Phosphate Mining Research Articles

Assessment and Mitigation of Groundwater Contamination from Phosphate Mining in Tunisia: Geochemical and Radiological Analysis

Groundwater contamination in the Mediterranean Basin is a severe problem that has a significant impact on environmental ecosystems and human health. The unconventional uranium and the potentially toxic elements (PTEs) of phosphate rocks are the principal contaminants in the phosphate mining industry in Tunisia. Phosphogypsum (PG) results from the valorization of phosphate to fertilizers and phosphoric acid. PG stocks can be used in cement production, brick manufacturing, and soil amendments in desertic land, and can be resolved by using nanomaterial adsorbents. In the flat area of the study area, the increase in radioactivity (40K) is due to abusive fertilizer use. Geochemical and radiological analyses in the northern part of Tunisia and its karst shallow aquifer indicate significant contamination levels. The northern part exhibits moderate contamination, whereas the karst shallow aquifer shows higher contamination levels, particularly with elevated nitrate concentrations. In the phosphate basin, both washing phosphate and phosphogypsum reveal high levels of radioactive elements, with the latter showing especially high concentrations of radium. The shallow aquifer in this region has moderate contamination levels, while the deep geothermal aquifer also shows noticeable contamination but to a lesser degree compared to the shallow aquifer. The shallow groundwater is characterized by a higher value of radioactivity than the groundwater due to the contamination impact from the phosphate industry and the cumulative radioactivity disintegration. Finally, the nanoparticles and the electrostatic adsorption can decrease the PTEs and radionuclides from the contaminated water in the study area. Moreover, other key issues for advancing research on groundwater contamination are proposed in this study. It is time to valorize this PG and the other mines of (Fe, Pb, and Zn) in the socioeconomic sector in Tunisia and to minimize the environmental impact of the industrial sector’s extraction on groundwater and human health in the study area.

Sustainable utilization of phosphate mine waste rocks as sand substitutes in cement mortar production

The extraction and processing of phosphate ores from sedimentary deposits generates large quantities of mine waste rocks, raising environmental concerns and contributing to landscape disfiguration. This study proposes an eco-friendly approach by exploring the extraction of sand from phosphate waste rocks (PWR) to mitigate the environmental impact associated with the disposal of mine wastes. The investigation focuses on the feasibility of creating masonry cement mortar by incorporating sand obtained from PWR. Three types of sand, Flint (FS), dolomitic limestone (DLS), and phosphate flint (PFS), obtained from the intercalation layers of phosphate were tested as partial replacements for reference sand at varying rates (0 %, 25 %, 50 %, 75 %, and 100 %). The sands were sieved through a 4 mm sieve and characterized to assess their geotechnical, chemical, and mineralogical properties. The toxicity characteristic leaching test analysis was conducted to ensure the environmental safety of recycled sands. Consistent mortar formulations were prepared and cured under uniform conditions. Results showed that a 25 % replacement ratio for each sand type yielded the highest 28-day compressive strengths, exceeding 30.5 MPa. Moreover, the water absorption of mortars decreased from 10.65 % to 8.39 %, 7.29 %, and 5.97 % with the incorporation of 25 % of FS, PFS, and DLS, respectively. Furthermore, toxicity tests revealed that recycled sand met the specified limits for toxic elements Ag, Hg, As, Cd, Cr, Pb, and Zn, and affirmed that incorporating these wastes into MCM significantly reduced the leaching of these metal ions to levels below detection limits (DL=0.01 mg/L). This research contributes to sustainable construction practices by providing a viable solution to minimize mine waste and reduce the construction industry's reliance on natural resources, ultimately addressing both environmental and resource-related challenges.

Radiation protection for Gabes phosphate area residents: Assessing natural radioactivity in soil and potable water samples

