rss_2.0Materials and Geoenvironment FeedSciendo RSS Feed for Materials and Geoenvironment and Geoenvironment 's Cover the Enthalpy of an Fe-Ni Alloy at Various Temperatures Using the ‘STA’ PT 1600 Equipment<abstract> <title style='display:none'>Abstract</title> <p>In this research paper we have determined the enthalpy of the Fe-Ni alloy using the ‘STA’ equipment at the laboratory of the University of Mitrovica “Isa Boletini”, Department of Materials and Metallurgy. The sample for analysis was taken at the Ferronikel plant, whereas the preparation of the sample for analysis on the ‘STA PT 1600’ equipment took place at the laboratory of the University of Mitrovica ‘Isa Boletini’.</p> <p>The sample of the Fe-Ni alloy analysed was 2–4 cm in size, in the shape of a granule. It contained, 22.55% Ni, 76.51% Fe, and small amounts of other elements [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_001">1</xref>, <xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_002">2</xref>]. During the analysis of the Fe-Ni alloy, we obtained three enthalpy values under analytical conditions that included a maximum temperature of 800 °C and a minimum temperature of 600 °C; the alloy was exposed to each temperature separately for 45 minutes at each temperature.</p> <p>The results showed negative enthalpy values during the three scenarios examined and an exothermic process where ΔH&lt;0 [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_003">3</xref>]. The enthalpy decreases as the system releases heat with an increase in temperature [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_004">4</xref>].</p> </abstract>ARTICLE2022-03-21T00:00:00.000+00:00Returning Electrostatic Precipitators to the Fe-Ni Production Process<abstract> <title style='display:none'>Abstract</title> <p>The process of frying the Fe-Ni charge in rotary kilns inherently produces large amounts of process dust, which rotary kilns clean out through the use of electro-static precipitators [<xref ref-type="bibr" rid="j_rmzmag-2021-0013_ref_001">1</xref>].</p> <p>One kiln contains two sections of electrostatic precipitators as a safety mechanism [<xref ref-type="bibr" rid="j_rmzmag-2021-0013_ref_001">1</xref>]. Electrodes installed in the sections produce electric fields when electricity passes through them, and ionize the dust.</p> <p>The timing of the process must be coordinated carefully, and these electrodes are struck with hammers and occasionally shaken, generating quantities of dust which are then collected in a snail dust conveyor, then returned to the production process and recycled. In addition, a smaller amount of dust is derived from the gas chamber, which returns to production without entering the cleaning process in the electro filters. The difference between the two types of dust is their granulation size [<xref ref-type="bibr" rid="j_rmzmag-2021-0013_ref_001">1</xref>].</p> <p>We conducted the research during the years from 2017 through 2020, calculating the components of the rotary kiln process. Here, we present a linear equation as a result of the ratio of calcine and electrofilter dust.</p> </abstract>ARTICLE2022-03-21T00:00:00.000+00:00Hydrocarbon Potential and Biomarker Studies of EE-1 Well, Offshore Eastern Dahomey Basin, SW Nigeria<abstract> <title style='display:none'>Abstract</title> <p>The hydrocarbon potential, organic source input, and paleodepositional environment of subsurface sediments from EE-1 well, offshore Eastern Dahomey Basin, were assessed using Rock-Eval pyrolysis and biomarker geochemistry. The total organic carbon (TOC) and soluble organic matter (SOM) in the sediments ranged from 0.96wt% to 8.92wt% and 676.12 ppm to 2883.85 ppm, respectively, indicating adequate to excellent organic richness. The pseudo-Van Krevelen plot classified the sediments as types II and III kerogen, which have the potential to generate both oil and gas. The T<sub>max</sub> and production index (PI) ranged from 422°C to 431°C (average, 426°C) and 0.03 to 0.24, respectively, suggesting low thermal maturity. The presence of C<sub>27</sub>–C<sub>29</sub> steranes, oleanane, and hopane/sterane ratio (1.53/16.11), indicated organic matter from mixed sources with more terrigenous input. Cross plots of Pr/nC<sub>17</sub> against Ph/nC<sub>18</sub>, C<sub>35</sub>/C<sub>31</sub> – C<sub>35</sub> homohopane index (0.05 – 0.17) and other related biomarker ratios such as C<sub>21</sub>/C<sub>23</sub> trycyclic terpane ratio (0.33 – 0.82) signified that the sediments were deposited in mixed marine/terrigenous environment under oxic – suboxic conditions. This study has demonstrated that sediments had adequate organic matter with the potential to generate both oil and gas at appropriate thermal maturity.