sand (���� �� ). The addition of Poraver's silica to moulding sand did not alter the permeability of the moulding sand samples, and consequently reduced their friability. Microstructure investigations (SEM) of microwave-cured samples have confirmed that heterogeneous sand grains are bonded to one another through a binder film (bridges).

The paper presents the results of an investigation of the thermal deformation 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 the hot-distortion method (DMA apparatus from Multiserw-Morek). The results were combined with linear deformation studies with determination of the linear expansion factor (Netzsch DIL 402C dilatometer). The study showed that the introduction of relaxation additive has a positive effect on the thermal stability of moulding sand by limiting the measured deformation value, in relation to the moulding sand without additive. In addition, a relaxation additive slightly changes the course of the dilatometric curve. Change in the linear dimension of the moulding sand sample with the relaxation additive differs by only 0.05%, in comparison to the moulding sand without additive.