Temat: laterite - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Removal of chromium and strontium from aqueous solutions by adsorption on laterite
Autorzy:: He, Yong
Chen, Yong-Gui
Zhang, Ke-Neng
Ye, Wei-Min
Wu, Dong-Yu
Tematy:: adsorption
isotherms
chromium
strontium
laterite; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/204768.pdf Link otwiera się w nowym oknie
Opis:: To investigate the adsorptive properties of a local laterite deposited in Chenzhou, Hunan province, China, the adsorptive properties of the natural laterite were investigated by batch technique in this study. The effects of contact time, pH, ionic strength, temperature, and the concentration on adsorption properties were also analyzed. The obtained experimental results show that the main mineral composition of laterite is kaolinite and montmorillonite. The adsorption process achieved equilibrium within 60 minutes and 90 minutes for Sr(II) and Cr(VI), respectively. The adsorption capacities for Cr(VI) and Sr(II) by the laterite were about 7.25 mg·g^-1 and 8.35 mg·g^-1 under the given experimental conditions, respectively. The equilibrium adsorption data were fitted to the second-order kinetic equation. The adsorption capacity for Sr(II) onto the laterite increased with increasing pH from 3–11 but decreased with increasing ionic strength from 0.001 to 1.0 M NaCl. The Sr(II) adsorption reaction on laterite was endothermic and the process of adsorption was favored at high temperature. Similarly, the adsorption capacity for Cr(VI) onto the laterite increased with increasing pH from 3–11, however, the ionic strength and temperature had an insignificant effect on Cr(VI) adsorption. The adsorption of Cr(VI) and Sr(II) was dominated by ion exchange and surface complexation in this work. Furthermore, the Langmuir and Freundlich adsorption isotherm model was used for the description of the adsorption process. The results suggest that the studied laterite samples can be effectively used for the treatment of contaminated wastewaters.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Leaching behaviour of a turkish lateritic ore in the presence of additives
Autorzy:: Basturkcu, H.
Acarkan, N.
Tematy:: laterite
nickel
agitation leaching
dissolution; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110446.pdf Link otwiera się w nowym oknie
Opis:: This paper investigates the dissolution mechanism of a lateritic nickel ore from the Caldag Region of Manisa in Turkey. The ore sample contained 1.2% Ni, 24.8% Fe, and 0.062% Co. The optimum leaching conditions were found to be temperature 80 oC, particle size -74 μm, H2SO4 concentration 200 g/dm3, solids ratio (by weight) 10% and leaching duration 8 h. The extractions of 98.2% Ni, 98.6% Fe and Co 98.9% were obtained under these conditions. Additionally, the effects of additional substances such as NaCl, Na2S2O5, Na2SO4, and KCl were investigated in order to decrease the leaching duration. The results showed that the additives accelerated the leaching kinetics and achieved nearly the same nickel and cobalt extractions at the end of 4 h compared to the results obtained after 8 h without the additives. If the additives containing chlorine were used, it was determined that the iron extraction showed no increase, although both the nickel and cobalt extractions increased.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Effects and mechanism of Bayer red mud on co-reduction with a saprolitic laterite ore to prepare ferronickel
Autorzy:: Wang, Xiaoping
Sun, Tichang
Wu, Shichao
Hu, Tianyang
Rong, Lingkun
Tematy:: red mud
laterite ore
co-reduction
ferronickel powder; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1449072.pdf Link otwiera się w nowym oknie
Opis:: Co-reduction of a saprolitic laterite and waste Bayer red mud was investigated to prepare ferronickel powder. The synchronous reduction and comprehensive recovery of nickel and iron in the low-grade laterite ores and iron in the red mud were realized. At the red mud dosage of 50 wt%, ferronickel powder with nickel and iron grades of 5.58 wt% and 89.91 wt% was obtained. The corresponding nickel and total iron recoveries were 93.11 wt% and 90.23 wt%, respectively. The red mud enhanced the nickel recovery of the saprolitic laterite ore evidently, attributing to the formation of low-melting anorthite, omphacite, and diopside during co-reduction. This led that NiO in the saprolitic ore was released. Meanwhile, obvious melting phenomenon of the roasting system was appeared, enhancing the growth of the ferronickel particles.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Study on leaching kinetics of laterite ore using hydrochloric acid
Autorzy:: Li, Jinhui
Xu, Zhifeng
Wang, Ruixiang
Gao, Yang
Yang, Yang
Tematy:: nickel laterite
hydrochloride acid
kinetics analysis
hydrometallurgy
leaching mechanism; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110911.pdf Link otwiera się w nowym oknie
Opis:: The process of atmosphere-pressure acid leaching of laterites has attracted considerable attention in the nickel industry in recent years. However, the leaching kinetics of laterite using hydrochloride acid has not yet been fully researched. In this paper, the mineral analysis of the ore was carried out, and the leaching mechanism of different minerals at different time was studied comprehensively. The kinetics analysis of the leaching process of nickel, cobalt and manganese showed that the kinetics model of diffusion controlling was suitable and could be described by the linear equation, 1-3(1-a)2/3+2(1-a)=k2t. Based on the linear equation and the Arrhenius equation, the values of activation energy of metal leaching can be deduced (11.56 kJ/mol for nickel, 11.26 kJ/mol for cobalt and 10.77 kJ/mol for manganese). Study of leaching mechanism shows that the order of these minerals dissolution is: goethite, lizardite, magnetite and hematite. Due to the original or product of silica, magnetite, hematite and talc, they can form the solid film which hinders the leaching of valuable metals. Thus, the diffusion controlling step is inner diffusion, namely solid film diffusion controlling.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Separation of nickel and iron from lateritic ore using a digestion – roasting – leaching – precipitation process
Autorzy:: Basturkcu, H.