Phosphate mining activities are recognized to be one of various industrial processes generating enhanced Naturally Occurring Radioactive Materials (NORM) by introducing natural radionuclides into the surrounding soils and water bodies, posing a risk to human health.This study was carried out to assess the level of natural radionuclides in soils and potable waters collected from the phosphate area of Gabes city, located in southeastern Tunisia, and to evaluate radiation protection measures by estimating radiological health hazard parameters. Gamma spectrometry system employing an HPGe detector was used in this study to assess 40K, 232Th and 226Ra activity concentration in soils. The average values were found to be 163.7, 14.5, and 7.7 Bq kg−1, respectively, which were lower than worldwide average values. The radiological hazard parameters assessed in this study were radium equivalent activity (Ra-eq), external hazard index (Hex), external gamma absorbed rate (GDR), external annual effective dose (Deff) and excess lifetime cancer risk (ELCR). The calculated average values of the above-mentioned parameters were of 41 Bq kg−1, 0.1, 20.2 nGy h−1, 24.8 μSv y−1 and 8.7 × 10−5 all of which were found to be below their permissible standards.For potable water samples, the activity concentrations of radium were analyzed using an HPGe detector and those of uranium were determined by alpha spectrometry. The average activity concentrations of uranium and radium isotopes in underground water samples were found to be higher than those obtained in tap water samples. For both types of water, the average values for all radionuclides were found to be below their respective reference limits.The annual ingestion effective doses were also estimated in this study. The estimated average values for infant and children for underground water samples were higher than the permissible limit of 100 μSv y−1 set by WHO. The 226Ra was the main contributor to the effective doses for different age categories, followed by 228Ra.

Utilizing waste rocks from phosphate mining in Jordan as concrete aggregates

This study investigates the potential of replacing natural aggregates in concrete with aggregates obtained from Phosphate Mine Waste (PMW) rocks in Jordan. Several tests were conducted to determine the PMW rocks' chemical, physical, and mechanical properties according to ASTM standards. A comprehensive experimental investigation was conducted, involving thirty-six concrete cylinder specimens, to evaluate the strength and durability properties of concrete made with PMW rocks compared to concrete made with natural limestone aggregates. The tested aggregates of PMW rocks consist mainly of quartz, dolomite, montmorillonite, and fluorapatite. Their physical and mechanical properties were found to be similar to the natural aggregates used for concrete. Concrete specimens made of waste rocks had an average compressive strength of 28.72 MPa at 28 days versus 30.18 MPa for concrete specimens made with natural aggregates. The tensile splitting strengths of the concrete made with PMW aggregates were higher than expected, with an average of 5.36 MPa at 28 days, whereas the reference specimens had an average tensile splitting strength of 5.49 MPa at 28 days. According to the findings, PMW rocks can successfully replace natural aggregates in structural and infrastructural constructions, enhancing the circular economy concept and contributing to a more environmentally friendly mining industry.

Sustainable Transportation Planning for Djebel Onk's Open-Pit Phosphate Mine in Algeria: Using Queuing Theory and Cost-Emission Analysis

Sustainable Transportation Planning for Djebel Onk's Open-Pit Phosphate Mine in Algeria: Using Queuing Theory and Cost-Emission Analysis

Phosphate mine by-products as new cementitious binders for eco-mortars production: Experiments and machine learning approach

Phosphate mining industry generates different types of by-products that have significant environmental impacts such as ecosystems destruction and soil contamination. To reduce their environmental footprint, these wastes were investigated as supplementary cementitious materials (SCMs). The generated by-products included a clayey material and calcareous marl which were used in the current study. Blends of the abovementioned materials with cement (ratio of 1:1) were investigated using X-Ray Fluorescence spectrometry (XRF), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TDA-TG), Mercury Porosimetry, Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Electromechanical testing device. Using these results, a learning model based on multiple linear regression (MLR) was proposed to predict the compressive strength and the specific surface area from the constituents of the material, the additives, the L/S ratio, and the hardening regime. The accuracy of the models was assessed using the correlation coefficient (R2), mean absolute error (MAE), and root mean square error (RMSE). Compressive strength results confirmed that the sample's strength improved with the amount of calcined clay. Unlike the water demand where the mixtures required more water than the OPC mixture. SEM-EDS examinations proved the existence of the C–S–H gel, responsible for the specimen strength. The used machine learning model demonstrated excellent performance and practical potential to predict both compressive strength (CS) and specific surface area (SS) by capturing both linear and nonlinear relationships. As well as time and plasticizer were the most influential factors on the properties studied (CS and SS) and their effect was positive. This sensitivity study provides important information on the critical factors influencing compressive strength and specific surface area in the different ranges considered.

