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It is estimated that the tailings dam of the Mouteh Gold Mine, in Iran, contains more than 770 kg of gold. Microscopic analysis reveals that sulphide minerals and active carbon are the main sources of the gold in the tailings residue. Flotation and cyanidation tests on the samples of tailings were conducted. Flotation concentrates, containing around 87.79% of the gold, which were associated with sulphide minerals, were recovered. By regrinding, roasting, and cyanidation of the flotation concentrate, the gold dissolution recovery was in the range of 87.8 to 98.4%. The carbon-in-column method was used to recover 98% of the gold from the solution. Keywords: gold ore, pyrite, flotation, roasting, cyanidation

Jan 1, 2009

By Michael J. Nicol

Growing environmental and occupational safety concerns about the use of cyanide in gold processing has increased the interest in more acceptable alternatives. The most likely of these is thiosulfate. However, the thiosulfate process lacks a proven in-pulp method of recovering the dissolved gold, because activated carbon is not effective for the absorption of the gold thiosulfate complex .. Anion exchange resins do offer a possible route for in-pulp recovery. This paper describes work aimed at the evaluation of the effectiveness of commercially available anion exchange resins for the recovery of gold from thiosulfate leach liquors? and pulps. It has been found that strong-base resins are superior to weak-base resins in that they have a larger capacity, which assists in reducing the competition from other anions within a leach solution. Further studies with a selected commercial strong-base resin have shown that competing polythionateanions (particularly tri-and tetrathionate). Lower the maximum possible gold loading but that gold is selectively recovered over other base metal anions in solution. Kinetic experiments found that while? competilig anibns did not affect the initial rate? of gold loading it was important to minimise the contact time of the resin in solution so to prevent displacement of loaded gold by competing anions over longer times. A small-scale resin-in-pulp plant investigation showed gold can be recovered from a leach pulp by a strong-base resin to yield gold loadings of 3000 mg/L, barren pulp containing less than 0.05 mg/L of dissolved gold and. copper loadings of 500 mg/L. Loaded copper was displaced gold and at a loading of 2000 mg/L gold the copper loading was minimal «500 mg/L). The resin was found to recover gold adsorbed on the solids that would, otherwise have. reported to tails if a solid/liquid separation method were used. A patented two-step elution process in which copper and then gold are separately eluted from the resin is also discussed.

Jan 1, 1998

By O. J. R. Baena, N. J. Zapata

In Colombia, more than 15 regions and around 100 municipalities develop gold mining at different scales, and these operations generate mining waste composed of processing fluids and crushed rock with metals and high silica content. Cement production requires clinker, gypsum and other corrective additives. Clinker results from the partial fusion of some minerals including silica. In this study is proposed to evaluate the effect of the use of mining tailings sands from gold mining in the manufacture of clinker. The proposed methodology will allow the characterization of the sands to manufacture a cement specimen and measure its physical and fire properties

Mar 2, 2022

By Ricardo Montero

At this time, over 300 tons of Au are used in electronic equipment each year with other precious and strategic metals such as Ag, Pt, Pd, Cu, Nb, Ta, etc. After the use-phase, the electronic devices become electronic waste (e-waste); consequently it is important to consider e-waste as a secondary supply for recovery of these metals. One of the most important components is the printed circuit boards (PCBs) because the amount of their precious metals is ten times higher than rich precious metals bearing ore. This paper presents the recovery of Au, Ag, Cu and Nb from PCBs of discarded computers using leaching column technique. The amount of these metals in used PCBs was: 613 g/ton of Au, 1515 g/ton of Ag, 36 g/ton of Nb and 23.4 % of Cu. The PCBs were crushed with a hammer mill until reaching a particle size between 3.33 mm to 0.43 mm. Then, it was leached with sodium cyanide solution in a glass column using the following conditions: sodium cyanide concentration 4 g/L, flux 20 L/kg PCBs day, pH between 10.5 to 11 and leaching time 15 days. Every day, after leaching, the pregnant solutions passed through a column with activated carbon to complete the closed loop system. The following recoveries were obtained: 46.6% of Au, 51.3% of Ag, 47.2% of Nb and 62.3 % of Cu. The products obtained are: a) loaded carbon that contains the desired metals and b) processed PCBs with precious metal contents. A preliminary technical-economic study shows the feasibility to create a small-scale PCBs recycling plant. The initial investment is on the order of US$ 155 639, considering the recovered metals from loaded carbon. The internal rate of return for 10 years period (IRR) and net present value (NPV) estimated are 27% and US$ 105 926 respectively. Keywords: printed circuit boards, recovery, precious metals, niobium, leaching column

