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By R. T. Johansen, R. J. Heemstra

In water flooding the gradual accumulation of insoluble materials on the sand face causes the injection pressures to increase while decreasing the amount of water injected . This plugging material often is composed primarily of insoluble precipitates of calcium , iron , and magnesium . Treatment with sodium tripolyphosphate ( STP ) either eliminates or reduces the formation of precipitates . Field tests are discussed showing the almost immediate effects of using STP in the injection water . Methods of treatment , solubility of STP in fresh water and brines , and precautions to observe when starting to treat a waterflood with this chemical are given . Laboratory data show that the preferential wettability of a crude oil for reservoir rock can be reversed by adding a small amount of STP to the flooding water . This reversal in wetting tendency should not only decrease the injection pressures but also increase oil recovery by improving the sweep efficiency of a water flood .

Jan 1, 1964

By K. E. Tame

An alkaline leaching procedure for recovering uranium from a submarginal 0.1 percent Ug Og calcareous carnotite ore from the Shiprock , N. Mex . , area was investigated . A recovery of 72 percent of the uranium was attained in a preliminary test embodying the commonly accepted practice of ( 1 ) alkaline leaching at 90° C , ( 2 ) multiple stage filtration and washing for recovery of a clear pregnant solution , and ( 3 ) caustic precipitation of uranium as sodium diuranate , with recycle of the barren solution to the leaching and washing circuits . Ion exchange resins were used in a second , less orthodox test that comprised ( 1 ) sodium carbonate leaching of minus 10- mesh ore at 90 ° C to dissolve the uranium , ( 2 ) filtration to recover the leaching reagent for reuse , (3 ) recovery of the uranium- bearing solution in the filter cake as a pregnant slime slurry by repulping of the filter cake followed by a sand- slime separation and countercurrent decantation (CCD ) washing for rejection of the sand fraction , (4 ) recovery of the dissolved uranium from the pregnant slime slurry by resin- in- pulp (RIP ) , ( 5 ) elution of the uranium from the resin with a solution of ammonium chloride acidified with hydrochloric acid , and (6 ) precipitation of the uranium with ammonia gas . About 83 percent of the uranium was extracted from the ore and 95.5 percent of the dissolved uranium recovered by ion exchange . Improved laboratory results were obtained using the RIP process , but larger scale tests would be necessary for economic evaluation of the two processes .

Jan 1, 1964

By J. A. Ruppert, P. M. Sullivan

A study was made of filtration techniques for recovering the major part of the tin contained in iron - tin alloys known as hardhead . Special smallscale filtering apparatus and a three - stage cyclic process were developed . Eighty- seven percent of the tin contained in an alloy of 82 percent tin and 17 percent iron was recovered as pure metal by pressing at 975° C followed by a second pressing at 800 ° C and a final filtering at 250 ° C. Small amounts of Sb , Cu , and Fe impurities were removed by adding Al to the molten product and performing another filtration at 250 ° C.

