Marek Osacký

Comenius University Bratislava

The non-aqueous extraction (NAE) is an alternative to the commercial water-based extraction technology used to liberate bitumen from oil sands. Although the impact of kaolinite, illite, chlorite, illite-smectite and montmorillonite on NAE process has been previously studied, the effect of different types of smectites has not been fully understood y...

The Dolná Ves K-bentonite deposit is one of a few known economic accumulations of illite-smectite in the world. Several studies have been done on the illite-smectitic component isolated from the Dolná Ves K-bentonite, but there is a shortage of analytical data on the K-bentonite itself. The main goal of the present study was to perform mineralogica...

The conversion of waste/by-product materials into efficient sorbents is at the forefront of innovative remediation techniques. In the present study, the relationships among the synthesis conditions, physicochemical properties of synthesized sorbents and Zn²⁺ and Ni²⁺ removal efficiencies were studied in detail. Zeolite X, zeolite P, phillipsite, an...

Although the potential of natural zeolites for water and soil remediation has been widely studied, the use of synthetic zeolites, especially from by-product/waste materials, is still rather scarce. Therefore, we present a complex study investigating the adsorption mechanisms of Zn(II) on natural (ZC), synthetic (13X), and perlite by-product (ZP) ze...

The fine powdered perlite, a by-product of processing of raw perlite was used for zeolite synthesis. Perlite by-product material (PBM) is not suitable for perlite expansion, due to fine particle size, therefore it has very limited application (recently only as additive to concrete). The conversion of PBM into zeolites is proposed to recover this ma...

In the past years an increasing demand for bentonites resulted in opening of new bentonite deposits in the Jastrabá Formation. The shortage of information, in particular analytical data, on the bentonites from newly opened Jastrabá Fm. deposits was the motivation for the current study. Smectite is the predominant mineral in all bulk bentonites from...

The Ceramic District of Santa Gertrudes (CDSG) is the most important producer of ceramic floor and wall tiles in Brazil. Industries that produce ceramic tiles by dry route process have researched new technologies to dry the Corumbataí Formation (Fm) raw materials. It is due to environmental problem related to the dust emission in the air, produced...

The mineralogy, chemistry, surface properties and pore structure characteristics of the four different petrologic types of Alberta oil sands were determined in order to better understand their impact on non-aqueous solvent bitumen extraction. Quartz, clay minerals and carbonates were the main mineral constituents of the studied samples. With increa...

The Ceramic District of Santa Gertrudes (CDSG) is the largest producer of ceramic floor and wall tiles in Brazil. Tile manufacturers in the CDSG use the single raw material, clayey rocks from the Corumbataí formation. Mineralogical, chemical, thermal and microstructural characterization of the clayey rocks from the Corumbataí formation have been pe...

Two natural clay standards, dominated by montmorillonite (SWy-2) and illite-smectite (ISCz-1) were mixed with bitumen and reacted for eight days. The clay-bitumen mixtures were then washed three times each with cyclohexane to extract bitumen from the clays. The aim was to better understand the role of swelling clay minerals on non-aqueous solvent b...

Artificial mixtures of bitumen with three natural clay standards, dominated by illite, kaolinite, and chlorite, were reacted for several days and washed three times each with cyclohexane to remove bitumen from the clays. The main goal was to determine and better understand the effect of nonswelling clay minerals (illite, kaolinite, and chlorite) on...

Clays cause problems in all crucial stages of bitumen extraction, and affect bitumen recovery and waste management. It is thus of great importance to understand the mineralogy, chemistry and surface properties of clays so as to improve both bitumen recovery and tailings treatment. Four petrologically different types of Alberta oil sands ores, calle...

The Alberta oil sands ores are a combination of four petrologically different kinds of rocks, called “end members”, deposited in marine and estuarine sedimentary environments. The combination of the different end members affects the properties of the oil sands. Applying organic solvents for bitumen extraction from the oil sands is an alternative to...

The aim of this study was to perform mineral and chemical characterisation of the four petrologic end members of Alberta oil sands in order to better understand the mineralogical and geochemical factors affecting bitumen extraction. X-ray diffraction (XRD) results revealed that the petrologic end members contain a variable amount of quartz, clay mi...

The stability of six dioctahedral smectites with different crystal chemistry was studied in the presence of iron to simulate the possible reactions of clay minerals in contact with Fe canister in a nuclear waste repository. The batch experiments were performed at 75 °C for 35 days in air. The reaction products were examined by XRD, QXRD, FTIR, BWA...

AB ST R ACT : The mineral stability of two bentonites was studied in the presence of pyrite concentrate to simulate the possible reactions between the bentonite barrier used in a high-level nuclear waste (HLW) repository and host rock containing up to 5 wt.% of admixed pyrite. Smectite was the only bentonite mineral affected by pyrite treatment und...

Bentonites which are characterized by good rheological, mineralogical and chemical stability is con-sidered used as sealing barriers in multibarrier Slovak system of deep geological repository for high-level radio-active waste and spent nuclear fuel. In Slovak Republic there are several significant deposits of bentonite, which are characterized by...

Slovak bentonites characterized by good rheo-logical, mineralogical and chemical stability are considered as suitable sealing barriers for construction of Slovak deep geological repository for high-level radioactive waste and spent nuclear fuel. There is several Slovak bentonite deposits, bentonites of which have appropriate adsorption properties m...

A temperature increase coupled with other geochemical perturbations is expected to occur during the heat phase of the geological repository due to the presence of heat-emitting radioactive waste and engineered barrier system. To study the impact of a temperature increase on the geochemistry of some candidate clay host rocks considered in Europe, we...

The stability of seven dioctahedral smectites coming from bentonites of different origin was studied in the presence of iron to simulate the possible reactions between clay minerals and Fe canisters in a nuclear waste repository. The batch experiments were performed at 75 °C for 35 days in a nitrogen atmosphere. The reaction products were examined...

Ultra-fine iron particles and clay minerals which coat quartz grains or are impregnated in silicate matrix are difficult to treat by conventional mineral processing methods. Treatment by basin water bioleaching in combination with electromagnetic separation can substantially improve the quality of quartz sands. The purpose of this in-situ study was...

Experimental interactions of Slovak bentonites with metallic iron The experimental stability of four bentonites and one K-bentonite from Slovak deposits in the presence of iron was studied to simulate the possible reactions of clays (bentonite barrier) in the contact with Fe containers in a nuclear waste repository. The batch experiments were perfo...

High-level waste and spent fuel emit significant amounts of heat when disposed of in a repository. The heat will modify water-rock interactions in an attempt to reach a new equilibrium. In addition, the heat effects might be coupled with other geochemical perturbations, such as alkaline plume, and alter near-field chemistry on the long-term. All th...