Gospodarka Surowcami Mineralnymi - Mineral Resources Management

Carbonate concretions are rather widespread throughout the Carpathians, being present in various strata from Lower Cretaceous toMiocene. Theirmineral composition is strongly diversified, with prevalence ofcarbonates of iron, magnesium, calcium and manganese. They occur as lenses, bread-like forms and irregular layers, and their diameters range from some centimetres to some metres. The carbonate concretions of the Skole Unit are reported mainly from its shaly horizons and were found in the Spas, Dolhe, Ropianka, Variegated Shale, Hieroglyphic and Krosno Formations. Mineralogical investigations (optical microscopy and scanning electron microscopy, X-ray, OTA, chemical analyses) have allowed to distinguish several varieties ofthese concretions, typical for individual formations. The total ofcarbonates in the concretions, irrespective ofthe horizon in which they occur, range between 70 and 90%. Besides the carbonates, the concretions contain quartz and clay minerals, and some of them feldspars and pyrite. The concretions of the Spas Fm are sideroplesites (Szczepańska 1998). Their content of FeCO3 is the highest (50----60%) among all the concretions studied. The concretions of the Dolhe, Ropianka, Variegated Shale and Hieroglyphic Fm arc built of various mineral mixtures ofbi- or three-component carbonate solid solutions. High total contents ofFeCO3 andMnCO3, ranging from about 50 to 75%, are their common feature. In the Krosno Fm the content of FeCO3 decreases (to several percents), while the contents of CaCO3 and MgCO3 increase (CaCO3 to more than 40%). These concretions are composed of ankerite and Fe-dolomite (Rajchel, Szczepańska 1997). The content of simple carbonates in concretions from individual horizons of the Skolc Unit varies with the geological time. Similar relationships were reported by Narębski (1958) from the Westem Carpathians. He distinguished four geochemical facies, considering the type of sediments and the type of concretions contained in them. In the Skolc Unit, the Spas Fm can be included into Narębski's (1958) sideritc-pyrite facies, the Ropianka Fm into the siderite facies, the Dolhe, Variegated Shale and Hieroglyphic Fm into the variegated facies, and the Krosno Fm into the dolomite-ankcrite facies. The carbonate concretions studied arc of early diagenetic origin.

In the paper, the effectiveness of the kriging application for the estimation of mineral deposits reserves was characterized. The effectiveness of kriging, when linear models of semivariograms of deposit parameters exist, was analized basing on model testing and results of practical applications of the method. It was found that the knowledge of semivariograms enables forecasting the effectiveness of kriging and thus, enables the choice of a method for the reserves estimation. The studies have been allowed to determine the range of effective usage of kriging. The issue is significant in order to define the rules of kriging application in routine elaboration of results of mineral deposits exploration.

This article presents considerations about meaning that has preliminary processing of chromium materials in process of sodium chromate production. This paper is divided into 2 main parts: theoretic introduction and description oflaboratory researches (including final results and conclusions). The first one indicates primary reasons for establish the studies: threats, as hazardous emissions from chemical industry to the natural environment and opportunities, as sustainable growth and development of technologies reducing negative impact of production processes. Scientific and practical experience has been also presented shortly. In the second part necessary assumptions have been formulated, used materials and constitution of chromic charge have been specified, and finally/methods, terms and way of running the researches has been defined. As an effect of the analysis, technological indices of sodium chromate production has been calculated and then used as a base for discussion about gained results and to formulate final conclusions.

In the period 1993-2000 several activities were undertaken in the hard coal mining sector aimed reduction of production costs. In the paper an analysis of changes between components of the unit cost of production based on tabular specifications and their graphical interpretations is presented.

The paper shows the results of investigations of ashes and slags derived from coal combustion in the "Łaziska" power station. Phase and grain composition of investigated wastes were determined. There was examined also a concentration of selected toxic trace elements: As.Cd, Zn, Pb, Cr. The results of the investigation will be useful for determining the relationships between mineralogical and geochemical composition of ashes and slags and contents of organic and inorganic matter in the coal.