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Number of results: 8
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Abstract

Lower Carboniferous limestone has been extracted in the “Czatkowice” open-pit hill-slope quarry in southern Poland since 1947, for the needs of metallurgical and building industries, as well as farming. We can distinguish two aquifers in the Czatkowice area: the Quaternary porous aquifer and the Carboniferous fissure-porous one. Two vertical zones representing different hydrodynamic characteristics can be indentified in the Carboniferous formations. One is a weathering zone and the other one the zone of fissures and interbedding planes. Groundwater inflows into the quarry workings have been observed at the lowest mining level (+315 m above the sea level (asl)) for over 30 years. This study concerns two hypotheses of the sources of such inflows originating either from (a) the aeration zone or from (b) the saturation zone. Inflows into the quarry combine into one stream flowing gravitationally to the doline under the pile in the western part of the quarry. This situation does not cause a dewatering need. Extending eastward mining and lowering of the exploitation level lead to increased inflows.
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Abstract

The article describes the testing of four selected samples of limestone originating from four commercially exploited deposits. The tests of sorbents included a physicochemical analysis and calcination in different atmospheres. The main aim of the tests was to determine the possibilities for using limestone during combustion in oxygen-enriched atmospheres. Tests in a synthetic flue gas composition make it possible to assess the possibility of CaCO3 decomposition in atmospheres with an increased CO2 concentration.
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Abstract

Widespread opinion holds that calcareous rocks have limited suitability for use in the production of aggregates and stone products having adequate frost resistance. However, some of the rocks, in particular those from earlier geological periods, provide a promising alternative to silicate rocks. The paper presents results of the analysis of Devonian carbonate rock originating from two selected mines in the Swietokrzyskie region. The examined mines extract limestone from two different deposits of the same age. The rock samples are collected from beds lying at different depths, distinct in texture and color in macroscopic examination. It was found that despite the changes in bulk density, porosity and absorption, all the examined samples were frost resistant. Using the Differential Analysis of Volumetric Strain method, the content of ice formed in the pore spaces was determined. In addition, the ratio of the content of water capable of freezing to the total pore volume, and the total amount of water absorbed due to capillary action in rock samples soaked in water, were analyzed. In all cases, it was revealed that the destructive action of freezing water was weakened due to a relatively low content of water capable of freezing and a substantial volume of pores that are not filled with water in capillary absorption. It is extremely important to be able to classify the available rock material. The generally adopted methods, including absorptivity tests, do not allow for precise categorization. In the investigations, the authors focused on the analysis of the basic factors that are decisive for rock durability, including bulk density, pore filling level and volume absorption. The authors do not correspond compressive strength and resistance to abrasion as this will be the subject of further research.
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Abstract

The article presents tests carried out on three selected samples of limestone originating from three commercially exploited deposits. The tests of sorbents included desulphurisation in different atmospheres and a physicochemical analysis of desulphurisation products. The aim of the tests was to determine desulphurisation efficiency and conversion degree as dependent on the concentration of O2 and CO2.
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Abstract

The correlation-regression method, as one of the indirect sampling methods, is only sporadically used in geological and mining activities. Theoretically, it should be particularly useful for predicting the content of some chemical components in limestone and marl deposits due to the correlation between them. The results of simple and multiple correlation and regression analysis for 5 selected components (CaO, SiO2, Al2O3, MgO, and SO3), determined in samples from exploratory boreholes and blast holes carried out in the Barcin-Piechcin-Pakość deposit, are presented in the article. The determination coefficients were used as a measure of the correlation power and the quality of the regression models. A very strong linear correlation between CaO and SiO2 content and strong linear correlations between CaO and Al2O3 and SiO2 with Al2O3 have been found. The correlation relationships of the remaining pairs of oxides are weak or very weak and do not provide a basis for prediction of their content based on regression models binding them with the content of other components. The use of nonlinear models for these pairs of oxides results in only a slight improvement in the quality of regression, insignificant from a practical point of view. The application of multiple regression models, linking the content of the mentioned components (with the exception of CaO), leads to similar conclusions. Compared to the determination coefficients of a simple linear correlation, a strong increase in determination coefficients obtained in two cases was found to be artificial and caused by a correlation between the content of the selected components acting as independent variables. From the geological and mining point of view, the results of the analysis indicate the possibility of a fully reliable prediction of SiO2 content and the limited reliability of the Al2O3 content prediction when the CaO content is determined using simple linear regression models.
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Abstract

Washing is very popular technological operation removing clay particles from aggregates. The amount of mineral washing sludges increases. Besides filling the excavations, there is no common method of their utilization. The usage of sludges from washing aggregates in building ceramics might be environmentally friendly way to utilize them. This paper presents laboratory research on two type of sludges: from dolomite and limestone aggregates washing. Selected properties of sludges such as water content, particle size distribution (sieve and areometric method), chemical composition (XRF), mineral composition (XRD), thermal properties (STA/EGA, dilatometry, heating microscopy) and stability of fired materials during steam exposure were determined. It was found that dolomite sludge contains more clay minerals and less carbonates, it is more finely grained than limestone sludge. Limestone sludge has large fluctuations in water content and has high content of potentially hazardous calcite grains. During heating up to 1300°C of both dried sludges decarbonation and sintering take place. Dolomite sludge softens, melts and flows below 1300°C. After firing sludges at 1000°C material made of limestone sludge is not resistant to steam. The obtained result suggests that dolomite sludge can be used in building ceramics technology without processing as main component of ceramic mass. Limestone sludge have to be ground before its application in building ceramic materials. Results suggest that it can not be used as the main raw material in ceramic masses, but only as an additive.
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