Sep 1, 2012

By Yehia M. Youssef, Nourhan Moukhtar, M. H. Abdel-Aziz, Ibrahim Hassan

Copper was recovered from copper sulfate solution in a batch-recycled galvanic reactor operated under forced convection with the generation of electrical energy during the cementation process. The divided galvanic cell consisted of parallel copper and zinc plates. The mass transfer rate and the amount of electrical energy generated were found to be directly proportional to the solution flow rate and the initial concentration of metallic ions and inversely proportional to the distance between electrodes. The experimental results were expressed in terms of a dimensionless correlation including all parameters. The wastewater treatment presented herein cell can be utilized to recover many soluble heavy metal ions from solution with high efficiency.

Oct 2, 2020

By H. Shafick Hanna

The major problems are identified the high phosphorus content and the fine dissemination or encapsulation of mineral impurities, in, ,the iron bearing minerals, A process which combined extreme fine grinding techniques with magnetizing roasting or flotation separation methods, is suggested. By these methods concentrates assaying 60-61 percent Fe exceeding the widely accepted upper limit of 56 percent Fe set for these ores, were produced with 75-90 percent iron recovery. Moreover it was shown that the phosphorus content of these concentrates could be reduced from 0.25 to 0.03 percent phosphorus by acid leaching. A brief discussion on production costs based on current and future developments in iron ore processing is given.

Jan 1, 1980

By Wen Chen, Xinghua Liu, Zeyou Peng, Qiulin Wang

"Limonite is a collective for iron hydroxide argillaceous materials. It is very difficult to be treated due to the wide variation in specific gravity and magnetism and the high argillization rate in the course of grinding and beneficiation. The iron ore in Huangmei, Hubei, China is the typical representative of limonite. If the limonite is processed using conventional physical beneficiation methods (e.g. magnetic separation, gravity separation, flocculation-desliming-flotation, or a combined process of the three), it can only be obtained an iron concentrate grade of 51.98% and an iron metal recovery of 86.64%. However, the technique of flash magnetic roasting-magnetic separation can improve the concentrate grade to 61.03%, iron recovery to 91.17%. This paper describes the tests of recovering limonite by flash magnetic roasting in detail.IntroductionLimonite (mFe2O3, nH2O)[1] is a general designation for hydrous iron hydroxides and argillaceous matters. Limonite is hard to be separated because of its complicated geneses, comparatively weak magnetism, nonuniform grain size and being easily slimed during grinding. So most small and medium enterprises sell deslimed limonite product which was dealt with just by simple methods of washing, magnetic separation or gravity separation and so on. In recent years with the iron ore prices soaring, significant progress was made in mineral processing research of limonite. Laboratory research and industrial test results showed that flocculation-desliming-flotation process and roasting-magnetic separation process are the two best methods to recover limonite till now. To compare these two methods, roasting-magnetic separation process is superior to flocculation-desliming-flotation process in aspects of beneficiation indexes and industrial stability."

Jan 1, 2012

By Mariana H. Staia

The present communication reports the results obtained by applying different concentration methods, at laboratory level, to the black sands from Estado Bolivar, Venezuela, with the aim of obtaining an adequate ilmenitic concentrate for the subsequent chlorination process. Sizing analysis was performed and plasma emission spectroscopy method was used to determine the chemical composition. It was found that from the two hydrogravimetric methods used, the Humphrey spirals is much more effective than Wilfley tables, leading to a 85% recovery. The most convenient particle size group for these concentration methods was the one corresponding to ASTM 40-140 mesh. When magnetic concentration was applied to the concentrate, obtained as a product from Humphrey spiral, a recovery of ilmenite more than 90% was obtained in the first step. It has been shown that the ore would respond to the separation techniques employed, giving individual minerals: ilmenite, zircon and silica as concentration products.

