The assurance of future raw materials supply to the EU mineral industry has become, in recent years, one of the priority tasks of the EU Commission, geological surveys and several research centers. After many years of negligence, the problem of developing supply risk of many raw materials in Europe has been perceived, along with the menace to the EU economy competitiveness coming from dynamically developing countries such as China, India and others - basically of Asian origin. This has initiated a new mineral policy within the EU zone, referring mainly to non-fuels. One of the starting points for this activity has become the assessment of the EU mineral resources potential and identification of the raw materials that are critical for the harmonious and sustainable development and technological progress. The paper briefly presents the results of research work focused on the critical raw materials assessment, which were conducted by the Initiative for the Raw Materials Supply. Its core is the presentation of Polish mineral reserve base and its potential as a possible source of critical raw materials for the European Union. The criticality analysis was based on three categories, i.e.: economic consequences of the supply limitation, supply risk of reduction (fluctuation or disruption), and environmental risk referring to countries with weak environmental performance in order to protect the environment that jeopardize the supply of raw materials to the EU. For their quantitative assessment there were proposed three aggregated indices, while for the forecast purposes - 10-year period. The criticality ratio was determined for the 41 most important and most frequently used raw materials. On the grounds of the research made up to now, these raw materials were preliminary divided into three groups. As a critical to the EU economy, 14 raw materials of major economic importance were discriminated, i.e.: antimony, beryllium, cobalt, fluorite, gallium, germanium, graphite, indium, magnesium, niobium, PGM, rare earths, tantalum, and tungsten. They are characterized by high supply risk, which is mainly due to limited number of their sources - dominated by a few countries, in particular China. The risk of supply disruptions is boosted by low rate of utilization of secondary sources, and limited scale of substitution as well. The majority of the above-mentioned raw materials are crucial for the new technologies development. The remaining minerals arealso - though to a lesser extent - imperiled with a supply deficit. Despite they are also of economic importance, their indispensability for the advanced technologies development is relatively smaller. Taking into account the raw materials that are critical for the European Union economy, Poland cannot be considered as its resource base. The source of these raw materials are not only scarce in Poland, but also they are not produced, and their demand is now - and according to forecasts is going to be in the future - met by imports. However, the role of our country as a manufacturer of finished products from components of foreign origin is anticipated to increase. The raw materials in question are not considered exactly critical for Polish economy, as any industrial branch based upon their utilization has emerged so far. Therefore, they are of limited economic importance. Presumable utilization of very limited sources of above-mentioned critical raw materials in Poland could be anticipated in a perspective of at least 20 years. The most probable in this respect are the following: opening out the new Mo-W-Cu ore deposit Myszków, and the promotion of exploration works for similar deposits.
The Polish basis of dolomites is remarkable. Their total reserves reported in the 62 deposits listed in current data bases of mineral resources amount to 1,500,000 t. However, there is a shortage of the so-called converter dolomites of high quality applicable in manufacturing of refractory materials. Such dolomites of the Triassic age have been quarried for many years in the Brudzowice and Ząbkowice Śląskie I deposits in the Silesian-Cracow region. The Libiąż deposit is perspective of this area, considering the character and properties of its dolomites. The dolomites of the Nowa Wioska and Stare Gliny deposits belong into the same group although their applying as refractories seems to be disputable at the moment and would require more detailed analyses of the chemical composition and firing properties of the rocks mentioned. The reason is that the dolomites of these deposits have been reported andmassively quarried up to now mainly for civil engineering (roads, buildings, etc.). Unfortunately, worsening properties of the dolomites occurring in Żelatowa, still another large and developed deposit of the region, have been excluded using these rocks in producing of refractories. Among the group of reserve converter dolomite deposits, the best rock properties have been found in four of them, i.e., Chruszczobród, Chruszczobród I, Chruszczobród II and Libiąż Wielki. The survey presented indicates that there are some possibilities of including dolomites of the Winna and, to a lesser degree, Radkowice-Podwole deposits as the raw materials in manufacturing of refractories. Again, more detailed analyses of the chemical composition and petrographical development, mainly of the grain size distribution, would be required. Dolomitic marbles of the Lower Silesia region represent a separate problem. Traditionally, they have been considered to be non-applicable in manufacturing of refractories because of too coarse grain size of these rocks. It should be stressed, however, that the Lower Silesian marbles occur in several varieties and among them also fineand coarse-grained dolomites occur. Their finest and chemically purest varieties can be an interesting option in extending the basis of refractory dolomitic raw materials in Poland, although selective quarrying would be required in such a case.
