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1

Nickel recovery from low-grade laterites: study of thermal pre-treatments to improve the efficiency of the hydrometallurgical process

Borda Johana, Torres Robinson

Journal of Sustainable Mining

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2023

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Vol. 22. iss. 3

219--226

EN

The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the heat treatment; this is why the dissolution of nickel is linked to that of iron. The highest extractions (64.7% nickel) were achieved by combining heat treatment and leaching with 1 M H2SO4 at ambient conditions. Compared to direct leaching of unpretreated laterite, leaching rates for this metal are increased by 26.5%. The chlorinating calcination and the optimization of the studied variables will be favourable to reach higher metallic extractions.

2

Removal of chromium and strontium from aqueous solutions by adsorption on laterite

He Yong, Chen Yong-Gui, Zhang Ke-Neng, Ye Wei-Min, Wu Dong-Yu

Archives of Environmental Protection

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2019

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Vol. 45, no. 3

11--20

EN

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.

3

Field trip in the Kerala : report

Rączkowska Z., Prokop P., Kijowska-Strugała M.

Landform Analysis

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2017

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Vol. 35

9--12

EN

This report contains short information about the geomorphological field trip in Kerala State. The field trip was largely focused on various geomorphological and geoecological aspects of laterites and backwaters which dominate in landscape of Kerala. One of the main highlights of the field trip was to the examination of type locality of laterite. Nearly 60% of the Kerala is covered by laterite or laterite-derived materials, and lateritisation process dominates the landform development from the coast to foothills. The second main highlights of the field trip was to the examination of backwaters which are a network of five big lakes (lagoons and estuaries) and rivers linked by natural and man-made canals.

4

Analiza możliwości zastosowania metody tomografii elektrooporowej (ERT) do rozpoznania miąższości pokrywy laterytowej

Pacanowski G., Czarniak P., Piechota A., Mieszkowski R.

Przegląd Geologiczny

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2016

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Vol. 64, nr 4

245--253

EN

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.

5

Separation of nickel and iron from lateritic ore using a digestion – roasting – leaching – precipitation process

Basturkcu H., Acarkan N.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 2

564--574

EN

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.

6

Leaching behaviour of a turkish lateritic ore in the presence of additives

Basturkcu H., Acarkan N.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

112--123

EN

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.

7

An investigation into structural strengths of laterized concrete

Tsado T. Y.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2013

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Z. 19 (169)

192--203

EN

This paper presents the results of an investigation into the characteristics of concrete containing laterite as a full or partial replacement of sand. Sand in a concrete mix proportion of 1:2:4:0.6 and 1:2:2:0.6 (cement: sand: coarse aggregate: water-cement ratio) was replaced with 0, 20, 40, 60, 80, and 100% laterite. The concrete strength was confined to characteristic concrete strength grade of 20 and 25 N/mm². Experimental results based on qualitative and quantitative data shows that, concrete produced at 28-day hydration period with up to 40%> replacement level of sand by laterite attained the designed concrete compressive strength of 20.48 N/mm² for concrete strength grade of 20 N/mm² but fell slightly below 25 N/mm² for concrete strength of grade 25 N/mm². This indicates the possibility of using laterite as a partial replacement for sand up to 40%>. It was also observed from the results obtained that the workability - of laterite concrete increased with increase in the replacement level of sand by laterite, while the cube compressive strength, split cylinder tensile strengths and the percentage water absorption of the concrete decreased with increase in the replacement level of sand. Regression models relating the split cylinder tensile strength and cube compressive strength of concrete strength grade of 20 and 25 N/mm² of partial sand replacement with laterite in the various percentage, yielded predictive models ƒt(C20) = 0.2093 (ƒcu)0.5259 and ƒt(C25) = 0.4961 (ƒcu)0.2945 with correlation coefficients R² = 0.8946 and R² = 0.947 respectively.

