scholarly journals Migration and Aggregation Behavior of Nickel and Iron in Low Grade Laterite Ore with New Additives

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2033
Author(s):  
Yuanbo Wang ◽  
Chaoqun Nie ◽  
Bo Li ◽  
Yonggang Wei
Keyword(s):  
Calcium Fluoride ◽  
Low Grade ◽  
High Grade ◽  
Recovery Efficiency ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Aggregation Effect ◽  
Activating Agent ◽  
Effects Of Temperature ◽  
Laterite Ore

This study focused on the preparation of high-grade ferronickel concentrate, the behavior of efficient migration and the polymerization of ferronickel particles during reduction roasting, by adding calcium fluoride and a ferronickel concentrate to low-grade laterite ore from Yunnan. The effects of temperature, holding time, reductant content, ferronickel concentrate content and magnetic field intensity on the preparation of the ferronickel concentrate were studied and the optimum conditions were determined as follows: 30% ferronickel concentrate (metal Ni-4.68%, metal Fe-45.0%), 8% coal, 7% calcium fluoride, reduction temperature of 1250 °C, reduction time of 60 min and the intensity of magnetic separation is 150 mT. The proportion of nickel and iron in ferronickel concentrate was 88.7% (metal Ni-8.62%, metal Fe-80.1%), and the recovery efficiency of nickel and iron are 98.8% and 82.4%, respectively. X-ray diffraction and scanning electron microscopy indicated that ferronickel-concentrate, as an activating agent, improved the aggregation effect of ferronickel particles. The efficient migration and polymerization of ferronickel particles in the ore significantly increased the size of the ferronickel particles with additives, therefore a high-grade ferronickel concentrate was prepared, and the reduction and recovery efficiency of laterite nickel ore was improved.

Biocatalytic and chemical leaching of a low-grade nickel laterite ore

2018 ◽  
Vol 115 (3) ◽  
pp. 305 ◽  
Author(s):  
Hasan Ciftci ◽  
Suleyman Atik ◽  
Fatma Gurbuz
Keyword(s):  
Sucrose Concentration ◽  
Low Grade ◽  
Optimum Conditions ◽  
Nickel Laterite ◽  
Chemical Leaching ◽  
Solid Ratio ◽  
Metals Recovery ◽  
Nickel Laterite Ore ◽  
The Difference ◽  
Laterite Ore

Nickel and cobalt recovery from a low-grade nickel laterite ore, supplied from Çaldağ deposit (Manisa, Turkey) were investigated by bio and chemical leaching processes. The fungus, Aspergillus niger was used for biocatalytic leaching experiments. The effects of parameters (solid ratio and sucrose concentration) on the biocatalytic leaching of the ore were initially tested in flasks to obtain the optimum conditions for the A. niger. Then chemical leaching was applied as a comparison to bioleaching, using organic acids (citric, oxalic, acetic and gluconic acids) as well as a mixture of acids. According the results, the maximum dissolution yield of nickel, cobalt and iron were detected respectively as 95.3%, 74.3% and 50.0% by biocatalytic processes which containing 25% (w/v) sucrose and 1% (w/v) solids. The increase in the solid ratio adversely influenced the biocatalytic activity of A. niger. Finally, further tests in reactors (v = 1 and 10 L) were performed using the optimum conditions from the flask tests. The difference in metals recovery between biocatalytic and chemical leaching was significantly important. Bioleaching produced higher Ni and Co extractions (34.3–75.6%) than chemical process.

scholarly journals Extraction of Potassium from Microcline by Chlorination

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 295
Author(s):  
Pablo Orosco ◽  
Oriana Barrios ◽  
Manuel Ojeda
Keyword(s):  
Electron Probe ◽  
Chlorination Reaction ◽  
Experimental Equipment ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Extraction ◽  
Chlorine Gas ◽  
Effects Of Temperature ◽  
Selective Formation

A pyrometallurgical route for the extraction of potassium from microcline was investigated. The reagents used were microcline, calcite and chlorine gas. Isothermal and non-isothermal chlorination assays were performed using experimental equipment adapted for working in corrosive atmospheres. The effects of temperature and reaction time on the chlorination reaction of the microcline-calcite mixture were studied. The reaction mechanism was also investigated. The techniques used to characterize reagents and products were thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The experimental results showed that the extraction of potassium in the form of KCl begins at 700 °C for 15 min. Anorthite also starts to be produced under these conditions. The optimum conditions for quantitative extraction of potassium and selective formation of anorthite were 900 °C for 60 min.