Acarkan, N.
Tematy:: laterite
digestion
roasting
salt addition
leaching
precipitation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109861.pdf Link otwiera się w nowym oknie
Opis:: This paper investigates extraction of nickel and iron from a lateritic nickel ore from the Caldag region of Manisa in Turkey. The ore sample contains 1.2% Ni, 24.77% Fe and 0.062% Co. The process applied includes digestion with 40 wt-% sulfuric acid at 200 C for 60 min, roasting at 700 C for 15 min, leaching with water for 30 min at 1:5 solid/liquid ratio (by weight) and precipitation of the remaining iron at pH 3 and 60 C. In order to improve nickel and cobalt extractions using the digestion-roasting- leaching-precipitation process (DRLP), Na2SO4 addition in the roasting stage was examined. Under the optimum conditions and in the presence of Na2SO4, 86.2% Ni and 94.2% Co extractions were obtained with almost zero iron content. As a result, 2.07 g dm-3 Ni, 0.12 g dm-3 Co and 0.05 g dm-3 Fe could be achieved in the pregnant leach solution within nearly 2.5 hours.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Atmospheric pressure leaching of nickel from a low-grade nickel-bearing ore
Autorzy:: Javanshir, S.
Mofrad, Z. H.
Azargoon, A.
Tematy:: leaching
kinetics
calcination
laterite ore
nickel recovery; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110534.pdf Link otwiera się w nowym oknie
Opis:: This study focused on the extraction of nickel from a low-grade lateritic ore. The characterization of representative samples was done by X-ray diffraction (XRD), X-ray fluorescence (XRF), and microscopic mineralogical studies. Nickel was uniformly distributed in iron (hydr)oxide minerals. The pre-concentration of nickel was attempted by magnetic separation, but was unsuccessful. The effect of the type of lixiviant, acid concentration, S/L ratio, time, and temperature were investigated in the atmospheric leaching process. Based on the experimental data, optimum conditions for the maximum recovery of nickel were determined under the following conditions: 5 M H₂SO₄, 25% (w/v), 90 ºC, and two hours. Pre-calcination, for increasing nickel extraction by converting goethite to hematite, was carried out on raw ores at different times (30-180 minutes) and temperatures (180-540 ºC). Recovery was found increasing from 69 to 95% under the same conditions. Kinetic studies were conducted by fitting the data with Shrinking Core (SC) models. The study determined, from the estimate of activation energy, that the rate of reaction controlled by chemical reaction.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Influence of chemical and biogenic leaching on surface area and particle size of laterite ore
Autorzy:: Pawlowska, A.
Sadowski, Z.
Tematy:: nickel
laterite ores
leaching
citric acid
Aspergillus niger; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110297.pdf Link otwiera się w nowym oknie
Opis:: Currently there is a decline in the world’s nickel sulfide deposits, which are the main source of this metal. Due to the fact, that more than 70% of nickel reserves are in the form of oxide ores, more attention is nowadays paid on laterites. Leaching processes using different organic acids are widely described in the literature, but there is a lack of works linking influence of leaching process with the surface area and particle size distribution. Therefore, the main aim of this study was to examine how citric acid produced by microorganisms and citric acid added as chemical affected the specific surface and particle size distribution of mineral particles. The laterite ore was obtained from Szklary deposit, Poland. This study also compared the effect of chemical citric acid and filtrate after cultivation of Aspergillus niger on nickel extraction. It was observed that higher nickel recovery correspond to higher surface area of particles. The highest yield of nickel extraction was observed for a citric acid concentration of 1 mol/dm3 (67%). The specific surface area after leaching was 159 m2/g. An analysis of particle size distribution showed increase in the median particle size of particles after leaching with citric acid. It may suggest that dissolution of Polish laterites follows a shrinking core-shrinking particle model.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Applicability analysis of the electrical resistivity tomography (ERT) method for the diagnosis of laterite cover thickness.
