Potash Mine Research Articles

The Stability and Failure of Deep Underground Structures at Potash Mining Deposits

The Stability and Failure of Deep Underground Structures at Potash Mining Deposits

Unsupervised clustering of mining-induced microseismicity provides insights into source mechanisms

Microseismic source mechanisms in underground mines can provide information about the rock mass response to mining. Conventional approaches to such studies rely upon moment tensor solutions that are susceptible to modeling assumptions and need reliable information about source locations and high-resolution velocity models. We propose the application of unsupervised clustering to group microseismic events into different classes directly from the waveform data such that the events in a specific class have similar source mechanisms. Our method has three main steps, first using spectral decomposition to separate the source terms from the path-receiver contributions in the observed amplitude spectra of events occurring in spatially dense clusters. Second, reducing the number of features from the source spectra using independent component analysis (ICA). Third, applying a Gaussian mixture model (GMM) to the reduced feature matrix to obtain event clusters. To test our method, we generate synthetic waveform data using the receiver network and the recorded microseismic event locations in an underground potash mine in Saskatchewan. Results show the ability of our method to separate events into different classes corresponding to differences in source mechanisms. Application to field data recorded in the mine during February 2021 successfully discriminates between blasts and microseismic events. The data recorded between 1 March and 30 June 2021 that contain microseismic events only are divided into two dominant classes. Using known moment tensors (MT) of some of these events for labeling, we interpret one of the two classes as having dominant double-couple mechanisms as compared to the other which most likely corresponds to the linear dipole-tensile mechanisms. Our method, combined with some expert knowledge such as MT of some larger magnitude events, can offer an assessment of source types of large microseismic populations as often encountered in induced seismicity.

Modeling and Mitigating Gas Hazards during Potash Mine Closure

The planned closure of potash mines achieved through the injection of highly mineralized brines into the worked-out area is a complex process. A critical concern arises when brines obstruct the aerodynamic connections between the flooded mine’s airspace and the atmosphere, potentially leading to the formation of closed cavities where explosive gases can accumulate. To address this hazard, it is imperative to develop systems capable of extracting the gas–air mixture from the unflooded part of the worked-out area. Two distinct scenarios are examined: the first involves controlled flooding with saturated brines, while the second contemplates flooding resulting from a hypothetical breakthrough of supra-salt strata, leading to the ingress of groundwater into the worked-out area. A novel mathematical model is introduced to predict the evolution of gas–air mixture parameters in the unflooded part of the worked-out area. Utilizing this model, we assess the effectiveness of proposed measures designed to eliminate explosive gases from the worked-out area. Specifically, a pipeline system is proposed for the removal of gases. The findings from this study contribute valuable insights into ensuring the safe and efficient closure of potash mines, shedding light on potential risks and effective mitigation strategies for gas-related hazards during planned flooding.

Leveraging the ETAS model to forecast mining microseismicity

SUMMARY Mining operations result in changes of the subsurface stress field that can lead to the occurrence of microseismic events. The development of strategies for forecasting and avoidance of significant events is crucial for safe and efficient operations of mines. One such example, discussed here is the observed induced microseismicity in soft rock potash mines. It is primarily driven by the rock excavations but can also be triggered by preceding events or can result from the delayed effects of plastic creep of soft rocks. Therefore, it is important from seismic hazard assessment and risk mitigation points of view to understand the statistical aspects of microseismicity in potash or other types of mines. In this study, the temporal evolution of the induced microseismicity from a potash mine in Saskatchewan is analysed and modelled. Specifically, the epidemic type aftershock sequence model is used to approximate the occurrence rate of the induced mining microseismicity. The estimated parameters signify that the microseismicity displays swarm-type characteristics with limited inter-event triggering. Moreover, the Bayesian predictive framework is used to compute the probabilities of the occurrences of the largest expected events above a certain magnitude for prescribed forecasting time intervals during the evolution of the sequence. This approach for computing the probabilities allows one to incorporate fully the uncertainties of the model parameters. The Markov Chain Monte Carlo sampling of the posterior distribution are used to generate parameter chains to quantify their variability. Furthermore, several statistical tests are conducted to assess the credibility of the obtained retrospective forecasts compared to the observed microseismicity. The obtained results show that the developed approach can accurately forecast the number of events and intensity of the sequence. It also provides a framework for computing the probabilities for the largest expected events.

Damage Self-Healing Property of Dissolved Salt Columns in Solid Potash Mine.