Burning Resistance of Lignitic Coals Under Oxygen-Enriched Conditions

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Ozlem Uguz ◽  
Hanzade Haykiri-Acma ◽  
Serdar Yaman
Keyword(s):  
Horizontal Tube ◽  
Treatment Temperature ◽  
Low Grade ◽  
Combined Effects ◽  
X Ray Diffraction ◽  
Heating Value ◽  
Inorganic Matter ◽  
O2 Concentration ◽  
Effects Of Temperature ◽  
The Individual

Abstract Oxygen-enriched air combustion of low-grade fuels with high inorganic matter is of great interest due to the efficient burning of such fuels and mitigation of emissions. For this purpose, this study aims to investigate the combined effects of oxygen enrichment and temperature on burnout levels. The oxygen-enriched air combustion performance of two Turkish lignites with different geological ages (early Miocene-Pliocene period Kutahya-Tuncbilek (KT) lignite and Pleistocene period Adiyaman-Golbasi (AG) lignite) was investigated in a horizontal tube reactor. The lignite samples were heated slowly (10 °C/min) to the temperatures of 200–600 °C for AG lignite and 200–800 °C for KT lignite under N2/O2 atmospheres with O2 ratios of 21, 30, 40, and 50 vol%. The solid residue remained after this oxidative heat treatment was characterized by proximate/ultimate analyses, higher heating value, (HHV) thermal analysis, Fourier transform infrared spectroscopy, (FTIR) X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. It was concluded that AG lignite that is relatively younger lignite is more susceptible to the O2-enriched conditions as the treatment temperature or O2 concentration increases. It was also determined that the combined effects of temperature and O2 concentration are much more profound than the individual effects of these parameters.

Klinische Wertigkeit der Positronen-Emissions-Tomographie (PET) bei onkologischen Fragestellungen: Ergebnisse einer interdisziplinären Konsensuskonferenz

1996 ◽  
Vol 35 (02) ◽  
pp. 42-52 ◽  
Author(s):  
R. Bares ◽  
U. Bull ◽  
A. Guhlmann ◽  
E. Moser ◽  
M. F. Wannenmacher ◽  
...  
Keyword(s):  
Low Grade ◽  
High Grade ◽  
Klinische Anwendung ◽  
Wissenschaftliche Studien

Zusammenfassung Ziel: Es ist das Ziel der vorliegenden Arbeit, an Hand bisher publizierter Studienergebnisse eine Beurteilung des klinischen Stellenwertes von PET in der Onkologie zu erarbeiten. Methoden: Im Rahmen einer interdisziplinären Konferenz mit namhaften Experten wurde eine Wertung des gegenwärtigen Stands von PET in der Onkologie an Hand der in der Literatur dokumentierten Studienergebnisse erarbeitet. Angestrebt wurde eine differenzierte Bewertung von PET für die klinische Anwendung in fünf Klassen (1a, 1b, 2a, 2b, 3) von »angemessen« (1a), »akzeptabel« (1b), »hilfreich« (2a), »noch keine Bewertung möglich« (2b), »ohne Nutzen« (3). Ergebnisse: Für den klinischen Einsatz in der Onkologie ist 2-F18-Fluorodeoxyglukose (FDG) das Radiopharmakon der Wahl. PET ist klinisch in der Patientenversorgung zur Rezidivdiagnostik von high-grade Gliomen (FDG), low-grade Gliomen (C-11 Methionin oder F-18 Tyrosin), für die Dignitätsdiagnostik des peripheren Lungenrundherdes bei Risikopatienten sowie für die Diagnostik des Pankreaskarzioms indiziert (Indikation 1a). PET kann in der Patientenversorgung bei folgenden Indikationen (1b) eingesetzt werden: »low-grade« Gliome, Suche nach unbekanntem Primärtumor bei Kopf-Hals-Tumoren, Rezidivdiagnostik des nicht kleinzelligen Bronchialkarzinoms sowie des Rektumkarzinoms, Lymphknotenstaging beim nicht kleinzelligen Bronchial-Karzinom, Pan-kreas-Karzinom, muskelinvasiven Blasen-Karzinom und Hoden-Karzinom. Staging bei M. Hodgkin (Stad. I/II versus III), frühe Therapiekontrolle bei Resttumor und Rezidivdiagnostik bei M. Hodgkin und hochmalignen Non-Hodgkin-Lymphomen, Lymphknoten-Staging und Fern-metastasensuche beim malignen Melanom (Breslow >1,5 mm), Lymphknoten- und Fernmetastasen-Nachweis beim Schilddrüsen-Karzinommit erhöhtem hTg und nicht radiojodspeichernden Metastasen. Zahlreiche weitere Indikationen zeichnen sich bereits jetzt ab, sind jedoch noch weniger gut durch wissenschaftliche Studien belegt. Für die meisten Indikationen außerhalb wissenschaftlicher Studien ist eine individuelle Kosten-Nutzen-Betrachtung durch den verantwortlichen Arzt geboten. Schlußfolgerungen: Die metabolische Bildgebung von PET besitzt für eine Vielzahl onkologischer Fragestellungen prinzipielle Vorteile gegenüber der anatomisch-morphologisch orientierten Schnittbilddiagnostik. Für die klinische Indikationsstellung ist allerdings eine differenzierte Betrachtung der spezifischen Leistungsfähigkeit von PET geboten.