Sustainable strategy for rehabilitating phosphate mining sites and valorisation of phosphate industry by-products and sludge using pistachio tree (Pistacia atlantica), false pepper (Schinus molle), and eucalyptus (Eucalyptus globulus) trees

The development of anthroposols has been proposed as a new environmentally friendly approach to ensuring the successful revegetation of phosphate mining sites. The phosphate industry's by-products, including phosphogypsum (PG), phosphate sludge (PS), and sewage sludge (SS), can be valuable resources in restoring the ecological balance of mined soil areas. The aim of this study was to safely and sustainably restore the ecological integrity of the phosphate mining site through the evaluation of nutrients and heavy metals dynamics in soil and plant tissues of three tree species and treated by-products containing 65 % PG, 30 % PS, and 5 % SS. The tree species used were Pistacia atlantica, Schinus molle, and Eucalyptus globulus. The experimental layout was a randomised complete block design with six replicates and three treatments. Growth diameter, height, nutrient uptakes and heavy metal dynamic were evaluated from the rhizosphere soils and plant tissues over two years. Hierarchical head maps of correlations between the measured growth parameters, soil and nutrient uptakes of the tree species were analysed using a phylogenetic generalised linear mixed model. S. molle and E. globulus had higher average diameter and height than P. atlantica plants. P. atlantica and S. molle showed greater nitrogen, phosphorus, potassium, calcium, and magnesium concentrations than E. globulus trees. Tree growth parameters were closely linked to soil nutrient bioavailability. The heavy metal accumulation ratio was higher in the E. globulus and S. molle leaves than in stems. Using by-products could be valorised for rehabilitating mine sites together with E. globulus and S. molle species.

Phosphogypsum-based building materials: Resource utilization, development, and limitation

Phosphogypsum (PG) is a major industrial waste emitted during phosphate production. Facing the environmentally risky challenges posed by PG emissions and stockpiles, a review of the state of PG resource utilization in civil engineering and searching for new ways to utilize PG to improve the utilization rate are necessary. Therefore, this paper compared the chemical composition and pretreatment methods of PG from different sources and outlined the application of PG-based building materials, including gypsum products, cement-based materials, and road materials. It was found that there are differences in the chemical composition and physical properties of PG due to differences in phosphate mines and production processes, which affected the way it was pretreated and applied. Currently, thermal treatment and synergistic treatment by various means are effective methods for cleaning PG, and future treatment processes should be developed to highly efficient, and low cost. PG-based building materials positively contribute to recovering PG and promoting resource recycling, but environmental safety and long-term stability need to be explored. In addition, the importance, limitations, and development trends of applying PG-based building materials were discussed. Future research focuses on solid waste-based cementitious and mineralized materials to inform harmless, high-value and large-scale utilization of PG.

Vegetation of the Pathorg Ora Phosphate Mines Area, Singhbhum District, Bihar

Vegetation of the phosphate mines area at Pathorgora, in Singhbhum Dist., Bihar is discussed. Near-absence of Sal (Shores robusta Gaertn. f.) is the most dominant feature. Occurrences of plants in relation to phosphate ore are also discussed.

Assessment of radiation exposure in the phosphate mining area of Gafsa (Southeastern Tunisia)

ABSTRACT This study investigates the radiological health implications of sixty-three (63) samples of soil, food, and drinking water collected from the phosphate mining area of Gafsa in Southeastern Tunisia. Additionally, it assesses the exposure to radon concentrations in houses located around the phosphate mining sites. The activity concentrations in soil samples were found to be 382.1, 36.1 and 16.3 Bq kg−1 respectively for 40K, 232Th and 226Ra. The average activity of 232Th was higher than worldwide average value of 30 Bq kg−1. Eleven (11) radiological hazard parameters were computed based on various exposure scenarios including external gamma dose rate (GDR), annual effective dose (AED) and risk assessment (RA). The calculated GDR values were of 3.2 nGy h−1 in food and 45.4 nGy h−1 in soil samples, while the average AED values were of 3.9 µSv y−1 in food and 83.5 µSv y−1 in soil samples. Internal AED due to ingestion of radionuclides was found to have a mean value of 0.1 µSv y−1 in soil, 264.4 µSv y−1 in food and 10 µSv y−1 in drinking water samples. The AED values due to inhalation of soil-dust and radon were assessed to be 2.1 and 1.2 µSv y−1, respectively. The RA average values in food and drinking water samples were found to be 3 × 10−5 and 2.4 × 10−4, respectively. Based on the exposure pathway, inhalation of radioactivity through soil and radon resulted in highest total AED values, which remained below the reference limit. This was followed by internal exposure, with total AED values of 274.5 µSv y−1.