The objective of this work was to investigate the self-healing properties and mechanical damage characteristics of dissolved salt columns under different humidity and time conditions. Based on the results of electron microscope scanning and uniaxial mechanical tests, the microscopic element distribution of the ore and the microscopic morphology of the minerals were investigated, and the healing, mechanical, and damage properties of the specimens were analyzed, which revealed the microscopic reinforcement mechanism of the damage healing of the dissolved salt columns. The results showed that the healing reinforcement, compressive strength, and modulus of elasticity of dissolved salt columns under uniaxial compression show a tendency to increase, then decrease with the increase of humidity, and gradually increase with the increase of the maintenance time and reach the maximum value at 10% humidity and 30 days of maintenance time, which are 3.48, 8.07, and 650 MPa, respectively. The damage type of the healed specimen as a whole gradually transitioned from tensile damage to shear-slip type, indicating that the brittle damage characteristics of the specimen under loading became more and more significant. Based on the principle of strain equivalence, the damage evolution equation under uniaxial compression of solid potash dissolved salt columns describes the damage evolution law and destruction process of the specimen, and the results of the damage characterization of the dissolved salt columns are consistent with the change rule of the healing properties and mechanical properties with humidity and conservation time. Based on the fine morphological features of the dissolved salt column specimens after self-healing, three different self-healing microscopic mechanisms for damage recovery of solid potash dissolved salt columns are summarized, namely, healing of damaged microcracks based on diffusion, recrystallization healing of brine-filled microfractures, and healing adhesion of crystal particles in dissolved zones. These microstructures effectively transform cracks into isolated sections and play a key role in improving mechanical properties. In addition, the higher the humidity, the thicker adsorbed water film is produced on the fissure surface, which accelerates the transportation of materials on the fissure surface, and the healing rate of the dissolved salt columns increases. However, when the humidity is too high, it causes the evaporation of the liquid film to be less than the recharge of water vapor, which reduces the healing rate of the dissolved salt columns. Thus, suitable humidity produces a more pronounced healing effect than an environment maintained at a constant high humidity level. The research results can provide theoretical guidance for the filling mining of solid potassium salt.

Оптимизация технологических способов отработки калийных запасов при камерной системе разработки

The diverse demand for inorganic fertilizers has predetermined the intensification of potash mining, which is a raw material for their production. In this regard, it has become necessary to create risk management technologies for underground mining of potash deposits considering the spatial planning of mining operations while increasing the technological productivity of underground combine machines. The purpose of the study is to develop a technology to increase the technological productivity of mining set equipment to a level as close as possible to a combine at a minimum volume of preparatory work coupled with stopping operations. The subject of the study is the procedure for mining a designated mine field of potassium-magnesium deposit. Methods. The study applies a formal logistics approach based on an analysis of known facts and existing problems at a mining enterprise, the regulatory and technical documentation used and current scientific trends in this field. Based on the results of the analysis, conclusions and justifications were made. Then, a solution to the problem is proposed. Results. The study presents a modernized and improved potash mining method considering spatiotemporal changes. When planning the development of individual sections of a deposit, geological services carry out underground additional exploration to supplement geological knowledge of the area in question. Such work includes geological exploration, drilling wells from the face and perimeter of the mined-out void to select core for mechanical and chemical (furrow and core) testing, geophysical studies, etc. Discussion. The set purpose is achieved by preparing and developing the field with diagonal rooms. Prior to stopping operations, additional exploration drifts are carried out along the upper edge of the mined seam by paired faces along the entire length of the selected block. These mined out voids allow obtaining additional geological information about the section of the mine field being mined. Conclusion. A scheme for mining a selected field with a described sequence of stopping and cutting is proposed. The proposed scheme allows: to increase the technological productivity of mining set equipment to a level as close as possible to a heading-and-winning machine; to minimize the volume of preparatory work coupled with stopping operations. Resume. The proposed scheme for mining a selected section of a mine field with the described sequence of excavation allows us to increase the technological productivity of the mining complex to a level that is as close as possible to the technical productivity of a mining and shearer while simultaneously minimizing the volume of preparatory work, combining these works with the work of mining. Suggestions for practical applications and directions for future research. The research results can be useful in potash deposit mining by chevron cutting method considering spatial planning, safe mining operations and replenishment of geological information about the field.