Jan 1, 1995

By S. M. Hay

The zinc content of blast furnace and basic oxygen furnace dusts is low compared with electric arc furnace dusts and it is generally not economical to treat the dusts to recover zinc. However, they have a high iron content and removal of the zinc would allow recovery of the iron values. A literature review and thermodynamic analysis was undertaken and, as a result, several smelting options were identified. This paper describes experiments undertaken to develop understanding of metallurgical aspects of these processes which are not amenable to theoretical analysis. Dusts from an Australian steelworks were characterised in order to determine their mineralogical make-up and the form of the iron. The processing aspects investigated in the laboratory were slag-metal equilibrium and solid-state pre-reduction using reducing gases of compositions expected from bath-smelting processes. Particular attention. was paid to the deportment of zinc, sodium, potassium, phosphorous and sulfur between the phases formed during smelting and pre-reduction. The smelting results indicate that less than 10% of the zinc, sulphur, sodium and potassium report to the metal. About 99% of the zinc and potassium and about 80% of the sodium could be volatilised from the dusts by reducing them at 1,000°C with mixtures of CO, CO2, H2 and H2O even when metallic iron was not formed. The experiments indicate that smelting of blast furnace and basic oxygen furnace dusts should produce hot-metal of a composition which can be blended into the main stream of hot-metal in the steelworks.

Jan 1, 1994

By R. Kumar, N. R. Mandre

"The beneficiation of iron ore slimes by selective flocculation was studied. Polyacrylamide (PAM) and guar gum were used as flocculant, along with sodium hexametaphosphate (SHMP) as a dispersant. The samples collected were initially subjected for chemical and mineralogical studies. The mineralogical studies indicated the presence of haematite and goethite as the principal iron-bearing minerals, with quartz and kaolinite as gangue minerals. The selective flocculation tests showed that the Fe grade can be enhanced from 58.24% to 64.60% Fe at a recovery of 66.33% using polyacrylamide as the flocculant. A Fe grade of 63.20% at a recovery of 68.04% was obtained using guar gum as flocculant. The efficacy of the studies was analysed using a separation index, which indicated that the higher separation index was obtained with the tests employing polyacrylamide as the flocculant. IntroductionIndia is endowed with huge reserves of highgrade iron ore and is one of the prominent producers in the world. As the high-grade iron ores have been exhaustively mined, it has become imperative to use low-grade iron ores, fines, and slimes to meet the growing demand. Also, generation of fines and slimes during mining and processing contributes to loss of minerals to the extent of 30% of the total value (Mandre and Panigrahi, 1997). These fines/slimes are often discarded as waste into tailing ponds, containing considerable amounts of iron. Therefore beneficiation of tailings/slimes has become necessary for optimal utilization of the resources.In recent years, interest in recovery of valuable minerals from low-grade ores, slimes, and tailings has increased worldwide. These activities are initiated not only to recover minerals but also to address various environmental issues associated with fine particle treatment. The literature reveals that several technologies have been employed in this regard, including flotation, advanced gravity separation, and high-intensity magnetic separation. However, these processes are found to be ineffective for fine particle treatment due to lower collision probability in flotation, decreased gravitational effect in gravity separation, and reduced drag force in magnetic separation, among other factors (Batisteli and Peres, 2008; Das et al., 2007; Dworzanowski, 2012; Rocha, Caneado, and Peres, 2010). Therefore, it is in this regard that selective flocculation has gained importance in treating slimes in recent years."

Jan 1, 2017

By M. Adnan Göksel

Pyrite cinder is generated by roasting pyrite for sulfur dioxide production. It contains up to 62% iron, but also may contain other hazardous or toxic materials such as Zn, Pb, As, T1, Cd, Cu, Sn and S. Furthermore, the physical characteristics are not properly suited for conventional sintering. As a result pyrite cinder is considered to be unsuitable for iron and steelmaking or for outside storage because of its potential for causing environmental problems. In recent years industrialized nations have put increasing pressure on the manufacturers to either use such waste products or properly dispose of them. In this study, solutions to both the iron recovery and disposal problem were attempted by pelletizing the pyrite fines with internal carbon. The pellets, after hydrothermal hardening, were reduced and melted in a furnace for hot metal production. Hot metal of usuable quality was produced and the hazardous materials were either collected with the fumes or in the slag.

