The mineral sequestration of CO2 with the use of fly ash from the co-combustion of coal and biomass

Summary As a result of energy production processes, the power industry is the largest source of CO2 emissions in Poland. Emissions from the energy sector accounted for 52.37% (162 689.57 kt) of the total emissions in 2015, which was estimated at 310.64 million tons of CO2. In recent years, the tightening of regulations on the use of renewable energy sources has resulted in an increased amount of biomass used in the professional energy industry. This is due to the fact that the CO2 emissions from biomass combustion are not included in the total emissions from the combustion of fuels, resulting in the zero- emission factor for biomass. At the same time, according to the hierarchy of waste management methods, recycling is the preferred option for the management of by-products generated during energy production. The fly ashes resulting from the biomass combustion in pulverized boilers (which, due to their chemical composition, can be classified as silicate ash) were subjected to analysis. These ashes can be classified as waste 10 01 17 - fly ash from co-firing other than mentioned in 10 01 16 according to the Regulation of the Minister of the Environment of December 9, 2014 on waste catalogues. The maximum theoretical carbon dioxide binding capacity for the analyzed fly ashes resulting from the co-combustion of biomass is 8.03%. The phase composition analysis of the fly ashes subjected to carbonation process has shown, in addition to the components identified in pure fly ash samples (SiO2, mullite), the presence of calcium carbonate − calcite − the primary product of the carbonation process, as indicated by the results of both X-ray and thermogravimetric analysis.The degree of carbonation has been determined based on the analysis of the results of the phase composition of fly ash resulting from the co-firing of biomass and bituminous coal. The calculated degree of carbonation amounted to 1.51%. The carbonation process is also confirmed by the lowered pH of the water extracts, decreasing from 11.96 for pure ashes to 8.7 for CO2 treated fly ashes. In addition, the carbonation process has reduced the leaching of pollutants, most notably chlorides, sulphates, and potassium.

The changes in the structure of mineral raw materials needs in Poland between 2011−2015

An assessment of current demand for mineral raw materials in the domestic economy as well possibilities to satisfy the needs of the industry has been performed for the period 2011-2015 on the basis of estimated values and volumes of their consumption, as well as indices of the share of importation in the consumption and percentage of production sold abroad. Domestically consumed mineral raw materials have been assigned to groups corresponding to the main way of their usage, distinguishing:fuels, metallic, ceramic, chemical, construction, and others. Complementary to the presented demand- supply relations are trade balances of selected commodities. Analysis of available statistical data showed that the demand for substantial number of mineral raw materials in Poland has been met by imports and this probably will be continued in future. The reasons for Poland’s sustained import dependency of mineral raw materials is the lack or insufficient reserve base, as well as low quality of raw materials available from deposits occurring in the country. The exceptions are construction raw materials and some ceramic ones, as well minerals exported in significant qualities (e.g.: refined copper, silver, zinc, sulphur, lead raw materials, or selenium), for which it can be stated that their domestic supplies may fully satisfy the demand of the national economy. On the other hand, the scale of utilization of such fuels as hard coal and lignite, which represent very significant item in Poland’s total energy mix, may be greatly reduced in the light of EU directives aimed at restricted use of these fossil fuels. The possible alternative is development of the use of renewable energy sources, while in the case of metals - improved recycling of scrap and metal-bearing wastes.

EIGR – knowledge base as a tool facilitating the management of groundwater resources in Europe

The KINDRA project is being implemented within the framework of the Horizon 2020 programme. Its main purpose is to carry out an EU-wide assessment of existing practical and scientific knowledge related to groundwater on the basis of an innovative classification system - the Hydrogeological Research Classification System (HRC-SYS). This assessment will be based on the knowledge repository, the European Inventory of Groundwater Research (EIGR). The EIGR database is also intended as a functional tool that will provide knowledge resources to be used by individuals and representatives of all institutions whose activities involve groundwater and water management. The purpose of this article is to outline the main assumptions underlying the KINDRA project and to present the methodology for creating the EIGR database, placing particular emphasis on the experience of experts who represent Poland. The materials and information they prepared as contributions to the EIGR have made it possible to review and evaluate the current state of the art as well as the publications resulting from the water management activities undertaken in Poland.

Mercury in grain size fractions of aggregates and extractive waste from hard coal mining

