Mud Concentration Research Articles

Application the Mike 3 model to simulate the turtibity dispersion due to sediment dumping activities in Nghi Son Port, Thanh Hoa Province

The study applied the Mike 3 hydrodynamic model to simulate the turbidity propagation from sediment mud deposition activities at sea in the Nghi Son port area, Thanh Hoa province. The research results show that during the northeast monsoon period, the sediment mud concentration field is distributed southward from the deposition area, with sediment mud concentrations ranging from 0.01 kg/m³ to 0.4 kg/m³ within an influence radius of approximately 2.5 km. During the southwest monsoon period, the turbidity concentration distribution expands northward from the deposition area due to the influence of wind and currents during this season. The northern area of Nghi Son port is affected by the dispersion of turbidity concentrations below 0.04 kg/m³. The area surrounding Hon Me island has sediment mud concentrations ranging from 0.015 kg/m³ to 0.025 kg/m³. The turbidity concentration distribution with depth ranges from 0.01 kg/m³ to 0.4 kg/m³ and is primarily located at the seafloor depths ranging from -14 m to -18 m. The turbidity concentration gradually decreases towards the water surface. The turbidity concentration in the upper water layer is relatively low, ranging from 0.01 kg/m³ to 0.08 kg/m³, with depths from 0 to -5 m.

Simulation of sand and mud transport processes in currents and waves by time-dependent 2DV model

This paper presents a time-dependent, two-dimensional vertical model for the simulation of sand and mud concentrations, transport and bed level changes in tidal conditions with or without surface waves. The model solves the advection-diffusion equation for suspended sediment. The horizontal velocities and the sediment mixing coefficients are modelled as function of x, z and t. The settling velocity is constant or modelled as function of the sediment concentration. The sediment mixing coefficient over the water depth is described by flexible expressions based on current and wave parameters which can be modified easily in the input file. To represent mud flocculation and hindered settling processes, the settling velocity can be set as constant or concentration-dependent (input). The bed boundary condition is modelled as a bed concentration as function of the bed-shear stress. The model is valid for low and high sand and mud concentrations including fluid mud concentrations. The numerical SUSTIM2V-model is herein used to simulate sand and mud transport as measured in tidal waters. The model is also successfully used for simulation of high mud concentrations in the near-bed region as measured in the mouth of the Amazon River. The model has also been used to simulate scour along an offshore caisson-type foundation structure.

Development of sustainable aluminum alloy‑tungsten carbide hybrid composites using industrial waste - An experimental analysis

The research article focuses on the development of aluminum alloy 6061 sustainable composites with the utilization of industrial waste through the use of the stir casting process. Recycling industrial waste is essential for reducing environmental impact. Thus, the red mud waste came from the aluminum production process, which was considered for producing sustainable metal matrix composites (MMCs). Also, tungsten carbide (WC) microparticles have been used to develop hybrid aluminum composite materials. The concentrations of red mud and tungsten carbide were 2 wt%, 4 wt%, and 6 wt%, respectively, and were used to achieve the desired strength performance of aluminum metal matrix composites. The elemental and bonding analyses of hybrid composites were analyzed using X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Mechanical characterizations of aluminum hybrid sustainable composites were also investigated, including tensile, compression, and microhardness testing. The results show that increasing reinforcement by up to 4 wt% increases the mechanical strength of aluminum alloy composites. The tensile, compression, and microhardness of metal matrix composites are increased by 25.24 %, 40.2 %, and 20.6 %, respectively, as compared to the aluminum alloy 6061 alloy. The surface morphology of metal matrix composites was analyzed by utilizing Field emission scanning electron microscopy. The proposed sustainable aluminum composites have the potential to develop structural and automotive components due to their higher strength-to-weight ratio.

