Mineral Processing
Chourouk MENIAI; Mohamed BOUNOUALA; Raouf CHAABIA; CHAHRA SIFI; Rim AMATA
Abstract
Phosphate mining at Djebel Onk (Tébessa, Algeria) generates large volumes of solid wastes that occupy land, release dust, and contaminate surrounding environments. This study aims to characterize and valorize two types of dry tailings, namely +15 mm screening rejects and fines from pneumatic separation ...
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Phosphate mining at Djebel Onk (Tébessa, Algeria) generates large volumes of solid wastes that occupy land, release dust, and contaminate surrounding environments. This study aims to characterize and valorize two types of dry tailings, namely +15 mm screening rejects and fines from pneumatic separation (TSV), in order to reduce their environmental impact and recover residual phosphate. Samples were analyzed using particle size distribution, atomic absorption spectrometry (AAS), X-ray diffraction (XRD), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS). Treatment tests included calcination (laboratory furnace, 700–1000 °C, 15–30 min) and direct flotation (Denver-type cell, with oleic acid and phosphoric acid as reagents).The results show that the +15 mm rejects and TSV fines contain 21.42 % and 23 % P₂O₅, respectively, while the richest fraction (-0.5 + 0.25 mm) reaches 28.99 % P₂O₅ with 1.01 % MgO. Calcination at 1000 °C for 30 minutes produced concentrates with 33.51 % P₂O₅ and near-complete CO₂ removal, whereas direct flotation yielded concentrates of ≈ 30 % P₂O₅ with MgO < 1 %. The novelty of this work lies in the combined application of calcination and flotation, which demonstrates their complementarity for efficient recovery of phosphate from dry tailings. These results confirm the potential for phosphate valorization while reducing environmental impacts and supporting more sustainable mining practices.Keywords: Phosphate, mining wastes, calcination, flotation, environmental management, Djebel Onk
Environment
B.G. Mousa; Marzouk Mohamed Aly Abdelhamid; Mohamed Elgharib Gomah; M. M. Zaki; H.A. Farag; W.M. Draz; Remonda Dimian; Yousef A. Al-Masnay
Abstract
Rock damage due to severe environmental conditions may affect durability over time. Therefore, this study aims to investigate the degradation of igneous rocks triggered by freezing-thawing weathering and to predict their loss of integrity. Four types of igneous rocks were collected from the Saint Katherine ...
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Rock damage due to severe environmental conditions may affect durability over time. Therefore, this study aims to investigate the degradation of igneous rocks triggered by freezing-thawing weathering and to predict their loss of integrity. Four types of igneous rocks were collected from the Saint Katherine mountain area, Sinai, Egypt, and subjected to 100 cycles of the freeze-thaw method. The land surface temperature variation was analyzed using remote sensing data as an indicator for selecting the freeze-thaw temperature for our experiments. The physical and mechanical characteristics of the studied rocks, such as dry bulk density, effective porosity, ultrasound pulse velocity, abrasion loss, unconfined compressive strength, and point load strength, were measured after 0, 20, 40, 60, 80, and 100 cycles of the freeze-thaw process and evaluated using deterioration ratios and statistical models. Exponential and linear decay function models were established to statistically assess the integrity loss rate of the mechanical strength properties of the selected rocks. Two critical factors, decay constant and half-life, were derived from the studied models and used to predict rock durability. This evaluation suggests that the behavior of rock decay is very similar across different types of igneous rocks, exhibiting a strong correlation and high precision. Therefore, these models are reliable and valid for predicting the durability of the studied igneous rocks. Results also showed that the tested igneous rocks can be used as construction stones in regions exposed to repeated cyclic freezing-thawing weathering and harsh environmental conditions over long periods without disintegration.
R. Kharzi; R. Chaib; I. Verzea; A. Akni
Abstract
This article describes the process of improving risk management practices in a foundry of the ALFET Company (Algeria). The proposed methodology is based on the decision matrix risk assessment technique. This technique allows making a risk assessment for each source of risk (machine, man, environment, ...
