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Due to the gradual increase of intensive livestock farming in the Netherlands, the amount of nutrients in animal manure exceeds the demand for nutrients on arable land at the national level. In order to account for total amounts of nutrient inputs and outputs on farm level by manure, sampling and laboratory analysis is nowadays a major instrument within the Dutch Fertilizer Law. The major disadvantage of the system the delay between sampling during transport and the moment the laboratory results about the manure composition become available. In recent decades miniaturized techniques, such as Near-Infrared Spectroscopy (NIRS) have become available to perform in situ fertiliser analysis, allowing direct availability of the measurement. The use of these techniques instead of the current system of sampling and analysis could solve the issue related to the time gap between sampling and the availability of the results and enables more precise application of slurry based on actual nutrient content. Over the past decade research has been performed to evaluate NIRS as a potential technique. In close collaboration with all parties involved, the Ministry of Agriculture designed a strategy for the gradual introduction of on board NIRS measurements at slurry transport vehicles for the determination of the total nitrogen and phosphorus content. This plan foresees an improvement of accuracy of NIRS systems over time to eventually meet the performance requirements of the fertilizer legislation. The aim of the NIMACO research project was to gather more information from scientific based research on the performance of NIRS systems for the estimating nutrient content in animal slurry. More specifically for the application of NIRS on board of transport vehicles, estimating the nitrogen (N) and phosphorus (expressed as P2O5) content. For this purpose, two protocols were established for the performance assessment of the NIRS systems. One to perform a Proof of Principle (POP), to evaluate the performance of the NIRS systems under laboratory conditions and one to perform a Proof of Application (POA), to evaluate the performance of the NIRS systems under field conditions. Furthermore, preparations were made to perform a comparison study where NIRS will be applied to monitor slurry data related to commercial transports that are carried out in the conventional way. The research on the latter topic will be addressed in a separate project directly following the NIMACO project. The performance of NIRS systems from three different manufactures have been evaluated according the POP. To date, the results of these tests do not show that the equipment has the accuracy deemed necessary to start a pilot where NIRS is used for the legal determination of the nitrogen and phosphorus content of slurry. Nonetheless, the observed accuracy of the equipment did increase over time by adjustments made by the suppliers to improve the systems.

The early stages of the development of a finite element method (FEM) based computational tool for numerically simulating mineral-slurry transport involving both Newtonian and non-Newtonian flows are described in this work. The rationale behind the conception, design and implementation of the referred object-oriented programming tool is thus initially highlighted. A particular emphasis is put on several architectural aspects accounted for and object class hierarchies defined during the development of the tool. Next one of the main modules composing the tool under development is further described. Finally, as a means of illustration, the use of the FEM based tool for simulating two-dimensional laminar flows is discussed. More specifically, canonical configurations widely studied in the past are firstly accounted for. A more practical application involving the simulation of a mineral-slurry handling device is then studied using the power-law rheological model. The results from the simulations carried out highlight the usefulness of the tool for realistically predicting the associated flow behavior. The FEM based tool discussed in this work will be used in future for carrying out high-fidelity numerical simulations of turbulent multiphase flows including fluid-particle interactions.

Particulate erosion is a major concern in slurry handling unit of a thermal power plant. The pipe bends are the most erosion affected element of a pipeline unit thus, a cost-effective method to reduce pipeline erosion is highly desirable. This work aims to suggest the optimal pipe bend design to minimize the particulate erosion by analyzing the erosion wear in geometrically different pipe bends for bottom ash slurry flow by using Computational Fluid Dynamics code FLUENT. A Three-dimensional simulation study of erosion wear is carried out by implementing Euler-Lagrange modeling along with the standard k-e turbulence model to solve the complex multi-phase flow. Pipe bends of different bending angle (30°, 45°, 60°, and 90°), diameter (50 to 250 mm) and bending ratio (r/D = 1 to 2.5) are evaluated at different flow condition. The wear location gets shifted to the upper section of the bend and its magnitude is significantly reduced with the increase in pipe diameter and bending angle. The dynamics of multiphase slurry through different bends is analyzed to understand the complex wear phenomenon. The simulation result shows good agreement with the published findings. Finally, a least erosion affected pipe bend profile is suggested for slurry transport unit.

Water and energy are essential requirements for mineral processing plants, and they can be either scarce or expensive. In the present paper, the implications of a remote water source location (typically the seashore) are analyzed in terms of a definition for the combined water and energy operational cost required to transport ore concentrate using long distance pipelines. A typical process route is defined to expose the relevance of key process variables, including source remoteness and water reclamation both from tailing storage facilities and thickeners. Both mass and energy balances have been made to give an estimation of specific energy consumptions for a typical large scale Chilean mineral processing operations, considering a number of realistic hydraulic design criteria to make a comparative analysis of different plant processing capacities. In the present cost function definition, an account has been made on whether the water is either makeup or has been recirculated on the plant, and a distinction has been made on whether tailings are conventional or thickened, which allowed to analyze the relevance of in-plant water recovery compared to water recovery from the tailing disposal site. This has allowed to express the cost of water in terms of the various energy cost terms, thus showing in this case that the cost of water is ultimately the cost of energy, and therefore all cost components become proportional to the unit cost of energy. A piecewise constant pipeline diameter analysis scheme has been defined to allow studying the implications of water recovery on widely different plant sizes. Results show that for fixed water recovery rates, increasing plant throughput tends to cause a decrease on the specific energy for water transport. On the other hand, for fixed pipeline diameters, increasing the throughput causes an increase on the specific energy consumption, but such increase rate becomes milder at higher throughput rates. This suggests the advantage of the existence of common makeup water supply systems for mining districts with more than one mineral processing plant. On the other hand, for constant pipeline diameters, increasing the water recovery from the tailing disposal site or from thickeners generates a decrease of water specific energy consumption, where in the case of the water recovery from the tailing disposal site such decrease rate becomes stronger with the amount of water recovered. Results also shows that, except for very high solid concentrations, water makeup costs dominate over recirculation ones, supporting that producing thickened tailings is a more efficient option than conventional ones in the sense of specific energy consumption, in spite of the additional energy costs due to slurry transport that this option implies.

