Characteristics Of Mud Research Articles

Geochemistry of REY-Enriched Phosphorites in Zhijin Region, Guizhou Province, SW China: Insight into the Origin of REY

The rare earth elements and yttrium (REY)-enriched phosphorites in the Zhijin region, southwest China, have attracted much attention, yet its origin has not been sufficiently addressed. The geology, mineralogy and geochemistry of samples from four sections of the early Cambrian age from the Zhijin region were studied to attain the redox condition and origin of REY. Data from in situ analysis show that REY are mainly contained in francolite, and the two types of francolite (bioclastic and granular) have no distinct difference in REY content (ΣREY). A Ce anomaly indicates an oxic condition in primary seawater. An Eu anomaly and ratios of redox sensitive elements (RSEs) indicate a fluctuating redox condition during phosphorite deposition. Shale-normalized REY patterns of whole rock and francolite show a hat-shaped pattern, indicating the effect of diagenetic processes. The Y/Ho ratio of the selected sections ranges from 38.13 to 61.93, and together with the Y anomaly, LaN/NdN ratio, LaN/SmN ratio, and LaN/YbN ratio, this indicates a seawater origin. This is supported by the Ce/Ce* of the phosphorite that ranges from 0.32 to 0.52 and the Eu/Eu* that ranges from 0.88 to 1.82, which is similar to the characteristics of seawater and deep-sea mud. We also propose a minor contribution of terrigenous debris and influence of diagenesis and hydrothermal processes.

Experimental studies on hydraulic conductivity of different straw fiber cement treated mud

Hydraulic conductivity characteristics of mud treated by rice straw fiber and cement were investigated by falling head permeability tests. The experimental results indicated that the water conductivity significantly decreased by the inserting of either cement or rice straw fiber. Comparing with cement-treated mud, the addition of rice straw fiber considerably reduced the water conductivity of the mud composite. Moreover, empirical equations were revealed to predict the value of hydraulic conductivity for the modified-mud.

Recovery of iron from high-iron red mud using suspension magnetization roasting and magnetic separation

• Suspension magnetization roasting and magnetic separation process treat red mud effectively. • Alumogoethite [Al x Fe (1- x ) ]OOH transformed into Fe-Al spinel phase Fe(Al,Fe) 2 O 4 . • Al-containing magnetite combined part of Fe(Al, Fe) 2 O 4 enter into the iron concentrate. • The saturation magnetization and specific magnetic susceptibility are enhanced via magnetization roasting. An innovative suspension magnetization roasting followed by magnetic separation process was developed to recover iron from high-iron red mud (HIRM), and the effects of roasting temperature, roasting time, CO concentration and grinding fineness on the recovery of iron were investigated. Under the optimized conditions, determined to be a roasting temperature of 560 ℃, reaction time of 15 min, CO concentration of 30% and total gas-flow rate of 500 mL/min, an iron concentrate assaying 55.44 wt% Fe with an iron recovery of 89.34% was prepared by magnetic separation. X-ray diffraction, chemical phase analysis, vibrating sample magnetometer, and scanning electron microscope were employed to assess the characteristics of red mud, roasted sample and magnetic separation products. The hematite in the red mud was transformed into magnetite during the suspension magnetization roasting, thus the magnetism was significantly enhanced. While, the alumogoethite was transformed into Fe-Al spinel phase Fe(Al,Fe) 2 O 4 , and entered the magnetic concentrate along with the magnetite. In addition, some fine-grained alumina particles were also easy to be wrapped by magnetic agglomerates and entered the magnetic concentrate, resulting in high aluminum content in the iron concentrate.