Mud matters: exploring the quality and composition of Estonia's curative mud deposits

The study focuses on the current state of curative mud deposits in Estonia as of 2022, examining changes over the past decade and providing essential information on curative mud quality. Total of 64 curative mud samples were collected in 2022, marking the first investigation into hazardous substances such as phenols, petroleum products, and pesticides. The study encompassed analyses of organic and mineral matter content, grain size, microbiology, and heavy metal concentrations, totalling 1649 measurements. Comparisons with previous data revealed stable organic matter concentrations in lake and marine sediments over the last decade. Microbiological contamination in curative mud samples was relatively low, indicating cleanliness. Petroleum product concentrations varied, with Haapsalu at 42 mg/kg, Värska at 118.6 mg/kg, and Käina below the limit of quantification. Phenol concentrations were generally below the limit of quantification, except for Värska. Pesticides were found in Värska samples, but in other sediments, levels were below the limit of quantification. Average heavy metal concentrations in curative mud decreased between 2013–2014 and 2022, remaining below the target value. The study's results are crucial for curative mud-related entrepreneurship in Estonia, facilitating compliance with the new regulatory standards. The comprehensive data obtained will contribute to the consistency and efficacy of curative mud-related practices in the country.

Waste-to-resource: Employing lime mud as a foaming agent in glass foam manufacturing

The paper industry globally releases vast amounts of lime mud waste annually, raising environmental concerns. Composed mainly of calcium carbonate, lime mud has been utilized in various research works, including catalyst synthesis, cement production, and ceramic fabrication. This study investigates the use of lime mud as an eco-friendly foaming additive in the production of glass foam. Glass foams were prepared through a simple sintering method, utilizing glass cullet collected from households and incorporating different lime mud contents (0.5–2.0 wt%). The effects of lime mud concentration on the density, porosity, and pore size distribution of the glass foams were examined. Additionally, the thermal conductivity, compressive strength, and Weibull modulus were investigated in relation to the average porosity. The results revealed that the pore size distribution was dependent on the amount of lime mud, exhibiting three distinct distributions: a positively skewed distribution, a non-symmetric bimodal distribution, and a positively skewed distribution with a wide range. The Weibull modulus markedly decreased with increasing pore size. The compressive strength of the prepared glass foams ranged from 5.53±0.40–12.73±0.46 MPa, while the bulk density and porosity fell within the ranges of 0.41±0.02–0.70±0.04 g/cm3 and 72.12±1.45–85.38±0.98 %, respectively. The thermal conductivity could be as low as 0.07 W/m·K, approaching the upper limit for commercial glass foams used in thermal energy storage systems and meeting the requirements for Type I cellular glass thermal insulation classified by ASTM C552–16.

Enhancing Detection and Mitigation of Toxicity in Marine Biota from Drilling Activities

The growing demand for petroleum-based energy has significantly contributed to environmental pollution, particularly in the oil mining industry. This study aims to evaluate the toxicity of oil drilling mud on marine biota, using tiger shrimp (Monodon peneus) as bioindicators. The shrimp were exposed to various mud concentrations (100%, 50%, 25%, 12.5%, 6.25%, 3.25%, 1.25%, and 0%) and observed over time intervals of 0, 24, 48, 72, and 96 hours. The methodology involved direct observation of the shrimp's survival rates at each mud concentration. The results revealed a significant decline in survival rates at higher mud concentrations, with a strong positive correlation (r = 0.81) between mud concentration and toxicity. The pH levels remained stable and alkaline (7.81–8.28), while turbidity at lower concentrations (6.25%) was within acceptable limits after 96 hours, with a strong correlation (r = 0.73). These findings underscore the importance of stringent monitoring and management of drilling mud disposal to safeguard marine ecosystems, aligning with Sustainable Development Goal (SDG) 14: Life Below Water.

