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By G. B. Harris, C. W. White

A study to investigate the recovery of base metals, notably copper, nickel, cobalt, zinc and manganese from iron-free concentrated chloride solutions using ion exchange was undertaken. In such solutions, apart from nickel and, to a lesser extent manganese, these metals are present predominantly as complex anions, and therefore conventional separation techniques based on cationic resins are not applicable. The results demonstrated that zinc, copper and cobalt can all be separately recovered leaving nickel and manganese behind. Specifically, zinc is a major nuisance element in nickel and cobalt processing, and the testwork showed that it can be preferentially removed prior to copper and cobalt. Selective resins for both copper and cobalt were identified, and it was demonstrated that the strength of the chloride background matrix has a significant effect on the efficiency of separation. An additional major advantage in such systems is that stripping can mostly be effected with water. Finally, some observations are made on the hurdles that must be overcome when attempting to introduce and commercialise new technologies.

Jan 1, 2015

By E. Vahidi

In this study, a hydrometallurgical treatment involving solvent extraction of zinc using D2EHPA (di-2-ethylhexyl phosphoric acid) has been investigated to recover zinc from an industrial zinc leach residue. The residue was leached with sulfuric acid producing leach liquor which was subjected to solvent extraction for enrichment of zinc and removal of impurities. Operating variables for the zinc extraction process, such as pH of the mixed solution (0.5~5.0), concentration of D2EHPA (5%~40%, w/w), temperature (25~60°?C), A/O volumetric phase ratio (1/2~4/1), concentration of tri-butyl phosphate (TBP) as modifier (3%~7%, w/w), concentration of NaR2RSOR4R in aqueous phase (0.05M, 0.1M, 0.2M) were also studied. Practically all zinc was extracted from the aqueous solution at pH 2.5 with 20% w/w D2EHPA in kerosene. At this operating condition, zinc could be extracted at one theoretical stage at A/O phase ratio of 1/1, as calculated by the McCabe-Thiele method.

Jan 1, 2014

By Matthew C. Binsfield

The simultaneous electro winning of zinc and manganese from waste water treatment plant sludge was studied as a part of the overall research program, which was conducted to develop the methods for removal of environmentally hazardous metals from the Bunker Hill Superfund Site. This paper discusses the electrolytic method for recovery of zinc and manganese from the solution produced by leaching of sludge with S02 + H2S04. After three stage purification of the leaching solution, zinc and manganese were electro won simultaneously in an undivided electrolytic cell. Zinc was deposited on an aluminum cathode, while manganese was simultaneously produced (as Mn02) on a lead silver anode. The electrowinning parameters studied were the effects of: temperature, current density, electrode material, spacing of electrodes, composition of electrolyte, and electrolyte additives. Anodic and cathodic efficiencies were 30 and 91%, respectively. In light of the process design parameters discussed in the paper, which are affecting the electrowinning, these efficiencies were found as acceptable with regard to the quality and marketability of the products.

Jan 1, 1996

By M. Kargar Razi

According to the unique properties and many applications of nano gold powder, it was prepared from an acid leaching tail solution. The low value residual gold ions were existed in acid leaching tail solution in Mouteh gold mine in Iran with fellow heavy metals as pollutants (FeP2+P, Cu P2+P, and ZnP2+P). Preparation of nano gold particles is achieved by two steps. First, by addition of ammonia as separation step and second using suitable reagents for precipitation/extraction step. Conditions control includes pH, residence time, temperature, agitation, and molar ratio of reducing agents to reagents. The optimum results show that nano gold powder was prepared by temperature of 250 °C, urea to gold molar ratio of 3:1, and reduction time of 20 min. Also, heat treatment improves dispersion of nano sized gold particles. The properties of gold nano powders were evaluated by SEM, A.A, and UV- Vis spectroscopy methods. The size of prepared particles were about 80nm to 90nm.