In deep ocean transportation pipeline, the swirling internal flow has a significant impact on the marine minerals transportation efficiency and safety. Therefore, the present work investigates various swirl flow motions for the slurry transport characteristics of the multi-sized particulate flow in a horizontal pipeline. Since the internal flow is a liquid-solid-solid mixture, a steady-state three-dimensional Eulerian-Eulerian multiphase approach in conjunction with the k-ω SST turbulence model is implemented for numerical simulation in the commercial CFD software ANSYS FLUENT 17.0. Numerical predictions of the mixture solid concentration distributions are generally in good conformance with experimental measurements. It is clearly revealed the transition of flow regime from heterogeneous to pseudo-homogeneous with the increasing level of swirl intensity at inlet. Compared to non-swirling flow, the swirling flow is of benefit to the multi-sized solid suspension capacity and the transportation efficiency. Moreover, the intense swirling vortex results in a strong influence on the characteristics of the lubrication layer formed by fine solid particles near the bottom of the pipe. These results provide valuable insights regarding the influence of swirl flow on the transport process for deep ocean mining.

Prediction of horizontal pressure drop in dilute phase pneumatic conveying or slurry transport is among the fundamental issues of designing these systems. In this work a thorough literature survey demonstrates that there is no consensus on an integrative solution for conveying pressure drop, therefore a large data base of conveying systems' operating points at dilute phase is established and analyzed. It includes measurements taken at our 52 mm bore laboratory pneumatic conveying line, as well as thousands of data points collected from the literature. Two modelling approaches are attempted – the first is frictional representation based on dimensional analysis, which presents linear dependency between the pressure drop and the superficial fluid velocity normalized by the minimum pressure velocity of the transport curve. It had also been found that the pressure drop increase rate has a strong dependency on the Archimedes number. The second approach is an energy balance between the power of the drag force applied to the particles and the additional power required to drive the fluid due to particle presence. Unlike the common expressions, a modification to the drag coefficient is suggested, which takes into account pipe turbulence and particle acceleration. The two presented models do not require pilot plant calibration, and an applicability of one of them to slurry transport is demonstrated. Some future research routes are offered.

Solid particle erosion is of great importance to many industries including oil and gas production, drilling, process and transportation of minerals including oil sands. The particles that may cause erosion are of various sizes, shapes and hardnesses. These particles may impact the surface at various speeds and angles, and the influence of these parameters is characterized to some extent in the literature. Experimental and numerical studies have shown that when particles are transported by liquid (e.g. slurry transport in the pipe) or dense gas, the particle impact angles are very low. The impact angles in these cases are sometimes less than the smallest value that can be obtained in a direct impingement erosion test in gas. In this work, the mechanistic erosion equation developed previously is extended to near zero impact angles for sharp particles. The abrasion erosion equation is developed by introducing an initial penetration of the sharp particle in the equation of the motion. This initial penetration may be attributed to the sharp particle rotation and/or turbulent flow fluctuations of the carrier fluid near the wall. The empirical constants are obtained from submerged erosion experiments in liquid. The equation has been implemented in a commercially available Computational Fluid Dynamics (CFD) code (ANSYS FLUENT) to calculate erosion for a submerged impingement jet geometry, and the result is compared with the experiment. It is shown that by neglecting the abrasive term in the erosion equation, the specimen mass loss does not match the experimental measured mass loss. While by including the abrasive term, the total mass loss of the specimen agrees well with the experimental data. Moreover, the erosion pattern becomes closer to the experimentally measured pattern especially farther from the center of the highly eroded area where abrasive wear is expected to dominate.

The marine area is the main direction of the development of oil and gas resources in the world. The pipeline transportation technology of natural gas hydrate slurry plays an important role in the exploitation of marine oil and gas and the exploitation of marine gas hydrate resources. In order to study the influence of pipe inclination on pipeline transportation, population balance model based on hydrate particle aggregation dynamics was coupled with the Eulerian–Eulerian two-fluid multiphase flow model to simulate the flow behaviors of hydrate slurry flow in pipes with different inclination angles. In the study, three variables of inclination, flow rate and initial particle size were considered. The results show that tilted pipes are beneficial to hydrate slurry transport rather than harmful. Meanwhile, higher flow rates and lower initial particle sizes are beneficial for promoting the flow safety of hydrate slurry transport. However, the flow pressure drop of the hydrate slurry increases with the increase of the flow rate and the decrease of the initial particle size, which is not conducive to the economics of mining. The research results in this paper can provide reference for the research of hydrate slurry flow safety and parameter guidance for hydrate solid fluidized mining.

