rss_2.0Materials and Geoenvironment FeedSciendo RSS Feed for Materials and Geoenvironment and Geoenvironment Feed glass wastes and bentonite to produce a new ceramic tile<abstract> <title style='display:none'>Abstract</title> <p>This paper discusses the recycling of glass waste as a compound in the production of ceramic tiles. The present study aims to investigate the effects of glass waste (with two different granulometries) on the physical and mechanical properties of ceramic tiles, in order to demonstrate their suitability for the production of ceramic materials. A series of ceramic tiles was prepared based on bentonite (B) by adding 70, 65, and 60 wt% glass wastes (GW1 and GW2 with two different granulometries) into the batch composition. The ceramic tiles were sintered at a constant temperature of 900 °C following the same production protocol. The physical-mechanical properties and chemical durability of all ceramic tiles produced were evaluated. The results show that ceramic tiles can be produced from a basic mixture of 35% bentonite and 65% glass waste, with good physical, mechanical, and thermal properties (the local Algerian bentonite is considered a clay binder and has excellent plasticity).</p> </abstract>ARTICLEtrue the rate of land use and land-cover changes in Gambari Forest Reserve, Nigeria<abstract> <title style='display:none'>Abstract in English</title> <p>This research work discusses the phenomenon of land use and land cover, which has undergone constant changes over the past few decades due to major variations in the environment caused by anthropogenic and natural factors. This study is supported by a long time series of land use and land-cover satellite data of the Gambari Forest Reserve boundary map for 1984, 2004, and 2020. A maximum likelihood classification scheme was employed to classify the satellite imageries using ArcGIS 10.1 software to derive the spatial patterns and temporal variation of the land-use and land-cover change (LULC) classes: dense forest (DF), light forest (LF) and non-forest (NF). Data on deforestation of the study area showed that the area of DF increased from 31.7 km<sup>2</sup> (23.4%) to 72.8 km<sup>2</sup> (54.4%) within a 36-year time series, with a percentage change of 31.0%. The area of LF decreased from 79.2 km<sup>2</sup> (65.4%) to 51.2 km<sup>2</sup> (41.5%), with a percentage change of −23.9%, and that of NF decreased from 14.7 km<sup>2</sup> (11.2%) to 2.6 km<sup>2</sup> (4.1%), with a percentage change of −7.1%. This indicates that it would be reasonable to anticipate an increase in deforestation in the future.</p> </abstract>ARTICLEtrue of Blast-induced Fragmentation Using Artificial Neural Network and BlastFrag© Optimizer Software<abstract> <title style='display:none'>Abstract in English</title> <p>The Golden Girl dolomite quarry was selected by the authors to develop predictive artificial neural network (ANN) models and software for optimization of blast fragment size distribution. Blast images from the quarry were analysed using WipFrag©. Seven controllable and two uncontrollable blast parameters, and WipFrag© image analysis results for fifty blasts were used to train ANN models. The reliability of the established models was tested, and the Bayesian regularization algorithm with the architecture of 9-8-3 was found to be superlative. The superlative model was compared with the modified Kuz-Ram model and found to be accurate. The optimum ANN models were translated into mathematical formulas and used to develop user-friendly software called BlastFrag optimizer. The software was validated with R<sup>2</sup> greater than 80% for all models and was found suitable for predicting blast fragment size distribution. The optimized result revealed that percentages for oversize and mean-size fragments were reduced from 68.4% and 418 mm to 27.83% and 101.6 mm, respectively, and undersize fragments increased from 50% to 72.17%.</p> </abstract>ARTICLEtrue Chemistry of Pyroxene Gneiss in Obudu, SE Nigeria, and Its Petrological Significance<abstract> <title style='display:none'>Abstract</title> <p>The pyroxene gneiss which forms part of the basement cover in southeast Nigeria is a coarse-grained weakly foliated rock that has experienced high-grade metamorphism and anatexis. Electron microprobe data obtained from samples of this pyroxene-bearing gneiss confirm that the essential minerals are plagioclase (andesine, An<sub>30 – 37</sub>), orthopyroxene (hypersthene, En<sub>55.3 – 61.2</sub>, Wo<sub>1.0 – 2.6</sub>, Fs<sub>36.3 – 43.7</sub>), and clinopyroxene (augite, En<sub>39.7 –42.3</sub>, Wo<sub>42.0 – 45.1</sub>, Fs<sub>14.2 – 17.0</sub>). This assemblage is a typical granulite facies mineralogy produced by igneous rocks with intermediate to mafic composition that have been metamorphosed at medium pressure. Other minerals are calcic amphibole (X<sub>Mg</sub> = 0.56–0.59), biotite (X<sub>Mg</sub> = 0.58–0.69), orthoclase, and quartz. Orthoclase occurs mainly in leucocratic bands and clinopyroxene absent samples and may have resulted from dehydration reaction and thus dissolved in the melt phase. Fe-Ti oxides of ilmenite, hematite, and magnetite occur as accessory minerals, giving the imprint of metamorphism under oxidizing conditions. The presence of exsolved titanohematite in ilmenite indicates retrogressive metamorphism.