Jan 1, 2014

By M. Kul

In this study, the effects of various extraction and stripping parameters, such as equilibrium pH (7.0, 8.5 and 10), extractant concentration (5, 10 and 20 volume %), organic-to-aqueous (O/A) ratio and stripping agent type and concentration were studied on chromium (VI) recovery from chromium electroplating rinse bath wastewater using Aliquat 336. Results showed that these parameters all had significant effects on chromium (VI) recovery. A pregnant strip solution from a chromium electroplating rinse bath wastewater with 33.4 g/L chromium content, suitable for sodium dichromate production, was generated by 20 vol. % Aliquat 336 in commercial kerosene. The O/A ratio was 1/4 and the equilibrium pH value was 0.87, the as-received pH value. The wastewater was treated with a two-stage countercurrent extraction process to produce a loaded organic phase, which was later stripped at the O/A ratio of two with a 4-M NaOH solution in a two-stage countercurrent stripping process using Taguchi?s optimization technique.

Jan 1, 2010

By Shubin Wang

Copper(II) and nickel(II) are often recovered from ammoniacal alkaline solutions by solvent extraction using hydroxyoxime extractants: both copper(II) and nickel(II) are extracted from ammoniacal alkaline solutions and, from the loaded organic phase, nickel(II) is selectively stripped with a dilute acid followed by copper(II) stripping with an acid of higher concentration. Since a small portion of ammonia is co-extracted with copper and nickel, the extracted ammonia should be scrubbed using a dilute acid before metal stripping. In the present study, a mechanistic model has been developed in order to support design and control of this process. The equilibrium distribution ratios of copper(II), nickel(II), and ammonia at 298 K using LIX® 84-I (active component, 2-hydroxy-5-nonylacetophenone oxime) as the extractant are successfully correlated by considering the relevant equilibria. Based on these results, quantitative prediction of equilibrium distribution ratios in the process has been made possible, and suitable conditions for the efficient separation of copper(II) and nickel(II) are discussed.

Prof. H. O. Hofman, Massachusetts Institute of Technology, Boston, Mass. (communication to the Secretary): When Mr. Stetefeldt quotes me as saying that " silver-assays are uniformly made by scorification," he has evidently not understood that I was referring solely to the practice of silver-lead smelting-works. Everybody knows that silver-mills do not employ the scorification-assay for regular work ; and it is equally certain that in very few, if any, silver-lead smelting-works will the crucible-assay be found in use for determining silver. The second part of the quotation, "as it is adapted to all kinds of ores and gives excellent results unless organic matter is present," although, of course, also intended in a restricted sense, might very well be extended to a general one. Mr. Furman, in his Manual of Practical Assaying,* says, on page 123: "We believe that the Colorado practice is preferable, as most ores will yield higher silver-results by scorification." The fact that the scorification-assay is the accepted one in Colorado is strong presumptive evidence for its accuracy, as exactness would nowhere else be more jealously demanded. Mr. Stetefeldt cites Albert Arents- as a supporter of his preference for the crucible-assay, although I had already done so in favor of scorification. Looking up again the reference, I find that I was justified in quoting him, as, while Mr. Arents advocates the crucibleassay for low-grade gold ores, not on account of the greater accuracy of its results, but because it is quicker and less expensive, he condemns it§ for the assay of silver-ores, and prefers the scorifier for rich goldores, and for coppery ores, and in general for ores containing both silver and gold. As I, like Mr. Stetefeldt, have kept no detailed