Estimating Wear Rate of Guide Vanes in High-Head Francis Turbines through Flow-Through Testing and DPM Simulation

Abstract The development of high-head water resources poses a significant concern due to hydro-abrasive erosion caused by entrained sediment particles. This issue is particularly prevalent in the muddy rivers of the Xinjiang region, China, where Francis turbines are commonly used. With increased soil erosion and rapid sediment transport, the erosion of Francis turbines, especially the guide vanes of high-head turbines, has become increasingly severe. The paper explores key factors that influence the erosion process caused by sediment-laden water. In addition to flow velocity and mud concentration, the properties of the sediment-laden water, such as hardness and size of sand particles, and the concentration ratio of sand particles with different hardness, also play a crucial role in the erosion process. The study is focused on analyzing the erosive effects of sediment-laden water on a high-head Francis turbine’s guide vane. The efficacy of the discrete phase model (DPM) as a simulation method for assessing wear on the guide vane is validated. This model helps analyze critical wear areas on the surface of the vane, enabling the identification of regions most severely affected by erosion due to sediment-laden water. By pinpointing these critical wear areas, the study provides valuable insights into the potential damage caused to the guide vane, thus contributing to better understanding and potential mitigation of erosion in similar turbine systems.

Experimental Study and Effectiveness Evaluation on the Rapid Antiquing of Red Sandstone in Ancient Buildings Restoration

As there are few cases of red sandstone rapid antiquing in ancient buildings and as it is difficult to reproduce, this paper carried out an experimental study and effect evaluation assessment on red sandstone rapid antiquing in the restoration of ancient buildings, based on a restoration project of an ancient town in Ganzhou. The method and the implementation process of red sandstone rapid antiquing are proposed by starting from color antiquing and texture antiquing. By controlling the concentration of red mud, grass ash, and carbon black in color coatings as variables, using the HSV (hue, saturation, value) color space and Tamura texture features (roughness, contrast, orientation) to quantitatively analyze the antiquing effect, an analytical model for evaluating the red sandstone antiquing effect based on image processing was established. The results showed that among all the antiquing groups, the group that used white cement, green zeolite, imitation greenery, red clay, grass ash, and 5 mL/L carbon black liquid at the same time had the best effect, with a qualified rate of 90%. The analytical model can improve the evaluation efficiency of red sandstone antiquing and avoid errors caused by subjective factors. With feasibility and practicability, the model is conducive for new red sandstone to meet the requirements of ancient building restoration through rapid antiquing. It provides a scientific basis and technical reference for red sandstone antiquing in stone cultural relics and ancient building restoration.

Bioleaching of rare earth elements (REEs) from Indonesian red mud by the bacterium Bacillus nitratireducens strain SKC/L-2

Red mud, a residue of the bauxite industry, represents a secondary source of rare earth elements (REEs) with substantial commercial value and untapped potential. Bioleaching, an innovative, cost-effective, and environmentally friendly method, offers a means of extracting valuable metals from mining wastes. This study explored the bioleaching of Indonesian red mud using Bacillus nitratireducens strain SKC/L-2 to recover REEs. The experiments were carried out over three days at 25 °C with different concentrations of red mud (1.5, 3, and 6 g/L) and a 10% v/v bacterial inoculum in a specific bioleaching medium. The findings indicated a slight reduction in REEs extraction by the bacterium as the red mud concentration increased from 1.5 to 6 g/L in the direct bioleaching process. In the experiment using 1.5 g/L red mud, 16 REEs were successfully extracted, with high extraction levels for specific elements such as Lu (92.0%), Tb (80.61%), and Gd (67.42%). However, when the red mud concentration was increased to 6 g/L, the survival potential of Bacillus nitratireducens strain SKC/L-2 decreased, leading to reduced recovery of elements such as Lu (76.80%), Tb (70.30%), and Gd (55.83%). The study reveals the behaviour of Bacillus nitratireducens in interacting with red mud and enduring high alkalinity, resulting in REEs extraction. These findings enhance the understanding of microbial interactions with red mud and provide insights into potential resource recovery applications.