Hard coal production is closely linked to the generation of significant quantities of extractive waste that require further use, in practice recognized as waste or as a raw material. It is therefore important to seek further or improve existing methods of waste material management. Studies conducted in earlier works have shown that it is possible to obtain a low-sulfur grain size fraction (grain class) so that it can be used in excavations requiring reclamation by filling. The purpose of the research presented in this paper is to determine the mercury content in hard coal mining by-products. The presence of mercury in the waste material is known and documented in the literature. However, the level of the content of this element in aggregates or wastes is important. This paper presents the problem of determining the minimum size of rock fractions meeting the specified limits for mercury content above which the material can be considered as safe are used to fill post-mining excavations. The total mercury content was determined using the classical atomic absorption method for all the collected and isolated samples (Altec AMA-254 analyzer). The total mercury content of the samples in the analytical state (Hga) was determined. Laboratory research included waste material directly from production (mining and processing of rock) from the one of the hard coal mine USCB. Coal sludge (silt) (after dewatering on filter presses) and 13 aggregates samples were analyzed, and then separated into 15 grain size fractions. The mercury determination method used in the study allowed its content in the range of 0.0568 to 0.0787 mg/kg, on an average mean of 0.0649 mg/kg (average moisture of the samples - 4.3%). On the other hand, the total mercury content of all the fractions extracted from 13 samples of aggregates showed a high variability in the content of this element, with a noticeabletendency of decreasing mercury content along with the increase in grain size. The average values of the total mercury content decrease from 0.4030 mg/kg for the finest fraction (0-6 mm) to 0.0291 mg/kg for the thickest fraction (120-200 mm) (aggregate sample moisture at approximately 1%). In general, it can be stated that the analyzed samples of coal sludge and grain fractions of aggregates meet the criteria for inert mining waste with respect to the mercury content. Based on the studies conducted, it can be concluded that due to the presence of mercury there is no need to discard fine fractions from aggregates. However, the removal of waste rock material less than 8 mm significantly increases the quality of the material. The obtained results and the statistical analysis clearly indicate a strong correlation between the occurrence of mercury and total sulfur in the material (R2 linear coefficient of determination at 0.9151), where no weathering has yet occurred. In the case of weathering, however, there is no correlation between the occurrence of mercury and sulfur, which may be due to the differences in the processes that govern the transformation and migration of mercury and sulfur compounds.

The choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material

This review article surveys the subject of choice of high gradient magnetic separation processes for removal of Fe2O3 carriers from quartz raw material by electromagnetic separator with magnetic field intensity of 1.4 T.

Exploring quality generating factors in customer-supplier relationships

The analysis of interorganizational relationships continues to attract academic research because of the influence that management of supply chain relationships has in business competitiveness. However, there are almost no studies about this decision in the mineral products industry. The purpose of this study is to investigate customer-supplier relationships in the non-metallic mineral products mining and manufacturing industry in order to determine what relational forms enable achieving better business competitiveness and higher quality relationships. To carry out this research, we propose a cohesive model comprising variables to characterize the transactions, the forms of governance and both economic and relational results. The paper is based on a transactional framework; thus, the adoption of one or another form of governance is addressed through the length of the relationship, the transmission of information and the dependencies between the agents. As for the outcome, the quality of the relationship is highlighted because of its importance in business competitiveness. The relational quality is understood as the stability of the relationship or the importance given by the buyer to maintaining the relationship or relational commitment.The hypotheses generated are contrasted by a structural equation model in a sample of 293 Spanish companies. The results confirm the importance of past relationships and integrated forms to get better results. In this sense, managers should encourage trust and dependencies because they positively affect performance. Trust and dependencies determine the choice of a vertical form of governance, and these factors, along with information, intervene in the quality of business relationships. Thus, it is possible to say that forms of governance do have effects on the interrelations between the characteristics of the transactions and the business performance.

Forecasting global coal consumption: An artificial neural network approach

In the 21st century, energy has become an integral part of our society and of global economic development. Although the world has experienced tremendous technological advancements, fossil fuels (including coal, natural gas, and oil) continue to be the world’s primary energy source. At the current production level, it has been estimated that coal reserves (economically recoverable) would last approximately 130 years (with the biggest reserves found in the USA, Russia, China, and India). The intricate relationship between economic growth, demographics and energy consumption (particularly in countries with coal intensive industries and heavy reliance on fossil fuels), along with the elevated amounts of greenhouse gases in the atmosphere, have raised serious concerns within the scientific community about the future of coal. Thus, various studies have focused on the development and application of forecasting methods to predict the economic prospects of coal, future levels of reserves, production, consumption, and its environmental impact. With this scope in mind, the goal of this article is to contribute to the scarce literature on global coal consumption forecasting with the aid of an artificial neural network method. This paper proposes a Multilayer Perceptron neural network (MLP) for the prediction of global coal consumption for the years 2020-2030. The MLP-based model is trained with historical data sets gathered from financial institutions, global energy authorities, and energy statistic agencies, covering the years 1970 through 2016. The results of this study show a deceleration in global coal consumption for the years 2020 (3 932 Mtoe), 2025 (4 069 Mtoe) and 2030 (4 182 Mtoe).

Depositional environment of Paleogen amber-bearing quartz-glauconite sands from Zdolbuniv (Rivne region, NW Ukraine): mineralogical and petrological evidences

Amber-bearing sands from Zdolbuniv mine are Paleogene fine-grained (0.6-0.12 mm) clastic rocks. The material is poorly rounded and moderately sorted out. It mainly consists of quartz, glauconite, and subordinately, feldspars (K-feldspars and plagioclases), mica, carbonates, zircon, epidote,fossil resins (Baltic amber) and ore minerals such as hematite, rutile, anatase, ilmenite. The presence of glauconite in the sands proves that sedimentation basin had to be marine reservoir. The variable composition of individual glauconite grains suggests the environmental conditions had to change during the sedimentation of clastic rocks. The occurrence of minerals, assembly such as zircon, epidote, ilmenite, rutile, anatase in the sands as well as the brown CL color of quartz grains, may suggest that majority of clastic material originated from metamorphic rocks, most probably coming from the Ukrainian Shield. Together with metamorphic material the fragment of fossil resins, i.e. Baltic amber, from the Paleogene off-shore forests could be transported to the sedimentation basin. Nowadays the bottom part of the analyzed profile is the most promising for the recovery of glauconite, whereas the exploration of Baltic amber may be initiated from the top of the profile.