Strength and leaching characteristics of red mud (bauxite residue) as a geomaterial in synergy with fly ash and gypsum

Red mud (Bauxite residue) comprises microscopic particles and other chemical constituents that pose a major threat to the environment. The most common solution to resolve issues related to any solid waste is its reuse in construction. This paper delves into the possibility of using red mud as a geomaterial in synergy with fly ash and gypsum. In this regard upon finding the geotechnical properties of virgin red mud, it is strengthened with fly ash by replacing 10, 20, and 30% of red mud by its dry weight and to these combinations gypsum was added by 0.5% and 1% and prepared various combinations. The impact of these material additions on the characteristics of red mud were investigated using the Unconfined compressive strength and California bearing ratio values and their environmental compatibility was further studied by conducting the leaching characteristics using Toxicity Characteristics Leaching Procudure (TCLP) method. The findings of the tests indicated that fly ash and gypsum significantly enhanced the strength qualities of red mud as compared to unstabilized red mud. The stabilization helps red mud to attain a minimum strength required to use as a subgrade material. Furthermore, leaching investigations performed on stabilised samples have revealed that the vast majority of leaching heavy metals are within the WHO's authorised threshold for toxicity.

Characteristics of Waste Mud Treated by Construction Waste-Slag Based Flocculation-Solidification Combined Method

Characteristics of Waste Mud Treated by Construction Waste-Slag Based Flocculation-Solidification Combined Method

Application of Cellulosic Fibrous Material from Agro Waste as Filtrate Loss Modifier in Aqueous Mud-Morphology at HTHP Conditions

Controlling the filtration characteristics of any drilling fluid does not only include the control of the filtrate volume penetrating into the formation; but also the ability of the mud to deposit a thin low-permeability filter cake on the wall of the wellbore quickly. The permeability of the filter cake is very dependent on the particle size because when small size particles are used, the permeability decreases, because of the fact that colloidal particles get packed very tightly. This study investigated the filtration and filter cake characteristics of water-based mud (WBM) using fibrous cellulose from Tiger Nut waste and the guar gum. American Petroleum Institute (API) Recommended Practice Standard Procedure for Field Testing Drilling Fluids, API RP 13B-1 was applied during the analysis. Statistical analysis of the experimental data was conducted and the R2 value (0.99) showed that the experimental method adopted was replicable. Mud samples B2 and C2 gave an optimum result and their mud cakes developed under High-Temperature High-Pressure (HTHP) condition were dried and further analyzed with scanning electron microscope (SEM). The results showed that the filter cakes SEM structure for cellulosic fibrous from agro waste and guar gum exhibits similar characteristics; and the mud cakes was firm after soaking with 15% HCl for thirty minutes but started dissolving after one hour. The SEM analysis inferred that the filter cake morphology shows a good particle-pore interlocking for sample C2 than B2.

Migration Characteristics of Boring Mud in Roadway Floor Anchor Wire Hole and Test in Coal Mine

Given the difficulty in drilling the anchor holes in the roadway floor of the coal mine, the characteristics of slag movement in the process of positive and negative circulation drilling are analyzed. It is concluded that the interaction between the three zones of drilling and slag is the fundamental reason restricting the rapid drilling of the anchor cable hole in the floor, and it is proposed that the pump reverse circulation drilling can effectively prevent the formation of the three zones of drilling and slag. According to the actual situation, the relationship between drilling depth, vacuum degree of the pump, and the velocity of drilling fluid and the volume of drilling slag is obtained. The results show that the pump suction reverse circulation is feasible for the rapid drilling of the anchor hole of the floor. A set of pump suction reverse circulation drilling systems has been developed, and floor anchor wire hole drilling and slag discharge operation at the same time were realized. The field test shows that the effective drilling time of the anchor cable hole in the depth of 5.6 m can be controlled within 30 min, which solves the problem of deep hole drilling in the anchor hole of the bottom plate and purifies the working environment.

Natural soil genesis in red mud and underlying microbial mechanism.

Soil genesis is important for ecological restoration of red mud disposal area. Soil genesis of red mud and the microbial mechanism were studied by analyzing the change of physicochemical and biochemical characteristics of red mud. We analyzed the microbial community structure in a red mud disposal area without any human-induced restoration through a space for time substitution approach. The results showed that, with the increases of storage time, the physical parameters of porosity, water-stable aggregates content, and mean weight diameter increased, but the bulk density decreased. The chemical parameters, including pH, electrical conductivity, acid neutralizing capacity, and exchangeable sodium percentage, decreased with increasing storage time. The bio-chemical parameters of total organic carbon, total nitrogen, available phosphorus, microbial biomass carbon and basal respiration increased, but the metabolic quotient decreased. The Shannon diversity index increased, and the dominant microflora in red mud changed from the oxygenic photosynthetic bacteria Cyanobacteria and thanaerobic anoxygenic phototrophic bacteria Chlorobi and Chloroflexi to Proteobacteria, Actinobacteria and Firmicutes. The ratio between eutrophic and oligotrophic bacteria substantially increased. The micromorphology results showed that the microorga-nism-red mud aggregates were formed through adsorption, linkage, intertwinement and package between red mud particles, microbial cells and their metabolites. The red mud biotope changed spontaneously from extreme and oligotrophic into soil-like under natural stockpiling. The soil genesis process was mediated by microbes through increasing nutrient level, decreasing alkalinity and sali-nity, and improving soil structure.

