Review of the Main Factors Affecting the Flotation of Phosphate Ores

The way to successfully upgrade a phosphate ore is based on the full understanding of its mineralogy, minerals surface properties, minerals distribution and liberation. The conception of a treatment process consists of choosing the proper operations with an adequate succession depending on the ore properties. Usually, froth flotation takes place in phosphate enrichment processes, since it is cheap, convenient, and well developed. Nevertheless, it is a complex technique as it depends on the mineral’s superficial properties in aqueous solutions. Aspects such as wettability, surface charge, zeta potential, and the solubility of minerals play a basic role in defining the flotation conditions. These aspects range from the reagents type and dosage to the pH of the pulp. Other variables namely particles size, froth stability, and bubbles size play critical roles during the treatment, as well. The overall aim is to control the selectivity and recovery of the process. The following review is an attempt to add to previous works gathering phosphate froth flotation data. In that sense, the relevant parameters of phosphate ores flotation are discussed while focusing on apatite, calcite, dolomite, and quartz as main constituent minerals.

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Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

Papers on Global Change IGBP ◽

10.2478/v10190-010-0002-6 ◽

2010 ◽

Vol 17 (1) ◽

pp. 17-30 ◽

Cited By ~ 1

Author(s):

Katarzyna J. Chwedorzewska

Keyword(s):

Environmental Variables ◽

Climate Changes ◽

Biological Significance ◽

Global Changes ◽

Factors Affecting ◽

Low Diversity ◽

Main Factors ◽

The Antarctic ◽

High Diversity ◽

Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

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Pitting Corrosion of Biomedical Titanium and Titanium Alloys: A Brief Review

Current Nanoscience ◽

10.2174/1573413716999201125221211 ◽

2020 ◽

Vol 16 ◽

Author(s):

Yu-Wei Cui ◽

Liang-Yu Chen ◽

Xin-Xin Liu

Keyword(s):

Corrosion Resistance ◽

Pitting Corrosion ◽

Potential Temperature ◽

Growth Stages ◽

Factors Affecting ◽

Ti Alloys ◽

Pitting Corrosion Resistance ◽

Superior Mechanical Properties ◽

Good Biocompatibility ◽

Main Factors

Abstract:: Thanks to their excellent corrosion resistance, superior mechanical properties and good biocompatibility, titanium (Ti) and Ti alloys are extensively applied in biomedical fields. Pitting corrosion is a critical consideration for the reliability of Ti and Ti alloys used in the human body. Therefore, this article focuses on the pitting corrosion of Ti and Ti alloys, which introduces the growth stages of pitting corrosion and its main influencing factors. Three stages, i.e. (1) breakdown of passive film, (1) metastable pitting, and (3) propagation of pitting, are roughly divided to introduce the pitting corrosion. As reviewed, corrosive environment, applied potential, temperature and alloy compositions are the main factors affecting the pitting corrosion of Ti and Ti alloys. Moreover, the pitting corrosion of different types Ti alloys are also reviewed to correlate the types of Ti alloys and the main factors of pitting corrosion. Roughly speaking, β-type Ti alloys have the best pitting corrosion resistance among the three types of Ti alloys.

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Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽

10.1177/2158244021989257 ◽

2021 ◽

Vol 11 (1) ◽

pp. 215824402198925

Author(s):

Isidoro Guzmán-Raja ◽

Manuela Guzmán-Raja

Keyword(s):

Data Envelopment Analysis ◽

High Efficiency ◽

Sport Performance ◽

Data Envelopment ◽

Professional Football ◽

Efficiency Measure ◽

Factors Affecting ◽

Football Clubs ◽

Main Factors ◽

Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

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Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽

10.3390/pr9050741 ◽

2021 ◽

Vol 9 (5) ◽

pp. 741

Author(s):

Doinita-Roxana Cioroiu Tirpan ◽

Ancaelena Eliza Sterpu ◽

Claudia Irina Koncsag ◽

Alina Georgiana Ciufu ◽

Tănase Dobre

Keyword(s):

Ethanol Production ◽

Alcoholic Fermentation ◽

Ethanol Yield ◽

Product Yield ◽

Liquid Ratio ◽

Experimental Conditions ◽

Factors Affecting ◽

Cystoseira Barbata ◽

Main Factors ◽

Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

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The role of serum β-trophin and endostatin in patients with polycystic ovary syndrome: Are they correlated?