Slurry transport is a very important means of transporting solids through a pipeline. To improve the efficiency of slurry transport, especially in coarse particle transport, which is subject to problems such as strong resistance and easy blockage, more of the internal structure of the flow must be known. Empirical and analytical models are inadequate for this purpose. Therefore, in this study, a coupling mechanism is established between the computational fluid dynamics (CFD) and discrete element method (DEM). The CFD-DEM coupling was applied and research was conducted on the internal flow structure characteristics of microscopic motion and flow transition for coarse particles in a pipeline. The flow-regime transition processes of coarse 10-mm particles were analyzed qualitatively at velocities of 2 m·s −1 , 5 m·s −1 , 8 m·s −1 and 10 m·s −1 in a 0.1524-m diameter pipe, and quantitative analyses were performed on both the concentration distribution and the pressure gradient of particles in regimes of fixed bed flow, sliding bed flow and heterogeneous flow. Moreover, from the perspective of force analysis of particles, the law of sedimentation movement of particles is discussed, and the reason for the change in concentration distribution is explained. The research presented here provides insight into the internal structure of the flow and gives quantitative indications of pressure gradient and concentration distributions.

Summary Sand and solids are removed from production separators either off line (shut down for physical removal) or on line by use of jetting systems. Traditional jetting designs use spray nozzles to fluidize and push the sand toward a covered outlet to evacuate the solids from the vessel. Cyclonic-jetting technology combines the fluidization and evacuation functions into a single, compact device. On the basis of a hydrocyclonic platform, this technology converts jetting spray water into shielded vortex flow that fluidizes sand in a circular zone without disturbing the oil/water interface. Total solids removal is primarily a function of set height, spray flow, and spacing. A single unit was optimized at a set height of 10 cm (4 in.) with spray pressure of 0.7 barg (11 psig) to provide an area of influence of 1.1 m2 (12.0 ft2) with 28 cm (11 in.) of sandbed depth. Placing two units in parallel with overlap of their affected zones reduces the ’egg-carton’ effect associated with this technology; however, optimum operation, in terms of total sand removed, occurs when the units do not overlap. Slurry at up to 60 wt% solids is transported from the jetting system to the handling equipment. The boundary design conditions for slurry transport are erosion velocity (upper limit) and particle-transport velocity (lower limit). By use of published models, the piping design for four-unit cluster of cyclonic-jetting devices was validated at 5.0-cm (2-in.) nominal size. Integration and operation of a jetting system with transport, dewatering, and disposal stages of facilities sand management are presented as guidelines for system design.

The Jorf Lasfar phosphate slurry pipeline in Morocco, commissioned in April 2014, is one of the world's largest slurry pipelines. The pipeline receives phosphate ore from the El Halassa, MEA and Daoui wash plants situated up to 22 km away. The product from these plants varies in grade and quality and is stored in separate agitated slurry tanks at the Khouribga head station. From the head station the slurry is pumped 187 km in batches separated by water to the terminal station at Jorf Lasfar. As these batches of phosphate slurry arrive at the terminal station they are diverted to dedicated storage tanks that feed separate process streams in the refinery. This means that the pipeline design needs to accommodate the slurry transport requirements of the different batches and to be able identify where these batches are during transport so as to ensure they are allocated to the appropriate tanks. As the batches are intermittent and have variable flow properties the design needs to accommodate a wide range of operating conditions. This is achieved by controlling the pipeline operation by varying the pumping head and through a series of pressure monitoring stations and a choke station at the terminal. Due to the scale of the project the system comprises some of the largest slurry handling equipment yet produced and this presented many unique challenges for the engineering team that required an innovative approach to solving such unique problems. This paper presents a few of the design and engineering challenges faced by the engineering team responsible for successfully delivering this project.

Hydrate slurry transport technology in deep-water pipelines has become a focal point among worldwide researches, due to its high economic efficiency. However, as the key part of the hydrate slurry transport technology research, the mechanism and laws of natural gas hydrate growth dynamics are still unclear in the flow emulsion system. On this basis, we have conducted a series of growth kinetic experiments in a high-pressure loop, investigated systematically several influencing factors (i.e. the flow rate, water-cut, AA concentration and so on) of growth kinetics, obtained the quantitative relations between these factors and the gas consumption as well as the hydrate growth rate (gas consumption rate). It could be gained from analysis of these influencing factors, that the hydrate growth rate has an extreme value (maximum) during the formation process in a slurry system. The controlling factor of hydrate formation differed at the stages before and after this maximum value. The intrinsic kinetics controlled before the value while heat/mass transfer influenced after it. The time needed for the hydrate growth rate to reach the maximum point was generally within 0.5 h after the hydrate mass formation.

Although sophisticated 2 and 3 layer models exist for slurry flow (here the flow of sand/gravel water mixtures), the main Dutch and Belgium dredging companies still use modified Durand and Condolios (1952) and Fuhrboter (1961) models, while the main companies in the USA use a modified Wilson et al. (1992) model for heterogeneous transport. These older models use one term for the excess pressure losses, the pressure losses resulting from the solids, with an empirical character. A new model has been developed based on energy considerations. The model consists of two terms for the excess pressure losses, one for the potential energy losses and one for the kinetic energy losses. This gives more flexibility matching experimental results. Although the model is derived fundamentally, the slip velocity of the particles is still an unknown in the model. An equation for this slip velocity is derived, based on physical parameters. The resulting model is validated with numerous experimental data from the literature and from the Delft Dredging Laboratory and matches very well. The advantage of this model is, that it requires the parameters known to the dredging industry and is thus easy to use.

Modern long distance ore pipeline systems are subject to strong costs, both from the economic and environmental standpoints. The task of assessing the relative importance of energy and water consumption without a detailed engineering analysis is often not obvious. In the present paper, the relative importance of water and energy unit costs is assessed by a novel dimensionless formulation accounting for the essential hydraulic and cost elements that conform the slurry transport. It is found that, for conditions resembling those of copper and iron concentrate pipelines, the ratio between energy and water costs has a wide range, depending on the particular transport conditions and unit cost scenarios. Although operating at similar volume fractions, results indicate that energy/water cost relations may differ between copper and iron concentrate pipelines and local conditions, thus suggesting the need to explicitly include energy and water cost in the design strategy.