Unraveling the molecular mechanisms of fish physiological response to freshwater salinization: A comparative multi-tissue transcriptomic study in a river polluted by potash mining

Freshwater salinization is an escalating global environmental issue that threatens freshwater biodiversity, including fish populations. This study aims to uncover the molecular basis of salinity physiological responses in a non-native minnow species (Phoxinus septimaniae x P. dragarum) exposed to saline effluents from potash mines in the Llobregat River, Barcelona, Spain. Employing high-throughput mRNA sequencing and differential gene expression analyses, brain, gills, and liver tissues collected from fish at two stations (upstream and downstream of saline effluent discharge) were examined. Salinization markedly influenced global gene expression profiles, with the brain exhibiting the most differentially expressed genes, emphasizing its unique sensitivity to salinity fluctuations. Pathway analyses revealed the expected enrichment of ion transport and osmoregulation pathways across all tissues. Furthermore, tissue-specific pathways associated with stress, reproduction, growth, immune responses, methylation, and neurological development were identified in the context of salinization. Rigorous validation of RNA-seq data through quantitative PCR (qPCR) underscored the robustness and consistency of our findings across platforms. This investigation unveils intricate molecular mechanisms steering salinity physiological response in non-native minnows confronting diverse environmental stressors. This comprehensive analysis sheds light on the underlying genetic and physiological mechanisms governing fish physiological response in salinity-stressed environments, offering essential knowledge for the conservation and management of freshwater ecosystems facing salinization.

Optimization of the Combined Ventilation System for Dust Reduction in Blind Headings of Potash Mines

Optimization of the Combined Ventilation System for Dust Reduction in Blind Headings of Potash Mines

The Influence of the Chemical Composition of Soil and Vegetation on the Soil Mesofauna in the Potash Mining Impact Zone in the Middle Prikamye Region

The Influence of the Chemical Composition of Soil and Vegetation on the Soil Mesofauna in the Potash Mining Impact Zone in the Middle Prikamye Region

Методика прогнозирования зон скопления сероводорода в сильвинитовых пластах калийных рудников и экспресс-определения газоносности пород по сероводороду

Intensification of potash salt mining, widespread use of high-performance continuous miners, involvement of gasbearing formations in mining are accompanied by release of natural poisonous gases into the atmosphere of mine workings, which explains the need to ensure safe working conditions for the miners. The article presents the researche results that helped to develop a methodology for predicting accumulation zones of one of the most hazardous poisonous gases, i.e. hydrogen sulfide. A correlation was established between the hydrogen sulfide concentration, presence of organic substances and the content of magnesium chloride in the rocks. The article describes methods to determine the accumulation areas of hazardous sulfurcontaining gases based on the trench sampling and laboratory test data, which makes it possible to take timely protective measures to ensure safety of the miners. The developed method is based on creation of the correlation fields for various geochemical attributes such as the NaCl, KCl, MgCl2 content and others. A close correlation between the content of organic carbon in the rocks and magnesium chloride indicates the degree of salt recrystallization, as evidenced by an increase in the hydrogen sulfide content. In addition, the article describes an express method to determine the gas content in rocks, which enables a quick and accurate assessment of hydrogen sulfide concentration directly in the mine workings, thus providing the possibility of prompt response to the hazards. Thus, the methodology proposed by the authors serves not only to identify the potentially hazardous areas, but also to prevent dangerous situations associated with the release of poisonous gases in potash mines. The research and practical approaches described in the article as well as the developed recommendations contribute to enhancing the efficiency of mine ventilation, which in turn leads to minimization of the risks to health and life of the miners.

Global food security threatened by potassium neglect.

Food security and healthy ecosystems are placed in jeopardy by poor potassium management. Six actions may prevent declines in crop yield due to soil potassium deficiency, safeguard farmers from potash price volatility and address environmental concerns associated with potash mining.

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%).