New sustainable strategy for rehabilitating phosphate mining sites using phosphate industry by-products and sludge integrating Argan, Carob, and Olive trees

In semi-arid context, the development of anthroposol from phosphate industry by-products and sewage sludge could be a new approach for sustainable phosphate mining soils. The objective of this 2 years field study carried out at Benguerir phosphate mine, was to evaluate nutrients and heavy metals dynamics in the soil-plant system of three species planted on anthroposol consisting of a mixture of 65% phosphogypsum (PG), 30% phosphate sludge (PS), and 5% sewage sludge (SS). The experimental layout was a randomized complete block design with six replicates and three species: argan, olive, and carob. No fertilizer was applied to the different plots. Heights and diameters of the different species were measured. Species were pruned, and leaves and stems were separated. The nutrients (N, P, K, Ca, and Mg) and heavy metals (Cd, Cu, Cr, Pb, Ni and Zn) contents in both soil and plant part were determined. The results of the Pearson correlation showed significant correlations between height and diameter of the different species. The strongest correlation was observed for the argan tree. Furthermore, nutrient contents in the rhizosphere of species were significantly reduced, excepted Ca. Also, nutrient contents in leaves were significantly higher than those in the stems. In addition, the concentration of heavy metals in argan, olive and carob leaves, were below international standards. In semi-arid contexts, argan tree could be the best candidate for revegetating mining sites and this anthroposol (65% PG – 30% PS – 5% SS) could be a new approach to rehabilitate mining site on large scale.

Assessment of clean production level in phosphate mining enterprises: Based on the fusion group decision weight and limited interval cloud model

To develop a robust cleaner production level assessment model for phosphate mining enterprises, this study investigated the key factors influencing their cleaner production levels. The model incorporates integrated group decision weights and a limited interval cloud model. Based on the comprehensive life cycle of phosphate mining production, we constructed a detailed evaluation index system to assess the cleaner production level of these enterprises. This system defined the quantitative ranges for each level and revealed the interrelationships among the indicators. To ensure comprehensive weight determination, we proposed a method that integrates the expertise of multiple stakeholders. This method leveraged group decision-making principles to effectively resolve conflicts in expert judgments during the weight determination process. In addressing the characteristics of evaluation indicators for the cleaner production level of phosphate mining enterprises, we proposed employing a finite interval cloud model to accurately characterize the distribution of the indicators. Leveraging the finite interval cloud model, we obtained numerical characteristics for various indicators and incorporated the weights of the integrated group decision-making attributes. This approach enabled us to determine the cleaner production level of phosphate mining using a finite interval cloud generator. Validation using five phosphate mining enterprises in Hubei Province, China, confirmed the model's high accuracy. This model demonstrated its applicability in evaluating cleaner production levels for phosphate mining enterprises, offering a theoretical foundation for developing targeted environmental management policies.

Smoothing the Phosphorus Resource Stress under the Socioeconomic Development in China.

Phosphorus (P) is the key in maintaining food security and ecosystem functions. Population growth and economic development have increased the demand for phosphate rocks. China has gradually developed from zero phosphate mining to the world's leading P miner, fertilizer, and agricultural producer since 1949. China released policies, such as designating phosphate rock as a strategic resource, promoting eco-agricultural policies, and encouraging the use of solid wastes produced in mining and the phosphorus chemical industry as construction materials. However, methodological and data gaps remain in the mapping of the long-term effects of policies on P resource efficiency. Here, P resource efficiency can be represented by the potential of the P cycle to concentrate or dilute P as assessed by substance flow analysis (SFA) complemented by statistical entropy analysis (SEA). P-flow quantification over the past 70 years in China revealed that both resource utilization and waste generation peaked around 2015, with 20 and 11 Mt of mined and wasted P, respectively. Additionally, rapidly increasing aquaculture wastewater has exacerbated pollution. The resource efficiency of the Chinese P cycle showed a U-shaped change with an overall improvement of 22.7%, except for a temporary trough in 1975. The driving force behind the efficiency decline was the roaring phosphate fertilizer industry, as confirmed by the sharp increase in P flows for both resource utilization and waste generation from the mid-1960s to 1975. The positive driving forces behind the 30.7% efficiency increase from 1975 to 2018 were the implementation of the resource conservation policy, downstream pollution control, and, especially, the circular agro-food system strategy. However, not all current management practices improve the P resource efficiency. Mixing P industry waste with construction materials and the development of aquaculture to complement offshore fisheries erode P resource efficiency by 2.12% and 9.19%, respectively. With the promotion of a zero-waste society in China, effective P-cycle management is expected.