</p> </abstract>ARTICLE2022-03-18T00:00:00.000+00:00Lateral squeezing effects on cement-slag-bentonite slurry wall performance<abstract> <title style='display:none'>Abstract</title> <p>Cement-slag-bentonite slurry walls are self-hardening structures, and they are mainly used to retard contamination transport into the groundwater stream. Whilst permeability of a mixture is an initial criterion in slurry wall design and material selection, long-term performance is mainly influenced by curing ages and stress-state caused by adjacent soil. In this study, the steady-state of effective stresses at 7 days and 28 days of curing age is predicted. The effect of the modulus of horizontal subgrade reaction, interface friction, and transition of the earth pressure from at-rest to the active condition was applied to develop the model. Unlike the quantities that the geostatic model presented, this method gives a slight decrease of stresses after a certain depth, and the trend is in good agreement with trends provided by previous studies. Furthermore, the predicted stresses are then applied to estimate the permeability of the wall at each depth and compare it with those obtained in the laboratory. Finally, predicted effective stresses stay lower than geostatic stress, and the slurry wall consolidation along with the sidewalls’ lateral squeezing leads to keeping the stress state under control.</p> </abstract>ARTICLE2022-03-02T00:00:00.000+00:00Valuation of Rubber Waste and Dune Sand: Mortar for Construction and Environmental Protection<abstract> <title style='display:none'>Abstract</title> <p>The main objective of this study is the recovery of dune sands and rubber waste (powders). The latter constitutes a potential source of several environmental and economic problems.</p> <p>The objective of this present work is to examine the ability to use dune sand for the preparation of mortars with sufficient physico-mechanical properties to allow them to be used in various building construction applications. The formulation of the mixtures is based on replacing dune sand with powders, at different weight contents: 10 %, 20 %, and 30 %. The quantity of cement is set at 450 <italic>g</italic>. The results obtained show in the first place that the particle size of the mixture tends to be spread out with a remarkable increase in the fineness modulus, and in the second place the density of the mixture decreases by 6.5 % (for the apparent) and by 10 % (for the absolute), which means the calculation of loads for the resulting mortar must decrease. Porosity has decreased to 20 % and absorption has increased to 30%. The strengths have decreased over 40 % for compressive strength and over 30 % for tensile strength, with an improvement in the relationship between the two strengths.</p> </abstract>ARTICLE2022-02-23T00:00:00.000+00:00Field Observations, Petrography, and Microstructures of Granite from Abeokuta Southwestern Nigeria<abstract> <title style='display:none'>Abstract in English</title> <p>The granite of Abeokuta is part of the Older Granite suite of the basement complex of southwestern Nigeria. Field observation has identified the granite as porphyritic in texture, with a preferred alignment of megacrysts of K-feldspar &gt;5 cm that are mostly euhedral to subhedral in shape. K-feldspar megacrysts are predominantly yellowish, but whitish and pinkish colouration has also been observed. The dark grey porphyritic, mafic rock composition occurs as enclaves within the granite, with phenocrysts having a preferred alignment as the enclosing granite. Also, K-feldspar megacrysts show zoning defined by concentric arrangement of inclusions of biotite relative to the crystal faces. Petrographic study shows the following minerals in order of abundance: K-feldspar, biotite, quartz, and plagioclase, with K-feldspar having a microperthitic intergrowth and biotite crystals aligned in a preferred direction. Evidence such as the crystal shape of K-feldspars, preferred alignment of K-feldspar phenocrysts, and concentric crystallographic arrangements of inclusions of biotite in K-feldspar support a magmatic/phenocrystic origin of K-feldspar megacrysts of Abeokuta granite rather than originating by growing in a solid state as porphyroblasts.