scholarly journals Heap Leaching of Greek Low-Grade Nickel Oxide Ores by Dilute Sulphuric Acid at a Pilot-Plant Scale

2021 ◽  
Vol 5 (1) ◽  
pp. 65
Styliani Agatzini-Leonardou ◽  
Paschalis Oustadakis ◽  
Dimitra Dimaki ◽  
John Zafiratos ◽  
Petros Tsakiridis ◽  

The present paper gives the thus far unpublished results of a pilot-scale heap leaching test of a Greek low-grade nickel oxide ore, aiming at verifying, at a large scale, the amenability of Greek laterites to heap leaching by the HELLAS (Heap Leaching LAteriteS) process, developed at the National Technical University of Athens for the first time worldwide and patented by some of the authors as early as in 1991. The test was conducted at the site of Aghios Ioannis mine of G.M.M.S.A. LARCO in 2006–2008 and was financed and supervised by the Institute of Geology and Mineral Exploration (I.G.M.E). The ore sample, 800 t, was from the “Triada” deposit of LARCO, in Euboea, and contained 0.73% nickel, 0.06% cobalt, 35.6% iron and 15% silicon. The ore was ground to −18 mm and the leaching agent was 2N (100 g/L) sulphuric acid solution. The nickel and cobalt recoveries obtained at the time of termination but not completion of the test, after four leaching cycles and 114 days of irrigation, were 60 and 36%, respectively. The corresponding nickel and cobalt concentrations in the produced leach liquor were 3.4 and 0.17 g/L, respectively. The value of the ratio Fe/Ni in the leach liquor was 10/1, much lower than the value 45/1 in the ore, thus showing the selectivity of the leaching of nickel over iron in the Greek ores by the above method. The consumption of sulphuric acid was 66 kg H2SO4/kg Ni recovered. The preliminary feasibility study, that followed the test, confirmed the economic viability of the integrated HELLAS process for the low-grade nickel oxide ores of Greece.

2020 ◽  
Vol 192 ◽  
pp. 02002
Anna Rasskazova ◽  
Paul Korpi

The difficulties associated with the hydrometallurgical processing of refractory ores and some methods of their solution are discussed in the article. Difficulties associated with leaching of goldcopper ores are characterized. Gold and copper content is 0.5 ppm and 0.37 % respectively in the primary ores of the Malmyzh deposit. The ore is characterized as low grade. The geotechnology method of heap leaching is feasible for low grade ores processing. The characteristics of ore material favorable for heap leaching are listed in the paper. The current trends in ore preparation for heap leaching are briefly described. Hydrodynamic parameters of spraying are one of the important aspects influencing the process result. The hydrodynamic regimes implemented in the processes of heap leaching are listed and methods for determining the rational irrigation regime and the method of feeding the solution are given. Technological studies are required for any type of ore to assess the feasibility of heap leaching. Typically, technological studies begin with laboratory stage, then large-scale research are performed and the pilot-plant tests allows assessing the feasibility of the technology on the industrial scale. In this study, laboratory scale column leaching research were carried out. A method of activation chloride leaching with sulfuric acid-peroxide pre-oxidation was developed and tested. The leaching solutions were activated by the method of electro-photo-chemical activation with sequential electrolysis and ultraviolet irradiation. As a result of the experiment, 68-80% copper recovery was achieved.

2019 ◽  
Vol 219 (3) ◽  
pp. 1698-1716 ◽  
M Malovichko ◽  
A V Tarasov ◽  
N Yavich ◽  
M S Zhdanov

SUMMARY This paper presents a feasibility study of using the controlled-source frequency-domain electromagnetic (CSEM) method in mineral exploration. The method has been widely applied for offshore hydrocarbon exploration; however, nowadays this method is rarely used on land. In order to conduct this study, we have developed a fully parallelized forward modelling finite-difference (FD) code based on the iterative solver with contraction-operator preconditioner. The regularized inversion algorithm uses the Gauss–Newton method to minimize the Tikhonov parametric functional with the Laplacian-type stabilizer. A 3-D parallel inversion code, based on the iterative finite-difference solver with the contraction-operator preconditioner, has been evaluated for the solution of the large-scale inverse problems. Using the computer simulation for a synthetic model of Sukhoi Log gold deposit, we have compared the CSEM method with the conventional direct current sounding and the CSEM survey with a single remote transmitter. Our results suggest that, a properly designed electromagnetic survey together with modern 3-D inversion could provide detailed information about the geoelectrical structure of the mineral deposit.

2017 ◽  
Vol 169 ◽  
pp. 99-105 ◽  
Baozhong Ma ◽  
Weijiao Yang ◽  
Peng Xing ◽  
Chengyan Wang ◽  
Yongqiang Chen ◽  

Arndt Wiessner ◽  
Jochen A. Müller ◽  
Peter Kuschk ◽  
Uwe Kappelmeyer ◽  
Matthias Kästner ◽  

The large scale of the contamination by the former carbo-chemical industry in Germany requires new and often interdisciplinary approaches for performing an economically sustainable remediation. For example, a highly toxic and dark-colored phenolic wastewater from a lignite pyrolysis factory was filled into a former open-cast pit, forming a large wastewater disposal pond. This caused an extensive environmental pollution, calling for an ecologically and economically acceptable strategy for remediation. Laboratory-scale investigations and pilot-scale tests were carried out. The result was the development of a strategy for an implementation of full-scale enhanced in situ natural attenuation on the basis of separate habitats in a meromictic pond. Long-term monitoring of the chemical and biological dynamics of the pond demonstrates the metamorphosis of a former highly polluted industrial waste deposition into a nature-integrated ecosystem with reduced danger for the environment, and confirmed the strategy for the chosen remediation management.

Geophysics ◽  
2013 ◽  
Vol 78 (3) ◽  
pp. B111-B119 ◽  
Xiangyun Hu ◽  
Ronghua Peng ◽  
Guiju Wu ◽  
Weiping Wang ◽  
Guangpu Huo ◽  

A controlled-source audio-frequency magnetotelluric (CSAMT) survey has been carried out to investigate potential iron (Fe) and polymetallic (Pb-Zn-Cu) deposits in Longmen region, which is one of the main metallogenic belts in southern China. Conducting geophysical surveys in this area is quite difficult due to mountainous terrain, dense forest, and thick vegetation cover. A total of 560 CSAMT soundings were recorded along twelve surveying lines. Two-dimensional Occam’s inversion scheme was used to interpret these CSAMT data. The resulting electric resistivity models showed that three large-scale highly conductive bodies exist within the surveying area. By integrated interpretation combined with available geologic, geophysical, and geochemical data in this area, three prospective mineral deposits were demarcated. Based on the CSAMT results, a borehole penetrating approximately 250-m depth was drilled at the location of 470 m to the northwest end of line 06, defined with a massive pyrite from the depth of 52–235 m with 7%–16% Fe content, as well as locally high-grade Pb-Zn- and Ag-Ti-bearing ores.

2016 ◽  
Vol 51 (3) ◽  
pp. 195-200 ◽  
I. M. Gharatloo ◽  
A. N. Golikand ◽  
M. B. Fathi ◽  
R. S. Gharabagh ◽  
I. Hasanzadeh

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