Chalcedonite is a diatomaceous sedimentary rock, which, on account of a very small occurrence area, is included into a group of unique rocks. It occurs at Dęborzynka, Gapinin, Lubocz and Teofilów deposits, located on the Rawska Plateau in the region of Tomaszów Mazowiecki and Nowe Miasto. The deposit in Teofilów is the only documented one and it is now being exploited. The surface of this deposit is 577 437 m2 and its geological resources were determined to be 21.587 - 106 kg (21 587.0 thousand tones). The main component of this rock is chalcedon (69.0-96.6 vol.%), however quartz, opal, iron hydroxides, pyrite, manganese compounds and clay minerals occur in small quantities. The active surface of chalcedonite is relatively small and it was determined as 3-6 m2/g. Chalcedonite had a mesoporous structure of a significantly high pore homogeneity, and the total volume of these pores was 0.03-0.04 cm3/g. On account of its small spatial distribution chalcedonite is a unique rock, which has multi-resource properties. It is useful for manufacturing perlite-like material, crystobalite, wollastonite and mullite. It was also found to be a valuable raw material for the production of pastes, scouring powders, grinder tools and also as good filler for the production of : paints, varnishes, enamel ware, lute and putty materials. Because of its mesoporous structure and due to extended outer surface of the grains, chalcedonite is utilized in water treatment technology, mostly as an effective filtration material. A high usefulness of chalcedonite bed for manganese and iron removal from water shows mostly the presence of a low height of iron removal zone in the filter, and it is also manifested by a relatively short time of introduction into effective manganese(II) removal, as well as by good hydraulic properties of the material, which enable to achieve high mass capacities of the filter and to reach long filtration cycles. Chalcedonit is a very good carrier of manganese oxides and its surface modification of leads to the creation of chemically active bed, which enables removal of manganese(II) from water with high efficiency and without the introduction process. Chalcedonite bed effective removes of ammonia nitrogen from the water in the process of nitrification and waste water treatment. Chalcedonite can be also taken into account as a sorbent for the removal of oil spills.
Investigations of n-dodecane used in flotation of copper ore from the Legnica-Glogow Copper Basin (LGOM) were presented in the paper. The aim of the work was estimation of influence of nonpolar reagent's on the results of copper ore flotation. Two series of flotation tests were conducted. The first series - flotation experiments with standard flotation with xanthate collector only (KEtX), were compared with the second series: flotation experiments with n-dodecane addition (C12) in the first stage and then xanthate addition (KEtX). n-dodecane was used in form of aqueous emulsion and frother was aqueous solution of \alfa-terpincol. Flotation results showed that a part of copper minerals float with n-dodecane, and the rest of them is recovered using xanthate collector. The best results were obtained for the first series (with xanthate only). These flotation results were compared with the results of copper sulphide ores flotation with n-heptane addition. It was found that with the doses reagent used, n-heptane has a higher selectivity in comparison with n-dodecane. In the presence of various doses of n-heptane, tested material enriched better in organic carbon carriers than in the copper minerals.
Earth Pressure Balanced shields are currently the most utilized tunnelling machines throughout around the world. The possibility of using conditioning agents that change the mechanical and hydraulic behaviour of a soil, changing it into a plastic paste and thus permitting soil pressure applications at the tunnel face, is the key point to explain the increasing utilization of this technology. Despite its great importance, not much laboratory researches can be registered on soil conditioning, particularly for cohesionless soils. The conditioning criterion is usually defined on the basis of a trial-and-error procedure developed directly at the job sites. A test that is able to simulate the extraction of soil from the bulk chamber with the screw conveyor inclined upwards, as in real machines, can offer a quantitative indication of the conditioned soil behavior for EPB use. The characteristics of the device and the results obtained on many different types of soil are discussed in order to point out the great importance and quality of results that can be achieved using the proposed test device.
In the last decades Real Options Valuation (ROV) has been gaining a leading role among methods of economic evaluation and risk analysis of projects. This method enables valuation of managerial flexibility which includes postponing investments and reformulating of operating strategies of companies. By doing this, the method delivers higher project values than derived from the classical discount approaches, such as NPV. The value of flexibility may be of lower or greater importance - depending on types, configuration and sequence of occurring real options. Common methods of real options valuation are built on lattice models which approximate continuous stochastic process. One of the most popular techniques used for real options valuation - a marketed asset disclaimer approach (MAD) - is based on the binomial tree. The paper presents valuation of the mineral project with three simultaneous options: option-to-expand, option-to-contract and option-to-abandon.