</p> </abstract>ARTICLE2022-02-04T00:00:00.000+00:00An analysis of coal consumption, CO emissions and economic growth in Slovenia<abstract><title style='display:none'>Abstract in English</title><p>The common characteristics and possible correlations between coal consumption, CO<sub>2</sub> emissions, emission productivity and economic growth in Slovenia are discussed in this article. The correlation between these variables was analysed by using the Pearson correlation coefficient, and we used linear regression and the least squares method to develop predictive mathematical models that can be used to estimate trends in coal consumption and CO<sub>2</sub> emissions in the future. The link between coal consumption, emissions, and emission productivity is significant, while the correlation between coal consumption and economic growth is minimal. Therefore, coal consumption and the resulting emissions do not have a significant impact on economic growth. Mathematical models show a good fit, which is a condition for the reliability of the prediction. Possible scenarios of the transition to carbon neutrality and the related problems of future electricity supply as a consequence of the cessation of coal mining and use are also discussed below.</p></abstract>ARTICLE2021-12-30T00:00:00.000+00:00Copper tailings reprocessing<abstract> <title style='display:none'>Abstract in English</title> <p>Copper is widely used in the modern world. An excellent conductor of electricity, it is used in the electrical industry, in the construction industry because of its good corrosion resistance, and in the manufacture of heat exchangers in heating and cooling systems owing to its excellent thermal conductivity. Copper production has increased throughout the twentieth century, and this trend has continued over the last twenty years. The demand for copper is expected to increase significantly by the year 2030. Owing to the high prices of this metal and the lack of deposits, part of the demand can be met by extraction from copper-bearing tailings. In the past, owing to the lower level of technological development and lower copper prices, materials comparable in copper content to the copper ores mined today have ended up in tailings. Since these are already processed materials, the costs of mining, crushing and milling are largely eliminated, making them promising raw materials. The article presents the technological possibilities of reprocessing and also estimates the amount of copper that could be obtained worldwide in this way.</p> </abstract>ARTICLE2022-01-10T00:00:00.000+00:00Physico-Chemical Trends in the Sediments of Agbede Wetlands, Nigeria<abstract><title style='display:none'>Abstract</title><p>This study assessed the physico-chemical status of sed­iments in the Agbede Wetlands with the aim to create a reference archive for the Edo North catchment and to further identify the characteristics mostly influenced by the natural and anthropogenic activities going on at the watershed. Nutrients, zinc, nickel and lead were identified to be mostly of anthropogenic origin, while alkali metals and alkaline earth metals were from both anthropogenic and natural sources. The clustering of stations 1 and 4 indicates that the sediment quality in the lentic systems was not completely excluded from the lotic system, suggesting that principal component analysis (PCA) and cluster analysis (CA) techniques are invaluable tools for identifying factors influencing the sediment quality. The mean values of the particle size distribution were in the following order across the ecosystems: sand (61.86-80.53%) &gt; silt (9.75-30.34%) &gt; clay (7.83-13.89%). The contamination of the water bodies was primarily derived from agricultural run-offs and through geochemical weathering of the top soils. Therefore, our analysis indicates that the concentra­tions of cations, anions and nutrients in the sediments of the lotic and lentic ecosystems in Agbede Wetlands are not at an alarming level.</p></abstract>ARTICLE2017-06-23T00:00:00.000+00:00Regression methods for evaluation of the underwater noise levels in the Slovenian Sea<abstract> <title style='display:none'>Abstract</title> <p>Anthropogenic underwater noise pollution of seas and oceans caused by shipping can have negative effects on marine animals. The aim of this study was to evaluate quantitatively how much the underwater noise levels in the Slovenian Sea were influenced by anthropogenic pressures and meteorological parameters in the period from 2015 until 2018. For this purpose, correlation method and least squares multiple linear regression analysis were used. The results of this study show that the correlation of underwater noise levels with the dredging activity is significant but low, while correlation with the ship densities is insignificant, which could be due to reduced sound wave propagation in the shallow sea levels. Correlation of the underwater noise levels with the wind speed was significant but low to medium, which could be explained by the breaking waves generated by the wind that produced sound.