</p> </abstract>ARTICLEtrue of VLF-EM and VES data for pavement failure investigation in a typical basement complex terrain of southwestern Nigeria<abstract> <title style='display:none'>Abstract</title> <p>Geophysical investigations involving very low frequency electromagnetic (VLF-EM) and vertical electrical sounding (VES) techniques were deployed to study the pavement failure along a major road in a typical basement complex terrain of southwestern Nigeria. This study was designed to assess the failure and provide a basis for ultimate engineering design. The study delineated a 3- to 4-layer geoelectric sequence: a topsoil of thickness varying from 0.4 to 1.2 m, a spectrum of clayey materials of thickness varying from 1.9 to 14.5 m and a weathered/fractured basement occurring at depths of between 3.6 and 15.0 m. The shallow basement indicated low bearing capacity, with resistivity values ranging from 62.1 to 377.9 Ωm. The presence of clay/clayey materials, linear features and the effect of rising water table within the influence zone underlined the pavement failure. This information will facilitate appropriate designing, soil improvements and selection of materials for road construction that can stand the test of time.</p> </abstract>ARTICLEtrue of foundry sand wastes in self-compacting concretes: Use as cementitious materials and fine aggregates<abstract> <title style='display:none'>Abstract</title> <p>This paper discusses waste recycling as a compound in building materials. Foundry sand-based self-compacting concretes (SCC) were investigated to see the possibility of recycling foundry sand wastes (FSW). FSW was used as a cementitious addition (by partial cement replacement: 10%, 20% and 30% wt. cement), then as a fine aggregate (by partial sand substitution: 10%, 30% and 50% wt. sand). For this, an experimental study was carried out to evaluate physical and mechanical properties of SCC at fresh and hardened states. The results show that the FSW also played the role of a filling material, which slightly improved the compactness of the concrete while saving part of the cement. According to the results of the non-destructive tests by ultrasonic tests, all concretes gave a dynamic modulus of elasticity that was almost identical and which was greater than 36 GPa. Compressive strength value slightly reduced with the cement substitution by the crushed foundry sand waste. However, up to 30% FSW, the compressive strength recorded after 28 days was around 30 MPa. A slight decrease in the fluidity of concrete at 10% substitution of natural sand by FSW was observed. After up to 30% replacement of sand by foundry sand wastes, the fluidity of the concrete was improved. The improvement in the fluidity of the concretes was perhaps due to the fineness of the natural sand and that of the foundry sand. When used as up to 50% of sand substitution, FSW can be used as a fine aggregate for concretes without affecting the essential proprieties of concretes.</p> </abstract>ARTICLEtrue of a 5x5 NaI(Tl) for Prompt In-Situ Gamma-ray Spectrometry System<abstract> <title style='display:none'>Abstract in English</title> <p>It is important to determine the presence of different radionuclides in the environment at all times in order to control and assess the risk level they pose to the environment. Laboratory and in-situ gamma-ray spectrometry can be used for detecting, monitoring, and assessing levels of radioactivity and radiation dose rates in the environment due to both natural and artificial sources. In this study, the greatest challenge in the calibration of detectors for in-situ gamma spectrometry has been solved. Calibration factors that can be used to convert the net count rates of collected spectrum's photopeak using a portable gamma-ray spectrometer, to quantitative specific activities have been derived. Calibration pads were simulated using standard materials RGU, RGK, and RGTh from International Atomic Energy Agency (IAEA). Region of interest (ROI) were carefully determined around these photopeaks in order to obtain count rates due to each radionuclide under its reference peak. The conversion factors obtained are reliable.