Jan 1, 1984

By Y. S. Sun, P. Gao

"In this investigation, a pilot-scale suspension magnetization roasting reactor was introduced and used to enhance magnetic properties of an iron ore. Consequently, the effects of roasting temperature, reducing gas CO flow rate and fluidizing gas N2 flow rate on the magnetization roasting performance were investigated. The results indicate that the hematite and siderite are almost completely converted into magnetite by a gas mixture of 3.5 Nm3/h CO and 2 Nm3/h N2 at roasting temperature of 520 °C. Under the optimized conditions, the magnetic iron concentrate with an iron grade of 60.18% and iron recovery of 90.17% was achieved. The XRD and Fe mineral phase analyses revealed that most of the hematite and siderite were converted to magnetite, and the magnetic properties were greatly enhanced. INTRODUCTION The steel and iron industry in China has rapidly developed in recent years requiring a large quantity of iron ores. Low-grade and complex iron ores are currently the overwhelmingly dominant mineral resource for iron in China. Therefore, China depends on imported iron ore resources heavily, resulting in an increase in the production costs of iron-making and steel-making[1-3]. Using domestic resources to produce a steady supply of high-quality iron ores is an important step toward the sustainable development of the steel and iron industry[4-5]. The iron ore from Jiuquan iron and steel company is abundant and recognized as typically complex iron ore resources in China. Magnetization roasting followed by low-intensity magnetic separation has been proven as the most feasible methods to upgrade refractory iron ore[6-10]. In present research, an innovative roasting technology, namely suspension magnetization roasting, was developed and applied to recover iron from a typical refractory iron ore. Suspension magnetization roasting technique and equipment developed by Prof. Yuexin Han’s Group at Northeastern University (NEU) is an effective way for the utilization of refractory iron ore. The advent of suspension magnetization roasting will, in China and even globally, produce a significant technological revolution in the field of iron ore beneficiation. Based on the previous works, this paper mainly described experiments on the separation and recovery of iron from a complex refractory iron ore by means of suspension magnetizing roasting and low-intensity magnetic separation processes. The purpose of the research is providing a new technology for effective utilization of refractory iron ore. Process parameters that affected the separation and recovery rate of iron were conducted and optimized, and the reaction process was analyzed by XRD and Fe mineral phase analysis."

Jan 1, 2018

By Yuexin Han, Jie Liu, Shuai Yuan, Yanjun Li

"In order to improve recovery efficiency of iron minerals from iron ore tailings and to reduce its connected environmental pollution, this article investigated the reducing roasting of iron ore tailing in a laboratory fluidized magnetization roasting reactor to optimize the roasting method and conditions. The examined parameters included roasting temperature, roasting time and reducing atmosphere. The parameters evaluating magnetizing roast efficiency and theoretical value were determined. X-ray diffraction (XRD) analysis was used to investigate the conversion of iron phase after roasting. The results show that the best magnetizing roast conditions are roasting temperature of 540?, holding time of 15min, and CO concentration of 20%. The magnetization conversion ratio of roasting products is over 80%, under the best magnetic separation condition, the concentrate grade of iron is 65.61 % and the recovery of iron is 83.77 %. The XRD analysis shows that Fe exists in hematite and siderite before roasting and exists in magnetite after roasting. The technique not only recovers the iron minerals from tailings with good economic benefit, but also reduces the environmental pollution of tailings accumulation.INTRODUCTION Iron ore tailings are the solid wastes generated during the beneficiation process of iron ore concentration and are one of the main pollution concerns in the mining industry (Das et al., 1996). Continuous development of the iron and steel industry has led to the increasing amount of iron ore tailings; there are over 300 million tons of iron ore tailings discharged per year (Rao et al., 2016). The huge amount of stockpiled iron ore tailings brings a series of environmental and social problems. Comprehensive utilization of iron ore tailings can not only reduce environmental load but also conserve resources, promoting sustainable development of the society. In recent years, iron ore tailings as secondary resources have received considerable attention in many countries in the word and numbers of studies on utilization of iron ore tailings were carried out, such as recycling the valuable minerals (Datta et al., 1996; Jia et al., 2013; Panda et al., 2018), used in construction material compositions as alternative source of raw materials (Das et al., 2012; Zhou et al., 2012; Luo et al., 2016) and other utilization. The iron minerals were recovery by magnetization roasting (Rao et al., 2016; Yang et al., 2013; Yang et al., 2011) and flotation (Kumar and Mandre, 2016). By comparison the reduction roasting has more advantages, but it was found that the conventional roasting equipment was inefficient, high energy consumption and un-economically applied on an industrial-scale."