Analiza możliwości zastosowania metody tomografii elektrooporowej (ERT) do rozpoznania miąższości pokrywy laterytowej
Autorzy:: Pacanowski, Grzegorz
Piechota, Arkadiusz
Mieszkowski, Radosław
Czarniak, Paweł
Wydawca:: Państwowy Instytut Geologiczny - PIB
Cytata wydawnicza:: Pacanowski, G., Czarniak, P., Piechota, A., Mieszkowski, R.(2016). Analiza możliwości zastosowania metody tomografii elektrooporowej (ERT) do rozpoznania miąższości pokrywy laterytowej. Przegląd Geologiczny, 64(4), 245-253.
Opis:: The paper discusses the problem of determining the thickness of a laterite cover using electrical resistivity tomography (ERT) in a selected area of the Seram Island in Indonesia. Seram Island lies in the tropical zone between the Seram and Banda seas. The laterite covers are rich in nickel, cobalt, iron and other metals. Concentrations of these metals in the laterites are high enough to form economic deposits. A significant part of the report concerns the measurement technique (ERT method) in difficult climatic (high humidity and temperature) and topographic conditions (equatorial jungle with significant variations in elevation) and the methods of processing and interpretation of the acquired data. The problem seems very interesting, because geophysical prospecting is currently more and more often conducted in poorly accessible regions of the world. Additionally, there are no sufficient and commonly available publications that would allow us to get acquainted with local measurement problems by potential contractors of similar geophysical investigations. The primary result of the geophysical survey was to determine the electrical resistivity of bedrock and laterite. This was the basis for the development of sections of electrical resistive distribution for the ERT profiles, which enabled to estimate the depth to the crystalline basement and the laterite thickness. It also facilitated to produce a map of laterite thickness, which may be an important material to develop the concept of searching and mining of nickel and cobalt ore.
Dostawca treści:: Repozytorium Centrum Otwartej Nauki

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Skocz do pozycji: 9.

Tytuł:: Adsorption Studies of Nitrate by Geo-Physical Environment (Laterite soil) of the Study Area Bidar Urban & its Industrial Area, Karnataka State, India
Autorzy:: Shivasharanappa, ---
Padaki, S.
Kushtagi, S.
Tematy:: Nitrate Adsorption
laterite
Batch Experiments
Freundlich isotherm
Langmuir isotherm; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/971327.pdf Link otwiera się w nowym oknie
Opis:: In the present work, adsorption of Nitrate on Laterite soil has been studied using batch adsorption techniques. Main objectives of this study is to study the physical properties of Laterite soil, detection of Nitrate removal by adsorbent Laterite soil as a function of contact time, adsorbent dosage, pH, to study sorption kinetics, and to study isothermal pattern. The results of this study showed that the Optimum contact time, Optimum dosage and Optimum pH for adsorption of Nitrate on Laterite soil reached to equilibrium after 130 minutes, with removal efficiency of 68 %, 1400 mg as optimum dosage and at optimum pH of 6. The rate of adsorption of Nitrate obeys first order rate equation. The obtained results of the batch experiments are best fitted to Langmuir and Freundlich adsorption isotherms. From the experimental analysis it is concluded that Laterite soil shows good removal efficiency and hence can be used as adsorbent.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Recovery of nickel and iron from low–grade laterite ore and red mud using co–reduction roasting: Industrial-scale test
Autorzy:: Guo, Xiaoshuang
Xu, Chengyan
Wang, Yingshuo
Li, Xiaohui
Sun, Tichang
Tematy:: co-reduction
low-grade laterite ore
red mud
rotary kiln
powdered ferronicke; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1447175.pdf Link otwiera się w nowym oknie
Opis:: In this study, the effects of red mud (RM) dosage during the co-reduction roasting of lowgrade laterite ore and RM were investigated. The expanded test was conducted under the following optimized conditions: RM-1 dosage of 15 wt%, anthracite dosage of 13 wt%, a roasting temperature of 1300oC, and roasting time of 3 h. Ferronickel powder was obtained with a nickel grade of 1.95 wt%, iron grade of 83.25 wt%, and nickel and total iron recoveries of 94.71 wt% and 95.98 wt%, respectively. The addition of RM improved the recovery of nickel and total iron in ferronickel powder. The reason was because of the increased intensity of the diffraction peaks of kamacite and iron, and the ferronickel particles grown due to the liquid phase were easier to achieve at a lower melting point. The industrialscale test results showed that ferronickel powder was obtained with average nickel and total iron grades of 1.76 wt% and 86.46 wt%, respectively, which indicated the successful industrial-scale test of co–reduction roasting. Thermodynamic analysis theoretically illustrated the feasibility of the co–reduction of low-grade laterite ore and RM. Increased roasting temperature promoted the reduction of iron oxide and nickel oxide.
Dostawca treści:: Biblioteka Nauki

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