</p> </abstract>ARTICLEtrue Relation Between Magnetic and Radiometric Survey in Bitumen Area, Ogun State, Nigeria<abstract> <title style='display:none'>Abstract</title> <p>One of the vital roles played by both magnetic and radiometric surveys is identification and delineation of mineral deposits. The study area, Imeri, which lies between latitude 6 °45′N to 6 °48′N and longitude 3 °58′E to 3 °59′E, has been established for bitumen deposition. The responses of mineral deposition to different geophysical methods differ from place to place due to variation in climate and bedrock composition. In this study, two geophysical techniques—magnetic and radiometric methods—were adopted to investigate the magnetic anomalous and radiometric flux responses around the bitumen deposit area. The study also intends to establish a model-like relation between the radiometric parameters and the magnetic anomaly observed. Statistical inferences for the established relations were deduced using the t-test at 0.05 significance levels. The result obtained showed that uranium and thorium concentration responses along the two traverses were in good agreement with that of magnetic intensity. The claim was accounted for based on the correlation result, which ranged between 74%–79% and 84%–89% for uranium and thorium, respectively, with magnetic intensity along the two traverses. In order to validate the claim, the t-test was used. The result obtained showed that there exists no significant difference between the two geophysical methods; the result for the t-test has critical value &gt; calculated value (<italic>p</italic>-values &gt; 0.05). Based on this, the empirical relations were deduced for magnetic anomalous response and radiometric parameters. This work has therefore proven the two techniques to be versatile for bitumen prospecting in the study area.</p> </abstract>ARTICLEtrue and Rare Earth Element Geochemistry of Magnesian Granitoids Within Proterozoic Schist Belt of Southwest Nigeria<abstract> <title style='display:none'>Abstract</title> <p>The increased global demand for and price of rare earth elements (REEs) has led to intensive search for them in rocks of the upper continental crust all over the world. This study is aimed at characterising the granitoids at Okeho within Southwestern Nigeria using geochemical data and assessing their potential for REE enrichment. Ten representative rock samples of the Proterozoic intrusives, syenite and granodiorite, were studied for their mineralogical and elemental compositions. Elemental concentrations were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).</p> <p>Average major oxide concentrations revealed SiO<sub>2</sub> (57.53 wt. %), Al<sub>2</sub>O<sub>3</sub> (13.25 wt. %), CaO (5.05 wt. %), and MgO (5.59 wt. %) for the syenite and SiO<sub>2</sub> (62.39 wt. %), Al<sub>2</sub>O<sub>3</sub> (14.98 wt. %), CaO (3.67 wt. %), and MgO (3.25 wt. %) for the granodiorite. Total Alkali–Silica (TAS), Aluminum Saturation Index (ASI), and La/10-Y/15-Nb/8 plots discriminated the granitoids as metaluminous monzonite-syenite and peraluminous diorite-granodiorite. Average total REE concentrations in the syenite (625.06 ppm) and porphyritic-granodiorite (364.51 ppm) were above values reported for the granites in some mines in Jiangxi Province, Southern China.</p> </abstract>ARTICLEtrue of a nickel insert, a special copper alloy, and a cast joint between them<abstract> <title style='display:none'>Abstract in English</title> <p>This work deals with the characterisation of the microstructure of a nickel insert, a special copper alloy and the cast joint between them after their use as a glass manufacturing mould. The microstructure was characterised by optical microscopy, scanning electron microscopy and microanalysis by energy dispersive X-ray spectroscopy.</p> <p>It was found that the nickel insert contained 7 at. % Si and 0.3 at. % Fe. The special copper alloy contains undesirable phases or compounds, including lead, aluminium-based oxides and borides. The borides are either iron-, iron-chromium- or chromium-based with different stoichiometries between metal components and boron. The cast joint between the nickel insert and the special copper alloy has evidence of mixing the two alloys, while only in some areas porosity and oxides prevented the formation of a suitable cast joint. Aluminium-based oxides and some borides could be the cause of the formation of cracks due to their morphology.