Jan 1, 2018

By M Gerards, M Steinberg, T Graham

The quality and quantity of Australia’s secondary deposits, which include tailings streams and tailings dams, are higher than most countries’ primary deposits. In addition, these secondary deposits have already been mined and processed, meaning that the recovery of high-grade product requires low capital and operating costs.The most widely used process for the recovery of these valuable fine and ultra-fine hematite iron particles is the wet high-intensity magnetic separation technique, originally developed by Dr Jones over 55 years ago. Many of the original machines are still working today.The aim of this paper is to demonstrate the capabilities in terms of grade and yield of using sophisticated magnetic separation modules. All results and figures are obtained from test work and design and engineering work with material from the Pilbara. In addition, consideration is given to dewatering of iron ore product and tailings.Two types of tailings have been identified for processing. Firstly, tailings that have already been deposited in a tailings storage facility, and secondly, live tailings streams from an existing wet iron ore beneficiation plant. In both cases, the technical and practical results are shown along with relevant flow sheets and plant layouts. Finally, this paper highlights the total predicted power and water consumption, capital requirements and projected operating expenses.The results show that the operating costs are significantly lower than the mining and processing operations that are required for an equivalent amount of iron ore. The recovery of iron depends on various factors but is within the 30–50 per cent range at an equivalent grade to the mainstream product. Another significant benefit is that the magnetic separation process is water positive, meaning that water is released rather than added in the process.The processing of the Pilbara’s secondary deposits will therefore result in an overall reduction in operating costs, an increase in product yield from a plant, extend the life-of-mine and offer environmental benefits by reducing the tailings footprint and water usage.The quality and quantity of Australia’s secondary iron ore deposits and tailings are such that many other countries would judge these as equivalent to primary deposits. Furthermore, these tailings are already mined, available and liberated to such an extent that the recovery of a valuable product is highly economical in terms of capital expenses and operating expenses.CITATION:Steinberg, M, Graham, T and Gerards, M, 2015. Recovery of iron ore fines and ultrafines from tailings by using wet high-intensity magnetic separation – JONES WHIMS, in Proceedings Iron Ore 2015, pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Cz. Mora, A. Pawelczyk, D. Hreniak, P. Nowak, A. Dyonizy, S. Strek, W. Strek, K. Grabas, A. Ostrowski

Globalization and a growing demand for limited raw material resources have forced changes in the approach to the supply chain. This is particularly true in the case of rare earths, which are regarded as one of the most important development indicators of modern technologies. To ensure a secure supply of commodities, the European economies have been prompted to investigate REE recovery from sources which until recently, for technical or economic reasons, were considered not sufficiently attractive. An interesting example is apatite phosphogypsum waste dumps. The REE content in these waste dumps averages around 0.5-1 %. One of the most important phosphogypsum locations in Poland is the Lower Silesia region where a phosphoric acid Chemical Plant "Wizów" operated for several dozen years. In this work, rare earths are leached from the phosphogypsum crystalline structure by a chemical treatment and can then be separated into individual chemical compounds. The technology used in these recovery tests, matches up to a coherent European raw materials policy supporting effective management of resources and promoting waste materials recycling.

