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By J. A. González-Anaya

This laboratory work presents a study of the effect of ultrafine grinding on the gold recovery of a highly refractory gold concentrate. The particle size of the concentrate was P80 = 46 µm and the main species present were quartz (28.58%), dolomite (25.63%), pyrite (20.93%), arsenopyrite (15.39%) and 112 g/t gold. After optimizing hydrated lime and lead nitrate additions, standard cyanidation with 1% NaCN, pH = 12.3, 25% S/L permits to recover only 9.4% of the gold. Different particle sizes were submitted to cyanidation. When the concentrate was ground to ultrafine sizes (P80= 4.6 µm), the gold recovery for the same cyanidation conditions increased to 67%, with cyanide consumption of 66.7 kg NaCN/t. Additional tests were performed in order to reduce the cyanide consumption. The reduction of the cyanide concentration in the leaching solution from 1 to 0.5% and the addition of 100 g Pb(NO3)2/t allowed the reduction of the cyanide consumption to 27.6 kg NaCN/t (58% reduction), while maintaining the same gold recovery of 67%. The remaining gold could be present as very fine inclusions or in solid solution in the matrix.

Jan 1, 2011

By Dr. Jagdish C. Agarwal

Kennecott Copper Corporation has developed a new hydrometallurgical process for extracting nickel, copper, cobalt and molybdenum from maganese nodules. This process (KCC Cuprion Process) utilizes a reduction leach operating at atmospheric pressure in the temperature range of 45 C to 50 C and has been successfully demonstrated in a continuous pilot plant processing 800 lbs of nodule ore per day. The chemistry, basic flow sheet and operating characteristics are presented and discussed.

Jan 1, 1978

By Taghi Sherizadeh, Kutay E. Karadeniz, Dogukan Guner, Samuel Nowak

Despite numerous empirical, numerical, and hybrid studies conducted on the subject of coal rib failure, mine fatalities related to rib failures continue to occur. To date, a standard methodology for the design of coal rib supports which can accommodate the wide range of unique conditions found in coal mines in the United States has not been developed, forcing mine operators to rely on the trial-and-error process or industrial legacy practices for the design of coal rib support patterns. In this study, to better understand the support systems' effectiveness, various rib bolting scenarios were investigated. A coal mass constitutive model is implemented to a Distinct Element Method (DEM) code, and rib factor-of-safety (RibFOS) analyses were performed by applying strength-reduction for the coal matrix and explicitly modeled face cleats. Ribs with various overburden depths and mining heights composed of solid Banded-Bright coal (BBC) were considered in this study. Different scenarios such as rib bolt length and the number of bolts were studied to quantify the effect of primary rib support density on rib stability. As a result of the unsupported coal rib analyses, a decaying exponential relationship is proposed between the mining height-overburden depth and the RibFOS. The developed coal rib models clearly show the coal-rib bolt interaction and illustrate how the addition of rib bolts restricts the movement of the coal rib. The results reveal that the strength reduction method in DEM code with the coal-mass model can aid in the development of practical primary support charts, which can help in the rib support design process. In addition, an unsupported RibFOS cutoff

By M. Paul

"INTRODUCTION In 1990, the uranium production of SDAG Wismut in East Germany was stopped. 45 years of inconsiderate destructive exploitation had scarred both landscape and nature. With the “Wismut law” which came into force in December 1991, the Federal Republic took responsibility of the remediation of the legacies from former uranium ore mining and milling in Saxony and Thuringia. A unique opportunity turned out in order to remove environmental damage, to enhance the life quality of the local population, to shape new landscapes and to advance the economic restart. (1) The results of nearly 25 years of remediation activity are evidence that this opportunity was used at all former SDAG (Sowjetisch-Deutsche Aktien-gesellschaft) Wismut sites. The reference project “Wismut“ has evolved into a joint project of all parties involved and radiates beyond the affected regions. This is particularly reflected by the Know-how transfer starting from Wismut and the increasing activities for third parties abroad.WATER MANAGEMENT AT WISMUT REHABILITATION Within the Wismut project, water management and conventional technical water treatment are by far the most cost-intensive long-term tasks of the remediation programme. Over the medium term, there is no viable alternative to the operation of active systems to catch and treat contaminated mine waters at the Ronneburg, Schlema, Königstein, Pöhla, Seelingstädt and Helmsdorf sites. Based on the status quo, this paper outlines the key issues of the Wismut GmbH water management strategy over the medium and long term. It is focused primarily on achieving protection goals for potentially impacted water bodies in the surroundings of Wismut sites and on optimising associated remediation expenditures as well as on creating the prerequisites for achieving low post-remedial care and maintenance or walk-away system status over the long term. (2) The applied mining practices during the active SDAG Wismut period have not been up to the high standards of modern mining operations and their requirement to leave former production premises and deposited residues in a condition that was not only physically but also chemically stable. Rather the emission of mine and seepage waters laden with high acidity, metal and salt content is a frequent corollary and difficult legacy of historic mining and processing operations (4, 5). As a consequence, the control or mitigation, respectively, of environmental impacts associated with contaminated mine waters ties up enormous public resources worldwide (6, 7)."