Jan 1, 1964

By H. R. Shell, John L. Miller, M. V. Denny

In the mica research program conducted by the Bureau of Mines at Norris , Tenn . , many micas other than silicon fluorphlogopite have been synthesized . It has been well established since the initiation of the program that synthetic micas are important materials useful for their superior or unique properties as well as substitutes for natural micas . The possibility of controlling the physical properties of synthetic mica by isomorphic substitution of other ions in the fluorphlogopite lattice further emphasizes the importance of these materials . Accurate measurement and reporting of their properties constitute an essential part of the research program . The study of germanium fluorphlogopite is in keeping with the requirements of a comprehensive study on isomorphic substitution , specifically to identify precisely the material -- chemically , structurally , and optically . The X- ray measurements , including indexed powder and single crystal data , with a description of the methods used to obtain these data , are provided . 5 Earlier work on germanium mica by R. A. Hatch et al . (5) gave an estimate of the cell parameters from X - ray powder data , but no attempt was made to index the diffraction pattern or to determine the space group symmetry . Later work by E. A. Schatz and J. C. Withers (9) listed X- ray and optical measurements , but no attempt was made to index the mica or determine its symmetry . Roth (7) found that germanium dioxide having the a - quartz structure , when heated with equimolar percentages of MgO , CaO , Sr0 , or Ba0 at 1,235 ° C , formed ABO3 -type compounds , e.g. MgGe03 isostructural with enstatite (MgSiO3 ) . Geo₂ also has a rutile - type polymorph with Ge ++ ions in octahedral coordination . Germanium was substituted for silicon in the serpentine structure by Roy and Roy (8 ) using hydrothermal techniques . These authors wrote as follows : "The substitution of Ge + for Si + yielded a magnesia - germania serpentine , formed easily in euhedral hexagonal plates which in some instances were visible in the light microscope . Electron micrographs and the sharp X - ray diffraction patterns confirm a plate - like rather than tubular habit . " It has been shown in this investigation that substitution of germanium for silicon in the mica structure is readily accomplished without radically changing the characteristics of the mica . Substitutions in the mica structure take place in three locations : Tetrahedral , octahedral , and interlayer positions . The tetrahedral positions are normally occupied by Sit or by a combination of Sit with Al +3 the most common combination being 2A1 +3 and 6Si +4 · , The octahedral position , which has six - fold coordination in phlogopite , contains a larger cation such as magnesium . In muscovite it contains only 2A1 ions ; therefore , this mica is considered a dioctahedral mica , whereas phlogopite is considered trioctahedral . +3 The interlayer position has twelve - fold coordination with six oxygen ions from each of two adjacent tetrahedral silica layers . This is the cleavage plane of the mica and commonly contains the largest cation in the mica structure (e.g. potassium) .

Jan 1, 1964

By Charles C. Myers, Robert M. Doerr

The apparatus described was developed for determining the kinetics of gas - solid reactions at high temperatures by measuring the volume of gas consumed with respect to time . This apparatus consists essentially of a horizontal precision- bore glass tube connecting a small reaction chamber in a furnace to a large constant - temperature reservoir . A drop of mercury in the tube separates the two sides of the system and serves as an indicator that moves at a speed proportional to the rate of gas consumption . The sensitivity of the apparatus depends inversely on both the density of the gas in the system and the cross - sectional area of the tube ; with a tube having an area of 0.079 cm² , the sensitivity for oxygen at 308 ° K and 0.5 atm is 20 cm/mg . The reproducibility of data with the volumetric apparatus is good .

Jan 1, 1964

By Lewis C. Karrick

This paper is based on data obtained in the course of the oil - shale investigations of the U. S. Bureau of Mines , conducted in cooperation with the State of Utah . The amount and quality of oil that can be produced from any shale may be made to vary to an important degree by changing the temperature relations existing in the shale charge during destructive distillation . The rate at which the oil is formed from the shale is affected by the rate of heat supply , and therefore by the temperature of the shale during its thermal de composition . The quality of the oil formed may be controlled by altering the temperature of the shale , and therefore , the rate of formation of the oil . Variations in the yield and quality of shale oils may be caused by inherent properties of the retort used , but in any event the properties of the crude oil and yield are very largely the result of the extent to which the thermal de composition has progressed . Recognition of these principles will aid in explaining to a large degree the reasons for the wide variations in oils produced from the same shales by different " processes " . These principles also may be applied in the operation of different types of retorts in order that crude oils of a type most profitable to the operator may be produced . The Bureau of Mines has conducted an extended series of tests in the dee structive distillation of oil shales , in order to determine the wide variations that may be effected in the quality and yield of shale oil by changing the rate and temperature at which the oil is formed . These tests furnished interesting information on the four related points : yield of oil , quality of oil , temperatures required to distill shales , and time required for distillation .

Mar 1, 1923

By Enrique Jelvez, Nelson Morales Varela, Christian Ihle, Joaquin Silva

All mineral beneficiation processes require water for its execution. Therefore, the availability and adequate management of water are key to the existence of any mine operation. However, many mines’ operations are affected by water scarcity and risk an increase of operational costs or even production in some cases. This paper proposes a model to minimize the losses of water due to evaporation and re-absorption by adjusting the active and inactive periods of the discharge in different points of the tailing. When applied, the model determines optimal or nearly optimal discharge operation in all the scenarios that were evaluated.

Jun 25, 2023

By John P. Turner, Steven S. Dapp, Dan A. Brown

"The Goethals Bridge Replacement (GBR) spanning the Arthur Kill Waterway between Elizabeth, NJ and Staten Island, NY consists of a dual-span 1,982.5-ft long cable-stayed bridge with approach spans of 2,545 ft on the NJ side and 2,788 ft on the NY side. The bridge is supported on over 200 drilled shaft foundations ranging in diameter from 4.5 ft to 10 ft and socketed into Passaic Formation siltstone. Drilled shaft resistances for design were based on load tests as described in a companion paper (Dapp et al. 2016). This paper presents the main foundation design considerations and challenges. The approach to construction of the rock sockets, with a focus on quality in order to support the use of high nominal values of side and base resistance, is described. Lessons learned from this project and their application to future similar projects are presented.INTRODUCTION AND BACKGROUNDThe Goethals Bridge Replacement (GBR) project is a Public-Private Partnership (P3) that represents a major milestone for the Port Authority of New York and New Jersey (PANYNJ) in its distinguished history of bridge building in the greater New York City metropolitan area. The new bridge will replace the existing Goethals Bridge, named after Major General George W. Goethals, Chief Engineer of the Panama Canal and the first consulting engineer for the Port Authority. The existing Goethals Bridge along with the Outerbridge Crossing and the Bayonne Bridge comprise the three Port Authority bridges connecting Staten Island with New Jersey. The existing Goethals Bridge and the Outerbridge Crossing are cantilever truss structures and both opened on the same day in 1928. They were designed by J.A.L. Waddell under the supervision of the eminent engineer Othmar H. Ammann (1879-1965), who was the designer of many other iconic bridges in the NY City area including the Bayonne Bridge (1931), the George Washington Bridge (1931), and the Verrazano Narrows Bridge (1964). The designer of record for the replacement Goethals Bridge is Parsons Corporation, which is the successor firm of Robinson & Steinman, whose principal David B. Steinman was also a notable NY area bridge designer and a contemporary and rival of O.H. Ammann.The replacement Goethals Bridge is supported on over 200 rock-socketed drilled shaft foundations. Each main pylon tower is supported on a group of six 9-ft diameter drilled shafts and each anchor pier is supported by two 10-ft diameter shafts. Each approach pier consists of a two-column bent with each column supported on a rock-socketed drilled shaft. A rendering of the Main Bridge crossing the Arthur Kill is shown in Fig. 1."

Jan 1, 2016

By A. V. Rasskazova

Theoretical substantiation of leaching of clustered ultra-fine gold by the electro-photo activated cyanide and chloride solutions is given in the paper; and processes of activation of leach solution by electrolysis and photo-activation are described. Comparative experiments on electro-photo activated leaching of ultra-fine gold from refractory ores by cyanide and chloride solutions were carried out. The material for research is primary ore of the Pogromnoe deposit (Russian Federation, Trans-Baikal Territory). The ore is characterised by the minimum sulfide minerals and the organic carbon content. Gold in ores of this deposit is presented as mainly ultra-fine. Gold inclusions in quartz and silica-alumina minerals (metasomatic minerals) are ultra-fine. Sulfide minerals (2.5-3%) are presented in ore generally by pyrrhotine (gold content does not exceed 10 g/t). Standard cyanide technology provides 49.5% gold recovery. Photo-electro activated air saturated NaCN provides 69.9% gold recovery. Laboratory research of chloride-hypochlorite column leaching demonstrated that the electro-photo activated method provided 78.9 % gold recovery to pregnant leach solution. Chloride-hypochlorite photo-electro activated solution can provide higher level of gold recovery with shorter process duration (10 days) in comparison with cyanide (40 days). The final decision regarding the choice of leach solution has to be done on the basis of technical and economic calculations. Keywords: Ultra-fine gold, cluster chemical reactions, active clusters, leaching, electro-photo activation of leach solution

Jan 1, 2020

By N. Mangadoddy, M. Padhi

The simulation of multi-component classification with modified viscosity model is the key focus in the current study. The classification of the ores using hydrocyclone is a renowned process and has a convoluted flow separation phenomenon. The highly turbulent flow inside hydrocyclone depends on the operating and design parameters apart from the feed mixture. Slurry viscosity also plays a dominant role in the classification of solid particles under the centrifugal settling action. A heterogeneous mixture with different components would result in different settling and rheological behaviour of particles’ suspension in the water medium. The newly proposed multi-component viscosity model (Mandakini et al. 2020) is implemented as a user-defined function to define the material property during the CFD study of the mixture rheology inside hydrocyclone classifier. The multiphase and turbulence model is solved using the modified Algebraic Slip Model and Large Eddy Simulation model. A comparison of the predicted component performance curves is evaluated with and without the corrected viscosity model. The density and size effect on the particle phase distribution inside the classifier are compared, where the misplacements of the finer particles are carefully assessed. Validation of the component classification in hydrocyclone with the laboratory experiments found a close agreement with the rheology based CFD data. Keywords: Dual-component, multi-component viscosity model, double-gap rheometer, computational fluid dynamics, high solids concentration

Jan 1, 2020

By L. M. Tavares, H. A. Petit, P. P. Cavalcanti

Iron ore pellets experience degradation during handling due low energy impacts and stresses. These impacts lead to volume or surface breakage of the pellets, creating fine particles that accumulate along the process. Some of the particles are in contact with the air and are dragged as dust into the workplace or into the atmosphere. The aerodynamic size of the particles allows them to be potentially inhaled by the workers or to be carried to nearby communities. Dust emission becomes critical at specific locations, such as transfer chutes and stockpiles. This work models the dust generation that occurs in an iron ore pellet stockyard using a methodology that combines experiments to quantify the degradation of the pellets to mathematical modelling of the dust emission mechanisms in the stockyard. First, laboratory tests were used to characterise the amount of mass and the particle size distribution of the dust generated by degradation under controlled conditions. Second, the flow over a stockpile of an iron ore pellet company was simulated with the aid of computational fluid dynamics (CFD) simulations. Third, semiempirical equations linked the data generated by simulations and laboratory tests to estimate the dust emission in the stockyard. Finally, results were validated with measured field data, obtained with a novel online measurement tool. Results suggest that the approach is able to predict dust emission with sufficient accuracy and can be used for further implementation in the management of operations and decision making in order to reduce the environmental impact of the process. Keywords: Iron ore pellets, abrasion, dust emission, mathematical modelling

Jan 1, 2020

By M. Shaw, H. R. Heydenrych, A. E. Lewis, E. Glass, J. Chivavava

The removal of calcium from the retentates of reverse osmosis (RO) treated minewater is desirable since it allows the recovery of both additional potable water (through RO) and higher-purity salts (in downstream processing). This, in turn, reduces the need for costly and unsustainable evaporation ponds and enhances the economics and operability of potential zero-liquid discharge downstream processes, e.g. evaporative-, cooling- and eutectic freeze-crystallisation. For this study, a multi-component retentate high in sodium content was considered, typical of those emanating from minewater reclamation plants in Mpumalanga, South Africa. Four technologies were evaluated to remove calcium: gypsum precipitation by addition of lime; calcium carbonate precipitation by addition of soda-ash; heating crystallisation of calcium sulphate anhydrite; and cooling crystallisation of gypsum. Full processes were developed and simulated using electrolyte thermodynamics. Using the results of these simulations, capital- and operating costs, as well as revenues were calculated and used in economic comparisons of the processes. Sensitivities to key purchasing and selling prices were also investigated to understand the impact of changes in these variables. For the case of a low magnesium-to-sodium ratio in the feed, gypsum precipitation through lime addition was found to have the lowest operating and total annualised costs; but, if revenue could be derived from the sale of sodium sulphate, calcium carbonate precipitation through soda-ash addition was favoured. Keywords: Calcium removal, gypsum precipitation, calcium carbonate precipitation, heating crystallsation, cooling crystallisation, economic comparison

Jan 1, 2020

By A. Della Rocca, P. Jonker, B. Henning

Successful prediction of the collection efficiency of cyclone separators is a necessary step in cyclone design and verification. Aside from standard empirical relations, CFD modelling is widely adopted to supplement the design of cyclone units in relation to the desired separation performance. Nevertheless, effective adoption of numerical modelling is sometimes prevented by large modelling errors, especially for small size particles which are more subject to turbulence effects than larger particle classes. In the past, this motivated the adoption of more refined turbulence modelling approaches, such as large-eddy simulations. These approaches provide greater insight into time dependent behaviour, while leading to larger computational cost with respect to more standard approaches. In this paper, an effective Eulerian-Lagrangian Reynolds-averaged Navier-Stokes (RANS) approach is investigated, which is able to predict the complete separation efficiency curve with satisfactory accuracy, without requiring prohibitively long computational times. An assessment of the proposed approach is carried out against experimental data from large laboratory scale cyclones, in the form of mean and fluctuating velocity profiles from LDA measurements (Hoekstra, 2000), as well as with respect to the experimental separation curve (Zhao, 2005). The final application to a full-scale industrial cyclone unit is then carried out with the aim of tuning the cyclone design to the separation efficiency curve as required by downstream processes. Keywords: Cyclones, separation, CFD, RANS, RSM, Lagrangian

Jan 1, 2020

By Y. Jiao, V. S. Thompson, D. W. Reed, Y. Fujita, J. E. Aston

Rare earth elements (REE) are vital components in modern electronics and green technology products. Supply is tight and global demand is expected to increase, leading to high risk for the economic and national security of countries largely dependent upon foreign supplies. Recycling of REE from consumer and industrial waste materials is a possible way to help meet demand. We have shown previously that biohydrometallurgy can play an economically and environmentally sustainable role in REE recycling, particularly if agriculture or food wastes are used to produce organic acid bioleaching agents. A challenge for organic acid-based bioleaching is the incomplete conversion of the carbon substrate to an optimal organic acid biolixiviant with high REE extraction capability from a variety of REE-containing feedstocks (e.g., mining wastes, magnets from end of life products, spent batteries, etc.). To help meet this challenge a metabolic model was developed for Gluconobacter oxydans to identify options for improving sugar conversion to organic acids. Model predictions were consistent with laboratory data for the microbial consumption of glucose and production of gluconic acid, and suggested that providing growth conditions with relatively high C:N molar ratios could result in lower pH biolixiviant production and thus improve bioleaching. Keywords: Gluconobacter oxydans, bioleaching, metabolic modelling, rare earth elements summaries 2019: U.S. Geological Survey, 200 p., https://doi.org/10.3133/70202434.

Jan 1, 2020

By L. A. Balzan, M. Kalicinski, F. Nieuwenhuys

GEOSCANs on belt analysers have been widely utilised in iron ore for nearly two decades. Since the first installations in 2003, the availability of accurate and reliable grade data has become standardised across iron ore mines in the Northern Cape, where various streams are monitored continuously to ensure the optimal functioning of plants. Assmang Khumani has been at the forefront of technology adoption and has implemented 19 GEOSCANs at various locations throughout the plant, monitoring run-of-mine, stockyard feed, beneficiation plant feeds, and products. Over the years, collaborative advances in the technology have allowed for numerous benefits and gains to be made. In recent times, there has been a concerted effort on the development of analysis for phosphorus in the material flows, and based on Scantech's experience in the phosphate industry, this element has now been calibrated to achieve statistically acceptable and repeatable accuracies for real time analysis of this element on many of Khumani's GEOSCAN analysers. This paper provides an overview of GEOSCAN use at Khumani, while focusing on the development of phosphorus analysis. A case study of analysis results is presented for a range of analysers that have been calibrated for this element, as well as a discussion on the benefits obtained as a result of this analysis. Keywords: Online analysis, real-time, process control

Jan 1, 2020

By B. k. Kenzhaliyev, M. A. Naimanbayev, Zh. A. Baltabekova, N. G. Lokhova

In research various desorbents were used to desorb the following rare-earth metals from Purosorb 140 cation exchanger, i.e. ammonium chloride; ammonium sulfate; a mixture of nitric acid and ammonium nitrate; a mixture of hydrochloric acid and ammonium chloride; a mixture of sulfuric acid and ammonium sulfate. It was established that a solution containing 30 g/dm3 of H2SO4 + 300 g/dm3 of (NH4) 2SO4 is the most optimal desorbing solution to desorb REMs from macroporous Purosorb 140 cation exchanger impregnated with rare-earth metals from industrial dihydrate wet-process phosphoric acid. It was established that the residual REM content in the cation exchanger decreased from 0.89 to 0.10 wt. % with an increase in the ammonium sulfate concentration from 10 to 400 g/dm3. Technological desorption regimes for rare-earth metals from cation exchanger were developed. The optimal conditions were determined to desorb rare-earth metals from the Purosorb 140 cation exchanger, particularly temperature 25°C; L:S ratio = (0.8 ÷ 1.1):1; duration = 1.0-1.5 hours. Keywords: Rare elements, sorption, cation exchangers, wet-process phosphoric acid, desorption

Jan 1, 2020

By C. Chibwe, M. Tadie

Copper electrowinning models are useful for prediction of process performance, optimisation and improved understanding of complex phenomena such as current distribution without the expense of physical experiments. Recently, finite element models such as those generated in COMSOL Multiphysics have been developed for the electrowinning process. The predictive capacity of these models is improved by incorporating physical and chemical phenomena. Since physicochemical properties of electrolytes can have a significant effect on the quality of copper produced, this work was conducted to investigate the effect of such properties on electrodeposition at varying levels of copper, sulphuric acid concentration, iron concentration and temperature, in the presence of a smoothing agent. Tests were conducted at conditions similar to those for industrial copper electrowinning. Mathematical correlations were developed for the following properties; density, conductivity and diffusivity which were compared to existing models in literature and thereafter applied in a COMSOL generated model. The model predicts, current distribution at the cathode surface, deposit thickness (morphology), concentration of species within the cell and current efficiency. Current distribution output shows the impact of several phenomena on the deposit generated including the relationship between increasing copper concentration and current density and lack of influence of acid concentration on this property. Keywords: Electrowinning, physicochemical properties, electrolyte composition, modelling

Jan 1, 2020

By Sebastian Avalos, Julian M. Ortiz

The long-term mine scheduling is the optimal decision on how to extract and process the mining reserves. The resulting plan is mainly driven by economic, metallurgical, and geological factors. Accounting for their uncertainties leads to a robust solution and the feasibility for economic-risk quantification. In this work, we model the spatial uncertainty of grade distributions of multiple correlated elements, by using a multivariate morphing transformation. The result is a set of multivariate geostatistical realizations of the grades, which honor the conditioning data, the direct and cross variograms, and the multivariate statistical distribution, inferred from a set of samples. These models are the input in a reinforcement learning framework, adopted to train a deep neural network that considers the grade uncertainty and leads to an optimum mine plan after training using deep Q-Learning. Mining and processing capacities, as well as economic parameters and metallurgical constraints, are incorporated as the reinforcement learning environment rules. The method is validated on a real deposit, providing insights for future applications.

Jun 25, 2023

By Cesar Carrasco, Heath Arvidson, Mark Forster

Block models built to represent the geology and rock characteristics of mineral deposits represent huge complex data sets, which form the basis of strategic and business planning, and public reporting of Mineral Resources and Mineral Reserves. Recent advances in cloud computing and database technology developed for the Internet of Things offer a different way of working with these critical data sets. Enabling a cloud based, open data structure with high performance data analytics capability presents a compelling improvement in governance and a democratization of ore body knowledge that can lead to automation use cases that support the digitalization of mining.

Jun 25, 2023

By Steven Keim, Steven Stansfield, Kevin Andrews

Geotechnical, geological, and hydrogeological fieldwork and data collection for the mining industry is often conducted by younger, less-experienced staff members. In many cases, fieldwork personnel are recent college graduates or are otherwise relatively new to the mining industry. Due to busy schedules, staffing shortages, project budgets, and in some cases, poor management, new fieldwork hires often do not receive thorough training. In the past and the present, many workers in the mining industry learn(ed) by “doing.” While this is still considered to be the most practical approach and the easiest way for a company to determine the skill set of an employee, there is always some risk involved in the “feet to the fire” method. The reality is that field personnel are often collecting data on which major operational decisions will be made or on which regulators will base enforcement decisions. Inadequately trained or inexperienced field personnel may collect inaccurate data or fail to recognize key conditions that may influence decisions made by regulators, design engineers, mine managers, and corporate leaders. Even the best engineers may come to incorrect conclusions if they are starting with poor input data. Decisions based on inaccurate data often result in delays, budget issues, unsafe conditions, or even worse consequences. This paper provides numerous mining industry examples of incidences where inaccurately collected field information did, or could have, resulted in major adverse consequences. The paper also offers some simple approaches to minimizing the potential for such problems.

Jul 1, 2023