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This article describes the process of improving risk management practices in a foundry of the ALFET Company (Algeria). The proposed methodology is based on the decision matrix risk assessment technique. This technique allows making a risk assessment for each source of risk (machine, man, environment, and management), which leads to the determination of the overall risk rate during the activity by a new concept. The latter giving a comprehensive vision of occupational health and safety, and compares it with the ALARP principle to determine the acceptability of risk. The main goal of this work is to inculcate a culture on the effects of changing behaviors and attitudes, to disseminate the culture of continuous and sustainable progress within the enterprise, and to ensure that a good atmosphere is maintained in the workplace. It aims to protect and promote the health and safety of workers and the working environment in order to promote a safe and sustainable development company. Our work shows that the working environment is tolerable in terms of health and safety at work. However, to promote a safe and sustainable development in company, an action plan based on the evaluation of the field and feedback through priority actions is recommended for continuous improvement in OSH. Toward the workplace should be continuously monitored to detect risk factors as early as possible before they have negative effects.
M. J. Sajid; N. Shahani; M. Ali
Abstract
Mining is among the oldest industries. It is the primary source of raw materials for most of the sectors. Little is known about the complex inter-sectoral carbon linkages of the mining industry. In this work, we estimate the inter- and intra-sectoral carbon linkage impacts of the mining sector across ...
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Mining is among the oldest industries. It is the primary source of raw materials for most of the sectors. Little is known about the complex inter-sectoral carbon linkages of the mining industry. In this work, we estimate the inter- and intra-sectoral carbon linkage impacts of the mining sector across ten major economies by applying an input-output model, and the hypothetical extraction method and its modified version. The hypothetical extraction method removes an industrial block from an economic system, and afterwards, it makes a comparison between the before and after removal values. China with 195.47 Mt has the highest mining emissions, followed by USA, India, and Canada with 110.99 Mt, 108.79 Mt, and 76.92 Mt, respectively. The India’s mining sector with 26.33 t/104 $ is the most carbon-intensive, followed by Japan and Canada with 6.84 t/104 $ and 5.22 t/104 $, respectively. China’s carbon emissions with -11.56% and -11.28%, respectively, have been affected the most by the total extraction of mining sector and forward carbon linkages, while for the backward carbon linkage, Canada with -1.33% has been affected the most. Canada has the highest mixed and internal emissions of 0.42 Mt and 47.88 Mt, respectively. However, China has the highest net-backward and net-forward emissions of 16.91 Mt and 189.22 Mt, respectively. For all nations, the mining sector is a net exporter of emissions to other industries. Based on the numerical findings, in this work, we discuss the mitigation measures for both the direct and indirect mining emissions.
O.E. Ifelola
Abstract
Metals are ubiquitous within the earth crust. However, the exceptional high-level concentration of heavy metals in the soil due to natural or anthropogenic activities and the chemical forms in which they exist determine the level of risk they portend to the environment. This work was aimed at determining ...
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Metals are ubiquitous within the earth crust. However, the exceptional high-level concentration of heavy metals in the soil due to natural or anthropogenic activities and the chemical forms in which they exist determine the level of risk they portend to the environment. This work was aimed at determining the background level of the presence of seven priority toxic metals (Cr, Ni, Pb, As, Cd, Cu, Zn) in the chemical phases of the overburden topsoil of a bituminous deposit prior to mining activities through the speciation analysis. The grab samples of overburden topsoil were initially obtained and homogenized to composites based on locations for the subsequent sequential extraction procedure (SEP). The specific physico-chemical properties of the sampled soils were simultaneously determined to complement the SEP inferential analysis. The results obtained showed that most metals were spatially bounded to the Fe-Mn oxides (reducible phase) followed by the organic (oxidizable) and the carbonates phases, respectively. Fractionally, the dominant soil texture in the studied area was sand (55.45%); however, the colloidal organic matter and Fe-Mn oxide phases played the dominant roles in the sorption activities of the selected metals. The soil chemical phase with the least metal pool was the exchangeable (water/salt) soluble fraction. The overall assessment revealed that the geogenic heavy metals in the topsoil posed no threats since a marginal fraction of the metals existed in the bio-available form in non-toxic concentrations in the order of Pb > Zn > Cu, while the potential mobility of metals showed that Zn was preferentially higher than Pb and Cu, respectively.