Jan 1, 2016

By Brendan Demich, MAHIYAR F. NASARWANJI, Alan G. Mayton

Nonfatal injuries from slips, trips, and falls (STF) that occur at surface mines can result from inadequate lighting. Mobile equipment operators are among the occupations associated with the nonfatal incidents reported to the U.S. Mine Safety and Health Administration (MSHA). In addition, getting on/off the equipment (ingress/egress) frequently adds to the highest proportion of nonfatal incidents. Accordingly, researchers at the Pittsburgh Mining Research Division (PMRD), National Institute for Occupational Safety and Health (NIOSH) conducted a field study to investigate lighting on haul trucks and wheel loaderswith regard to glare and illuminance levels recommended by the Illuminating Engineering Society (IES). The objective was to determine whether two light-emitting diode (LED) area luminaires—a Mr. Beams® (model MB390 Ultrabright) (area luminaire-1) and a NIOSH-developed Saturn (custom-designed for a mine roof bolter study) (area luminaire-2)—could complement a headlamp luminaire. Measured levels of visual tasks, with the headlamp alone and the area luminaires plus the headlamp, demonstrated that illuminance met or exceeded IES-recommended levels. Nevertheless, the area luminaires illuminated a much broader area, which is key to increasing hazard awareness. Discomfort and disability glare were lower with area luminaire-1 than with area luminaire-2. Differences in glare were more noticeable for newer models of haul trucks and loaders featuring updated ingress/egress system designs. This study demonstrates that commercially available luminaires, such as area luminaire-1, are capable of complementing headlamp lighting, and can thus improve a miner’s ability to detect and avoid STF hazards.

Jun 17, 2020

By E. Karampinos, P. Morissette

"INTRODUCTION Ground support is a critical element in maintaining the stability of mining drives in deep and high stress mines. In challenging ground conditions, it is necessary to continuously explore ground support strategies that can control the resulting large deformations. It is an objective of mining operations to optimize the ground support by selecting both appropriate systems and the time of installation of each reinforcement element. A successful ground support strategy will result in the use of a system that ensures both the structural and operational integrity of the excavations and mitigates the need for rehabilitation. Preliminary ground support design is often based on empirical observations and methods. Once a design is implemented, field trials, observations and in situ pull tests are used to fine tune or improve the design. Although not often employed during this process, numerical modelling can provide helpful insights on the impact of different ground support strategies. In this respect, it is possible to explore the use of multiple options before selecting the most promising ground support system for implementation in field trials. The challenges associated with the numerical modelling of rock support for mines have been described by Lorig and Varona (2013) and Potvin (2017). The employed numerical models should capture all potential failure modes of reinforcement over the mining sequence of the excavation. In particular, it is important to emulate the observed in situ ground support performance, as well as the influence of the installation sequence of the support. However, the time and expertise required for this type of modelling of ground support is not often available at mine sites. Even when the expertise is available it requires a major time and commitment of resources to set up, run and calibrate the sophisticated models capable of explicitly capturing the behavior of ground support. Rock reinforcement is an integral part of all ground support systems used in underground mines. Long flexible tendons can reinforce the rock mass deeper into the walls and create a thicker reinforced shell around the underground excavation. This paper focuses on the optimization of the cable bolting strategy in squeezing conditions at the LaRonde Mine by integrating the 3D distinct element method (DEM) in the design process. A calibrated numerical model is used to investigate a series of cable bolt configurations and provide recommendations for the ground support design."