Preliminary assessment of the possibility of mercury removal from hard coal with the use of air concentrating tables

Mercury is characterized by highly toxic properties. The natural biogeochemical cycle of mercury occurs in the environment, which results in the fact that even a small amount of mercury emitted to the environment is a potential threat to human health. The process of coal combustion is one of the main sources of anthropogenic mercury emissions. For this reason, on 31 July 2017 the European Commission has adopted the mercury emission standards for large combustion plants. The issue of mercury emissions is particularly important for Poland. Forecasts concerning energy consumption in Poland show that coal will be the main source for energy production in the coming decades. Therefore, actions enabling the reduction of mercury emissions from coal-fired power plants will have to be implemented. The mercury emissions from coal-fired power plants may be reduced through the application of a number of methods. These methods can be divided into two main groups: the post-combustion methods which allow for mercury removal from flue gases, and the pre-combustion methods which allow for mercury removal from coal before its combustion. The effectiveness of mercury removal from coal is determined by the mode of its occurrence in coal. In the case of mercury occurrence in the adventitious inorganic constituents of coal, high effectiveness will be obtained in the coal cleaning processes. In the case of mercury occurrence in the organic matter as well as in the inherent inorganic constituents of coal, the effectiveness of this method will be low. Mercury could be removed from such coals through the process of thermal pretreatment at the temperature of 200-400°C (mild pyrolysis). In the paper, the possibility of mercury removal from hard coal through the process of dry deshaling on an air concentrating table was examined. Six raw coals (coal feed), clean coals and the rejects derived from their dry deshaling were analyzed. The mercury content was measured in the examined samples. The content of mercury in raw coals and clean coals were compared. Additionally, the effectiveness of mercury removal from coal with rejects was determined. For the analyzed coals, the effectiveness of mercury removal from coal in the process of dry deshaling on an air concentrating table ranged from 9 to 96%. This effectiveness is similar to the effectiveness of mercury removal from coal in the processes of coal washing. It should be mentioned that, when compared to the coal washing processes, the dry deshaling process is characterized by lower investment and operating costs. Therefore, the dry deshaling process on an air concentrating table should be considered as a competitive method for the coal washing processes. There is also a possibility of an increase in the mercury removal efficiency from coal in the process of dry deshaling as a result of the thermal pretreatment of clean coal derived from dry deshaling. This solution is only recommended for coals in which mercury occurs in the organic matter as well as in the inorganic constituents characterized by a relatively low temperature of mercury release.It should be emphasized that the dry deshaling process allowed for a decrease of mercury content is not suitable for every coal. Although for five of the analyzed coals the mercury content in clean coal was lower in the range from 11 to 53%, for one coal the mercury content was higher by 19%. The effect of decreasing the mercury content in coal is more evident when it is related to the amount of energy contained in coal (i.e. for example to the lower heating value). For five of the analyzed coals mercury content expressed in such a way decreased in the range from 11 to 53 %, and for one coal the mercury content was, however, higher. Nevertheless, the difference was not very significant (ca. 5%).

Geochemical modeling of the Cu-Ag deposits from the Lubin-Głogów Copper District (Poland) supported by lithological modeling

The most important reasons for the limited credibility of 3D geochemical models of the Cu-Ag deposits (The Lubin-Głogów Copper District) are unfavorable statistical characteristics of the main metals (Cu, Ag), and the unfavorable structure of their variability with a relatively poorly marked non-random component of variability. It is hoped that the accuracy of geochemical models can be increased by previous lithological modeling of a given deposit. This is due to significant differences in mean Cu content in both the main lithological series (carbonates, shales and sandstones) and individual lithological units within them, which justifies separate geochemical modeling of each. The paper presents the results of the comparison of the reliability of 3D modeling of Cu content carried out in both individual and main lithological units of the Cu-Ag Rudna deposit (The Lubin- Głogów Copper District). The 3D lithological models were made using ordinary kriging (main lithological units) and Plurigaussian simulation (individual lithological units). The 3D estimation of Cu content within lithological models was carried out using the ordinary kriging (OK ) and squared inverse distance (ID2) methods. The verification of the accuracy of Cu estimates in the 3D model using spot samples of the test data set has shown only a slight increase in the accuracy of the estimates of Cu content within the individual lithological units of the shale series compared to the estimates of Cu content in the whole main lithology. In most cases, 3D models of Cu content carried out using the ordinary kriging method are slightly more accurate than the analogous squared inverse distance weighting method.