This study shows the results of the investigation of the strength performance, and residual strength of a single component inorganic binder

system Cast Clean S27®. The study was conducted using three different foundry sand sources in South Africa. Sample A is an alluvial

coastal sample, sample B is an alluvial riverbed sample and Sample C is a blasted sample from a consolidated quartzite rock. The binder

was also cured using three different curing mechanisms. The aim of the investigation was to determine the variation of strength

performance and residual strength between the different South African sand sources based upon the physical and chemical properties of

the sand sources. The moulding sand was prepared using three possible curing mechanisms which are carbon dioxide curing, ester curing

and heat curing. The strength measurements were determined by bending strength. Sample A and sample C sand had good strength

development. Sample B sand had inferior strength development and excellent high temperature residual strength. The study showed that

the single component inorganic binders have good strength development and low residual strength. The silica sand properties have major

contributing factors on both strength development and residual strength. The degree of influence of silica sand properties on strength

performance and residual strength is dependent on the time of curing and method of curing.

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 objective of the presented paper is to investigate the performance of concrete containing volcanic scoria as cement replacement after 7, 28, 90, and 180 days curing. Five performance indicators have been studied. Compressive strength, water permeability, porosity, chloride penetrability, and reinforcement corrosion resistance have all been evaluated. Concrete specimens were produced with replacement levels ranging from 10 to 35%. Test results revealed that curing time had a large influence on all the examined performance indicators of scoria-based concrete. Water permeability, porosity, and chloride penetrability of scoria-based concrete mixes were much lower than that of plain concrete. Concretes produced with scoria-based binders also decelerated rebar corrosion, particularly after longer curing times. Furthermore, an estimation equation has been developed by the authors to predict the studied performance indicators, focusing on the curing time and the replacement level of volcanic scoria. SEM/EDX analysis has been reported as well.

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.

The results of investigations of spent moulding sands taken from the mould in which the metal core cooling system - to increase the

cooling rate of the ladle casting - was applied, are presented in the hereby paper. The changes of the spent moulding sand at the casting

external side being the result of degradation and destruction processes of organic binder, were analysed in this publication. Since the

reclaimed material, obtained as a result of the mechanical reclamation of spent sands of the same type, is used as a grain matrix of the

moulding sand, the amount of a binder left from the previous technological cycle is essential for the sound castings production. On the

bases of investigations of the thermal analysis, ignition losses, dusts contents and pH values of the samples taken from the spent sand the

conditions under which the process of gases displacing in the casting mould was realised as well as factors limiting the efficient mould

degassing - were considered in this study. The possible reason of a periodical occurrence of an increased number of casting defects due to

changing gas volume emission, being the reason of the realised technological process, was indicated.

One of the purposes of the application of chemically modified inorganic binders is to improve knocking out properties and the related reclamability with previously used in foundry inorganic binder (water glass), which allowing the use of ecological binders for casting nonferrous metals. Good knocking out properties of the sands is directly related to the waste sands reclamability, which is a necessary condition of effective waste management. Reclamation of moulding and core sands is a fundamental and effective way to manage waste on site at the foundry, in accordance with the Environmental Guidelines. Therefore, studies of reclamation of waste moulding and core sands with new types of inorganic binders (developed within the framework of the project) were carried out. These studies allowed to determine the degree of recovery of useful, material, what the reclaimed sand is, and the degree of its use in the production process. The article presents these results of investigation. They are a part of broader research programme executed under the project POIG.01.01.02-00- 015/09 "Advanced materials and technologies".

The paper presents the results of analyzes of gases emitted during exposure to high temperature foundry molding sands, where binders are

organic resins. As a research tool has been used special gas chromatograph designed to identify odorous compounds including the group of

alkanes.

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 results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are

presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in

the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional

crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different

temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when

a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning

process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of

organic binders on grain surfaces). This process is spontaneously sustained and decreases the demand for gas. However, due to the

significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

The results of investigations of spent moulding sands taken from the mould at various distances from the surface of the produced casting,

are presented in the paper. The casting mould was made with an application of the cooling system of the metal core in order to increase the

cooling rate of the ladle casting. As temperature measurements in the mould indicated the heat flow from the metal did not create

conditions for the complete burning of a moulding sand. The analysis was performed to find out changes of spent moulding sands caused

by degradation and destruction processes of organic binders. Conditions occurring in the casting mould were discussed on the bases of

testing: ignition losses, dusts contents, pH reactions and the surface morphology of the moulding sand samples. Factors limiting the

effective mould degassing were pointed out. Operations, possible for realization, which can limit the reasons of a periodical occurrence of

increased amounts of casting defects due to changing gas evolution rates being the result of the technological process, were also indicated.

The investigation results of the kinetics of binding ceramic moulds, in dependence on the solid phase content in the liquid ceramic slurries being 67, 68 and 69% - respectively, made on the basis of the aqueous binding agents Ludox AM and SK. The ultrasonic method was used for assessing the kinetics of strengthening of the multilayer ceramic mould. Due to this method, it is possible to determine the ceramic mould strength at individual stages of its production. Currently self-supporting moulds, which must have the relevant strength during pouring with liquid metal, are mainly produced. A few various factors influence this mould strength. One of them is the ceramic slurry viscosity, which influences a thickness of individual layers deposited on the wax model in the investment casting technology. Depositing of layers causes increasing the total mould thickness. Therefore, it is important to determine the drying time of each deposited layer in order to prevent the mould cracking due to insufficient drying of layers and thus the weakening of the multilayer mould structure.