Design of polyurethane composites obtained from industrial plastic wastes, pyrite and red mud

The purpose of this study consisted in the synthesis and characterization of composite materials based on polyurethane (PUR) rigid foam reinforced with two industrial wastes such as pyrite and red mud for the retention of mercury ions, Hg2+, ions from contaminated water and applications as paving stones in construction area. The diol used to create the urethane bond resulted from the depolymerization of poly(ethylene terephthalate) (PET) wastes in the presence of diethylene glycol (DEG). The resulted diol was characterized by gel permeation chromatography (GPC), registering a molecular weight, Mn = 420 g/mol. The hydroxyl index of the diol, IOH = 256.731 mgKOH/g was determined based on ASTM D4274-99. In this study, 6 types of PUR foams were obtained by reacting the diol with the polycondensation agent, 4,4′-methylene diphenyl diisocyanate (MDI) in the presence of different concentrations of filling agents. All specimens were characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), EDX mapping, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and compression tests. The formation of urethane group was confirmed by FT-IR for all specimens. The porous structure of the PUR foams was evidenced by SEM, while (EDX) and EDX mapping were used to analyze the elemental composition of the composite materials and the uniform distribution of the filling agents within the cellular structure. TGA proved that both types of PUR foams increased their thermal resistance compared with blank samples. However, the specimens loaded with red mud exhibited increased thermal resistance as the concentration of red mud was increased compared with pyrite-based samples. The final residual mass registered for red mud was 24%, compared with pyrite-based samples that registered 21%. Unexpectedly, the DSC analysis indicated that Tg values decreased up to 47 °C as the pyrite concentration was increased compared with blank sample (57 °C), while the Tg values for red mud-based samples increased as the concentration of the red mud was increased up to 60 °C. Similar results were confirmed by the compression tests, this behavior being attributed to pyrite aggregate formation in PUR matrix and confirmed also by the density values for which a correlation between the filling agent concentration and density was not possible. In the case of red mud-based PUR foams the mechanical resistance decreased as the concentration of the filling agent was increased as expected.

Phytoremediation Potential of Shallots (Allium ascalonicum L.) in Iron-Contaminated Mudflow Sites: A Case Study from Lapindo, Indonesia

This research investigates the potential of shallots (Allium ascalonicum L.) for phytoremediation in land areas contaminated with high levels of iron (Fe) metal due to the 2006 Lapindo mudflow in Indonesia. The study was conducted in the Jetis Village, Sidoarjo District, from December 2021 to February 2022, employing the Randomized Complete Block Design (RAK) method. The methodology involved the addition of different concentrations of Lapindo mud (0% as control, 10%, 20%, and 30%) to the planting medium. Our findings reveal a significant relationship between the concentration of Lapindo mud and several plant metrics, such as plant height, leaf count, and wet and dry weight, all of which were assessed using regression and correlation analysis. Additionally, we observed that a 30% concentration of the mud led to physical stunting in the shallot plants, implying that excessive absorption of heavy metals can inhibit growth. Notably, in the 30% mud concentration scenario, the Fe content was reduced from an initial 11.82% to 4.52% post-planting. The study thus confirms the capacity of shallots to perform phytoremediation, specifically by decreasing Fe content, thereby offering a potential sustainable solution to manage metal-contaminated sites resulting from geological disasters.

Epsom Salt-Based Natural Deep Eutectic Solvent as a Drilling Fluid Additive: A Game-Changer for Shale Swelling Inhibition.