CD133/CD166/Ki-67 Triple Immunouorescence Assessment for Putative Cancer Stem Cells in Colon Carcinoma*

2014 ◽  
Vol 23 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Claudiu Margaritescu ◽  
Daniel Pirici ◽  
Irina Cherciu ◽  
Alexandru Barbalan ◽  
Tatiana Cârtâna ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Stem Cells ◽  
Colon Cancer ◽  
Cancer Stem Cells ◽  
Colon Carcinoma ◽  
Sodium Dodecyl ◽  
High Grade Dysplasia ◽  
Early Event ◽  
Low Grade ◽  
High Grade

Background & Aims: Colorectal cancer represents the third most common malignancy and the fourth most common cause of cancer death worldwide. The existence of drug-resistant colon cancer stem cells is thought to be one of the most important reasons behind treatment failure in colon cancer, their existence putatively leading to metastasis and recurrences. The aim of our study was to investigate the immunoexpression patterns of CD133 and CD166 in colon carcinoma, both individually and in combination, assessing their significance as prognostic markers.Methods. A total of 45 retrospective colon adenocarcinoma cases were investigated by enzymatic and multiple fluorescence immunohistochemistry for their CD133 and CD166 expression and colocalization.Results. Both CD133 and CD166 were expressed to different extents in all cancer specimens, with apredominant cytoplasmic pattern for CD133 and a more obvious membranous-like pattern for CD166.Overall, when comparing their reactivity for the tumoral tissue, CD166 expression areas seemed to be smaller than those of CD133. However, there was a direct correlation between CD133 and CD166 expression levels throughout the entire spectrum of lesions, with higher values for dysplastic lesions. Colocalization of CD133/ CD166 was obvious at the level of cells membranes, with higher coeficients in high grade dysplasia, followed by well and moderate differentiated tumours.Conclusions. CD133/CD166 colocalization is an early event occurring in colon tumorigenesis, with thehighest coeficients recorded for patients with high grade dysplasia, followed by well differentiated tumours. Thus, we consider that the coexpression of these two markers could be useful for further prognostic andtherapeutically stratification of patients with colon cancer.Abbreviations: AJCC - American Joint Committee on Cancer; CCD - charge-coupled device camera sensor; CD133 - prominin-1 (PROM1); CD166 - Activated Leukocyte Cell Adhesion Molecule (ALCAM); CRC - colorectal cancer; CSC - cancer stem cells; DAB - 3,3'-diaminobenzidine chromogen; DAPI - 4',6-diamidino- 2-phenylindole; HE - Hematoxylin and eosin staining; HGD - high grade dysplasia; HRP - horseradish peroxidase; LGD - low grade dysplasia; SDS - sodium dodecyl sulfate*Part of this work has been accepted as a poster presentation at the Digestive Disease Week (DDW) meeting, Chicago, IL, USA May 3-6, 2014