Jan 1, 1895

By T. Kimura, H. Ohba

"Much effort has been made to reduce the energy requirement in zinc electrowinning. In order to keep energy consumption low, either to make cell voltage low or current .efficiency high is necessary. Decrease of cell voltage practically depends on how to reduce ohmic resistance in the electrolyte and the anode crust. To realize these, new concept was proposed and the pilot plant has been operated. The space between a cathode and an anode is halved by utilizing the frame insulator. With these frames the anodes and cathodes compose of a unit of electrodes, and this unit is handled by newly designed electrode handling machine (E.H.M.). The process includes lifting up electrodes, expanding the space between a cathode and an anode, cleaning them, stripping the deposited zinc and returning the unit to the cell. As a result, cell voltage is kept as low as calculated and predictable energy reduction has been achieved. IntroductionIn the recent trend of a rapid appreciation of the Japanese yen, Akita Zinc Refinery of Mitsubishi Metal Corporation has been confronted by problems of relatively high operating costs. In order to compete with other overseas zinc refineries, it is necessary to reduce the cost of zinc production, especially the cost of electric power which now accounts for .up to 35 % of the entire cost of production. Three fourth of the electric power used at Akita Zinc Refinery is for the electrolysis. Therefore it is extremely important to reduce the cost of electrolysis.There are two possible measures for solving the problem; one is to use more nighttime electricity taking the advantage of its inexpensive power price, and the other is to reduce electric power consumption.As a part of a rationalization plan carried out in 1986, Akita Zinc Refinery increased the number of operating cells. As a result, when nighttime electricity is used, the silicone rectifier has been able to operate at full capacity. Moreover, by new schemes of ""increase of area for electrodeposition by ralslng the liquid level of electrolyte"" and ""increase of the number of electrodes in each cell"", current density could be lowered and as a result, the electric power consumption has been improved. In order to raise nighttime ratio even higher, installation of an additional rectifier and cells would be required."

Jan 1, 1988

By AIME AIME

ARGUMENTS and discussions were not lacking either Wednesday or Thursday mornings, when the geophysicists got together. The first session, under the chairmanship of Paul Weaver, was devoted largely to theoretical papers, except for the first one by F. W. Lee, which was a progress report. This speaker mentioned some of the high lights of geophysical exploration during the last year, such as the recently announced extension of the Rand gold fields through magnetic exploration, and the continued activity in the oil fields of this country. Even this brought forth some disagreements, Paul Weaver feeling that credit was being given geophysics where it was not due for the discovery of certain oil fields. In this criticism Everette DeGolyer concurred, and both agreed that geophysicists must lean over backward when it comes to taking credit for discoveries. The troublesome question of interpreting resistivity curves is always being aired, and Lynn G. Howell's paper, presented briefly by the chairman, served to clear up a moot point raised last year by M. King Hubbert's work. By use of Maxwell's theory of images the author calculated that the effect of a thin, conductive sheet placed perpendicularly across the middle of a four electrode system should bring the resistivity curve up to a figure equivalent to the resistivity of the surrounding medium, but no higher. Variations from this he explained as being due to dirt on the surface of the sheet. The difficult question of interpreting three-layer curves was tackled bravely in Thomas Manhart's paper, presented in abstract by S. F. Kelly. The author seems to be attaining some success through dividing three-layer curves into two approximation curves of the two-layer type.

Jan 1, 1933

By Renfeng Song, Shaoyan Wang, Zhiqiang Zhang, Ke Guo

Leaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

Jun 16, 2021

By Hui Wang

With the great increasing use of nickel metal hydride batteries recently, the waste of this kind batteries have been paid for close consideration. For the main reason that the waste of the batteries contained precious metals and lanthanide which cost great lose. This paper introduces the pyrometallurgical process of recovering nickel and cobalt from the waste of the nickel metal hydride batteries. Particularly, the waste for the process was from factory during the producing program. The use of designed solvent to divide nickel and cobalt in melted state from the waste is described. Also, the result of the nickel and cobalt and melted gangue that mainly consist of lanthanide oxide are included in details. The aim of the paper is to find out a simple and feasible way to reuse waste from nickel metal hydride batteries.