Shale rock swelling poses a significant challenge during drilling a well, leading to issues related to wellbore instability. Water-based mud with specific shale inhibitors is preferred over oil-based drilling mud due to its lower environmental impact. Recently, ionic liquids (ILs) have emerged as potential shale inhibitors due to their adjustable properties and strong electrostatic attraction. However, research has shown that the most commonly used class of ILs (imidazolium) in drilling mud are toxic, non-biodegradable, and expensive. Deep Eutectic Solvents (DESs), the fourth generation of ionic liquids, have been proposed as a cheaper and non-toxic alternative to ILs. However, ammonium salt-based DESs are not truly environmentally friendly. This research explores the utilization of Natural Deep Eutectic Solvent (NADES) based on Epsom salt (a naturally occurring salt) and glycerine as a drilling fluid additive. The drilling mud is prepared according to API 13B-1 standards. Various concentrations of NADES-based mud are tested for yield point, plastic viscosity, and filtration properties for both aged and non-aged samples. The linear swell meter is used to determine the percentage swelling of the NADES-based mud, and the results are compared with the swelling caused by KCl- and EMIM-Cl-based mud. FTIR analysis is conducted to understand the interaction between NADES and clay, while surface tension, d-spacing (XRD), and zeta potential are measured to comprehend the mechanism of swelling inhibition by NADES. The findings reveal that NADES improves the yield point and plastic viscosity of the mud, resulting in a 26% reduction in mudcake thickness and a 30.1% decrease in filtrate volume at a concentration of 1%. NADES achieves a significant 49.14% inhibition of swelling at the optimal concentration of 1%, attributed to its ability to modify surface activity, zeta potential of clay surfaces, and d-spacing of clay layers. Consequently, NADES emerges as a non-toxic, cost-effective, and efficient shale inhibitor that can replace ILs and DESs.

Numerical Simulation and Experimental Study on Sediment Wear of Fixed Guide Vanes of Hydraulic Turbines in Muddy River Based on Discrete Phase Model

The erosion of the fixed guide vane of a hydraulic turbine by sandy water is influenced not only by flow velocity and mud concentration but also by the direction and speed of the sandy water over the surface. This study aims to investigate the erosive effect of sediment-laden water on a specific type of hydraulic turbine’s fixed guide vane, validate the efficacy of the discrete phase model (DPM) in simulating wear on the fixed guide vane, and identify the critical areas of wear on its surface. To achieve these objectives, the wear model and DPM model are employed to conduct numerical simulations on the fixed guide vane. Additionally, samples of sand are collected from the power station site, and laboratory tests are conducted on the hydraulic turbine’s flow passage components using actual sediment concentration and sand-to-water ratio to determine the sediment wear conditions. The numerical simulation results of the guide vane’s surface wear rate are compared with the experimental data to verify the wear condition of the fixed guide vane under its rated working condition. These findings serve as a reference for the later-stage design of erosion-resistant solid guide vanes for hydraulic turbines.

The Flocculation State of Mud in the Lowermost Freshwater Reaches of the Mississippi River: Spatial Distribution of Sizes, Seasonal Changes, and Their Impact on Vertical Concentration Profiles

AbstractWe use in situ measurements of suspended mud to assess the flocculation state of the lowermost freshwater reaches of the Mississippi River. The goal of the study was to assess the flocculation state of the mud in the absence of seawater, the spatial distribution of floc sizes within the river, and to look for seasonal differences between summer and winter. We also examine whether measured floc sizes can explain observed vertical distributions of mud concentration through a Rouse profile analysis. Data were collected at the same locations during summer and winter at similar discharges and suspended sediment concentrations. Measurements showed that the mud in both seasons was flocculated and that the floc size could reasonably be represented by a cross‐sectional averaged value as sizes varied little over the flow depth or laterally across the river at a given station. Depth‐averaged floc sizes ranged from 75 to 200 microns and increased slightly moving downriver as turbulence levels dropped. On average, flocs were 40 microns larger during summer than in winter, likely due to enhanced microbial activity associated with warmer water. Floc size appeared to explain vertical variations in mud concentration profiles when the bed was predominately composed of sand. Average mud settling velocities for these cases ranged from 0.1 to 0.5 mm/s. However, Rouse‐estimated settling velocities ranged from 1 to 3 mm/s at two stations during winter where the bed was composed of homogeneous mud. These values exceeded the size‐based estimates of settling velocity.