Subsea minerals exist in the deep water within Japanese exclusive economic zone. Development of slurry pump passing large particles is required for lifting ore. In design of slurry pump, it is significant to estimate the pressure loss in a riser pipe for large particle slurry transport. Therefore the authors have been studied the slurry flow model for large particle slurry transport. In addition, the authors developed the model for the static pipe including the inclined configurations. Since the lifting pipe will be oscillated due to the connected ship motion and VIV (Vortex Induced Vibration), the authors conducted the scaled model experiment to investigate the effects of pipe oscillation on the pressure loss. The model scale was 1/8. Alumina beads and glass beads were used as solid particles in the experiment. The pipe was vertical, and oscillated in horizontal or vertical direction. The experimental results showed that the horizontal and vertical oscillation had little influence on the static pressure loss in most of the experimental conditions. However the influence was observed for the horizontally oscillating pipe in the low slurry velocity and short oscillation period condition. On the other hand, the significant fluctuation components of pressure loss and flow rate were observed in vertically oscillating pipe. The results also indicated that the density of slurry and amplitude of oscillation had influence on the fluctuation components of pressure loss and flow rate but the particle diameters had little influence on them.

The results of a long term abrasion test on 10" hoses were compared to flow simulation based abrasion calculations. An impact angle dependent small scale abrasion test was carried out on the rubber liner material to establish input data for abrasion simulation. The simulation proved to be very sensitive to the dependence of the impact angle on the abrasion rate, particularly at low impact angles. Three different lining materials were applied in the full scale test: rubber, a proprietary plastic liner and rubber with built in hard steel rings using a purpose built machine. The abrasion rate increased in the following order: armored liner, rubber and plastic, although the plastic had better Schopper abrasion than rubber.

The pulp lifter is an integral component of autogenous (AG) and semi-autogenous (SAG) grinding mills as it controls the throughput, performance and efficiency of mills. The slurry transport from the AG/SAG mill through grate holes into the discharge trunnion is the main function of the pulp lifter. This process develops complex flow behaviour in the region of the grate and pulp lifter. Efficient and effective removal of pulp/slurry from the mill is the key objective of the pulp lifter design. This work aims to understand slurry flow behaviour in pulp lifter sections and its contribution to mill performance using computational fluid dynamics (CFD) modelling and Laser Doppler Anemometry (LDA) measurements applied to a laboratory scale mill. The CFD model is validated against the LDA measurements, and then used to build a cohesive computational framework for modelling industrial pulp lifters, to investigate unique problems associated with their design and performance.

The term efficiency in hydraulic transport system design and operation has several possible interpretations. Whether it may stand for energy consumption, it may also aim to the minimization of the water or the carbon footprint. All these tentative means of efficiency should meet project and operational goals, including throughput constraints. The consideration of these aspects altogether, seeking for best project and operational conditions, represents a major optimization problem which, on the other hand, depends on the evolution of input variables for slurry transport along with environmental, energy and water consumption costs. In this paper, an example of a long distance ore pipeline with plant demand-dependent inputs is studied in the light of the implementation of an optimization problem. Results have been compared with those corresponding to typical transport modes, and show that common operational conditions differ from those optimized in terms of system utilization, flow rate and slurry concentration. In particular, the optimal computed parameters include lower fractions of the total available times, lower flow rates and higher concentrations than in typical systems, thus suggesting a different design and operational rationale.

In dredging the main process to transport soil is slurry transport. The most well-known models to predict head losses are the models of Durand and Condolios which were presented in 1952, of Newitt et al. in 1955, Jufin and Lopatin in 1966, Wilson et al. in 1992 and Führböter in 1961. All models describe heterogeneous flow and some, namely those of Newitt et al. and Wilson et al., also apply to a stationary and sliding bed. The heterogeneous models are all empirical, based on the experiments carried out and contain one term for the excess hydraulic gradient losses. In 2013 Miedema and Ramsdell developed a new model based on energy considerations, containing a potential energy term and a kinetic energy term for uniform sands and gravels. An attempt is made to explain the Führböter model more physically based on the model of Miedema and Ramsdell. The use of the so-called Skt factor is rejected based on the arguments presented. A set of equations and curves are derived for the so-called Sk factor of Führböter with mean, lower limit and upper limit curves, enabling the user to adapt the Sk curve depending on the pipe diameter and the liquid viscosity. The new Sk equations are based on physics and match the experiments of Führböter very well.

Continuous operation allows process conditions that are not attainable within batch crystallizers to be utilized. This in turn allows for product crystal attributes that are not possible in the equivalent batch crystallizations to be produced. In this study, the product crystal size distributions attainable from the anti-solvent crystallization of benzoic acid in plug flow, MSMPR and the equivalent fed batch and batch reverse addition crystallizations, were characterized. It was found that the continuous plug flow and MSMPR crystallizers were able to access crystal size distributions that are both smaller and larger than could be produced via the equivalent batch crystallizations, in addition to providing huge increases in productivity. In-situ process analytical techniques (FBRM, ATR-FTIR) were employed to characterize each of these processes, including a calibration-free ATR-FTIR technique. Furthermore, a novel intermittent pneumatic MSMPR withdrawal method, which negated clogging/fouling of transfer lines, is demonstrated. It is hoped that the use of such techniques may facilitate the uptake of continuous processes in pharmaceutical crystallization where limitations on development time and concerns about slurry transport are perceived to be barriers to the implementation of this technology.