Down-streaming Small-Scale Green Ammonia to Nitrogen-Phosphorus Fertilizer Tablets for Rural Communities

This study aims to evaluate the growth and production of sweet corn plants in response to the application of commercial NPK fertilizer and various doses of nitrogen-phosphorus fertilizer tablets. From early October 2022 to late January 2023, research was conducted at Research and Development Luas Birus Utama to produce nitrogen-phosphorus fertilizer tablets and at Research and Development Syngenta Indonesia Cikampek Station, Karawang, to perform a semi-field analysis. A factorial randomized block design with two treatment factors was employed in this study. The first factor was five types of nitrogen-phosphorus fertilizer tablets, namely, A (0% nitrogen and 6.3% phosphorus), B (0.81% nitrogen and 6.3% phosphorus), C (1.57% nitrogen and 6.1% phosphorus), D (2.33% nitrogen and 6.2% phosphorus), and E (3.06% nitrogen and 6.2% phosphorus). The second factor was F (standard nitrogen, phosphorus, and potassium). The results revealed that applying different dosages of nitrogen-phosphorus fertilizer tablets in combination with potassium chloride fertilizer yielded no different effect on the growth, biomass, and yield components of sweet corn plants when compared to applying NPK fertilizer. A comparison between the soil test results before and after application revealed that the formulation of fertilizers in tablet form helps plants to effectively absorb the required nutrients. It is currently possible to develop small-scale or microscale green ammonia production technology to fulfill the fertilizer requirements of rural communities because of its low cost, low carbon emissions, and low renewable energy consumption. The scarcity of fertilizer supplies endangers Indonesia’s food sustainability. Nitrogen-phosphorus fertilizer tablet production technology can be used in areas with a scarcity of inorganic fertilizers but with the potential for low-grade phosphate mines using commercial ammonia solutions. Thus, understanding how to produce nitrogen-phosphorus fertilizer tablets from ammonia solution will aid in the acceptance of microscale green ammonia production technology. Doi: 10.28991/ESJ-2024-08-02-016 Full Text: PDF

Study on the acoustic-thermal effects and damage models during uniaxial compression failure process of phosphorite with different H/Di

Determining the size of ore pillars is crucial for the stability of mining structures and the recovery rate in mining design. To investigate the damage characteristics of phosphorite under different height-to-diameter ratios (H/Di), uniaxial compression tests were conducted on phosphorite specimens with varying H/Di. The effects of these H/Di on the mechanical properties and acoustic-thermal signals were analyzed, leading to the establishment of a joint acoustic emission-infrared damage model. Results showed: (1) Peak stress and ultimate strain of phosphorite specimens were negatively correlated with the H/Di, with compressive strength decreasing and stabilizing as the H/Di increased. (2) Increasing H/Di led to a transition from tensile to shear crack dominance during specimen failure, with cumulative acoustic emission energy and ringing counts positively correlated with H/Di. (3) Infrared radiation temperature before instability failure showed a cyclic pattern of slow increase, sudden rise, and sudden decrease, reaching a peak at failure. Using these findings, separate damage models for different H/Di were established based on two characteristic signals, correcting for monitoring losses, and finally merged into a joint acoustic-thermal damage model. The resulting model aligned well with experimental data, validating its rationality and significantly improving damage prediction accuracy. Thus, the model holds promising application prospects for calculating recovery rates, designing ore pillar sizes, managing goafs, and maintaining abandoned mine stability in phosphate mining design.