Jan 1, 2009

By G. Diaz

Técnicas Reunidas (TR) has been involved for over 30 years in the development of process technologies for the recovery of zinc from different primary and secondary feed materials, such as the ZINCEXTM process. Because of the complexity of the feed mineral resources, solvent extraction (SX) is an invaluable technique to concentrate and purify zinc solutions. When applied to a pregnant leach solution, solvent extraction can produce an extremely high quality zinc electrolyte, suitable for obtaining SHG zinc ingots, after electrowinning and melting and casting processes. However, the high affinity of most organic extractants for Fe(III) poses a serious problem, which may adversely affect the zinc extraction process. Different methods may be applied to deal with the negative effect caused by Fe(III). An acid regeneration step and electro-reduction stripping have been considered as the most viable techniques to remove the iron from the organic phase. This paper describes some findings of Técnicas Reunidas in the area of zinc solvent extraction, especially on removing Fe(III) from the organic phase.

Jan 1, 2006

By E. Fockedey

he destruction of free cyanide on a Co3O4 doped carbon felt was studied. The experiments were done with an eiectrochemical filter press cell on dilute alkaline solutions containing 250 mg/l NaCN. No chloride ions were added to the solutions. The cobalt oxide protects the felt against corrosion and has a catalytic effect on the degradation of the cyanide. This kind of electrode allows working with current density as high as 1200 Aim without any visible degradation of the felt. The most interesting results were obtained with a current density of 400 Aim' at which the cyanide concentration can be lowered to 5 mg/l with a current efficiency of more than 70 % and a specific energy consumption of about 10 kWh/ kg CN.

Jan 1, 1998

A saturated, metal-free solution of alum can be used as a fiocculant to speed up the sampling procedure during a geochemical survey of stream silts.

Jan 1, 1969

By F. Dutoy, M. B. Stella, C. F. Carrozza

Rare earth elements (REEs) are indispensable components in the manufacturing of high-tech devices, renewable energy technologies, and defence applications. As global demand for these elements continues to rise, there is a pressing need to optimize extraction processes for both efficiency and environmental sustainability. This study explores approaches to rare earth extraction using Ionquest® 801 and integrates a predictive modelling to enhance process understanding and optimization. We conducted a screening test varying pH process to evaluate the best extraction efficiency. Starting pregnant leach solution (PLS), solution was prepared in the lab with the following rare earth elements: La, Ce, Gd, Dy, and Υ, at 0.02 M for each element. The data obtained were used to develop empirical and mechanistic models to predict rare earth extraction yields and flowsheet. Further tests were performed by mixing specific concentrations of different extractant and/or phase modifier. Our experimental results demonstrated the effectiveness of the proposedextraction methods, highlighting improvements in both yield and selectivity. The developedmodels successfully captured the complex relationships between process parameters and extraction efficiency, providing valuable insights for process optimization.

Nov 6, 2024

By Donald S. Macdonald

"I AM thankful for this opportunity to address the Toronto Branch of The Canadian Institute of Mining and Metallurgy. The Members of your Institute can have a great influence on the direction in which the mineral policies of Canada will evolve, and to assure that optimum benefits from our country's vast mineral resources will accrue to the nation as a whole and to all its citizens. Today, I want to: (1) offer an outlook on the mineral industry for 1973; (2) talk briefly about the role of minerals in the total economy; and (3) outline some of our thinking with respect to a national minerals policy for Canada."