High-cencentration slurry transport can reduce the water content in bottom sludges and relieve the dehydration pressure in slurry storage areas, therefore accelerating the follow-up dealings with sludges and improving resource utilization. To meet such demand for high-concentration slurry transport, this article makes designs for a set of pipeline transportation testing apparatuses, and offers possible follow-up research with testing evidences such as measurements of pipeline pressure and concentration distribution, as well as monitored slurry flow regimes inside the pipes.

One of the important trends of development of hydromechanization in hydraulic engineering is the transport of solids in the form of slurries. Slurry is a thick suspension of solids in a liquid. Clogging of the pipeline carrying slurry will not occur if the velocity of the slurry is more than some critical value. Critical flow velocity, which is the minimum velocity to maintain all solid particles in a suspension condition, is the important design parameter in slurry transport through pipelines. Gene-expression programming (GEP) and adaptive neuro-fuzzy inference system (ANFIS) models are developed in this study for the estimation of critical velocity. The estimated critical velocity by GEP and ANFIS models are compared with existing empirical equations and it is found that the ANFIS model produces better results compared with GEP and other existing equations.

Solid–fluid multiphase flows are often encountered in chemical engineering operations, such as bead milling, slurry transport, and mixing. Numerical simulation is a promising approach for the design and investigation of operational conditions. In previous studies, an Eulerian–Lagrangian coupling method was developed for solid–liquid flows. However, it is difficult to apply this method to moving boundary problems because of the excessive calculation costs due to adaptive mesh or sliding mesh. To solve the difficulty, a Lagrangian–Lagrangian coupling method has been developed, which couples the Discrete Element Method (DEM) for the solid phase and the Moving Particle Semi-Implicit (MPS) method for the fluid phase. It can successfully calculate solid–fluid flows and has been validated, although it has been applied only to two-dimensional systems. In the present study, we develop a three-dimensional DEM–MPS method and apply it to bead mill systems, and show the effectiveness of the method. The simulation results, namely, the solid particle distribution and velocity are compared with experimental results and we thus demonstrate the validity of the method.

It is known that the rheological behaviour of mineral slurries affects their processing. However, in addition to controlling the transportation of slurries around processing circuits, rheological behaviour also influences separation processes such as flotation. The rheological behaviour of mineral slurries is indicative of the level of inter-particle interaction or aggregation. In fact, rheological studies can be used as a direct approach to investigating such phenomena, thereby furthering our understanding of inter-particle interactions and potentially of bubble–particle interactions in mineral slurries. Although the impact of rheology in unit operations such as grinding and slurry transport has received considerable attention, this has not been the case for flotation. The pathways by which the rheology influences the flotation performance are not yet fully understood. These pathways may include various mechanisms occurring in the pulp and froth phases. However to date, little work has been done on froth rheology. Measuring the rheological properties of mineral slurries is also difficult since particles tend to settle during measurement. Finding a proper practical way for taking such measurements remains a challenge for research. In this paper the importance of rheology in mineral flotation is reviewed, and the gap of knowledge in this area is highlighted for further research.

Solid–liquid flows involving a free surface are widely encountered in chemical engineering, such as wet ball milling, slurry transport and mixing. Numerical simulation is useful both for the design and investigation of operational conditions in the industrial processes. However, numerical approaches for modeling solid–liquid flows were not yet established. This is because the modeling of the free surface and solid phase has been difficult and because the calculation cost may become huge. To solve the difficulties, we have developed a new method for numerical modeling of solid–liquid flows involving a free surface. In this study, we present the DEM–MPS method, in which solid–liquid flows are computed by combining the discrete element method (DEM) with the moving particle semi-implicit (MPS) method. Besides, new wall boundary modeling was proposed to perform the simulations of the solid–liquid flows in practical systems by the DEM–MPS method. The DEM–MPS method was validated against a solid–liquid flow in a rotating tank.

Although multi-sized particles slurries are transported in practical pipelines, most reported correlations were proposed for single-size slurries. If the average diameter of solids is used to estimate the drag coefficient of multi-sized particles slurries, the hydraulic gradients with these correlations lead to considerable scatter of data . Kazanskij , Moro , and STSJ (Slurry Transport Society of Japan) [4] summarised some empirical equations of hydraulic gradient of slurry flow with experimental data. The Wasp method [5] recommended by Liu [6] has been used by designers of pipeline systems for predicting hydraulic gradient of compound slurries of homogeneous and heterogeneous flows. However, the method is limited for application to a wide range of transport conditions. Kaushal et al. [7] also discussed the limitations and attempted to modify the method. They concluded that the Wasp method provided reasonable accurate results at limited low concentrations. The purpose of this paper is to discuss the limitations of application of other researchers' correlations and to develop innovated models, based on the single-size slurry model of Seitshiro et al. [8] The analytical models depend on particle size distribution: (1) coarse-coarse model; for a slurry consisting of two fine particles in high concentration. The fine solids are defined as particles with sizes smaller than the critical diameter [9] in this study. For both models, it is assumed that the coarse solids in the slurry do not hinder each other's movements. Experiments were performed in a 1-inch transparent pipe with sand-bakelite mixed slurries. The data of Shook et al. , Boothroyde et al. , and that of this study were used to verify the application of the models. The analytical results suggest that the innovated models can be effective for designing slurry pipelines.

A clear understanding of pipeline dredge production capacity provides dredge operators and dredging project planners with the capability to accurately and effectively determine a project’s cost and duration. Dredge pump and pipeline hydraulics coupled with slurry transport principles present a complex and challenging engineering system requiring specialized knowledge and understanding of how the system will operate. This study determines how well the theoretical principles of hydraulics and slurry transport govern the actual pipeline dredging process, compared with dredge pump and pipeline instrumentation data. Results indicate that the delivered pipeline slurry mixture incurred more friction losses during transport than water alone. This study further determines the maximum pumping capability of the dredge pump in terms of its maximum dredging depth and maximum pipeline length. These results determine that the pipeline dredge operated well within its operating limits during the case study. Overall, the c...

Slurry suspension in holding tanks and transport through pipelines are essential elements in the modern mining and mineral processing industry. This paper presents methods to improve the energy efficiency of solids suspension in tanks and slurry transport through pipelines for low viscosity Newtonian slurries. Research has been conducted using laboratory experiments and analysis using established equations. It is shown that there are many similarities between these two traditionally separated research areas. It is concluded that energy per unit solids mass generally varies with solids concentration for both systems. The specific energy can be minimised by operating at a suitable solids concentration, for example in the range of 20-30% (v/v) for the slurry properties considered in this paper. It is also concluded that the specific energy generally decreases with the size of equipment, i.e. tank diameter or pipe diameter, although this effect tends to plateau at large sizes. It was found that when a slurry pipeline is used as a reactor, it generally requires more power to suspend solids per unit solids mass than a mixing tank. Great energy saving can be achieved by operating a slurry tank with baffles removed, if off-bottom solids suspension is the limiting factor. Basic equations for specific energy consumption (SEC) are included.

Mineral and metal extractive industries play an important role in the current global economics, and mineral processing is one of the key areas to achieve and maintain sustainability. It is known that the rheological behaviour of mineral slurries affects their processing. However, in addition to controlling the transportation of slurries around processing circuits, rheological behaviour also influences separation processes such as flotation. Although the impact of rheology in unit operations such as grinding and slurry transport has received considerable attention, this has not been the case for flotation. This paper explains the relationship between rheology and froth flotation performance. The results revealed that the mineral flotation performance can be improved by controlling the rheology in flotation process.

Four distinct regimes were found existent (namely sliding bed, saltation, heterogeneous suspension and homogeneous suspension) in slurry flow in pipeline depending upon the average velocity of flow. In the literature, few numbers of correlations has been proposed for identification of these regimes in slurry pipelines. Regime identification is important for slurry pipeline design as they are the prerequisite to apply different pressure drop correlation in different regime. However, available correlations fail to predict the regime over a wide range of conditions. Based on a databank of around 800 measurements collected from the open literature, a method has been proposed to identify the regime using artificial neural network (ANN) modeling. The method incorporates hybrid artificial neural network and differential evolution technique (ANN - DE) for efficient tuning of ANN Meta parameters. Statistical analysis showed that the proposed method has an average misclassification error of 0.03%. A comparison with selected correlations in the literature showed that the developed ANN - DE method noticeably improved prediction of regime over a wide range of operating conditions, physical properties, and pipe diameters. .

Four distinct regimes (namely sliding bed, saltation, heterogeneous suspension, and homogeneous suspension) were found existent in slurry flow in a pipeline depending upon the average velocity of flow. In the literature, a few numbers of correlations have been proposed for identification of these regimes in slurry pipelines.Regime identification is important for slurry pipeline design as it is the prerequisite to apply different pressure drop correlations in different regimes. However, available correlations fail to predict the regime over a wide range of conditions. Based on a databank of around 800 measurements collected from the open literature, a method has been proposed to identify the regime using support vector machine (SVM) modeling. The method incorporates hybrid support vector machine and genetic algorithm technique (SVM-GA) for efficient tuning of SVM meta-parameters. Statistical analysis showed that the proposed method has an average misclassification error (AARE) of 0.03%. A comparison with selected correlations in the literature showed that the developed SVM-GA method noticeably improved prediction of regimes over a wide range of operating conditions, physical properties, and pipe diameters. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.

Shock wave interactions with a cloud of particles were analysed using an Eulerian–Lagrangian numerical technique. In this approach, the particle–particle and particle–wall interactions can be modelled directly. Simulations were carried out in a channel with two bends: an issue important for pneumatic and slurry transport of particles, as well as for dust explosions in industrial facilities. At the beginning, the results are shown as snapshots, showing the reader how the particle cloud propagates through the channel. At the next stage some statistics is performed in order to analyse the influence of channel geometry. The following parameters are analysed: the history of the percentage of particles that have travelled along the whole channel and the history of the average kinetic energy of the particles. It is shown how the channel structure and particle diameter influences the parameters.

For subsea mining, the estimation of pressure loss in the pipe of lifting system and the flexible pipe to connect the mining tool and the lifting system is important to design the mining system. The configuration of flexible pipe is expected to have an inclined part. In the present paper, the authors carried out the experiment to measure the pressure loss in inclined pipes using alumina beads to investigate the effect of inclination angle of pipe on the pressure loss. Furthermore, a mathematical model to estimate the pressure loss in inclined pipes was proposed and validated through the experiments. As the result of the validation, it was confirmed that the proposed model could be applied to the pressure loss estimation in inclined pipes.

DEM modelling of the motion of coarse fractions of the charge inside SAG mills has now been well established for more than a decade. In these models the effect of slurry has broadly been ignored due to its complexity. Smoothed particle hydrodynamics (SPH) provides a particle based method for modelling complex free surface fluid flows and is well suited to modelling fluid flow in mills. Previous modelling has demonstrated the powerful ability of SPH to capture dynamic fluid flow effects such as lifters crashing into slurry pools, fluid draining from lifters, flow through grates and pulp lifter discharge. However, all these examples were limited by the ability to model only the slurry in the mill without the charge. In this paper, we represent the charge as a dynamic porous media through which the SPH fluid is then able to flow. The porous media properties (specifically the spatial distribution of porosity and velocity) are predicted by time averaging the mill charge predicted using a large scale DEM model. This allows prediction of transient and steady state slurry distributions in the mill and allows its variation with operating parameters, slurry viscosity and slurry volume, to be explored.

Indian high-ash coal contains alpha-silica components of the mineral matter. When coal is transported in the form of a slurry, alpha-silica adds to the settling properties of coal and enhances erosion of pipelines. As such any technique that will contribute to changing the characteristics of mineral matter by selective demineralization is bound to supplement the knowledge of coal slurries in the science of rheology. One such method is the use of a novel microwave technology, which changes the alpha-silica to less harmful beta-silica. Thus microwave-treated coal slurry facilitates enhanced flow characteristics and abates the erosion problem in pipeline transport as well as in coal-slurry injection furnaces. This paper reports on the rheological study of closely sized coal particles of medium-volatile, low-ash, low-moisture cleans and high-ash rejects with and without microwave treatment. Viscosity of suspensions of microwave-treated coal was found to be less than that of untreated coal, in the case of both cleans and rejects. Microwave pretreatment thus reduces the viscosity and the pumping cost and opens a new outlook for pipeline transport. An attempt has been made to quantify the improvement of rheological characteristics due to microwave pretreatment.

We describe a modelling approach to slurry transport in dynamic beds. Volume and time averaging are combined to obtain a dynamic replacement for the static Ergun equation. Solutions of the resulting dynamic equation are exhibited for a simple charge-motion model, which serves as the prototype for a practical slurry transport model.

Pulp lifters, also known, as pan lifters are an integral part of the majority of autogenous (AG), semi-autogenous (SAG) and grate discharge ball mills. The performance of the pulp lifters in conjunction with grate design determines the ultimate flow capacity of these mills. Although the function of the pulp lifters is simply to transport the slurry passed through the discharge grate into the discharge trunnion, their performance depends on their design as well as that of the grate and operating conditions such as mill speed and charge level. However, little or no work has been reported on the performance of grate-pulp lifter assemblies and in particular the influence of pulp lifter design on slurry transport. Ideally, the discharge rate through a grate-pulp lifter assembly should be equal to the discharge rate through at a given mill hold-up. However, the results obtained have shown that conventional pulp lifter designs cause considerable restrictions to flow resulting in reduced flow capacity. In this second of a two-part series of papers the performance of conventional pulp lifters (radial and spiral designs) is described and is based on extensive test work carried out in a I m diameter pilot SAG mill. (C) 2003 Elsevier Science Ltd. All rights reserved.

The Julius Kruttschnitt Mineral Research Centre (JKMRC) has been involved in the study and modelling of industrial autogenous (AG) and semi-autogenous (SAG) mills for over 25 years. Recent research at the JKMRC has developed a new AG/SAG mill model which is based on charge dynamics. The model relates charge motion and composition to power draw and size reduction. Size reduction is described by considering impact and attrition/abrasion as separate processes. These are linked to energy available in the mill, the charge size distribution and the relative motion of the grinding media. Ore specific energy-breakage are described using laboratory data which are obtained from breakage tests over a wide range of energies and particle sizes. Slurry transport is described using the JKMRC’s latest model which incorporates the effect of grate design. This paper describes the overall structure of the model together with its main sub-processes.

In Deep Sea Mining, material will be excavated at the sea floor and transported to the surface. This transport always consists of horizontal and vertical transport and can be carried out mechanically or hydraulically. If the transport is hydraulically, during the horizontal transport there is a danger of bed formation and plugging the line. This is similar to the horizontal transport in dredging with the difference that in deep-sea mining the line length is much smaller, but also the line speeds may be smaller. To avoid plugging the line, the line speed has to be higher than a certain critical line speed. In literature there are many theories about this critical line speed and about bed forming in the pipe, but these theories are usually empirical and cannot be applied under all circumstances. Different particles sizes, pipe diameters and line speeds require different equations, although a generic theory should cover everything. For the critical velocity different definitions exist. Some researchers use the definition that above the critical velocity no bed, either stationary or sliding, exits. This definition is also referred to as the limit deposit velocity. Others use the transition between a stationary bed and a sliding bed as the definition of the critical velocity. Whatever definition is used, the Moody friction factor on the bed always plays an important role. Since in literature no explicit formulation for this Moody friction factor exists, an attempt is made to find an explicit formulation for the Moody friction factor for the interface of the fluid flow and the bed, where this interface consists of sheet flow.Copyright © 2014 by ASME

An in situ optical method was developed to determine the thickness of the cake layer by using a low-cost photointerrupt sensor. The effects of slurry concentration, agitating speed (i.e. slurry transport velocity), background light and color of slurry on the accuracy of measurement were examined to verify the validity of this method. The accuracy of the thickness measurements was confirmed using uniform sized PMMA spheres. Experimental results show that the developed technique is useful for cake thickness ranging from 10 μm to 5 mm and yields a vertical resolution as high as 10 μm in the same order as that of gamma-ray absorption and NMR micro-imaging methods. This method has benefits of inexpensive, easy installation and a comparable accuracy compared with gamma-ray absorption, NMR micro-imaging and CATSCAN techniques. The developed method was then applied to measure the time course of cake layer thickness variation on the membrane surface during cross-flow micro-filtration of a PMMA suspension. Results of measurements show that the dynamic surface shape is not at all flat during a course of CFMF.

In the capsule hoist system, cylindrical capsules, loaded with minerals, are inserted into the lower end of a vertical water-filled shaft. The capsules having low mass density are lifted due to natural buoyant forces. These capsules are taken out at the upper end of the shaft. The attractive feature of the system is that it only requires power for inserting the capsules. Compared with slurry transport no mechanism is required to separate the transported mineral from water, and it does not require a continuous supply of water. Although some research work has appeared in this area, the design equations have not been attempted as yet. In this paper the design of a capsule transporting hoist system has been formulated as a constrained geometric programming problem having zero degree of difficulty. The solution of the problem yielded the design variables in the form of explicit equations.

Pipeline transport of solids containerized in capsules has several attractive features. As compared to slurry transport the cargo is not wetted or contaminated by the carrier fluid; no mechanism is required to separate the transported material from the fluid other than the use of capsules; and foremost, it requires less power for maintaining the flow. Although considerable research work has appeared in the last three decades, design equations have not been attempted as yet. In this paper the design of a capsule transporting pipeline has been formulated as a geometric programming problem. The solution of the problem yielded the design variables in the form of explicit equations.

In order to provide a technical basis for preventing the blockage of heterogeneous slurry pipelines, the unsteady characteristics of slurry transport were studied. Our experiments were carried out using a test pipeline of about 130m long and 50mm in diameter. The flow rate, the solid concentration and the pressures were measured in the pipeline, in terms of responses to a stepwise charge of solid particles. It became clear how behavior of slurry changed in the pipeline if it changed with the feed rate of solid particles and how the phenomenon of the pipe blockage happened. Various information and data were obtained from these experiments, which will be useful in planning and in operating heterogeneous slurry pipelines.

The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scalingmore » up with Confidence and Ensuring Safe and Reliable Long-Term Operation.« less

Present research work describes the issues associated with slurry transportation systems in thermal power plants. It not only explores the importance of such ash handling systems but also embarks upon a step-by-step procedure to optimise slurry contents, without ignoring flow process parameters like velocity and pipe diameter to ensure least possible drop in the flow pressure, along the length of pipe. After analysing the research gaps, a strategic methodology based on the philosophies of mixture design of experiments (DoE) and computational flow dynamics (CFD) was suggested. Experiments were designed and performed in a balanced orthogonal matrix, before simulating through CFD. A deviation of mere 8% (approximately) was found in the end results, and hence an average drop in pressure from 3176 to 1252 KPa was unleashed, in the first attempt itself. The rheological properties (like pH value or settling properties) of slurry were assumed to be in required ranges and their relative impacts on critical flow metrics of slurry transportation system were not studied. The present study used an integrated approach to study the flow and further proved its authenticity by implementing it in an Indian thermal power plant successfully.

Recent developments in subsea mining as well as oil & gas exploration and development drilling will require the use of a subsea pumping solution capable of handling slurries. These slurries are characterized by relatively large particle sizes and non-uniform flow conditions including fluctuating solids concentrations, densities, viscosities, and maximum particle size in both the mining and drilling applications. While challenging enough in surface applications, slurry transport problems are exacerbated by the vertical lift required in subsea use. This paper will first present the effect of each varying parameter on the overall horsepower required. Additionally, the pumping efficiency of some different pump types when responding to these changing conditions will be shown. From a control perspective, altering a pump’s speed in response to changing flow conditions presents some unique challenges. As an alternative to adjusting a rotary pump’s speed, an algorithm to control a positive displacement pumping solution to automatically adjust its output in this application is presented.Copyright © 2010 by ASME

Experience in the area of wet mining and the dredging industry learns that the excavation system cannot be seen separate from the slurry transportation system. These two key systems in a deep sea mining operation interrelate to such extend that they must be developed towards an integral solution. The nominal production, peak production and variability of these figures must match for all sub-systems in the overall mining system to optimize for mining efficiency; we call this the ‘game of capacities’. Also the configuration of the excavation and transport system has great consequences. For instance an important question is whether to place the first pump and its drive of the slurry transport system on the seafloor mining tool or in the riser system. The choices made impact amongst others on; the mining tool’s reach (and thus efficiency), the seafloor mining tool’s propulsion system and its geo-mechanical interaction, the slurry transport flow and pumping power requirements. This paper will discuss the several dependencies of the (producing) subsystems and important choices for configuration and their consequences regarding technology, capex, opex, reliability and maintainability.Copyright © 2010 by ASME

Four distinct regimes were found existent (namely sliding bed, saltation, heterogeneous suspension and homogeneous suspension) in slurry flow in pipeline depending upon the average velocity of flow. In the literature, few numbers of correlations has been proposed for identification of these regimes in slurry pipelines. Regime identification is important for slurry pipeline design as they are the prerequisite to apply different pressure drop correlation in different regime. However, available correlations fail to predict the regime over a wide range of conditions. Based on a databank of around 800 measurements collected from the open literature, a method has been proposed to identify the regime using artificial neural network (ANN) modeling. The method incorporates hybrid artificial neural network and genetic algorithm technique (ANN-GA) for efficient tuning of ANN meta parameters. Statistical analysis showed that the proposed method has an average misclassification error of 0.03%. A comparison with selected correlations in the literature showed that the developed ANN-GA method noticeably improved prediction of regime over a wide range of operating conditions, physical properties, and pipe diameters.