Determining the composition of therapeutic mud and sewage sludge of mud baths for their subsequent disposal

The composition and characteristics of therapeutic mud and sewage sludge of mud baths are studied in the article. The use of the X-ray fluorescence method makes it possible to determine the composition and percentage of elements in the resulting waste of mud baths. The studies are carried out using a sample of natural therapeutic mud from the Sulfatnoe Lake of the Kurgan Region and natural sewage sludge generated after treatment. The study of the elemental composition of natural mud and sludge have shown a high content of silicon dioxide, aluminium oxides, as well as compounds of calcium, magnesium and other elements. Possible options for the disposal of waste mud and sludge by using them in various industries, such as road construction, agriculture, production of structural materials, are proposed. Based on the results of the study, the article also concludes that it is possible to use the sludge in the construction industry.

Effects of sulfate on the mechanical performances and hydration characteristics of red mud based non-burnt brick

In this work, red mud based non-burnt brick (RMNB) was prepared by using red mud (RM), fly ash (FA) and desulfurized gypsum (DG). The effects of sulfate on the mechanical performances, hydration characteristics, internal structure and micrographs of RMNB were studied. The hydration characteristics were tested by using XRD and other microanalysis methods. The environmental performance was tested by ICP-MS. The results show that the RMNB has the best mechanical performances when the dosage of DG is 6 wt%. The hydration products of the matrix consist of AFt and small number of C-S-H gel, and the amount of AFt in the matrix gradually increases with the increase of sulfate dosage. The mechanical performances of the matrix are mainly associated with the amount and morphology of AFt. The AFt can effectively fill the internal structure of the matrix and improve the mechanical performances when the sulfate dosage is optimum. However, the excessive SO42− continues to react with [Al(OH)6]3− and Ca2+, which makes the AFt will continue to grow. The coarser and wider AFt enlarges the internal pore size, and declines the mechanical performances when the sulfate dosage is excessive. The leaching results indicate that the leaching concentrations of Na+ and heavy metals meet the Chinese national standard. This research provides a significant way for the utilization of RM and other solid wastes.

Flow analysis in right-angled pipes with different geometric shapes and parameters for sludge discharge in slime shield machines measured using a CFD-DEM method

Mud and gravel deposition often occurs in circulation systems of pumps. In this paper, a liquid-solid coupling method combining CFD and DEM is proposed to study two-phase flow behavior of water, The flow characteristics of water-clay mud and the motion characteristics of gravel were simulated under different discharge pipe bending radii and geometry shape conditions. Numerical results showed that for a circular cross section pipe with a fixed bending radius, the collision times between the gravel particles and the pipe wall decreased with the increase of the bending radius.

The origin, differential diagenesis and microporosity characteristics of carbonate mud across a late Paleogene ramp (Iraqi Kurdistan region)