Hydration characteristics of tailing mud–42.5 OPC composite cementitious system and its application to dry-mixed mortar

This study investigated the influence of the raw material ratio on the product quality of tailing mud with type-I 42.5 ordinary Portland cement (OPC) in a binary cementitious system. In particular, this research aimed to expand the applicability of tailing mud and tailing waste rock while minimizing the production cost of dry-mixed mortar. The results demonstrated a synergistic reaction between the tailing mud and 42.5 OPC, which was beneficial for enhancing hydration and gelation, increasing the production of calcium silicate hydrate (C–S–H) and calcium hydroxide (C–H), promoting more free magnesium oxide (MgO) in the cement to participate in the hydration reaction, and improving the structure of the composite gelation system. When the concentration of tailing mud in 42.5 OPC was 20%, the cementitious block attained a 28-day compressive strength of 44.85 MPa. To manufacture the dry-mixed mortar product, 80% mud and 20% 42.5 OPC were mixed with equal amounts of tailing mud and waste rock aggregate. For the dry-mixed mortar, the 28-day compressive strength was 7.32 MPa, 2-h consistency-loss rate was 12.4%, and water retention rate was 99.2%. To further explore the synergistic reaction mechanism between the tailing mud and 42.5 OPC, the energy calculations, geometric optimization, and dynamic modeling of the tailing mud–42.5 OPC cementitious system were performed using the Forcite module in Materials Studio software. Overall, the results indicated that including tailing mud improved the mechanical strength of 42.5 OPC.

Effects of Mud Supply and Hydrodynamic Conditions on the Sedimentary Distribution of Estuaries: Insights from Sediment Dynamic Numerical Simulation

Estuaries are important sediment facies in the fluvial-to-marine transition zone, are strongly controlled by dynamic interactions of tides, waves, and fluvial flows, and show various changes in depositional processes and sediment distribution. Deep investigations on the sediment dynamic processes of the sand component of estuaries have been conducted; however, the understanding of how mud supply affects estuaries’ sedimentary characteristics and morphology is still in vague. Herein, the effects of mud concentration, mud transport properties, fluvial discharge, and tidal amplitude on the sedimentary characteristics of an estuary were systematically analyzed using sedimentary dynamic numerical simulation. The results show that the mud concentration has significant effects on the morphology of tidal channels in estuaries, which become more braided with a lower mud concentration, and straighter, with reduced channel migration, with a higher mud concentration. The mud transport properties, namely, setting velocity, critical bed shear stress for sedimentation, and erosion, mostly affect the ratio between the length and width (RLW) of the sand bar; a sheet-like sand bar with a lower RLW value develops in the lower settling velocity, while there are obvious strip shaped bars with a high RLW value in the higher settling velocity case. Moreover, the effects of hydrodynamic conditions on sedimentary distribution were analyzed by changing the tidal amplitudes and fluvial discharges. The results show that a higher tidal amplitude is often accompanied by a stronger tidal energy, which induces a more obvious seaward progradation, while a higher fluvial discharge usually yields a higher deposition rate and yields a greater deposition thickness. From the above numerical simulations, the statistical characteristics of tidal bars and mud interlayers were further obtained, which show good agreement with modern sedimentary characteristics. This study suggests that sedimentary dynamic numerical simulation can provide insights into an efficient quantitative method for analyzing the effects of mud components on the sediment processes of estuaries.

Intelligent short-term forecasting for mud concentration in CSD dredging construction

It has long been a challenge in the design of cutter suction dredgers (CSD) that the measurement of mud concentration lags behind other indicators like vacuum and flow rate. This phenomenon is named the time-lag effect. It significantly hinders the optimization and automation of CSD operation, for the mud concentration is a primary reference during CSD operation. As such, this study presented a data mining-based solution for short-term forecasting of mud concentrations. To accomplish this goal, first, an integration method based on hydraulics principles was proposed to align mud concentrations with other indicators over time. Second, normal construction identification, data filtering, and data smoothing were used to preprocess data. Third, a feature selection process, named "indicator class", was applied regarding the construction technology and the characteristics of the pump-pipeline system of CSDs. Last, a short-term forecasting algorithm was presented based on a hybrid ensemble strategy; this established the relationship between the actual mud concentration and the selected indicators. The validity of this algorithm was tested by a case study that collected a group of raw data logged by a CSD monitoring system. The result showed that the real-time prediction could reach a high accuracy where the coefficient of determination (R2) is 0.886 and the mean square error (MSE) is 4.708, and the short-time forecasting result within 12s is consistent with the actual trend of the mud concentration. The proposed approach has a significant deal of potential to enhance the quality and efficiency of operations by providing operators with essential references to real-time mud concentrations.