Jan 1, 2018

By Laurent Rus, Bakar Amara, Jean Habimana

The La Fontaine Tunnel in Montreal, Quebec is currently undergoing major structural rehabilitation work and systems upgrade work to comply with current codes, standards and best practices in fire life safety and to extend its lifespan of this 55-year-old immersed tube tunnel for at least another 40 years. The paper discusses design consideration of ongoing works that include structural analyses to evaluate repair strategies for the post-tensioned reinforced caissons, the scheme to repair two leaky joints between caissons, the design of passive fire protection that involved in situ and real scale laboratory tests, and other tunnel systems upgrades.

Jun 13, 2023

By B. A. Barnum

The Chino mine is an open pit copper mine located in southwestern New Mexico, at an elevation of 1890 m (6200 feet) above sea level, approximately 117 km (70 miles) north of the Mexican border. It is owned by Chino Mines Co., a Phelps Dodge Corporation-Mitsubishi Minerals partnership, and is operated by Phelps Dodge Corporation. As part of an effort to maximize production and minimize costs, a computerized truck dispatching system was approved for purchase and installation at the Chino mine in March. 1984. Modular Mining Systems, Inc. was commissioned to install their system, trade named DISPATCH. The system installation was completed and operation began in July, 1985. Installation and operation of the system has presented some interesting challenges and problems, which have been overcome, resulting in increased productivity for the haulage truck and shovel fleets.

Jan 1, 1987

By Zhenzhong Bian, Ruiyang Zhang, Xiaofeng Zhong, Zhangxuan Ning, Yuanping Zhang, Jie Lu, Airan Zhang

This study addressed the separation and recovery of vanadium(IV), iron, and titanium from synthetic and real leach solutions of vanadium-bearing titanomagnetite using extractant P204 (di-(2-ethylhexyl) phosphate) and P507 (2-ethylhexyl hydrogen- 2-ethylhexyl phosphonate). Based on the speciation analysis of vanadium in sulfuric acid medium, the single-stage extraction efficiency of vanadium, iron, and titanium was 94.21%, 3.45%, and 5.32%, respectively, under the optimal extraction condition of P204-P507 concentration of 15% (v/v), P204 to P507 ratio of 3:1 (v/v), TBP (Tributyl phosphate) concentration of 5%, sulfonated kerosene concentration of 80%, initial pH of 1.8, contact time of 8 min, and phase ratio (O/A) of 2:1. By confirming the predictions of the McCabe-Thiele diagram, a five-stage countercurrent extraction was carried out and the desirable extraction efficiency for vanadium reached 98.13%. The maximum co-extraction coefficient and distribution ratio of vanadium were 2.58 and 26.23, respectively. The stripping efficiencies and concentrations of a vanadium-rich solution by three stages of countercurrent experiments with 20 vol.% sulfuric acid reached 99.14% and 0.58 g/L, respectively, while almost all of the titanium remained in the organic phase. The mechanism of synergistic extraction between hydrogen ions of P–O–H and VO2+ in acidic conditions was confirmed by ATR-FTIR spectroscopy and molecular structure derivation. Besides, the separated impurity ions ( Fe2+) after oxidation, precipitation, and roasting process form a qualified iron oxide pigment with a total iron content of 97.2%.

Apr 25, 2023

By Jean-Michel Rendu

In most circumstances, the traditional methods of. ore reserve estimation for large undulating sedimentary deposits, such as coal and iron formations, do not allow the accurate prediction of grade for mining blocks. The problem is Particularly accute when the mining blocks are small with respect to the thickness of the geological zones in the deposit, and when there are significant grade changes between the foot-wall and hanging-wall of these zones. A simple geostatistical model has been developed, which takes into account the grade changes not only in the direction of the geological strata, but also in the direction normal to these strata. The genesis of sedimentary deposits and the resulting geological properties of these deposits were considered in the development of the model. The model has been successfully applied to the evaluation of a large coal deposit. Eventhough some practical difficulties have been encountered, for example when part of a geological zone was missing or had not been sampled, these difficulties have been .resolved. Both the theory and its practical application are presented in this paper.

Jan 1, 1979

The dissolution behavior of gold and copper from their elemental states and from Au/Cu alloys in cyanide solutions has been investigated using a rotating disc electrode. The anodic and cathodic reactions were studied separately and the resulting polarization curves were combined to examine the overall dissolution reactions. The dissolution rate of pure gold in the aerated cyanide solutions was inhibited by the anodic passivation on the gold surface, while the dissolution rate of pure copper was found to be mass-transfer-controlled. On the other hand, the dissolution of gold and copper from the alloys was partially controlled by electrochemical reaction and largely by mass transfer.

Jan 1, 1994

By R. L. Guerguerian

Hydrostatic trunnion bearings were recently provided on large Semi-Autogenous Grinding (SAG) mills driven by wraparound motors assembled on the head to shell flanges. A conventional SAG mill would have a ring gear driven through one or two pinions. The effects of the magnetic air gap forces from this new SAG mill drive arrangement on the performance of the bearing are discussed. A step-by-step systematic analytical de-sign of the hydrostatic trunnion bearing is presented, followed by a discussion of grinding mill erection requirements to conform with the design. A brief comparison with other bearing types and their response to the effects of magnetic air gap forces are also presented.

Jan 1, 1992

"Twin Creeks is a gold mining complex that is part of Newmont’s Nevada operations. The mining complex is composed of two openpits, Mega and Vista, external ore sources and a set of existing stockpiles, all of which provide ore for an autoclave, an oxide mill and a heap leach. Mega pit provides sulfide ore for the autoclave, whereas Vista pit provides oxide ore for the oxide mill and the heap leach. Both pits operate the same mining equipment and their extraction sequence must, therefore, be optimized simultaneously. Stringent blending requirements are associated with the operation of the autoclave for the sulfide ore. Strategic blending optimization on a large scale has brought significant value to the operation by increasing synergies. This paper presents the implementation of a stochastic optimization framework for the long-term production planning at Twin Creeks that simultaneously optimizes mining, stockpiling, blending and processing decision variables. The uncertainty and variability associated with the different sources of material are incorporated in the optimization model by means of stochastic simulations. The stochastic solution generated shows substantial benefits by increasing forecasted recoverable gold, leading to increased cash flows, while reducing the risk of not achieving forecasts by increasing the probabilities of meeting production and blending targets.IntroductionMine operations consist of multiple components such as mineral deposits, stockpiles, external sources, mills and autoclaves. These components represent a mineral value chain, also known in the literature as a mining complex (Montiel and Dimitrakopoulos 2015; Goodfellow and Dimitrakopoulos 2016). The material extracted from the mines flows through the different components and is transformed into sellable products. This flow of material in a mineral value chain involves complex, nonlinear transformations that render the use of industry-standard optimizers difficult. Furthermore, the optimization of a mining complex can be formulated as a mixed-integer, nonlinear optimization program with millions of integer variables representing mining, blending, stockpiling and processing decisions, prohibiting the use of conventional nonlinear optimization approaches. Previous methods that consider the joint optimization of multiple components of the mineral value chain are available (Hoerger, Seymour and Hoffman, 1999; Chanda, 2005; Stone et al., 2005; Wooller, 2005; Whittle, 2007, 2010; Bodon et al., 2010). Although these methods add value by increasing the synergy between the different components of the mining complex, they rely on simplifying assumptions that constrain their efficacy, while ignoring a most critical aspect. The latter aspect includes the geological uncertainty and actual variability of the materials in the mineral deposits mined and are supplied to the related mineral value chain, similarly to conventional life-of-mine planning methods used for individual mines (Dimitrakopoulos, Farrelly and Godoy, 2002; Godoy and Dimitrakopoulos, 2011; Spleit and Dimitrakopoulos, 2017). Additional simplifying assumptions may include: the consideration of a limited number of components, the combination of different methods, the aggregation of variables, fixed production schedules the definition of policies prior to optimization, such as cutoff- grade definition or destination of mining blocks, the linearization of nonlinear transformation functions and/or the disregard for the uncertainty of several critical parameters (Whittle, 2007). The simultaneous optimization of multiple components of a mining complex was introduced by Newmont. Hoerger, Seymour and Hoffman (1999) implemented a mixed-integer programming formulation to optimize Newmont’s Nevada operations. The model is based on the work of Urbaez and Dagdelen (1999) and simultaneously optimizes the extraction of materials from multiple deposits and the delivery of ore to multiple plants, as well as as"

Dec 1, 2018

By Tassos Grammatikopoulos, Mike Johnson, Niels Verbaan

Seabed polymetallic nodules, which contain significant quantities of metals key to electrification such as nickel (Ni), cobalt (Co), copper (Cu) and manganese (Mn) can be processed using several different metallurgical processing options, including direct smelting and subsequent hydrometallurgical refining of the copper/nickel matte; ammoniacal leaching (gas reduction or Cuprion); and acid leaching (often reductive). Many of these approaches suffer from reduced cobalt extraction, difficult physical performance, or overall circuit complexity in general, leading to increased risk to the overall project. SGS has considered the pressure acid leaching of nodules for further investigation, as publicly shared data on this processing route stem from the 1970s and 1980s, and are not always easily accessible. This article details the series of tests conducted and provides updated results obtained — high Ni/Co/Cu recovery with limited manganese/iron (Mn/Fe) — as well as comments on the potential treatment options on the product solution and residue.

Sep 1, 2025

By B. J. Scheiner

The presence of organic materials in gold ores cyanidation. The presence of organic materials interferes with gold extraction by The carbon contained in the ore has been shown to adsorb gold cyanide complex from solution. Removal of the carbon content by roasting or chemical oxidation prior to cyanidation results in gold extractions of 85 to 95 pct. This paper by the Bureau of Mines, U.S. Department of the Interior, discusses how the mineralogy of the carbonaceous gold ores affects gold recovery by cyanidation. It also discusses the advantages and disadvantages of roasting and chemical treatment to render the ore amenable to cyanidation.

Jan 1, 1987

By Carson Rife, Michael L. Clark

INTRODUCTION Zortman Mining Inc. is a wholly owned subsidiary of Pegasus Gold Corporation of Spokane, Washington. Pegasus has been producing gold and silver from the Zortman and Landusky mines since 1979. The Zortman and Landusky mines are two distinct open pit mines located approximately 6 kilometers apart in the Little Rockies Mining District of north central Montana. The two mines use large-tonnage, low- grade heap leaching techniques to efficiently process the gold and silver ore. PROJECT DESCRIPTION The Little Rockies rise abruptly 914 metres from the surrounding plains to about 1829 metres above sea level. The topography is quite steep, making efficient leach pad construction a major challenge. The climate is semi-arid with moderate summers and occasionally severe winters. Freezing temperatures usually arrive in late October or early November, influencing the effectiveness of leaching operations. GEOLOGY AND MINERALOGY The geology of the Little Rocky Mountains consists of steeply dipping sedimentary ridges forming an elliptical dome surrounding a core of intruding syenite porphyry. Within the syenite porphyry are well fractured and mineralized shear zones where the existing reserves and open pits are located. The ore is presently divided into oxidized, mixed, and sulfide. Only the oxides and mixed zones that are of ore grade are placed on the leach pads. The syenite porphyry host rock enables effective leaching of gold and silver to depths of 61 metres, having a major impact on leach pad construction costs. MINING All mining since 1979 has been by contractor. This enabled initial mining to commence without capital investment in equipment. Through competitive negotiations, Pegasus has been able to keep contract mining costs at levels very close to what would be experienced if Pegasus had purchased equipment initially. Contracts are negotiated yearly and are based on a unit price and haul distance for ore and waste. Haul distances have ranged from as little as 457 metres to as much as 3,050 metres. At present, Pegasus is developing a 27,000,000-tonne leach pad at the Landusky project that is adjacent to the minine area. This design feature will reduce the mining cost by 20 percent over the life of the mine. In 1987, over 5,900,000 tonnes of ore and 3,200,000 tonnes of waste will be mined at the Landusky project. Through 1986, 13,763,000 tonnes of ore have been mined at a waste-to-ore strip ratio of 0.60:l at the Zortman project, and 13,005,000 tonnes of ore at a waste-to-ore strip ratio of 0.79:l have been mined at the Landusky project. Current mining reserves are 32,769,000 tonnes of ore at a waste- to-ore strip ratio of 0.59:l. Through efficiencies of large-scale heap leaching, Pegasus has been able to lower the mining cutoff from 0.34 grams per tonne gold to 0.27 grams per tonne gold. This has reduced the mining cost per tonne of ore h percent through a reduction in strip ratio of 14 percent. Beginning in 1984, all pits were designed based on computer-generated "floating cone" pits. The geologic models were developed by Pegasus staff with a series of economic models evaluated. The resulting computer-generated pits were used as a guideline in designing the mine plans, including haul roads for final calculation of tons and grade. Input to the floating cone models consisted of mining cost, processing cost, cutoff grade (0.34 grams gold per tonne), recovery (67 percent) and gold price. Due to the gold being deposited primarily on the fractures of the syenite host rock, no crushing of ore is needed prior to leaching. This characteristic of the ore is a key in being able to profitably mine and process gold ore at an average grade of 0.69 grams of gold per tonne. Strict blasting control is also a key in success of the leaching operation. A system of splitting ore and waste in blast patterns has been devised to reduce dilution. Also, drill hole spacings are varied from 3m x 3m in breccia ore to 4m x 4m in syenite ore to 5m x 5m in waste. Drill holes

Jan 1, 1987

By D. R. Gehring

Effective project management is an excellent technique for meeting a goal through set, well-defined objectives. Even though project management is successfully used throughout the world in various construction projects, underground mining has unique characteristics that require approaches that vary from classical project management theory. Typically, a project includes four main stages: definition, planning, implementation and control. Definition and planning are often the most overlooked stages, but are arguably the most important. This paper addresses practical techniques for the definition and planning of projects for underground construction.

Jan 1, 1996

By M. L. Free

Several studies of the fluorite/oleate flotation system have shown that under certain conditions calcium dioleate is formed at or transported to the fluorite surface. Adsorption of significant amounts of calcium dioleate is generally observed above oleate concentrations of -6 -5 between 4 x 10 and 4 x 10 M, yet little explanation of the onset of calcium dioleate adsorption is provided. In this study in-situ and ex-situ FTIR/IRS experiments have been performed in connection with thermodynamic solution phase analysis to better understand oleate adsorption as well as the onset of calcium dioleate formation. Results from this study are analyzed and compared to industrial practice.

Jan 1, 1995

By L. A. Puchkov

Problems of how to use artificial intelligence (AI) methods and expert systems (ES) to control complex industrial projects have lately become significant in practical terms. Mining ventilation systems undoubtedly belong to complex multi dimensional objects of control with stochastic nonstationary and nonlinear processes. Formal models based on automated ventilation control, do require awkward algorithmic solutions, moreover, a number of tasks become the operator's headache, and the quality of their solution depends on his experience and intuition. These tasks include: - identifying pre-accidental situations and determining their causes; - making well-grounded decisions with regard to changing ventilation regimes, forecast of mining operations taken account of; - controlling ventilation systems in emergency situations, e.g. when in accident, etc. It is in this context that we have for a number of years been investigating how to practically use AI methods for operative control in dynamic aero-and-gas mining processes, one of our research directions being devoted to working out a consulting programme for the ventilation system operator. Our researching and modeling problem was identification of aero-and-gas situation in different parts of ventilation network and its interpretation in order to determine possible causes for gas regime changing and unexpected consequences. We would single out the following stages in this task: I. Operative information procession coming to the data base from the sensors and analysis of hypothetical versions (using the associative rules base) with regard to factors which have caused significant parameter fluctuations (e.g. C%(t), H(t), Q(t) etc.)., 2. Selection of hypotheses in the knowledge base and forming conclusions in accordance with reliability scale. 3. Clarifying the obtained conclusions in dialogue with the operator. 4. Correcting the associative rules base.

Jan 1, 1992

By M. Tanaji

Over the last many decades, a significant amount of research has gone into the domain of slurry transport. However, design engineers still face many challenges with respect to prediction of pressure drop, critical velocity and other design parameters as a function of Solids % and Particle Size Distribution (PSD). The industry requirement is to transfer the slurry at the maximum concentration as possible (above 30% (volume %)) to make slurry transport more economically viable and to reduce water consumption. To facilitate the design and scale-up of slurry transport in pipelines and in process plants, there is a need for a correlation that can predict slurry pressure drops over a wide range of operating conditions and physical properties of different slurries. The objective of this study is to overcome the limited range of applicability and validity of existing correlations and to develop a generalized but more rigorous correlation applicable to a wider range of slurry sys-tems. The existing Wasp et al. (1977) method is based on multi-phase flow modeling approach. This study attempts to modify this approach by considering material-specific values of Durand?s equation co-efficient and by defining flow regimes based on particle Reynolds number. When compared with experimental data, the modified Wasp method proposed in this study predicts the pressure drop for slurry flows more accurately than other available correlations. Also, the pro-posed method requires minimal test/experimental data for a particular slurry system and can be extended over different input conditions. An iterative computer algorithm is developed to calculate the criti-cal settling velocity and pressure drop in a pipe as a function of Solids % and PSD. The solution method can easily be implemented in de-signing slurry pipes, design validation, and studying the different slurry transport scenarios. The modified method can also be extended to accurately predict pressure drops in dynamic pressure flow networks used in commercial process simulators.

Feb 23, 2014