MOLECULAR AND GENETIC SUBTYPES OF OVARIAN CANCER: PROSPECTS FOR FURTHER STUDIES

2019 ◽  
Vol 65 (1) ◽  
pp. 56-62
Author(s):  
Alisa Villert ◽  
Larisa Kolomiets ◽  
Natalya Yunusova ◽  
Yevgeniya Fesik
Keyword(s):  
Ovarian Cancer ◽  
Ovarian Carcinoma ◽  
Molecular Subtypes ◽  
Survival Rates ◽  
Consensus Algorithm ◽  
Histopathological Diagnosis ◽  
Low Grade ◽  
High Grade ◽  
Ovarian Carcinomas ◽  
Genetic Subtypes

High-grade ovarian carcinoma is a histopathological diagnosis, however, at the molecular level, ovarian cancer represents a heterogeneous group of diseases. Studies aimed at identifying molecular genetic subtypes of ovarian cancer are conducted in order to find the answer to the question: can different molecular subgroups influence the choice of treatment? One of the achievements in this trend is the recognition of the dualistic model that categorizes various types of ovarian cancer into two groups designated high-grade (HG) and low-grade (LG) tumors. However, the tumor genome sequencing data suggest the existence of 6 ovarian carcinoma subtypes, including two LG and four HG subtypes. Subtype C1 exhibits a high stromal response and the lowest survival. Subtypes C2 and C4 demonstrate higher number of intratumoral CD3 + cells, lower stromal gene expression and better survival than sybtype C1. Subtype C5 (mesenchymal) is characterized by mesenchymal cells, over-expression of N-cadherin and P-cadherin, low expression of differentiation markers, and lower survival rates than C2 and C4. The use of a consensus algorithm to determine the subtype allows identification of only a minority of ovarian carcinomas (approximately 25%) therefore, the practical importance of this classification requires additional research. There is evidence that it makes sense to randomize tumors into groups with altered expression of angiogenic genes and groups with overexpression of the immune response genes, as in the angiogenic group there is a comparative superiority in terms of survival. The administration of bevacizumab in the angiogenic group improves survival, while the administration of bevacizumab in the immune group even worsens the outcome. Molecular subtypes with worse survival rates (proliferative and mesenchymal) also benefit most from bevacizumab treatment. This review focuses on some of the advances in understanding molecular, cellular, and genetic changes in ovarian carcinomas with the results achieved so far regarding the formulation of molecular subtypes of ovarian cancer, however further studies are needed.

Low Utility in Colposcopy-directed Biopsies for Non-high Grade Cytological Abnormalities on PAP Smear

2020 ◽  
Vol 16 (1) ◽  
pp. 18-22
Author(s):  
Eronmwon E. Gbinigie ◽  
Joshua Fogel ◽  
Maggie Tetrokalashvili
Keyword(s):  
Pap Smear ◽  
Multinomial Logistic Regression ◽  
Cervical Dysplasia ◽  
Outcome Variable ◽  
Low Grade ◽  
High Grade ◽  
Squamous Intraepithelial Lesion ◽  
Intraepithelial Lesion ◽  
Cytologic Abnormalities ◽  
Cytology Screening

Background: Clinicians commonly perform colposcopy directed biopsies on patients with low grade squamous intraepithelial lesion (LSIL) on PAP cytology even when not consistent with clinical guidelines. Objective: We study the association of PAP cytology screening results with cervical intra-epithelia neoplasia (CIN) 2-3 high-grade dysplasia, as confirmed by colposcopy-directed biopsy. Methods: A retrospective study of 263 women with an abnormality on the PAP smear. Multinomial logistic regression was performed with predictors of PAP cytology screening results with the outcome variable of colposcopy-directed biopsy. Results: High grade squamous intraepithelial lesion (HSIL) had significantly increased relative risk for CIN 2-3 (RR: 9.85, 95% CI: 1.84, 52.79, p=0.008). LSIL was not significantly associated with CIN 2-3. In the comparisons of negative with CIN-1, both HSIL and LSIL were not significantly associated with a negative biopsy. Conclusion: HSIL is associated with cervical dysplasia of CIN 2-3 while LSIL is not associated with cervical dysplasia of CIN 2-3. We do not recommend routine biopsies in patients with LSIL cytologic abnormalities unless additional compelling factors exist.

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