The structure of electricity production in Poland has not changed dramatically recently. Approximately 93% of electricity is currently produced from coal and lignite. Environmental charges have a significantly impact on costs of production. This paper analyses the impact of environmental charges influenced by coal quality on the production cost of power generation. A simulation of the impact of coal quality (Q, A, S) on the environmental charges was carried out. The study was extended by the analysis based on improved relationship between coal quality and emission charges. The calculations included also charges related to the NOx, CO and CO2. The results are presented per 1 ton of coal burned and per 1 MWh of electricity produced.
Geological carbon dioxide storing should be carried out with the assumption that there are no leakages from the storage sites. However, regardless of whether the gas which is injected in leaks from the storage site or not, the carbon dioxide stored will influence the environment. In a tight storage site the carbon dioxide injected in will dissolve in the reservoir liquids (groundwater and oil) and react with the rocks of the storage formation. Dissolving CO2 in underground water will result in the change of its pH and chemism. The reactions with the rock matrix of the storage site will not only trigger changes in its mineralogical composition, but also in the petrophysical parameters, because of the precipitation and dissolution of minerals. A leakage of CO2 from its storage site can trigger off changes in the composition of soil air and groundwater, influence the development of plants, and in case of sudden and large leaks it will pose a threat for people and animals. Carbon dioxide can cause deterioration of the quality of drinking waters related to the rise in their mineralization (hardness) and the mobilization of heavymetals' cations. A higher content of this gas in soil leads to a greater acidity and negatively affects plants. A carbon dioxide concentration of ca. 20-30% is a critical value for plants above which they start to die. The influence of high concentrations of carbon dioxide on the human organism depends on the concentration of gas, exposure time and physiological factors. CO2 content in the air of up to 1.5% does not provoke any side effects in people. A concentration of over 3% has a number of negative effects, such as: higher respiratory rate, breathing difficulties, headaches, loss of consciousness. Concentrations higher than 30% lead to death after a few minutes. Underground microorganisms and fungi have a good tolerance to elevated and high concentrations of carbon dioxide. Among animals the best resistance is found in invertebrates, some rodents and birds.
Fly ashes from the combustion of lignite coal are suitable materials for the creation of suspensions in which CO2 is bound by mineral carbonation. Considering their limited economic uses, mineral sequestration, as a stage of the CCS technology in lignite coal power plants, can be a way of recycling them. Mineral sequestration of CO2 was researched using fly ashes from the combustion of lignite coal in the Pątnów power plant, distinguished by a high content of CaO and free CaO. Research into phase composition confirmed the process of carbonation of the whole calcium hydroxide contained in pure suspensions. The degree of CO2 binding was determined on the basis of thermogravimetric analysis. A rise in the content of CaCO3 was found in the suspensions after subjecting them to the effects of carbon dioxide. Following carbonation the pH is lowered. A reduction in the leaching of all pollutants was discovered in the studied ashes. The results obtained were compared to earlier research of ashes from the same power plant but with a different chemical composition. Research confirmed that water suspensions of ashes from the combustion of lignite coal in the Pątnów power plant are distinguished for a high degree of carbonation.
Metallurgical slag is often treated as a material which could be used in the waste management, especially for production different kinds of aggregate. So it is necessary to know that material not only considering technical properties, but also its mineral and chemical composition. Such researches could deliver many valuable information during the waste utilization. Researches were made for samples of the metallurgical slag after steel and Zn-Pb production. Samples were taken from chosen dumps localized in the Upper Silesian District. Beside metallic aggregates, silicate and oxide phases, glaze is one of the main component of the metallurgical slag. The following stages of the glaze devitrification were presented; from not transformed and isotropic glaze pieces to the strong weathered glaze. Transformed glaze is red or brown with the cracks on the surface. Cracks are often filled by the metals oxides, which can be liberated during the glaze devitrification. On the base of researches executed using the electron microprobe the chemical glaze composition was presented. The chemical composition of the glaze is variable what is connected with the kind of the metallurgical slag. The following main elements were distinguished in the metallurgical slag: Si, Al, Fe, Ca and Mg. Slag after steel production contains also Mn, P, S and the slag after Zn-Pb production contains: As, Cd, Cu, Mn, Ni, Pb, Ti, Zn, Na, K, P and S.
The subject matter of the articles published in Mineral Resources Management covers issues related to minerals and raw materials, as well as mineral deposits, with particular emphasis on: