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By A. Quilodran, B. Jakovljevic, T. McCallum, P. Wong

"Rare earth separation by solvent extraction (SX) requires multiple separation plants each consisting of many extract, scrub, and strip stages to separate the individual metals. SX modeling advances have brought benefits to circuit design and process optimization by quickly narrowing test conditions without the need for exhaustive laboratory studies. Modeling can be used to optimize circuit configuration, O/A ratios, and acidities, which allows for CAPEX and OPEX savings. A comparison between pilot plant data and the results expected from modeling is presented for rare earth separations with CYANEX® 572.INTRODUCTIONRare earth separations can be difficult due to limited separation between the elements (Xie, Zhang, Dreisinger, & Doyle, 2014). This requires relatively complex solvent extraction circuits utilizing multiple extract, scrub, and strip stages as well as multiple SX configurations to achieve the desired metal purities. Designing rare earth circuits can be complex, and significant time and testing may be necessary to determine the required staging and optimal conditions.Circuit modeling for rare earth separations has been introduced to the industry using CYANEX® 572 extractant (Soderstrom, McCallum, Jakovljevic, & Quilodran, 2014). CYANEX® 572 is an acidic organophosphorus extractant formulation which has a weaker ligand-metal complex strength than that of the traditionally used phosphonic acid extractants. This allows efficient extraction while requiring a significantly lower acid concentration for stripping (Wang, Li, Zhao, Dong, & Sun, 2015). The reduced acid requirement in strip is expected to provide OPEX savings.The modeling can be utilized to quickly determine the required acidity and organic/aqueous (O/A) ratio for a given separation. It is also expected to reduce CAPEX requirements as optimal staging can be determined, and implemented.CYANEX® 572, combined with modeling, was utilized to produce a purified dysprosium (Dy) stream. To achieve this separation, multiple SX circuits were designed and operational conditions specified to separate Dy from the mixed rare earth chloride feed."

Jan 1, 2016

By M. K. Gangal, M. A. Stoakes, A. E. Hall

"The major features of the CANMET thermodynamic mine ventilation network program, developed by the Mining and Mineral Process Engineering Department of the University of British Columbia for the Canada Centre for Mineral and Energy Technology (CANMET), are described.The program is designed for use by deep Canadian mines in planning ventilation flows where the effects of auto-compression of air, moisture lift work and natural ventilation are significant. Routines to simulate stalled fans and give an optional cost printout have been included in the program.A supplementary plotting program used to simplify data interpretation is also described.The program is described with a test data example of a deep mine. It is a valuable analytical tool which can assist ventilation engineers to simulate many alternative ventilation strategies at a low cost in a very short time.IntroductionCanadian underground mines are becoming deeper and more extensive. The use of more and larger diesel-powered equipment increases the amount of air required to be circulated in these complex systems. These effects, coupled with the increasing unit cost of the energy required for mine ventilation, require that the air is used with maximum efficiency.Optimum airflow distribution can be obtained by using network computer programs enabling engineers to plan future ventilation systems based on quantitative assessments. The programs used for deep mines must make allowance for the change of air density with depth, as the assumption of incompressible flow leads to serious errors. Natural ventilation effects may vary with depth and from part to part of the mine; this must be catered for by the program. The air moisture content changes throughout the circuit and a significant portion of the fan work may be used in removing moisture from the mine; as this work varies directly with the flow, a suitable relationship must be utilized in the program."

Jan 1, 1982

By P. Samanta, Mohammed N. Azad, Gustad F. Taraporewalla, A. K. Mukherjee, Abhay S. Patra, D. Sachinraj

Beneficiation of coal is a water intensive process, and the water is recovered in downstream operations in the high rate thickener (HRT) and vacuum belt filtration (VBF). Clean coal particles entering the HRT have an inherent tendency to enter the overflow because they are extremely fine and hydrophobic. Hence, flocculants (polymers) are used to floc the ultrafine particles so that they settle and enter the underflow. Ultrafine coal particles (−37 μ), which are highly hydrophobic, if present in the stream, will not be efficiently captured by using flocculants alone. This is observed in the normal plant operation at one of the beneficiation plants in the Jharia region, Jharkhand, India. Approximately 6–7% of the feed to the HRT enters the over flow (supernatant water). Hence, this amount of clean coal particles is not recovered and account for production losses. A comprehensive settling and dewatering test work was conducted with clean coal slurry using several commercially available reagents. Studies were also done on different combinations of reagents, including coagulants and surfactants along with flocculants, to improve the settling behavior of the coal particles. The reagents were assessed based on their performance with respect to settling rates, overflow water clarity, and compaction of the underflow solids. Emphasis was given to the ability of the reagents in compacting thickener underflow to higher densities so that maximum water could be recovered from the thickener. Pretreatment of highly hydrophobic coal slurry with a combination of coagulant and surfactant followed by flocculation showed very good settling characteristics with clear overflow.

Sep 30, 2021

By Richard S. Olsen

Prior work by the Bureau of Mines demonstrated a feed preparation method that eliminates the formation of slime during leaching of calcined kaolinitic clay and makes leached residues fast settling and easy to filter. Nitric acid leaching rates determined for calcined kaolinitic clay prepared by this method were found to correspond to a zero-order reaction model for both batch and continuous, stirred-tank leach-ing. A rate constant of 0.136 min-1 was determined. Separation of solid residues from the reacted slurry was examined, and filtration rates were determined. Permeabilities of the flocculated, leached residues were around 51 darcys, or 5.0 x 10-7 cm2 for laminar flow through 4-ft-deep beds.

Jan 1, 1983

By Prakash Venkatesan, Mehmet Ali Recai Ӧnal, Shaik Saida, Veerendra Singh, Chenna Rao Borra, Manish Kumar Kar

A laboratory-scale investigation of the effect of milling operation and catalyst addition ( K2CO3) on the partial reduction of low-grade pyrolusite ore pellets was carried out using coke as a reductant. Thermogravimetric analysis was used to understand the correlation between milling and catalyst addition parameters with the reduction temperatures. DTG analysis of pyrolusite pellet reduction showed three distinctive peaks associated with a three-step reduction mechanism (i.e., MnO2→ Mn2O3→Mn3O4→MnO). The results showed that the grinding and addition of the catalyst have a significant effect on lowering the MnO2 reduction temperature independently. But maximum reduction temperature drop is obtained when combining grinding and catalyst addition in this work. By 3 h milling and 10 wt% catalyst addition, the reduction temperatures were reduced by more than 200 °C compared to the raw ore pellets. These results obtained from the DTG analysis were further supported by XRD analysis of the reduced samples.

Dec 20, 2022

By Kazutaka Kunii

It is invariably certain that after punching for IC Leadframes, scrap metal were generated. These seraps were re-dissolved and in order to use as raw material for leadframes, it is necessary to remove the Ni plating. In this study a simple method was developed for the removal of Ni plating by surface oxidation of Ni plating. For this purpose a fundamental study was carried out on the oxidation behavior of Ni plating. Results showed that by controlling the oxidation condition, a considerably high rate of Ni could be removed.

Jan 1, 1996

By A. Rai

"This paper provides an overview of the current use of auxiliary ventilation product and the challenges with limited air quantity in dead-end entry or working face. The PVC low frictional factor, low physical constraint and minimum leakage ventilation duct was development with ""made in US and used in US"". The PVC duct development covering operational and total cost of ownership with on-going success will be presented. This paper will discuss mine sites using new PVC vent duct underground and the results from operational and technical side making a difference. INTRODUCTION The Turquoise Ridge Joint Venture (TRJV) is located in northern central Nevada, and is situated within the Basin and Range province, near the northeast end of the Osgood Mountains (see Figure 1). The TRJV mine consists of typical Carlin type- gold mineralization characterized by low strength rock of altered limestone’s, siltstones, and mudstones. The weak nature of the ground facilitates the underhand cut and fill mining methods [3].Mining Method; Underhand cut and fill : The mine uses underhand cut and fill method which has 12’x12’ top cuts and several different size undercuts. The ore body is accessed off of a secondary development heading, utilizing a heading with a cross section of 14W x 14H or 15W x 16H configuration. In the wider and more massive zones, two headings in a production panel may be worked at any one time. Drift round lengths are determined by the type of drilling machine being used. An example of a typical topcut and associated undercut layout is shown in Figure 2. SECONDARY / AUXILIARY VENTILATION IN UNUNDERGROUND METAL MINES The auxiliary ventilation system provides the required air volumes at the face of dead-end developments and production workings, which in many cases may be considered as the primary method of assuring that the air quantity and quality standards in these working areas are satisfied. The Auxiliary fans and ducting systems are usually the primary means of delivering the required air volumes to the face of dead-end developments and production workings. Both centrifugal and axial-flow fans are used in underground auxiliary ventilation systems, usually electric powered. The internally direct driven axial-flow fans tend to be more popular because of their compactness and adaptability to staging. The most commonly used materials for ridged tubing are coated steel, alloyed steel, fiberglass and resin. Flexible (collapsible) ventilation tubing is also used and is usually made from neoprene-coated or nylon material. To add stiffness and reduce collapsibility these fabric ducts can be formed over a steel spring frame. A very important factor in the design of an auxiliary ventilation system is to minimize leakage and reduce the frictional pressure losses along the auxiliary ducting systems by minimizing their friction factors (K)."

Jan 1, 2015

By Henrique Hipolito, Caio Alves

Waelz process is a method applied in the zinc oxide production and is one of the largest sources of carbon emissions within the zinc industry. The solid carbon used for heating and for reduction reactions is provided mainly by the coke fed with the EAFD in the Waelz kiln. Both chemical composition and physical properties of the coke are important to transportation and to the process. Decarbonizing the Waelz process by replacing the traditional fuel source using alternative biogenic fuel, for example, offers a potential solution to reduce the carbon footprint, which is aligned with the ESG perspective.

Sep 29, 2023

By W. Kobal

The extraction of nickel (Ni) and cobalt (Co) from the laterite deposit of Ramu nickel-cobalt Project in Papua New Guinea was performed in this study. Chemical analysis by Inductively Coupled Plasma (ICP-AES) atomic emission spectrometer, SPS-3000 (Seiko Instruments (Inc.), shows the ore contains 48% Fe, 1% Ni, 0.1% Co, 1.8% Al, 0.14% Mg, and 0.8% Mn. Characterization by X-ray diffraction (XRD) analysis of the laterite ore obtained from the mine site shows the ore contains 70 to 80% goethite (FeOOH), assuming Fe content of 48% is mainly from geothite. The main leaching parameters investigated include; slurry temperature, leaching time and sulphuric acid (H2SO4) concentration to evaluate nickel and cobalt extraction. For all experiments, 10g batch samples are put into 300 ml beaker containing 100 ml of sulphuric acid of varying concentrations (1M, 2M, 4M). During the leaching period, 5 ml slurry samples are withdrawn at different times and filtered to obtain filtrate for ICP analysis to monitor nickel and cobalt extraction. Solid samples at the end of all tests are also obtained by filtration and after drying, XRD and ICP tests are performed to monitor nickel and cobalt contents. According to the test results performed at normal atmospheric pressure, over 99% of nickel and over 50% cobalt were extracted into solution within 120 min at 95ºC in 2M H2SO4 solution. Similar results were obtained when only temperature was reduced to 90ºC, but cobalt extraction increased to over 70% when leaching time was increased to 240 min. Further reduction in temperature to 80 and 60ºC resulted in reduction of nickel and cobalt extraction. At the end of each leaching test, magnetite was seen to attach to magnetic stirrer. The study showed nickel can be completely leached into solution but cobalt only up to 70%. Keywords: atmospheric pressure, sulphuric acid leaching, nickel laterite

Sep 1, 2012

By Manuel Villanueva Bullón

El presente texto describe el proceso de optimización en las operaciones mineras del yacimiento minero San Vicente a través del empleo de las microcomputadoras, las cuales al ser fácilmente transportables, de bajo costo y no requerir de ambientes especiales, permiten brindar in situ con amplitud al soporte que se requiere. Por ello, esta red de microcomputadoras desarrollan sistemas de carácter técnico y administrativo que controlan y retroalimentan información de todas las operaciones, optimizando el control de la producción en la mina y planta concentradora.

Nov 24, 1986

By Ravi S. Bellur-Ramaswamy, Daniel A. Tortorelli, Robert Haber, Nahil A. Sobh

We optimize continuous quench process parameters to produce functionally graded aluminum alloy extrudates. To perform this task, an optimization problem is defined and solved using a standard nonlinear programming algorithm. Ingredients of this algorithm include 1) the process parameters to be optimized, 2) a cost function: the weighted average of the precipitate number density distribution, 3) constraint functions to limit the temperature gradient (and hence distortion and residual stress) and exit temperature, and 4) their sensitivities with respect to the process parameters. The cost and constraint functions are dependent on the temperature and precipitate size which are obtained by balancing energy to determine the temperature distribution and by using a reaction-rate theory to determine the precipitate particle sizes and their distributions. Both the temperature and the precipitate models are solved via the discontinuous Galerkin finite element method. The energy balance incorporates nonlinear boundary conditions and material properties. The temperature field is then used in the reaction rate model which has as many as 105 degrees of- freedom per finite element node. After computing the temperature and precipitate size distributions we must compute their sensitivities. This seemingly intractable computational task is resolved thanks to the discontinuous Galerkin finite element formulation and the direct differentiation sensitivity method. A three-dimension example is provided to demonstrate the algorithm.

Jan 1, 2001

By Joseph Hyde Pratt, Douglas B. Sterrett, CHAPEL HILL

I. DESCRIPTION. MONAZITE is one of the minerals which, for a long time, was considered rather rare in its occurrence, but, upon a commercial demand arising for it, prospectors and engineers soon located large deposits of it in the Carolinas and Brazil, and the supply has always been able to meet the demand. During 1908 further sources of supply of monazite have been discovered and developed in Idaho. North and South Carolina, however, are the only States that have thus far put any monazite on the market. Monazite is essentially an anhydrous phosphate of the rare-earth metals, cerium, lanthanum, and didymium (Ce, La, Di)PO;. There is nearly always present a varying but small percentage of thoria, ThO2, and silicic acid, SiO, which are very probably united in the form of a thorium silicate, ThSiO4 Some monazites contain but a fraction of a per cent. of thoria, while others have been recorded that showed the presence of from 18 to 32 per cent. ; but the majority contain from 3 to 9 per cent. of this oxide. It is the presence of the thorium oxide that gives the monazite its commercial value. The analysis occasionally shows also the presence of other constituents, as the yttrium and erbium oxides, zirconia, alumina, magnesia, lime, iron oxides, manganese oxide, and titanium oxide. Monazite is light-yellow, honey-yellow, reddish-, brownish-, or greenish-yellow in color, with a resinous to vitreous luster, and is translucent to subtransparent. It is brittle, with a conchoidal to uneven fracture, and is from 5 to 5.5 in hardness, and from 4.64 to 5.3 in specific gravity. It crystallizes in the monoclinic system, and some crystals have been observed that were 6 in. in length. The more perfect crystals are, however,

Jun 1, 1909

By Robert Goldstein

A computer program for calculating the illumination on coal mine surfaces due to machine-mounted lights is described. Utilizing numerical models of mining machinery and measured data on luminaire output characteristics, the program computes the ft-candle levels incident on the mine entry surfaces for any desired machine/luminaire/ entry configuration. Shadowing effects of the machine are taken into account. Results are provided at 2 ft. intervals on the face, left and right walls, floor and roof. To provide a data base for these calculations, eleven 3-D machine models were prepared and the outputs of three luminaire types were measured. Calculations were done for thirty different configurations.

Jan 1, 1977

By S. Y. Ezz, K. El•Guindi

A vertical tube, 8 m long and 2.5 cm in diameter, electrically heated to 650°C throughout the majority of its height, was used to study the-effect of ore feed rate and hydrogen flow rate on the reduction of fine iron ore particles. A correlation could be obtained between the combined effect of the amount of reducing gas and reduction time and the per-cent reduction. The results suggest that a method based on the reduction of fine iron ores while falling through up-streaming hydrogen cannot be recommended for industrial application.

Jan 1, 1969

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By AIME AIME

PETROLEUM technology was the sole subject of discussion at the meeting of the Petroleum Division at the Baker Hotel, Dallas, Texas, Oct. 6-7, except for the brief talks by President Becket and Secretary Parsons at the dinner on Friday evening. Even on this occasion, following the scheduled official features, it was in order to talk "shop." W. E. Wrather and E. A. Stephenson, respectively Chairman and Secretary of the Division, had planned for a meeting of this nature and by preference, apparently, the 122 who registered fell in with the scheme wholeheartedly. Not because the competent local committee had not provided for it, but by choice, the members just did not sign up for entertainment or field trips, but did attend largely the three technical sessions and engage in earnest discussion of the approximately dozen excellent papers. In this connection, and without question, the high lights of the meeting were the papers by Morris Muskat and R. D. Wyckoff, and Prof. W. K. Lewis. The former, entitled, "A Theoretical Analysis of Waterflooding Networks," had been entirely demathematized by the authors for presentation at this and the Los Angeles meetings; the author of the latter, which was on the "Physical-chemical Relationships of Hydrocarbon Gas-liquid Mixtures at High Pres¬sures," had airplaned to Dallas in the company of Dr. H. D. Wilde from Chicago in order to present his paper at the final session on Saturday morning.

Jan 1, 1933

By H. Jiang, S. Yang

"The main processes for nickel metallurgy in China consist of electric arc furnace smelting to produce low grade nickel matte and converter to high grade nickel matte, grinding and flotation to separate nickel sulfide from copper sulfide and direct electrolysis of nickel matte. Systematic studies on the properties of electric furnace slag, smelting process for nickel matte, anodic process of nickel matte, cathodic process of nickel electrolysis have been done in our labs. In addition, an approach to a new hydrometallurgy process for nickel matte has been done. The feature of the new process is one stage acidic leaching of high grade nickel matte. The leaching solution could be purified by deposition way or by solvent extraction way. There are two leaching rate-determing steps, chemistry reaction-determing one at temperatures below 600C and diffusion-determing one at temperatures higher than 600 c. The acidic leaching fraction reacted dvaties with leaching time t according to the equation 1-(1- a ) 1/3=kt. The experimental data also show that the leaching reaction rate varies with concentrations of H+, Cl-, and it is also effected by copper sulfide and Cu++. The Cu++ ion can retard the leaching reaction due to forming a copper sulfide layer on the matte surface and the equation 1- 2/3 a. - (1- a: ) 2/3 akt can be used for the case. However the copper sulfide added into nickel matte can facilitate the leaching process. The research work for nickel metallurgy done by others in China has also been mentioned in this paper.Large scale production of nickel in China started in 1960s.The main processes consist of electric arc furnace smelting to produce low grade nickel matte and converter to high grade nickel matte grinding and floatation to separate copper sulfide from nickel sulfide and direct electrolysis of nickel matte.To reduce nickel loss in slag a reseaech group organized by Jinchuan Company and Central South Institute of Mining and Metallurgy (now the Central South University of Technology) measured the viscosity surface tention density conductance melting point and structure of the slag(I).lt has been found that the physico-chemical properties of the slag depend on the components SiO2 ,MgO and FeO but FeO in the slag is too high and the statistic analysis of data from industry gave an equation to correlate the content of Ni in slag with the content of Ni in matte and the composition of slag again it was pointed out that the content of FeO in slag effected the loss of Ni in slag very much (2). The ratio (FeO+MgO) to SiO2shouid be less than 1.13 and the content of Fe3O4should be as low as possible but the reaction"

Jan 1, 1988

By J. G. A. Stevenson

GENERAL Location of Property THE Stirling zinc-lead-copper deposit is in Richmond county, Cape Breton, about a quarter of a mile southwest from Stirling P.O., and some 45 miles southwest from Sydney. The property is accessible by road for at least nine months of the year, and during the navigation period coastal boats maintain a service touching at the port of Fourchu, eleven miles from the mine. When flying conditions permit, the Cape Breton Flying Club, of Sydney, will carry passengers to or from the property, a service which has been particularly advantageous on two occasions when hospitalization was urgently required. The Company has mining rights on leases Nos. 73-74, 78-80, and 101-104, inclusive, and owns 166 acres at Stirling and one acre at Fourchu. The ore deposit is in lease No. 73. History The Stirling deposit was discovered in the 'nineties', probably about 1895. The original discovery is said to have been made in the bed of Copper creek, which traverses the ore-zone. For a number of years, indifferent development work was carried on with a view to copper production only, and it was not until1915-16 that attention was directed to the possible production of zinc. Previously, the ore had been considered too complex for metallurgical treatment. During the period 1916-24 several operators attempted to develop the property, among them being the Stirling Exploration Company, Stirling Mining & Smelting Company, New Jersey Zinc Company of New York, Hayden & Stone Company of Boston, and The Eastern Mining & Milling Company. Up to 1924, the work was limited mainly to trenching, stripping, ? diamond drilling, and shot drilling.

Jan 1, 1937

In many base metal sulphide concentrators reagents such as collector and cyanide are often added to the grinding mill as well as to the flotation circuit. Whilst good reasons can be cited for splitting the reagent addition in this way, the benefits of such are rarely quantified and the complex reagent-mineral-media interactions occurring during milling are often poorly understood in terms of pulp chemistry. A new laboratory batch grinding mill designed by Magotteaux allows the user to measure, monitor, and control the pulp chemical conditions during grinding when testing different ores and media. Some of these parameters include pulp pH, pulp Eh, temperature, gaseous atmosphere, and dissolved oxygen concentration. In a recent development, the mill has been coupled with a simple on-line reagent monitoring system, designed by CSIRO, which allows the levels of species such as xanthate and cyanide in the grinding pulp to also be measured continuously during milling using a robust UV detection system. In this way the uptake of collector during grinding and the rate and ex-tent of cyanide interaction with the minerals and media can be determined as a function of grinding time. A series of grinding tests using an Australian nickel sulphide ore was conducted with the coupled system in which the cyanide dose, xanthate dose, and media type were systematically varied. The xanthate and cyanide levels were monitored as a function of grinding time and the data collected are discussed in terms of the pulp chemistry of the system and implications for plant reagent dosing strategies.

Jan 1, 2014

By D. R. Nagaraj, Raymond Farinato

Water constitutes one of the most valuable resources employed in mineral recovery and processing. Identifying potential problems encountered in mineral processing in waters unusable for drinking or agriculture (including seawater and even hypersaline waters), understanding chemical factor interactions, and optimization of flotation reagents will greatly expand our ability to create more sustainable beneficiation technologies. The current paucity of our knowledgebase regarding high salinity effects on flotation clearly signals a need for a significant research effort. We report here results of a study designed to probe effects of pulp chemistry on metallurgical performance in the flotation of Cu and Cu-Mo ores in saline waters. The results clearly demonstrate that pH (more correctly dosage of pH modifier to target a pH set point) has the most significant effect on Mo recovery when using seawater. This is linked to the formation/precipitation of Mg(OH)2 when pH = 10.3 (in seawater). The type of pH modifier used, NaOH or Ca(OH)2, had no impact on Cu or Mo recovery, indicating that Ca2+ ions were not involved in any reduction in Mo recovery in the pH range of 9-11. Our results in tap water spiked with either Ca2+ or Mg2+ ions in the same pH range (controlled by NaOH), confirmed that Ca2+ ions had no effect on Cu or Mo recovery, but that addition of Mg2+ ions had a severe adverse effect on Mo recovery at pH = 9.5, and to a lesser extent on Cu recovery. The onset of Mg(OH)2 precipitation occurred at a higher pH, and the adverse impact of Mg(OH)2 on Cu recovery (and perhaps Mo recovery as well) was less, in sea water than in tap water spiked with Mg2+. These effects are attributed to the mitigating role of the high electrolyte concentration, notably NaCl.

Jan 1, 2014