</p> </abstract>ARTICLE2021-12-11T00:00:00.000+00:00Influence of cooling mode in relation to casting and extrusion parameters on mechanical properties of AA6082<abstract><title style='display:none'>Abstract</title><p> In this study, conditional average estimator neural networks (CAE NNs) were used for an analysis of the common influences of the cooling mode in relation to the ram speed, extrusion ratio, casting speed and casting temperature on the yield strength and the elongation of an extruded profile made from aluminium alloy (AA)6082. The obtained results from the analysis revealed very complex relationships between these parameters. In order to maximise the values for the yield strength and the elongation, the values for the ram speed, extrusion ratio, casting speed and casting temperature should be optimised in relation to the mode of cooling.</p></abstract>ARTICLE2017-06-01T00:00:00.000+00:00Geochemistry of Fluvial Sediments from Geregu, Southwest Nigeria<abstract><title style='display:none'>Abstract</title><p> Geochemical analysis of fluvial sediments on the banks of River Ero using inductively coupled plasma mass spectrometry illustrates their maturity, provenance and tectonic setting. The analysed sediment samples show low SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratios of 2.92-2.99 (units FL_A, FL_B and FL_E) and high SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratios of 4.064-4.852 (units FL_C, FL_D, FL_F and FL_G). Sediments were geochemically classified as shales (units FL_A, FL_B and FL_E) and greywackes (units FL_C, FL_D, FL_F and FL_G). Variability in sediment maturity (FL_F &gt; FL_G &gt;FL_C &gt;FL_D &gt;FL_A &gt; FL_B &gt; FL_E) parallels a decreasing order in the ratios of SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> and K<sub>2</sub>O/Al<sub>2</sub>O<sub>3</sub>, as well as the proportion of quartz grains and matrix components. Evidence from Al<sub>2</sub>O<sub>3</sub>/TiO<sub>2</sub>, K<sub>2</sub>O, Rb, La/Co, Th/Co, Cr/ Th, Th/Cr, La/Th-Hf, Th-Hf-Co and rare earth element contents of sediment samples suggest felsic protoliths of upper continental crust in a passive margin tectonic setting. An insignificant contribution of mafic components from the source is, however, inferred based on the Ni and Cr contents of the sediment samples. Combined Eu anomalies &lt;0.85 and (Gd/Yb)<sub>n</sub> ratios &lt;2.0 (1.53- 1.82, average 1.65) suggest post-Archean protoliths.</p></abstract>ARTICLE2017-06-01T00:00:00.000+00:00The flexural stiffness and tension state of basalt filter<abstract><title style='display:none'>Abstract</title><p> In recent years, there is a growing demand in Uzbekistan for new, cheap and competitive products from local raw materials, the demand being directly connected with the expansion and development opportunities of the mining, metallurgical and processing industries. In such conditions, the need for providing a solution of the problems faced by these industries is a very urgent one and requires further comprehensive studies. One of these tasks includes assessment of the force parameters and bending stiffness of basalt fibre filters, aimed at further improving the efficiency of local basalt raw materials and aiding in the manufacture of new, long-lasting, reliable and high-quality products. In this case, we studied the interaction of basalt fibre filter with a gas or liquid medium, the deformed state of the fibres under the action force of the gas or liquid, and the filter recovery process after removal of the load, all of which occur during mechanical filtration. These tasks are of interest because during the mechanical filtration of a gas or liquid (hereinafter, mechanical filtration) from solids, all attention is paid to the quality of the filtering process. The filtering quality, as known, is determined by the degree of contamination in the liquid undergoing treatment, duration of separation of the pulp into solid and liquid phases during the decantation process of the mixture and the amount of gas/ liquid released into the atmosphere along with carbon monoxide and toxic impurities. At the same time, the state and behaviour of the filtering material remain as minor factors, the consideration of which can play a decisive role in the establishment of filter life and work capacity. Solutions to these problems are very urgent and allow one to create new technologies for the production of basalt filters based on force parameters and bending stiffness, wherein the purification occurs without the intervention of chemicals.