</p> </abstract>ARTICLEtrue squeezing effects on cement-slag-bentonite slurry wall performance<abstract> <title style='display:none'>Abstract in English</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>ARTICLEtrue Earth Element Geochemistry and Abundances in Syenites and Charnockitic Rocks of Selected Locations within Southwestern Nigeria<abstract> <title style='display:none'>Abstract in English</title> <p>Rare earth elements (REE) are critical metals widely used in modern technology. There is an increased demand for these elements which has necessitated additional exploration. The REE geochemistry of syenites and charnockitic rocks from selected locations within southwestern Nigeria were studied to determine their concentrations, distribution patterns, and mineralisation potential to deduce if they can be economically exploited. Mineralogical studies were carried out using scanning electron microscopy (SEM). Ten rock samples including five syenites and five charnockites were analysed for their elemental composition using inductively coupled plasma – mass spectrometry (ICP-MS). The REE-bearing minerals identified from the SEM analysis include apatite and monazite. The fractionation ratio (La/Yb)<sub>N</sub> ranged from 29.36 to 48.75 for the syenites and from 24.43 to 48.29 for the charnockites, indicating magmatic differentiation. Total REE (∑REE) in the syenites (342–675 ppm) and charnockites (220–802 ppm) suggests that they are enriched with respect to REE but the REE concentration in the rocks of the study area had very low ∑REE compared to the REE contents of the rocks where they have been mined and may therefore not be economically viable.</p> </abstract>ARTICLEtrue Mineral Potential and Geothermal Energy Reserve of Northern Basement Complex, Nigeria<abstract> <title style='display:none'>Abstract in English</title> <p>The spectral analysis of aeromagnetic data over the study area (Northern basement complex, Nigeria) revealed the existence of two major source depths. The second segment of the spectrum layer shows shallow sources ranging in depth from 0.135 km to 0.201 km, with an average depth of 0.140 km. The depth to the basement or deeper source ranges between 1.655 km and 2.021 km, with an average depth of 1.882 km. The Precambrian basement is reflected in the deeper sources, beginning with the first segment of the power spectrum. Structural and topographic relief of the basement surface, lateral differences in basement susceptibilities, and intra-basement features such as faults and fractures contribute to the variation in basement composition. The mean thickness of sediments in the study area is represented by the D2 values obtained from the spectral plots. The depths revealed by this study appears to be reasonable and consistent with previous researchers’ findings. Tectonically active regions have a major impact on heat flows. The average heat flow in thermally normal continental regions is reported to be above 60 mW/m<sup>2</sup>. Values between 80 and 100 mW/m<sup>2</sup> indicate a good geothermal source; values in excess of about 80–100 mW/m<sup>2</sup> indicate anomalous geothermal conditions.</p> </abstract>ARTICLEtrue source rock characteristics of the Mesozoic units, Mekelle Basin, northern Ethiopia<abstract> <title style='display:none'>Abstract in English</title> <p>The Mekelle Basin comprises carbonate and siliciclastic rocks which could have potential for petroleum as previous studies reported without enough evidence. This research is intended to assess source rock characteristics of selected samples from the Adigrat Sandstone, Antalo Limestone and Agula Shale. Four outcrop sections were investigated and fifteen limestone and shale samples were collected. TOC was deduced by <italic>Leco SC-632</italic> carbon analyzer, and Rock-Eval pyrolysis was determined using <italic>Rock-Eval 6</italic>. The TOC values range from 0.11 wt.% to 0.42 wt % for 80% of the samples which is less than the minimum requirements for source rocks. However, a few samples have TOC between 0.5 wt % and 1.0 wt %, indicating fair organic matter richness. The kerogen is mainly Type IV and inert. The S<sub>1</sub> (0–0.02 mgHC/g) and S<sub>2</sub> (0–0.07 mgHC/g) values are very low, with very high T<sub>max</sub> (475–527 °C), indicating very poor potential with over-mature dry gas. Therefore, the analyzed samples have low organic content for hydrocarbon, implying that the studied units have no feasible source rock potential.</p> </abstract>ARTICLEtrue 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>ARTICLEtrue methods for evaluation of the underwater noise levels in the Slovenian Sea<abstract> <title style='display:none'>Abstract in English</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>ARTICLEtrue Electrostatic Precipitators to the Fe-Ni Production Process<abstract> <title style='display:none'>Abstract in English</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 electrostatic 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>ARTICLEtrue 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>ARTICLEtrue 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>ARTICLEtrue 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>ARTICLEtrue