Waste management in potash mining companies

Relevance. Related to the need to carry out environmental protection measures in potash mining areas exposed to the environmental consequences of the impact of multi-tonnage salt waste. Aim. To summarise and analyse the geography of potash mining operations, the environmental impact of these operations, and potash waste management practices. Object. Potash mining waste. Methods. Theoretical and logical analysis of the data. Results. The research considers the geographical distribution of potash deposits and presents the characteristics of potash mining waste using the example of the Verkhnekamskoe Potash Deposit. The paper provides both domestic and foreign analyses of ecological consequences of waste storage on the day surface. Several options for potash mining waste management are analysed. For the management of clay-salt slurry, the most effective approach is its injection into underground horizons, which includes the use of saturated solutions as a fertiliser component, as a part of a product in construction, and in the oil industry. A more comprehensive approach to halite waste management is needed. Waste disposal to waste dumps is relevant due to the presence of mined-out areas on the territory of long-operating enterprises. Reclamation of the salt dump will help to isolate it from atmospheric precipitation, thereby reducing the inflow of saturated water into the environment. Utilising waste for production of construction materials is the most economically and environmentally favourable option. Extracting valuable components, producing fertilisers, concentrates, etc. from waste is the least practical approach due to the ecological and economic expenses involved in acquiring extraction equipment and the repeated generation of waste. The most challenging aspect of reducing waste generation in terms of technology lies in improving mining operations and implementing selective mining.

Evaluating potential impacts of industrial activities at depth on shallow groundwater: Holistic integration of results from multidisciplinary research in eastern Canada

A multidisciplinary project was carried out in New Brunswick (eastern Canada), where hydrocarbon exploration was stopped in 2015 due to a moratorium on hydraulic fracturing, to investigate the vulnerability of shallow aquifers to industrial activities from both potential surface contamination and upward fluid migration. The study area included an active unconventional gas field (which also encompassed a potash mine in operation until late 2015) and a prospect hydrocarbon field. This project, a collaboration between two levels of government, universities and an oil and gas operator, created an unprecedented opportunity by allowing several monitoring wells to be drilled directly on gas well pads.Multiple datasets from geological, geophysical, geomechanical, hydrogeological and geochemical studies were collected and the interpretation of aquifer vulnerability resulted from the integration of their findings. The data coverage from reservoir depths to the surface provided no evidence for the presence of a natural connection between the deep units targeted by the industry and the shallow aquifers, or of contamination from the surface. The intermediate zone between the shallow aquifers and reservoirs appears to provide an effective barrier preventing upward migration of fluids. In particular, the locally ambiguous origin of methane in groundwater and the presence of salts in a few shallow monitoring wells were resolved through a sound understanding of the interacting elements of the geological – geophysical – geomechanical and the hydrogeological – geochemical components of the holistic system. Although this article focuses primarily on the hydrogeological component, highlights of the other components are presented here to give an overview of this multidisciplinary project's results and their contribution and to provide readers with a practical framework that can be used in other regions or other industrial contexts involving deep subsurface activities.

Investigation into the Long-Term Stability of Carnallite Pillars Considering Creep Influence

Abstract In subterranean potash mines utilizing the room-and-pillar mining method, maintaining the long-term stability of carnallite pillars is imperative for the safety and ongoing viability of operations. This study undertakes uniaxial compression creep tests on carnallite samples sourced from the Dongtai Potash and Magnesium Salt Mine in Laos. The durability of carnallite pillars is evaluated using an advanced Burgers creep model combined with Flac3D numerical simulations. Results indicate that the creep strength of carnallite is approximately 60%–70% of its immediate strength, demonstrating significant creep behavior. The refined Burgers model provides an accurate representation of the carnallite’s creep characteristics. Post-excavation, the internal compressive stress within the pillars progressively increases, registering an approximate rise of 1 MPa, and stabilizes under pressure after one year. After three years of continuous observation through creep tests and Flac3D simulations, the maximum deformations detected in the roof and floor of the mining house, as well as the adjacent rock masses, were 60mm and 20mm, respectively, indicating minimal overall deformation. The width of the plastic zone within the pillars exhibits time-dependent growth, with rapid expansion occurring in the internal plastic zone and a significant deformation rate within the first six months post-excavation. To ensure the long-term stability of the mining pillars and voids, it is recommended that backfilling operations be conducted within six months following the excavation.

Microseismic event locations and source mechanisms using dominant guided waves recorded in an underground potash mine