</p></abstract>ARTICLE2017-06-01T00:00:00.000+00:00Diversity of Soil Microbial Communities from an Iron Mining Area (Oued Zem, Morocco)<abstract><title style='display:none'>Abstract</title><p> Microbial communities in the soil were collected from 20 samples of an iron mining area (Ait Ammar, Oued Zem, Morocco), and unaffected samples were analysed to identify the effects of metal concentrations on functional diversity (Biolog<sup>®</sup> EcoPlates), and structural diversity (polymerase chain reaction-denaturing gradient gel electrophoresis of 16S rDNA). Aliivibrio fischeri is mainly used for evaluating polluted soil. The functional diversity was assessed by using such indices as area under substrate utilisation curve, richness, Shannon- Weaver and evenness indices. The analysis of similarities and the non-metric multidimensional scaling analyses of DGGE profiles showed that metals in the soil do not have a significant influence on bacteria. Principal component analysis of Biolog data revealed the similarity in the metabolic profiles of mining samples. These results suggest that the direction and the distance from the iron mine tailings do not have significant effects on the metabolic and structural diversity of the soil bacterial population. The toxicity of metals in soils heavily contaminated with Fe and P did not affect the quantities of microbial populations and did not significantly change the microbial diversity of contaminated soils.</p></abstract>ARTICLE2017-06-01T00:00:00.000+00:00Structural drilling using the high-frequency (sonic) rotary method<abstract><title style='display:none'>Abstract</title><p>In Slovenia, there is widespread use of structural drilling along with classical core drilling. Recently, however, the need has arisen for a highly effective core drilling method with the aid of which high-quality core might be obtained. In order to achieve this aim, one among several Slovenian companies dealing with geological surveying has decided to implement structural drilling using a high-frequency drilling method. The following article presents the theoretical foundations for such a high-frequency method, as well as the manner of its implementation. In the final part of the article, a practical comparison between the conventional and the high-frequency core drilling methods is also provided.</p></abstract>ARTICLE2017-06-01T00:00:00.000+00:00Underwater noise in the Slovenian Sea<abstract> <title style='display:none'>Abstract</title> <p>Continuous underwater noise has been monitored in the Slovenian sea near the lighthouse foundation at Debeli Rtič since February 2015, according to the EU Marine Strategy Framework Directive (MSFD). Anthropogenic noise sources (e.g. seawater densities, dredging activities and cleaning of the seafloor) and meteorological noise sources (e.g. wind speed and precipitation) were analysed in relation to the measured underwater noise levels using several graphical and statistical methods. The results of this study showed that average equivalent continuous underwater noise levels were, by 11 dB (<italic>L</italic><sub><italic>eq</italic>,63 Hz</sub>) and 5 dB (<italic>L</italic><sub><italic>eq</italic>,125 Hz</sub>), higher in the intervals when dredging activities took place than in the intervals when these activities were absent. Variation in underwater noise levels was partly related to the variation of the ship densities, which could be explained by the relatively small acoustic propagation in the shallow seawater. Precipitation level did not indicate any significant association with the variations in continuous underwater noise levels, though some larger deviations in the wind speed were found to be associated with the larger fluctuations in continuous underwater noise levels.</p> </abstract>ARTICLE2021-04-29T00:00:00.000+00:00Site characterization for engineering purposes using geophysical and geotechnical techniques<abstract> <title style='display:none'>Abstract</title> <p>Geophysical and geotechnical techniques were applied to determine the suitability of the sub-surface structure of Akole community area, Abeokuta, Nigeria, for the construction of engineering structures (CES). Four vertical electrical soundings (VES) were carried out, and 10 samples from different points at 1 m depth were analysed to determine soil moisture content, specific gravity (SG), Atterberg limits and California bearing ratio (CBR). The geoelectric sections revealed a maximum of five layers with the typical sounding curves of AKH and HKH types. Sieve analysis and tests for compaction limit, Atterberg limits, SG, optimum moisture content and maximum dry density for compaction limit revealed that samples SP2, SP3, SP4, SP6, SP7, SP8, SP9 and SP10 are of low plasticity with SG values that fall within the permissible range, while SP1 and SP5 are of medium plasticity and their SG values fall below the range of standard specifications. CBR analysis showed that SP1 and SP5 have low load-bearing capacities. VES 1 and 2, linked with SP1 and SP5, are considered unstable and unsuitable to support the CES with shallow foundations; however, excavation of weak layers up to a depth of 5 m and reinforcement will enable the support.