Multiscale Investigations of Overtopping Erosion in Reinforced Tailings Dam Induced by Mud-Water Mixture Overflow

The overtopping failure that occurred to the reinforced tailings dam has led to devastating catastrophes, including severe environmental disasters as well as tragedy in terms of any loss of properties and life. To study the feature of overtopping erosion for the reinforced fine-grained tailings dam induced by mud-water mixture overflow, the red mud concentration of overflow, the erosion depths and erosion rate have been consistently detected and recorded by a series of physical model tests. This investigation conclusively showed that the red mud concentration for flooding over the dam slope had a nonlinear trend of first becoming larger, subsequently decreasing with the time going on in the process of tailing dam overtopping; the maximum red mud concentration achieved 19.0%. The erosion on the dam slope was shaped like a trumpet. The red mud concentration of the mud-water mixture flow affected the erosion depth significantly. The hydraulic tests simulating erosion behaviour in the reinforced fine-grained tailings were carried out with different red mud concentrations (0%, 10%, and 20%). For the mud-water mixture flow in a red mud concentration of 20%, the final erosion depth exhibited a ladder shape from the front to the trailing end (dam toe) of the tailings sample. The final erosion depths were 1.56 cm, 0.9 cm, and 0.55 cm at the front, middle, and trailing end, respectively. With the red mud concentration decreasing, the final erosion depth at the front of the tailings sample reduced significantly while increasing at the trailing end. This study brought more scientific insights into the overtopping erosion process to the reinforced fine-grained tailings dam triggered by the mud-water mixture flow at multiscale.

Analysis of Chemical Stabilizer on the Behavior of Expansive Soil

Abstract: Rapid growth in industrialization and urbanization in developing countries like India, leads to increasing scarcity of land which forces us to utilize the available land even though it is problematic. Problematic soils are those having low bearing capacity, high compressibility and high swelling/shrinkage and as such they are not suitable for any geotechnical application. In most geotechnical engineering projects, increase in concentration of Red mud, Maximum dry density of mixture increases. The mix containing 30% Red Mud + 67% Soil + 3% Fly Ash has good bearing strength characteristics. The bearing strengths of Red Mud were increased to 7.354% on addition of Red Mud and Fly Ash in the ratios of 30% and 3% respectively. With increase in concentration of red mud, California bearing ratio increase up to a fixed concentration of Red mud. With increase in percentage concentration of Red Mud, Optimum moisture content of the mixture (Red Mud + Fly Ash + Soil) increases. With increase in concentration of Red mud, Maximum dry density of mixture increases.

Case studies of radioactivity of drilling mud for in situ leaching uranium mining in China

The drilling mud from in situ leaching uranium mining is a type of low-radioactivity waste that contains natural nuclides and other harmful substances. In order to determine whether the drilling mud can meet the requirements of radioactive exemption management standards, field investigations and data simulations were conducted in this study. Two typical uranium mines were selected for onsite investigations. Drilling mud from different layers (i.e., the upper covering layer and ore-bearing layer) and from different stages (e.g., logging stage mud, drilling expansion stage mud, and mixed mud) was sampled. For each sample, the 238U and 226Ra concentrations of the solid components and the U and 226Ra concentrations of the supernatant were analyzed. The results revealed that the highest 238U and 226Ra concentrations of the solid components were 4122 Bq/kg and 4077 Bq/kg, while the 238U and 226Ra concentrations of the mixed drilling mud were all less than 300 Bq/kg. A radioactivity estimation model was established for scenario analysis. Exemption management screening lines of waste drilling mud, which can be used to classify and treat the drilling project according to the deposit's grade and conditions, were proposed for in situ leaching drilling projects.