Time-resolved diffraction studies into the pressure acid leaching of nickel laterite ores: a comparison of laboratory and synchrotron X-ray experiments

2008 ◽  
Vol 41 (3) ◽  
pp. 572-583 ◽  
Author(s):  
Nicola V. Y. Scarlett ◽  
Ian C. Madsen ◽  
Barry I. Whittington

This paper compares time-resolved diffraction experiments that have been performed using laboratory and synchrotron X-ray sources. The experiments investigated the mechanism and kinetics of pressure acid leaching of nickel laterite ores. The sample environment was a purpose-built capillary reaction vessel, and extensive method development was conducted in the laboratory using Mo Kα radiation prior to repeating and extending the experiments at the Daresbury Synchrotron Radiation Source, beamline MPW6.2. In general, the synchrotron results confirmed the findings from previously reported laboratory work and also confirmed the presence of a minor phase that had been ambiguous in the laboratory experiments,i.e.the formation of hematite in the pressure acid leaching of saprolite. The synchrotron measurements also extended the experimental programme to include poorly diffracting laterite components that could not be examined in the laboratory,e.g.nontronite. The results from these components supported the reaction mechanisms determined fromex-situanalyses conducted in larger scale autoclaves.

2005 ◽  
Vol 38 (6) ◽  
pp. 927-933 ◽  
Author(s):  
Ian C. Madsen ◽  
Nicola V. Y. Scarlett ◽  
Barry I. Whittington

This paper outlines the use of an innovative system for thein situinvestigation of hydrothermal reactions by X-ray diffraction. The key features are the use of: (i) a purpose-built capillary reaction vessel which allows close emulation of the conditions present in mineral processing plants; (ii) MoKα radiation, to ensure that the X-ray beam penetrates through the capillary, and (iii) an Inel CPS120 position-sensitive detector, to enable simultaneous collection of a wide range (120° 2θ) of diffraction data. The pressure acid leaching (PAL) of nickel laterite ores is used to illustrate the capabilities of this system, with a particular focus on the PAL of saprolite in strong H2SO4at 493 K. Saprolitic ore, which largely consists of serpentine mineral phases [(Mg,Fe,Ni,Al)3(Si,Al)2O5(OH)4], undergoes a number of mineralogical changes during both the acid leaching reaction and subsequent cooling, thus making it difficult to examine accurately using traditional post-reactionex situtechniques. In particular, kieserite (MgSO4.H2O), which forms during leaching, has a negative temperature coefficient of solubility, causing it to dissolve on cooling. Thein situtechnique described in this paper allows the direct observation of kieserite formation during the saprolite PAL at 493 K and its dissolution upon cooling to ambient temperature.


2017 ◽  
Vol 133 (4) ◽  
pp. 68-75
Author(s):  
Shinichi HEGURI ◽  
Hirofumi SHOJI ◽  
Isao NISHIKAWA ◽  
Hiroshi KOBAYASHI ◽  
Atsushi IDEGAMI

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.


FEBS Letters ◽  
1994 ◽  
Vol 337 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Hideo Arakawa ◽  
Takuji Urisaka ◽  
Hirotsugu Tsuruta ◽  
Yoshiyuki Amemiya ◽  
Hiroshi Kihara ◽  
...  

FLUIDA ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 81-92
Author(s):  
Ade Yanti Nurfaidah ◽  
Dheana Putri Lestari ◽  
Rheisya Talitha Azzahra ◽  
Dian Ratna Suminar

Abstrak Nikel merupakan unsur logam yang penggunaannya sudah dikenal dalam industri, terutama pada pelapisan logam dan paduan. Pengolahan nikel dari bijih nikel laterit (jenis Limonit) menggunakan proses hidrometalurgi Atmospheric Pressure Acid Leaching (APAL) yang dinilai lebih ekonomis karena pemakaian energi dan biaya operasional cukup rendah. Media pelarut yang digunakan berupa larutan asam sulfat (H2SO4). Sebelum dilakukan pengolahan, karakterisasi bijih dilakukan menggunakan X-Ray Diffraction (XRD), X-Ray Flourscence (XRF), dan Scanning Electron Microscopy (SEM). Metode penelitian yang dilakukan yaitu literature review. Hasil review dari beberapa artikel jurnal menunjukkan bahwa kadar nikel yang terkandung pada suatu bijih sekitar 1,42%, 2,94 dan 0,95% serta sisanya adalah pengotor. Kondisi operasi yang tepat akan menghasilkan pemurnian nikel yang cukup tinggi. Parameter kondisi operasi yang dapat memengaruhi proses pemisahan nikel diantaranya suhu operasi yang ditunjukan dengan semakin meningkatnya % ekstraksi nikel seiring dengan kenaikan suhu. Selain suhu operasi, konsentrasi pelarut juga salah satu parameter yang mempengaruhi % ekstraksi karena semakin tinggi ion H+ akan memudahkan proses pelarutan sehingga akan mengikat Nikel Oksida yang terdapat pada bijih. Suhu paling optimal untuk menghasilkan nikel dengan kemurnian tinggi dalam operasi pelindian atmosferik adalah 90°C dan konsentrasi asam sulfat 5 M.  Kata Kunci: Nikel, pelindian, suhu, konsentrasi   Abstract  Nickel is a metal element whose use is well known in industry, especially in metal and alloy plating. The processing of nickel from laterite nickel ore (Limonite type) uses a hydrometallurgical process of Atmospheric Pressure Acid Leaching (APAL) which is considered more economical because energy consumption and operational costs are quite low. The solvent medium used is a solution of sulfuric acid (H2SO4). Prior to processing, ore characterization was carried out using X-Ray Diffraction (XRD), X-Ray Flourscence (XRF), and Scanning Electron Microscopy (SEM). The research method literature review article. The results of reviews from several journal articles show that the nickel content contained in an ore is around 1.42%, 2.94% and 0.95% and the rest is impurity. The right operating conditions will result in relatively high nickel refining. The operating condition parameters that can affect the nickel separation process include the operating temperature which is indicated by the increasing % nickel extraction along with the increase in temperature. In addition to operating temperature, solvent concentration is also one of the parameters that affects the% extraction because the higher the H+ ion will facilitate the dissolving process so that it will bind to the Nickel Oxide contained in the ore. The optimal temperature to produce high-purity nickel in atmospheric leaching operations is 90°C and a sulfuric acid concentration of 5 M. Keywords: Nickel, leaching, temperature, concentration


2010 ◽  
Vol 104 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Minting Li ◽  
Chang Wei ◽  
Shuang Qiu ◽  
Xuejiao Zhou ◽  
Cunxiong Li ◽  
...  

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