Microseismic event locations and moment tensors (MT) in underground mines can provide insights into the subsurface deformation and current state of stress. However, reliable estimation of these source parameters is rather challenging due to high-frequency waveforms and a low signal-to-noise ratio for negative magnitude events. We study microseismicity in an underground potash mine in Saskatchewan, Canada, recorded between 1 March and 30 June 2021, by a network of broadband seismometers. The active mining is carried out in low-velocity evaporites at depths of approximately 1 km below the ground level. The theoretical dispersion curves show that guided waves in the form of leaky P and P-SV/SH normal modes can exist in a 1D velocity model representing mine geology. These guided waves are detected as high-energy dispersive arrivals on the seismograms recorded at the underground receivers. We locate the events using the arrival times of the guided waves and their mean group velocities. Most (approximately 80%) of the detected events cluster around the mine layout between depths of 0.95 to 1.05 km. Next, we compute MT for 92 events using waveforms of guided phases. The MT show nondouble-couple components with only 28 events having double-couple percentages greater than 50%. These events occur near mined-out cavities with source mechanisms corresponding to the layer delamination in the roof and floor or pillar yield related to the closure of cavities. No abnormal microseismicity is detected away from the mine levels in the more competent carbonate rocks above or below the evaporite formations. Thus, guided waves enable the detection of microseismic events up to large distances and can provide high-resolution event locations and MT inversion. These can be interpreted in the context of local geology and mining activities to identify the dominant factors affecting microseismicity.

The Impact of Compliance with Regulations and Laws in Reducing Strategic Contradiction Field Study: Arab Phosphate and Potash Mining Companies

This paper assesses the impact of compliance of organizations with the application of laws and regulations in reducing the strategic contradiction in the two companies of the Jordanian phosphate mines public shareholding limited, and the Arab Potash Company in Jordan. The study was conducted by distributing questionnaires to administrative staff from all career levels. Several questionnaires were distributed, and 215 valid questionnaires were retrieved for analysis. The data was entered into the SPSS program.V.25 the use of descriptive statistics measures to be able to apply statistical methods and indicators such as frequency, percentage, and arithmetic averages. The results of the analysis of the data showed that the "application of laws and regulations" index reached (3.94) and "strategic contradiction reduction" index reached (3.95). The study recommended a set of recommendations, including "strengthening periodic commitment to establish better procedures to monitor and ensure regular compliance with regulations and laws".

Club cell protein (CC16) in serum as an effect marker for small airway epithelial damage caused by diesel exhaust and blasting fumes in potash mining

ObjectiveThe effect marker club cell protein (CC16) is secreted by the epithelium of the small respiratory tract into its lumen and passes into the blood. Increased amounts of CC16 in serum are observed during acute epithelial lung injury due to air pollutants. CC16 in serum was determined as part of this cross-sectional study in underground potash miners on acute and chronic health effects from exposures to diesel exhaust and blasting fumes.MethodsNitrogen oxides, carbon monoxide, and diesel particulate matter were measured in 672 workers at a German potash mining site on a person-by-person basis over an early shift or midday shift, together with CC16 serum concentrations before and after the respective shift. CC16 concentrations and CC16 shift-differences were evaluated with respect to personal exposure measurements and other quantitative variables by Spearman rank correlation coefficients. CC16 shift-differences were modeled using multiple linear regression. Above-ground workers as reference group were compared to the exposed underground workers.ResultsSerum concentrations of CC16 were influenced by personal characteristics such as age, smoking status, and renal function. Moreover, they showed a circadian rhythm. While no statistically significant effects of work-related exposure on CC16 concentrations were seen in never smokers, such effects were evident in current smokers.ConclusionThe small airways of current smokers appeared to be vulnerable to the combination of measured work-related exposures and individual exposure to smoking. Therefore, as health protection of smokers exposed to diesel exhaust and blasting fumes, smoking cessation is strongly recommended.

Enhancing efficiency in the control of artificial ground freezing for shaft construction: A case study of the Darasinsky potash mine

Artificial ground freezing during mine shaft construction is a costly endeavor. For effective decision-making in mining operations, it's essential to establish robust control over frozen soil conditions. This control holds paramount importance for ensuring mining safety. After considering the existing approaches to the control of artificial ground freezing, we conducted an analysis of their respective advantages and disadvantages. We introduced two novel principles for controlling the freezing process. These principles mark a substantial advancement from the previously proposed freeze-on-demand concept. Subsequently, we illustrated the practical implementation of these principles by sharing our experience in controlling artificial ground freezing during the construction of two potash mine shafts in the Republic of Belarus. One of the most noteworthy outcomes of this control is the development of innovative technical solutions aimed at enhancing energy efficiency and operational safety in shaft sinking. These solutions encompass interval-based permission for mining activities, facilitating earlier shaft sinking initiation. Another significant solution pertains to swiftly responding, devising, and implementing strategies to counteract groundwater infiltration within one of the frozen soil layers.

Rock pressure-induced events in deep potash mines

Rock pressure-induced events in deep potash mines