Jan 1, 2014

By J. L. Watson

n the U.S., lead has been produced via blast furnace processing for over a century, and the slags from that pyro-metallurgical process have been accumulating on industrial sites over that extended period. Lead blast furnace slags typically contain both lead and zinc compounds in an iron-silicate matrix, and it appears highly likely that such materials will have to be processed in the near future to meet with EPA regulations. Thus it is appropriate to investigate possible processing routes to render the slags non-hazardous and simultaneously to recover metal values to partially off-set the inherent high cost of processing such materials. There are two major processing alternatives: one being pyrometallurgical and the other hydrometallurgical. The research reported here investigates leaching/solution purification/recovery processes for lead and presents experimental data for the treatment of lead blast furnace slags from S.E. Missouri. The results of the research suggest that both lead and zinc can be removed effectively from the slag, and that metallic lead can be recovered directly from the organic extractant utilized for solution purification.

Jan 1, 1995

By M. K. Mohan

Lead recovery from process solutions contributes not only to the conservation of resources but also clean environment. Zeolites are natural aluminosilicates, which finds applications as catalysts and in wastewater treatment. In the present investigation, studies were taken up on the processing of Pb from process solutions by zeolites. Effects of pH of the solution, time and type of zeolite viz. chabazite, mordenite, erionite and clinoptilolite on the removal of Pb from solutions was investigated. Rate of sorption was found to depend on the pH of the solution and about 99 pct. recovery was observed at pH 6. Optimal conditions were established for the maximum recovery of lead from process solutions. Possible sorption mechanisms were proposed. The calculated adsorption constants calculated from Langmuir and Freundlich equations showed that the adsorption of lead on chabazite was strong.

Jan 1, 1999

By J. Rastas

The recovery of lead, silver and gold from existing and potential zinc process residues using a sulfidization-flotation method was investigated on a laboratory scale. The following residues were tested: neutral leach residue, high acid leach residue, and hematite residues. The sulfidization of lead and silver is carried out at low pH by the addition of a stoichiometric amount of sulfide at a controlled rate. To increase the particle size of the sulfides, seeding with synthetic lead and silver sulfides -is employed. The flotation is carried out at pH 2-4 using low pH-collectors such as dithiophosphates and dithiophosphinates. Special attention must be paid to the role of oxygen in the conditioning stage. The effect of different parameters on both the sulfidization and the flotation has been evaluated. Recoveries of 85-90, 90-95 and about 80 % were obtained for lead, silver and gold, respectively. Typically, concentrates containing 50-60 % lead, 3-5 kg/t silver and 10-15 git gold were produced.

Jan 1, 1990

By Rajashekhar Marthi

Lithium is a key component for future electric vehicle batteries and energy storage. The future availability of lithium to meet the growing demands remains in question. Around 60% of lithium resources exist in the form of continental brines. Traditional methods to recover lithium from brines use solar concentration with precipitation and have found limitations in lithium extraction due to interference of Mg in high Mg/Li brines. Thus, there is a need for highly selective adsorbents. Recently, spinel structured delithiated lithium manganese oxides have demonstrated promising results. However, due to the small particle sizes, it is economically difficult to recover the adsorbents and thereby limits industrial applications. In our work, LiMn2O4 ion sieve was synthesized and immobilized on diatomaceous earth. Fundamental adsorption studies were carried out in lithium buffer solutions to understand the nature of adsorption and kinetics. The adsorbents were also tested for recycle stability, as well as recovery of lithium from Great Salt Lake water samples.

By G. M. Ross, I. M. Ross, J. A. Scott

"The otherwise waste heat in many water streams in the mining industry can be used to provide space heating of adjacent infrastructure including laboratories, workshops, and offices. This can be achieved by using heat pump systems, which can work as a replacement or in conjunction with existing space heating. In the example investigated—process cooling streams at an ore smelter—the analysis provided illustrates that annual heating costs can be 19% lower and a simultaneous 62% reduction in CO2 emissions can be achieved.RÉSUMÉ Dans l’industrie minière, la chaleur qui serait normalement perdue des circuits d’eau pourrait servir à chauffer des structures adjacentes incluant les laboratoires, les ateliers et les bureaux. Cela pourrait se faire en utilisant des systèmes de thermopompes, qui pourraient remplacer ou s’ajouter au chauffage existant. Dans l’exemple étudié, des circuits de refroidissement de procédé à une fonderie, l’analyse fournie illustre qu’il est possible de réduire les coûts annuels de chauffage de 19 % et d’obtenir une réduction simultanée de 62 % des émissions de CO2."

Jan 1, 2016