Microporosity is common in many Middle Eastern carbonate reservoirs and various interpretations have been offered to explain its development, especially in Cretaceous reservoirs. In this study outcrops of late Paleogene carbonates of the north-eastern Iraq have been studied to assess the variation of porosity across a carbonate ramp and the factors that control its distribution. The depositional system of this late Paleogene succession was a homoclinal ramp dipping SW. Inner-mid ramp carbonate facies are massive to thick bedded units, mostly composed of packstone to grainstone, characterized by high diversity of benthic foraminifers, red algae, corals, gastropods and bivalves. Outer ramp carbonate facies are thin bedded wackestone to calcimudstone. In terms of matrix-dominated facies two distinct rock fabrics and pore systems have been identified: low porosity inner-mid ramp facies and higher porosity outer ramp facies. The inner-mid ramp carbonates show evidence of neomorphism and recrystallization of matrix mud which forms larger crystal size (average 3–4 μm) with smaller pore size (0.5 μm or less) and average porosity (8.7%). The outer ramp mud matrices exhibit the major component of planktic foraminifera and coccolith debris have smaller crystal size (average 1 μm) with larger pore size (1–2 μm), the average porosity (13.1%). For the inner-mid ramp matrices carbon and oxygen (C & O) stable isotopic values are negative indicating likely meteoric diagenesis. The relatively low strontium (Sr) and magnesium (Mg) values and high manganese (Mn) implies likely recrystallization and replacement of the marine precursor, probably high Mg-calcite and aragonite. In the outer ramp facies, the presence of coccolith and planktic foraminiferal debris indicates less diagenetic modification; the C & O stable isotopic values show less altered range with very low Mn and relatively high Sr and Mg also supporting less alteration. The textural and geochemical evidence supports an origin from a more stable, likely low Mg-calcite precursor.

A semi-industrial experiment of suspension magnetization roasting technology for separation of iron minerals from red mud

Red mud is a type of solid waste derived from the alumina extraction process. It can be considered as a secondary resource for recovering iron values because of its high content of ferric oxide. In this study, an innovative technology called suspension magnetization roasting (SMR) was applied to treat red mud to recycle iron. Based on the lab-scale experimental basis, we adopted the single factor method to perform the semi-industrial scale experiments. Under the optimum conditions, the recovery and grade of iron in the iron concentrate were 95.22 % and 55.54 %, respectively. Chemical phase analysis, vibrating sample magnetometer, and XRD combined with Mössbauer spectroscopy were employed to assess the characteristics of red mud and roasted products. Occupancy of Fe content in magnetite was raised to 89.91 % in SMR products from 0.75 % in the red mud; saturation magnetization was enhanced from 0.40 A·m2/kg to 32.44 A·m2/kg; and the hematite and goethite phase were transformed into Fe3O4 (A), Fe3O4 (B) and γ-Fe2O3 phase. In addition, transmission electron microscopy analysis revealed that both magnetite and maghemite were found in the roasted product. This study demonstrates that SMR is a promising technology for the recovery of iron from red mud.

Remediation of contaminated soil by red mud and paper ash

Remediation of contaminated soil can be performed by using various techniques, which must be adequately tailored for each specific case. The aim of this research is to critically evaluate the potential use of red mud and paper ash and a combination of the two as immobilization additives for the remediation of contaminated soil from one of the most polluted sites in Slovenia. The proposed procedure involves the preparation of geotechnical composites made from contaminated soil and mixed with 25 wt% of immobilization additives and an optimal quantity of water to achieve consistency, at which maximum compaction according to the Proctor Compaction Test procedure can be achieved. The results reveal a positive, time-dependent trend for the immobilization of potentially toxic elements in the composite with paper ash, because of the formation of the new hydration products with potentially toxic elements. In a composite containing only red mud, potentially toxic elements were immobilized by sorption mechanisms with no general time-dependent trends. The composite with a combination of additives demonstrates the remediation characteristics of both red mud and paper ash. Using this approach excavated contaminated soil, red mud and paper ash can be successfully recycled in the proposed composites, which can be beneficially used in situ for rehabilitation of contaminated sites. Nevertheless, mobilization of some potentially toxic elements at high pHs may represent a limiting factor and has to be taken into the consideration when a combination of red mud and paper ash is used as immobilization additive.