</p> </abstract>ARTICLE2021-05-08T00:00:00.000+00:00Estimation of Depth to Bouguer Anomaly Sources Using Euler Deconvolution Techniques<abstract> <title style='display:none'>Abstract</title> <p>The geophysical measurement of variations in gravitational field of the Earth for a particular location is carried out through a gravity survey method. These variations termed anomalies can help investigate the subsurface of interest. An investigation was carried out using the airborne satellite-based (EGM08) gravity dataset to reveal the geological information inherent in a location. Qualitative analysis of the gravity dataset by filtering techniques of two-dimensional fast Fourier transform (FFT2D) shows that the area is made up of basement and sedimentary Formations. Further enhancements on the residual anomaly after separation show the sedimentary intrusion into the study area and zones of possible rock minerals of high and low density contrasts. Quantitative interpretations of the study area by 3-D Euler deconvolution depth estimation technique described the depth and locations of gravity bodies that yielded the gravity field. The result of the depth to basement approach was found to be in the depth range of 930 m to 2,686 m (for Structural Index, SI = 0). The research location is a probable area for economic mineral deposits and hydrocarbon exploration.</p> </abstract>ARTICLE2021-05-03T00:00:00.000+00:00Geochemical Fingerprinting pf Oil-Impacted Soil and Water Samples In Some Selected Areas in the Niger Delta<abstract> <title style='display:none'>Abstract</title> <p>With over 50 years of oil exploration and exploitation in the Niger Delta, there has been an increasing rate of environmental degradation due to hydrocarbon pollution. This study is aimed at tracing the sources of the oil spills and the distribution of pollutants in selected communities in the Niger Delta using geo-chemical techniques. A total of sixteen samples made up of ten crude oil-impacted soil samples taken at a depth of 30 cm and six water samples (two from boreholes, two from burrow pits and two from surface water – one from a river and the other from rain harvest as control) were collected. The identification and quantification of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the samples were performed with an Agilent 7890B gas chromatography flame ionisation detector (GCFID). The AHs including pristane and phytane, together with seventeen priority PAHs, were identified. The values of AHs and PAHs in the water samples ranged from 0.13 mg/l to 5.78 mg/l and 0.09 mg/l to 1.109 mg/l, respectively, while that for the soil samples ranged from 22.52 mg/kg to 929.44 mg/kg and 10.544 mg/kg to 16.879 mg/kg, respectively.</p> </abstract>ARTICLE2021-05-08T00:00:00.000+00:00Monitoring after the conclusion of mining works<abstract> <title style='display:none'>Abstract</title> <p>After mining works are completed and the mine is permanently closed, the holder of the mining rights must carry out monitoring in accordance with the applicable legislation and for the purpose of controlling the extraction area. This includes monitoring of the changes that have occurred during the process of mining, both on the surface and below it. This article presents an example of a monitoring program after the mining works are completed. The extraction of raw mineral material in an underground mine results in various impacts on the surface and underground space. The areas or segments of monitoring are divided into two parts in this article: The underground part includes monitoring of the geomechanical, climatic, and hydrogeological changes, while monitoring on the surface requires special attention to be paid to the stability conditions of the surface above old mine works and hydrogeological conditions in the area above the extraction or impact area. A practical example of the monitoring program that needs to be made when a mine closes is given in the article. The program covers areas, presents the ways and methods of measurement, as well as reporting of the measurements. The analysis procedure of already existing measurements, which need to be analyzed and included in the preparation of the monitoring program, is also presented.</p> </abstract>ARTICLE2021-05-03T00:00:00.000+00:00en-us-1