PL

W artykule przedstawiono wyniki badań w zakresie właściwości betonu zawierającego lateryt jako całkowity lub częściowy substytut piasku. Piasek z mieszanki betonowej o proporcji 1:2:4:0.6 i 1:2:2:0.6 (cement : piasek : kruszywo grube : stosunek cementowo-wodny) zastąpiono układem 0, 20, 40, 60, 80 i 100% laterytu. Wytrzymałość betonu została ograniczona do charakterystycznej wytrzymałości betonu - 20 i 25 N/mm². Eksperymentalne wyniki oparte na danych ilościowych i jakościowych pokazują, że beton po 28-dniowym okresie dojrzewania, w którym na poziomie do 40% zastąpiono piasek laterytem, osiągnął wytrzymałość na ściskanie 20,48 N/mm² dla zaprojektowanej klasy 20 N/mm², ale wartość wytrzymałości na ściskanie dla zaprojektowanej klasy 25 N/mm² spadła poniżej 25 N/mm². Wskazuje to na możliwość wykorzystania laterytu do częściowego zastąpienia piasku do 40%. Na podstawie otrzymanych wyników stwierdzono również, że urabialność betonu z wykorzystaniem laterytu wzrosła wraz ze wzrostem poziomu zastąpienia piasku przez lateryt, zaś wytrzymałość na ściskanie, wytrzymałość na rozciąganie i procent zużycia wody w betonie zmniejszyły się wraz ze wzrostem poziomu zastąpienia piasku. Modele regresji odnoszące się do wytrzymałości na rozciąganie i wytrzymałości na ściskanie betonu klasy 20 N/mm² i 25 N/mm², w którym piasek w różnych procentach częściowo zastąpiono laterytem, pozwoliły przyjąć modele analityczne: ƒt(C20) = 0.2093 (ƒcu)0.5259 oraz ƒt(C25) = 0.4961 (ƒcu)0.2945 ze współczynnikami R² = 0.8946 i R² = 0.947.

8

Adsorption Studies of Nitrate by Geo-Physical Environment (Laterite soil) of the Study Area Bidar Urban & its Industrial Area, Karnataka State, India

Shivasharanappa, Padaki S., Kushtagi S.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 6

66-76

EN

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.

9

Angkor - światowe dziedzictwo architektury kamiennej i geoturystyki

Skoczylas J.

Górnictwo i Geologia

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2011

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T. 6, z. 4

83-98

PL

Na przykładzie Angkom w Kambodży, kamiennego miasta-państwa funkcjonującego w latach 802 - 1431, wskazano, jak niezbędne są badania z zakresu nauk geologicznych, odkrycia, wyeksponowania i ochrony tego światowego dziedzictwa kultury. Agkor Thorn, a w nim świątynia Bayon, a także Angkor Wat to obiekty wybudowane z piaskowca i laterytu. Problemy ich poszukiwań, eksploatacji, transportu, wykorzystania, użytkowania, a także ochrony również powinny być przedmiotem praktycznych i teoretycznych zainteresowań geoturystyki.

EN

On the example of Angkor in Cambodia, a stone city-state, which existed in the years 802-1431, it was pointed out how including of research in the field of geological sciences is necessary to discover, exhibit and protect this monument of World Heritage. Angkor Thom, and the Bayon Tempie as well as Angkor Wat are the edifices built from sandstone and laterite. The problems of searching, transport, usage and maintenance as well as protection of stone should also be the subject of practical and theoertical interest of geotourism.

10

Heavy minerals in the serpentinite weathering cover of the Szklary massif

Sachanbiński M., Piórewicz R., Michalin R.

Geologia Sudetica

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2000

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Vol. 33, nr 2

131-141

EN

Forty minerals were identified belonging to the heavy mineral (d > 2.98 g/cm3) suite of the Szklary massif. They are: actinolite, almandine, anthophyllite, apatite, biotite, brunsvigite, chlorite, chromite, chrysolite, zircon, enstatite, epidote, ferroplatinum, goethite, haematite, hornblende, clinochlore, leucoxene, magnesioferrite, magnetite, magnesite, molibdenite, monacite, muscovite, niggliite (PtSn), olivine, orthopyroxenes, an osmium-bearing phase (Ba2CaOsO6), native palladium, pyrope, native platinum, pleonaste, rutile, native silver, talc, tremolite, trevorite, tourmaline, native gold and zoisite. The mineralogical characteristics of the most common phases are presented in this paper, and three paragenetic groups of heavy minerals are distinguished.