Sedimentary characteristics of coral mud in the South China Sea during the reclamation process

Coral mud is a form of calcareous ooze composed of fine-grained coral debris distributed as interlayers due to particle sorting during the formation of reclamation reefs in the South China Sea. To analyze the effect of coral mud on the stability of reef foundations formed by dredger fill, in this paper, the effects of initial concentrations, initial settlement heights, and salinity levels on the sedimentary characteristics of coral mud are discussed based on laboratory simulation tests. Comparative tests of marine sedimentary soil with similar particle compositions and of terrestrial silty clay with similar plastic indexes were carried out, and the sedimentation velocity characteristics of coral mud were identified at the microscopic level. The experimental results show that reducing initial concentrations and initial settlement heights are conducive to the coral mud filling process and that a medium salt content has no significant effect. The sedimentation rate of coral mud is roughly 3–7 times that of common soil, and the time spent in the isokinetic sedimentation stage is only 1/3 that of common soil. Microscopic studies show that the settling velocity of clay in water is proportional to the sphericity of flocs. According to our experimental results, the relationship between the sedimentation velocity and initial concentrations of coral mud is obtained and can be used to guide the design of similar calcareous soil projects across the globe and of dredger filling projects in particular.

Spatial configuration of sand and mud in the lacustrine nearshore sand bar deposits and its geological implications

Different configurational orders of sand bodies and interlayers in lacustrine nearshore sand bar reservoirs frequently interact, causing complicated genesis and distribution of argillaceous sediments, as well as other issues. This paper investigates the spatial configuration of sand and mud in the sand bar reservoir, and analyzes its internal structure. Modern sand bar deposits in the Xiashan Lake, Shandong Province, China, were analyzed and compared with the sand bar reservoirs of the Member 2 of the Paleogene Shahejie Formation in the Banqiao Sag, China. The configurational mode of sand bar deposits was explored from the perspective of the spatial distribution and composition relationships between sand and mud. Based on the alternate deposition characteristics of sand and mud in the longitudinal direction, lacustrine nearshore sand bars can be divided into three sedimentary combination patterns: thin-sand and thin-mud interbed pattern, thick-mud thick-sand pattern, and thin-mud thick-sand pattern. Their mud components manifest as the deposition of fine-grained lithofacies of multiple genetic types. These include (semi-)deep lacustrine mud, sand and mud interbedded beach, argillaceous sediments in the water retention area behind the bar, and fall-silt seams that resulted from flood discharge. By summarizing the specific developmental locations and sequential relationships of each fine-grained argillaceous facies in modern sand bar deposits, a depositional process-based argillaceous sediment composition model is proposed. Based on this, this paper discusses the spatial configuration of sand bodies and argillaceous sediments in sand bar reservoirs, and introduces the typical stratigraphic structures of sand bars in two environments, i.e., vertical superposition and lateral migration. In lacustrine nearshore sand bar reservoirs, the deposition and preservation degrees of mud mainly depend on three factors: accommodation space change, frequency of base-level cycles, and exposure-erosion time. These in turn influence the continuity and relative contents of sand and mud in reservoirs. The distribution of argillaceous sediments forms different orders of interlayers, which affects the heterogeneity and fluid percolation of sand bar reservoirs. Clarifying the space-matching relationship of sand and mud in sand bar deposits provides geological models and information parameters for the refined characterization and modeling of the internal configuration of sand bar reservoirs. Furthermore, this work offers guidance for the optimal adjustment of reservoir development strategies or the optimization of reservoir development plans.

Modification of rheological and filtration characteristics of water-based mud for drilling oil and gas wells using green SiO2@ZnO@Xanthan nanocomposite.

In this study, a green, simple and economical approach was used to synthesise the SiO2@ZnO@Xanthan nanocomposite (NC) to modify the rheological and filtration characteristics of the water-based drilling mud. The green synthesised NCs were identified using scanning electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction and UV-Vis analytical techniques. Additionally, the effect of SiO2@ZnO@Xanthan NCs on the filtration and rheological properties of mud including apparent viscosity, plastic viscosity, yield point, gel strength, mud cake and fluid loss was investigated. The obtained results confirmed that the synthesised NCs effectively improved the rheological properties of drilling mud, and considerably decreased its fluid loss and filter cake by about 54 and 92.5%, respectively. The results highly recommend the SiO2@ZnO@Xanthan NC as an excellent additive to improve the rheological properties, and reduce the fluid loss and the filter cake of the drilling mud.