Ecological Assessment of Restored Rock Phosphate Mine Spoils in the Maldevta Area of Garhwal Himalayas

This research explores the complex interaction between vegetation restoration and soil recovery, with a particular focus on the ecological restoration of an area in Maldevta, Garhwal Himalayas, that was once mined. The Himalayan ecology, which is abundant in minerals and biodiversity, is under a great deal of stress from mining, building roads, and grazing. The research area experienced open-pit mining, which degraded the soil and eliminated vegetation from what had once been a tropical dry mixed deciduous forest. Analyzing the restored soil's physical and chemical properties reveals a varied profile that affects fertility, structure, and nutrient composition. The loamy sand is made up of different percentages of sand (72.4%), silt (16.96%), and clay (9.89%). The chemical characteristics of the soil include potassium (5.10%), phosphorus (0.33%), nitrogen (0.042%), and electrical conductivity (EC) of 0.21 ohms/cm. The pH of the soil is 7.80. Employing the quadrat method for vegetation analysis, the study underscores the dominance of key plant species like Lantana camara, Mallotus philippensis, and Bombax ceiba in the restored ecosystem. The results demonstrate how restoration initiatives improve soil conditions, vegetation structure, and species diversity. By highlighting the crucial relationship between soil and vegetation dynamics, this study adds insightful information that can improve the effectiveness of ecological restoration projects. The work supports the long-term establishment of self-sustaining ecosystems by offering a thorough grasp of the intricate biological mechanisms leading to the rehabilitation of degraded landscapes in the fragile Himalayan region.

Application and Evaluation of Stage–Storage–Discharge Methodology in Hydrological Study of the Southern Phosphate Mining Model Domain in Southwest Florida

This hydrological study investigated a combined rating methodology tested on a 14,090 km2 area in Southwest Florida. The approach applied the Hydrological Simulation Program-Fortran (HSPF) over a 23-year period and was validated by 28 stream gauging stations. The regional hydrological complexity includes natural and agricultural areas, as well as extensive phosphate mining and urbanizing areas. This application is a novel and efficient methodology for generating stage–storage–discharge relationships using a geographic information system (GIS), empirical equations, and spreadsheets for 148,000 isolated and connected alluvial wetlands within the model domain. The validation metrics used to evaluate the applied methodology for populating the stage–storage–discharge relationship demonstrated the model effectiveness in simulating a range of hydrological events across various regions. For discharge prediction, the Nash–Sutcliffe efficiency values surpassed 0.7 at most stations, with an average of 0.67, and the average R squared was 0.74. This methodology, when applied, achieved a root-mean-square error of 4 m3/s for discharge prediction and 0.47 m for stage prediction. However, limitations emerged in simulating baseflow (low flows), highlighting the need for integrated modeling approaches to accurately capture groundwater–surface water interactions. The research provides an improved means for modeling regional water resources and lays the groundwork for enhanced hydrological modeling in watersheds with complex alluvial and isolated wetland systems.

Design and Implementation of Sampling Wells in Phosphate Mine Waste Rock Piles: Towards an Enhanced Composition Understanding and Sustainable Reclamation

Establishing a circular economy in mining begins with a dedicated sampling strategy as its fundamental phase. This specific approach is crucial for enhancing resource retrieval and isolating essential minerals from mining residues. By carefully examining and defining the makeup of waste materials, mining activities can discover overlooked possibilities, promoting sustainability. A thoughtfully planned sampling strategy not only reduces environmental harm but also sets the stage for the effective use of resources. In doing so, the mining industry can shift towards a circular model, adhering to the principles of waste reduction, material reuse, and ultimately promoting a more environmentally conscious and economically viable industry. In the phosphate industry and during the pre-concentration process of phosphate ore through screening, significant amounts of mining waste, consisting of various lithologies including indurated and fine phosphate, coarse-grained silicified phosphate, limestone, and marls, are deposited in waste rock stockpiles. Collecting representative samples from these heterogeneous materials presents challenges in accurately characterizing the entire stockpile. To overcome this issue, circular mining wells were implemented as a novel sampling method in waste rock stockpiles, enabling the collection of intact representative samples. This paper shares a successful experience in constructing three concrete-lined wells within a phosphate mine waste rock stockpile measuring 662 m in length, 240 m in width, and ranging in height from 0 to 65 m. The wells were dug at various depths, ranging from 20 m to 55 m, with a circular section and a diameter of 1.5 m. An integrated method utilizing analytical techniques in conjunction with numerical modeling via Robot Structural Analysis software (version of 2020) was utilized to assess the stress on the well supports and confirm their stability. This methodology serves as a valuable tool for evaluating the stability of similar wells, ensuring the safety of operators. The structural model yielded a stress level of 1 MPa, which aligned with the values obtained from the analytical model. Sensitivity analysis was performed on various parameters (friction angle, Poisson Ratio, and gravity), and the safety factor consistently remained above 1.5 for all scenarios investigated up to a depth of 60 m. Consequently, this study demonstrates that concrete-lined wells can be utilized safely for intact sampling in waste rock stockpiles. This sampling operation will allow the pursuit of optimizing resource utilization and enhancing environmental sustainability, by studying phosphate distribution in the Phosphate Mine Waste Rock (PMWR) for better recovery.

