scholarly journals Alkaline leaching of titanium from ilmenite of Irshansk deposit

S.V. Pysarenko ◽  
V.Yu. Chernenko ◽  
O.E. Chygyrynets ◽  
O.M. Kaminskiy ◽  

X-ray spectral studies of the chemical composition of Irshansk ilmenite concentrates showed that it is leukoxenized mineral with a high (up to 79%) content of titanium oxide and inclusions of pseudorutile. The process of alkaline leaching of Ti4+ from ilmenite is investigated in the work. The study of the temperature effect on the reaction of ilmenite with potassium hydroxide at atmospheric pressure revealed that a temperature of 453 K is sufficient to obtain potassium titanate. A further increase in temperature does not provide a significant increase in the yield of water-soluble titanium. It is found that the optimal and sufficient ratio between ilmenite and potassium hydroxide is 1:2. An increase in the amount of potassium hydroxide in the reaction mixture is unsuitable, since it reduces the yield of soluble titanium and the final product will have a high alkalinity due to the presence of alkali which did not react. The main process of leaching with the formation of solid melt is completed in the first 30 minutes of the process. Infrared spectroscopy and X-ray diffraction showed that potassium titanate (K2TiO3) is formed under the studied conditions of alkaline leaching of ilmenite.

2020 ◽  
Vol 235 (10) ◽  
pp. 465-475
Ozge Gungor ◽  
Seda Nur Kertmen Kurtar ◽  
Muhammet Kose

AbstractSeven biguanide derivatives were prepared by the nucleophilic reaction between dicyandiamide and p-substitute aniline derivatives or memantine or adamantine under acidic conditions. The cyclization of the biguanide compounds were also conducted via acetone to give 1,3,5-triazine derivatives. The structures of the synthesized compounds were characterized by analytical methods. The solid state structures of [HL5]Cl, [H2L7]Cl2, [HL1a]Cl and [HL5a]Cl were investigated by X-ray diffraction study. The acetylcholinesterase and α-glucosidase inhibitor properties of the compounds were then evaluated by the spectroscopic method. The compounds were found to show considerable acetylcholinesterase and α-glucosidase inhibitory activities compared to the approved drugs. The cyclization of biguanide derivatives with acetone did not affect inhibition of acetylcholinesterase, yet increased the α-glucosidase inhibition.

1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.

2007 ◽  
Vol 1040 ◽  
Hiroaki Yokoo ◽  
Naoki Wakiya ◽  
Naonori Sakamoto ◽  
Takato Nakamura ◽  
Hisao Suzuki

AbstractWe have grown indium nitride (InN) films using In buffer layer on an a-plane sapphire substrate under atmospheric pressure by halide CVD (AP-HCVD). Growth was carried out by two steps: deposition In buffer layer at 900 °C and subsequent growth of InN layer at 650 °C. In order to compare, we also grown InN films on an a-plane sapphire. The InN films are investigated on crystal quality, surface morphology and electrical property using high-resolution X-ray diffraction (HR-XRD), X-ray pole figure, scanning electron microscope (SEM), Hall measurement. The results show that the crystal quality, surface morphology and electrical property of InN films are improved by using In buffer layer.

1991 ◽  
Vol 243 ◽  
A. Greenwald ◽  
M. Horenstein ◽  
M. Ruane ◽  
W. Clouser ◽  
J. Foresi

AbstractSpire Corporation has deposited strontium-barium-niobate by chemical vapor deposition at atmospheric pressure using Ba(TMHD), Sr(TMHD), and Nb ethoxide. Deposition temperature as 550°C in an isothermal furnace. Films were deposited upon silicon (precoated with silica), platinum, sapphire, and quartz. Materials were characterized by RBS, X-ray diffraction, EDS, electron, and optical microscopy. Electrical and optical properties were measured at Boston University.

2021 ◽  
Vol 71 (5) ◽  
pp. 393-409
Earle Radha-Rani ◽  
Gadela Venkata-Radha

In the present study, co-crystals (CCs) of Paliperidone (PPD) with coformers like benzoic acid (BA) and P-amino benzoic acid (PABA) were synthesized and characterized to improve the physicochemical properties and dissolution rate. CCs were prepared by the solvent evaporation (SE) technique and were compared with the products formed by neat grinding (NG) and liquid assisted grinding (LAG) in their enhancement of solubility. The formation of CCs was confirmed by the IR spectroscopy, powder X-ray diffraction and thermal analysis methods. The saturation solubility studies indicate that the aqueous solubility of PPD-BA and PPD-PABA CCs was significantly improved to 1.343±0.162mg/ml and 1.964±0.452mg/ml, respectively, in comparison with the PPD solubility of 0.473mg/ml. This increase in solubility is 2.83-and 3.09-fold, respectively. PPD exhibited a poor dissolution of 37.8% in 60min, while the dissolution of the CCs improved tremendously to 96.07% and 89.65% in 60min. CCs of PPD with BA and PABA present a novel approach to overcome the solubility challenges of poorly water-soluble drug PPD.

2020 ◽  
Vol 13 (2) ◽  
pp. 81-92
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

2021 ◽  
Vol 4 (2) ◽  
pp. 78-81
N.S.W. Zulkefeli ◽  
W.M.I.W. Ismail ◽  
M.K.A.A. Razab ◽  
M.N. Masri

The conductive paint coating can be used to control the electromagnetic interference in electronic application. Conductive paint coating was made by mixing the epoxy and hardener with cathode waste material (CWM) in order to manipulate their properties. In this study, the conductivity and the thickness of the paint has been studied. The thickness of conductive paint coating was depends on the agglomeration of CWM content. The increasing of wt% of CWM, the thickness of paint is increasing. Bruker D2Phaser X-Ray diffraction has been used in order to get the phase analysis of the paint before and after soaking into Potassium Hydroxide solution

2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

2014 ◽  
Vol 354 ◽  
pp. 85-91
Denise A. Lopes ◽  
Thomaz Augusto Guisard Restivo ◽  
Angelo Fernando Padilha

Abstract. Metallic nuclear fuel plates are nowadays an alternative to the ceramic ones in the sense that the uranium density can be increased at lower enrichment. Higher thermal conductivity is also a key factor favouring such fuels for power reactors. Uranium reacts promptly with oxygen and nitrogen at high temperatures to catastrophic corrosion due to non-protective oxide layers, which imparts hot forming processes. The gamma phase body centred cubic structure can be retained at room temperature by annealing the U-7.5Nb-2.5Zr (wt.%) alloy followed by quenching, where the deformation can be extensive. The resulted highly deformed gamma supersaturated structure is subjected further to competitive recovery/recrystallization and phase precipitation phenomena whose are studied in the work. The U-7.5Nb-2.5Zr alloy was melted into plasma and induction furnaces and afterwards annealed to gamma phase. The normalized alloy was cold rolled and underwent isochronal and isothermal treatments. The microstructure evolution was monitored by optical microscopy, X-ray diffraction analysis and hardness measurements. The results show the precipitation events of α” and α+γ3phases are dominant over recovery in the range 200oC < T < 500oC. Above 500oC the recrystallization is the main process leading to softening and initial Vickers hardness recovery. One refined gamma phase grain structure was obtained (~8.0 μm) after annealing at 700oC for 2.5 hours.

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