Theory of sound propagation through a fluidic medium with suspended clay and silt particles having the general characteristics of mud

Work presented at previous meetings and in various publications for propagation of sound through mud continues with a theory that simultaneously takes into account viscous flow past both suspended clay and silt particles. Why silt particles do not settle under the action of gravity to the bottom of the layer is explained because (1) the clay particles adhere together in a flocculated card-house configuration and (2) the silt particles are trapped in the clay matrix. The conjecture is defended that the clay matrix and the silt particles move in lock-step under the influence of an incident sound wave. Neighboring particles of different sizes move with the same velocity amplitude, although they are subjected to different viscous forces. The theories of Stokes, Happel, and Brenner are used to calculate viscous forces at low frequencies for particles of different shapes, with the clay particles idealized as thin platelets and the silt particles idealized as spheroids with different eccentricities and random orientations. The forces on the clay particles continue to be given by the low frequency approximation for all frequencies of interest, and the deviations from Stokes's low frequency law are taken to be what corresponds to a sphere with the equivalent radius. The size distributions of the particles are taken from existing data. Modified fluid dynamic equations are derived using basic principles. The attenuation is shown to vary as frequency squared at low frequencies and as the square root of frequency for higher frequencies.

Investigations on dry sliding frictional and wear characteristics of SiC and red mud reinforced Al2024 matrix hybrid composites using Taguchi's approach

In this study, frictional and wear behavior of Al2024/SiC/red mud hybrid composites processed by stir casting route has been investigated under dry sliding conditions. Further, influence of parameters, namely red mud fraction (5–20 wt%) and particle size (37–125 µm), applied load (10–40 N), sliding distance (3000–6000 m), sliding velocity (0.5–2.0 m/s), and their interaction terms on multiresponse characteristics has been examined by employing Taguchi's approach. The wear behavior of hybrid Al composites has been investigated using pin-on-disc apparatus at room temperature and optimization of parameters has been carried by statistical analysis. The adequacy of the developed model has been checked by conducting confirmation experiment and studying the worn surface morphology. The analysis of variance indicates that sliding distance has highest influence (with a contribution of 19.74%) on the wear loss characteristics, while applied load has a maximum contribution of 38.86% in the friction coefficient of the hybrid composites. It has also been revealed that the wear resistance of the hybrid composites is improved with an increase in red mud fraction and decrease in the magnitude of applied load and sliding distance. The morphology of worn surfaces shows that ploughing and abrasion of the wear surface is considerably increased with an increase in the magnitude of wear parameters. But, an increase in red mud fraction reduces the plastic deformation (delamination) of the wear surface since it favors formation of a protective layer between the sliding surfaces. The results of the confirmation experiment indicate that wear loss and friction coefficient of the developed composites have been reduced by 400 and 51%, respectively, in comparison to unreinforced alloy under optimized conditions. The errors in the measurements of the wear loss and friction coefficient have been found to be 4.26 and 2.63%, respectively.

Mechanism of dyeing technique of Xiang-yun-sha and bioaugmentation of its coating mud with iron reducing bacteria

The dyeing technique of Xiang-yun-sha , with a history of more than 600 years, is a kind of unique hand-made dyeing process that combines both plant dyeing (immersed with Juliang extract) and mineral dyeing (mud coating). It has been included in the national intangible cultural heritage. However, the scientific mechanism of this heritage has not been systematically explained. In this study, the composition and structure of Juliang were analyzed with ionizing-spray high-resolution mass spectrometry and infrared spectroscopy, and the interaction mechanism of the Juliang with silk protein was explored. The mud-coating process was explained from the molecular level through a chemical simulation method, and the maintenance effect of microbes on characteristics of river mud was examined. Results showed that there are phenol and quinone of catechin condensed tannin in the Juliang extract, and they were combined with silk protein peptide bonds through multi-sites hydrogen bonds. The gial pigments on the silk surface after exposure further reacted with Fe(II) in the mud to form soluble condensed tannin complex, and then this complex was rapidly oxidized to form black precipitate containing Fe(III). Eventually, lustrous dark brown was formed on sun side, brown on the other side. Further, it was found that microbial iron reduction played a key role on maintaining the mud properties, because the addition of Shewanella decolorationis S12 with iron reducing function can significantly improve the dyeing performance of unqualified mud. This study provides reliable scientific support to protect inheritance of dyeing technique and promote the standardized production of the industry.