Application research on low cost support method for surrounding rock of broken section roadway in phosphate mine area

Introduction: Taking a phosphate mine in Yunnan as the engineering research background, the fractured rock mass of the No. 1 belt roadway is selected as the research object.Methods: To reduce the cost of tunnel surrounding rock support and optimize construction technology, a combination of numerical simulation software Midas and on-site experiments was used to compare and analyze the distribution characteristics of the plastic zone of tunnel surrounding rock, deformation characteristics of tunnel surrounding rock, and stress characteristics of tunnel support anchor bolts under two support methods: double-layer spray anchor mesh and single-layer spray anchor mesh with steel bar.Results: Research findings indicate that adopting the single-layer spray anchor mesh with steel bar support method results in a more uniform distribution of the plastic zone at the top of the tunnel surrounding rock, with a smaller range. The settlement of the roof and bulging of the bottom plate in the roadway’s surrounding rock, supported by a single-layer spray anchor mesh and steel bars, measure at 75.033 mm and 82.165 mm, respectively. Additionally, the internal bulging on both sides of the roadway’s surrounding rock is recorded as 37.835 mm and 37.470 mm, respectively. On the other hand, when utilizing a double-layer spray anchor mesh for support, the settlement of the roof and bulging of the bottom plate in the roadway’s surrounding rock are measured at 84.199 mm and 85.255 mm, respectively. Correspondingly, the internal bulging on both sides of the roadway’s surrounding rock records measurements of 41.670 mm and 41.756 mm, respectively. Furthermore, adopting the single-layer spray anchor mesh with steel bar support method ensures a more even transfer of axial forces to the steel bars, thereby increasing the overall load-bearing capacity. In contrast, the anchor bolts in the double-layer spray anchor mesh support method experience higher axial forces, leading to more pronounced stress concentration.Discussion: By comparing the field monitoring data, it is evident that the single-layer spray anchor mesh with steel bar support method exhibits significantly better control over the tunnel surrounding rock than the double-layer spray anchor mesh support method. Therefore, replacing the double-layer spray anchor net support with a single-layer spray anchor net with steel bar support method is entirely feasible and can meet on-site practical production requirements. The research results hold significant value in providing guidance and reference for selecting cost-effective support schemes for tunnel surrounding rock.

THE STATUS OF THE ENVIRONMENTAL MANAGEMENT SYSTEM, ITS IMPROVEMENT ASPECTS UNDER COVID-19 CRISIS, AND ITS IMPACT ON SUSTAINABLE ENVIRONMENTAL DEVELOPMENT IN JORDAN (AN APPLIED STUDY ON MINING INDUSTRIES SECTOR)

Objective: Identify the impact of the new conditions created by Covid-19 crisis on achieving sustainable environmental development by studying the environmental management system and the impact of improving energy use, improving water use, and improving the impact of emissions in Jordanian mining industrial companies in achieving sustainable environmental development as a useful framework in the post-pandemic recovery period. Research Design & Methods: The descriptive correlational method was used where a questionnaire. The research population consisted of specialists in of safety, environment, and occupational health in the Jordanian extractive industries and mining companies. A total of (8) companies were identified, of which the two largest companies were chosen as a cluster sample for this study: Arab Potash Company with 33 employees in safety and environment, and Jordan Phosphate Mines Company with 45 employees. Findings: The results showed from the point of view of the workers in the Jordan Phosphate Mines Company and the Arab Potash Mines that there is a positive and statistically significant impact of improving aspects of the environmental management system in light of the Covid-19 crisis in general on sustainable environmental development by (77%). Conclusion: The results showed from the point of view of the workers in the Jordan Phosphate Mines Company and the Arab Potash Mines that the level of improvement of the environmental management system in the field of energy use, in the field of water use, and in the field of the impact of gas emissions, ranges between medium and high level, and the results showed that there is a positive and statistically significant impact of improving aspects of the environmental management system (improving energy use, improving water use, improving the impact of gas emissions) in light of the Covid-19 crisis in general on sustainable environmental development by (77%).