Vojtech Dirner

Capillary Active Insulations Based on Waste Calcium Silicates

The issue of capillary active calcium silicate insulation used in the systems of energy redevelopment of historic buildings is a very up-to-date topic. This article describes the properties of the developed material structures built on cement composites with a defined inner surface using industrial waste materials containing aluminosilicates. The article presents the structures containing fly ashes from heating plants improving the rheological properties of the mixture and the latent hydraulic properties allowing a reduction of the necessary amount of the binding matrix, represented by cement in this case, which has a direct impact on the economy of the final material. The aim of the developed material is to extend the segment of capillary thermal insulation board materials used for the purpose of energy redevelopment of historic buildings. The article will present the parameters evaluating the capillary activity of the material, the coefficient of diffusion resistance, the thermal conductivity coefficient and the physical and mechanical properties. The acquired values are then implemented into the simulation software Delphin, taking into account the moisture transport in porous materials under non-stationary conditions. The output of the software is a simulation describing the developed material in time, after the incorporation into a moisture-defined building structure showing a disruption of the waterproofing layers of the lower structure.

Sediment matrix characterization as a tool for evaluating the environmental impact of heavy metals in metal mining, smelting, and ore processing areas

In this work, the matrix characterization (mineralogy, total and local chemical composition, and total organic (TOC) and inorganic carbon (TIC) contents) of different types of sediments from mining- and metallurgy-influenced areas and the assessment of the impact of the matrix on the association of potentially hazardous metals with the mineral phases of these samples, which affect their mobility in the environment, are presented. For these purposes, sediment samples with different origins and from different locations in the environment were analyzed. Anthropogenic sediments from metal-rich post-flotation tailings (Lintich, Slovakia) represent waste from ore processing, natural river sediments from the Hornád River (Košice, Slovakia) represent areas influenced predominantly by the metallurgical industry, and lake sediments from a water reservoir Ružín (inflow from the Hornád and Hnilec Rivers, Slovakia) represent the impact of the metallurgical and/or mining industries. The total metal contents were determined by X-ray fluorescence (XRF) analysis, the local chemical and morphological microanalysis by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and the TOC and TIC contents by infrared (IR) spectrometry. The mobility/bioavailability of Cu, Pb, and Zn in/from sediments at the studied areas was assessed by ethylenediaminetetraacetic acid (EDTA) and acetic acid (AA) extraction and is discussed in the context of the matrix composition. The contents of selected potentially hazardous elements in the extracts were determined by the high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

Present and Trends of Reclamations within North Bohemian Brown-Coal District

Mining coal in opencast mining not only brings positive economic benefits, but also serious negative consequences, involving the destruction of biological productivity of the landscape, its hygienic, aesthetic and social values. These socially significant issues to be addressed by corrective measures, which are the remediation and reclamation of mining areas devastated. Their task is to modify and restore the landscape to suit the system of reclamation measures not only the economic interests of human society, but also ecologically, it is in favor of newly created nature.

Analysis of Emissions from Selected Wood Charcoal Species Combustion

This study quantified selected emissions (carbon monoxide and nitrogen oxides) that are produced during combustion of beech wood, birch wood and spruce wood charcoal in the combustion tube furnace. The maximum concentration of carbon monoxide and also the nitrogen oxides have been measured in the case of the spruce wood charcoal. The minimum concentration of carbon monoxide and also nitrogen oxides have been measured in the case of the beech wood charcoal. Although the difference between maximum emissions concentration of examined samples has been smooth. The comparison of obtained results with data published by previous studies can be made a suggestion, that the maximum concentrations of measured emissions are higher for wood than for charcoal. The nitrogen oxides yield per weight loss is higher for wood than for charcoal. On the other hand the carbon monoxide yield is higher for charcoal than for wood.

Recycling Polyurethane Foam and its Use as Filler in Renovation Mortar with Thermal Insulating Effect

Renovation mortars with thermal insulating effect are characterized by thermal conductivity λ, within the range from 0.060 to 0.200 W·m−2·K−1. To achieve such low values of thermal conductivity coefficient of composite mortar, it is essential that the structure of this composite contains a sufficient percentage of pores filled with air and has a low volume weight. Lightweight fillers, mostly crushed or crumbled polystyrene, expanded clays, expanded obsidian or volcanic glasses, for example perlite or vermiculite, are used to achieve this effect. The article presents the results of the basic research, where polyurethane foam at the end of its life cycle, in the form of crushed polyurethane with a maximum grain size of 4 mm, is used as new filler for renovation mortars with thermal insulating effect. It describes the current methods of recycling polyurethane foam, the physical and mechanical properties of experimental mixtures of renovation mortar with thermal insulating effect and the method of its application to masonry. This is a new way of utilization of polyurethane foam at the end of its life cycle in the segment of renovation mortars with thermal insulating effect.

ACIDIFICATION PROCESS IN THE AREA OF THE ABANDONED ĽUBIETOVÁ - PODLIPA CU-DEPOSIT, SLOVAKIA PROCES ACIDIFIKÁCIE V OBLASTI OPUSTENÉHO CU-LOŽISKA ĽUBIETOVÁ - PODLIPA, SLOVENSKO

Abstract Acidity in surroundings of the abandoned Ľubietová-Podlipa Cu-deposit depends predominantly on the geochemical behaviour (weathering) of particular minerals (mainly pyrite). The article presents the results of measurements of basic physicochemical parameters - pH and Eh in technogenic sediments and in surface and drainage water of a dump-field. Although the dump material shows a significant amount of mobility-able metals and thus also a potential to form acidity, a massive AMD formation in future is not probable. Abstrakt Acidita v okolí opusteného Cu-ložiska Ľubietová - Podlipa závisí predovšetkým od geochemického správania sa (zvetrávania) niektorých minerálov (hlavne pyritu). V článku sú prezentované výsledky meraní základných fyzikálno-chemických parametrov - pH a Eh v technogénnych sedimentoch a v povrchovej a drenážnej vode haldového poľa. Haldový materiál síce stále vykazuje značné množstvo mobilizovateľných kovov a teda aj istý potenciál tvoriť kyslosť, podľa výsledkov výpočtu rizika, k masívnejšej tvorbe AMD nebude v budúcnosti pravdepodobne dochádzať.