Jan 1, 1973

By Mike Samuels, John Starkey

"This paper examines test results and grinding mill design for the recent Fortune Minerals’ NICO Project, located in the Northwest Territories. SAG milling and rod milling options are compared. Rod milling is clearly shown to be the best option because of the ore’s extreme resistance to breakage in a SAG mill environment.Surprisingly, the Bond Ball Mill Wi was 13 kWh/t for this ore. The Bond Rod Mill Wi was 20 kWh/t, whereas the SAG pinion energy to grind the ore to T80 1.7 mm was 30 kWh/t. The existence of ore with this ratio of SAG hardness to Bond BM Wi has not been previously observed. If not considered, this critical relationship may adversely impact the accuracy of mill design. This paper substantiates the significance of these findings to achieve successful grinding design on ore that is macro-competent during primary size reduction, but relatively normal during secondary grinding.INTRODUCTIONThe NICO Cobalt-Gold-Bismuth-Copper deposit is located 160 km northwest of the City of Yellowknife, Northwest Territories. It is the largest IOCG-type deposit (aka Olympic Dam-type) currently recognized in Canada with Mineral Reserves of 21.8 million tonnes contained within a larger 57 million tonne, lower-grade Mineral Resource. The project, owned 100% by Fortune Minerals Limited, has been assessed in a positive definitive feasibility study, subject to underground test mining and pilot plant testing, and is now in the permitting stage to develop a combined open pit and underground mine and process plant. An updated process flow sheet incorporates conventional crushing, grinding and bulk flotation, followed by filtration for shipment of a concentrate to a purpose-built refinery proposed to be built near Saskatoon, Saskatchewan. At the refinery, separate bismuth and cobalt concentrates will be produced following regrinding. The hydrometallurgical process methods include: pressure acid leach, precipitation, ion exchange, and electro-winning for recovery of cobalt as 99.8% cathode; solvent extraction and electro-winning of by-product copper cathode; ferric chloride leach and electro-winning for recovery of bismuth as 99.5% cathode; and cyanidation of the leach residues for recovery of gold as doré."

Jan 1, 2010

By B Mohanty

Several parameters such as, Energy, Strength, Brisance, Impulse, and Bubble Energy, are in common use in the explosives industry today to rate commercial explosives in terms of blasting performance. However, this multiplicity of terms, their frequent interchange and their purported one-to-one correlation with expected performance have given rise to a considerable amount of confusion, and have often resulted in unrealistic rating of explosives. In this paper, various theoretical and experimental methods of estimating energy and performance of explosives are discussed and their relative merits examined. These methods include, Computer Code Calculations, Cylinder Test, Trauzl Test, Ballistic Mortar Test, Underwater Test and Model-scale blasting. It is shown, in the light of actual blasting process, that such measures cannot be considered accurate indicators of expected blasting performance as the properties of rock to be blasted are either totally ignored or only partially accounted for in these methods. It is also shown that no single technique alone among those currently employed by the explosives industry can lead to realistic rating of explosives in terms of expected blast results. The need for the adoption of a two-tier rating system, one based on chemical potential "energy", and the other based on blasting "performance" is proposed, and specific approaches to achieve this objective are outlined.

Jan 1, 1981

By Masanori Mori, Hajime Miki, Osamu Ichikawa, Tsuyoshi Hirajima, Mitsuru Sawada, Keiko Sasaki

For pretreatment of selective flotation, surface oxidation of chalcopyrite and molybdenite was applied by oxygen plasma then the minerals were washed by solution at pH 9 with oxygen bubbling. Surface characteristics of these minerals were investigated with AFM, XPS, zeta potential and contact angle measurements. Contact angle of chalcopyrite and molybdenite decreased a lot by plasma treatment. When they were washed with pH 9 solution with oxygen bubbling, contact angle of molybdenite increased whereas chalcopyrite one kept low. Adhesion force measurements indicated similar behavior. Result of flotation experiments indicated low recovery of both chalcopyrite and molybdenite after plasma treatment and only molybdenite recovery became higher after washing. Selective flotation of chalcopyrite and molybdenite could be achieved with this process. Possible mechanism of selective flotation was proposed from the results of XPS, AFM, etc.

Jan 1, 2014

Researchers with the National Institute for Occupational Safety and Health (NIOSH) have developed a training module to educate both new, inexperienced miners as well as veterans on important issues related to self-rescue and escape procedures. These include: (1) physical and environmental conditions that can be encountered in a mine after a major explosion, (2) knowledge of emergency meeting locations and escape routes, (3) the importance of using self-rescuers, even in seemingly clear air, to keep the lungs isolated from contaminants, and (4) why miners should not go off to look for others who are missing. In addition, the module may stimulate miners to think about and discuss mine explosions and the devastating effects of such an event.

May 1, 2009