BMC Women s Health ◽

10.1186/s12905-021-01198-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Wei Gong ◽

Aikmu Bilixzi ◽

Xinmei Wang ◽

Yanli Lu ◽

Li Wan ◽

...

Keyword(s):

Polycystic Ovary Syndrome ◽

Influencing Factors ◽

Polycystic Ovary ◽

Pearson Correlation ◽

Healthy Controls ◽

Newly Diagnosed ◽

Ovary Syndrome ◽

Factors Affecting ◽

Main Factors

Abstract Background It’s necessary to investigate the serum β-trophin and endostatin (ES) level and its influencing factors in patients with newly diagnosed polycystic ovary syndrome (PCOS). Methods Newly diagnosed PCOS patients treated in our hospital were selected, and healthy women who took physical examination during the same period as healthy controls. We detected and compared the related serum indicators between two groups, Pearson correlation were conducted to identify the factors associated with β-trophin and ES, and the influencing factors of β-trophin and ES were analyzed by logistic regression. Results A total of 62 PCOS patients and 65 healthy controls were included. The BMI, WHI, LH, FSH, TT, FAI, FBG, FINS, HOMA-IR, TC, TG, LDL, ES in PCOS patients were significantly higher than that of healthy controls, while the SHBG and HDL in PCOS patients were significantly lower than that of healthy controls (all p < 0.05). β-trophin was closely associated with BMI (r = 0.427), WHR (r = 0.504), FBG (r = 0.385), TG (r = 0.405) and LDL (r = 0.302, all p < 0.05), and ES was closely associated with BMI (r = 0.358), WHR (r = 0.421), FBG (r = 0.343), TC (r = 0.319), TG (r = 0.404, all p < 0.05). TG, BMI, WHR and FBG were the main factors affecting the serum β-trophin levels (all p < 0.05). FBG, TC and BMI were the main factors affecting the serum ES levels (all p < 0.05). The TG, β-trophin, ES level in PCOS patients with insulin resistance (IR) were significantly higher than that of those without IR (all p < 0.05). Conclusion Increased β-trophin is closely associated with increased ES in patients with PCOS, which may be the useful indicators for the management of PCOS.

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Specific Ion Effects on the Behavior of Mixtures of Sodium Iso-Butyl Xanthate and Sodium Diethyl Dithiophosphate during the Flotation of a Cu-Ni-PGM Ore: Effects of CaCl2 and NaCl

Environmental Sciences Proceedings ◽

10.3390/iecms2021-10632 ◽

2021 ◽

Vol 6 (1) ◽

pp. 22

Author(s):

Malibongwe S. Manono ◽

Katlego Matibidi ◽

Kirsten C. Corin ◽

Catherine K. Thubakgale ◽

Iyiola O. Otunniyi ◽

...

Keyword(s):

Froth Flotation ◽

Monovalent Cation ◽

Process Water ◽

Polyvalent Cation ◽

Flotation Reagents ◽

Sulfide Flotation ◽

Froth Stability ◽

Ion Effects ◽

The Relationship ◽

Diethyl Dithiophosphate

Inorganic electrolytes present in the process water used during froth flotation may have both beneficial and detrimental effects. These effects are said to be ion specific, as some ions may result in enhanced froth stability, increased mineral recoveries and decreased concentrate grades, while others may bring the opposite effects. Onsite process water quality variations have intensified the need to understand the relationship between inorganic electrolytes and flotation reagents on flotation performance. The use of mixtures of thiol collectors in sulfide flotation is a common practice across the globe; however, very few investigations have considered these in process waters of varying compositions. This study considers the effect of common cations, Na+ and Ca2+, in process water on the behavior of mixtures of thiol collectors. Single-salt solutions of NaCl and CaCl2 at an ionic strength of 0.0213 mol·dm−3 were used to investigate the behavior of mixtures of two thiol collectors. These were carefully selected to understand how mixtures of thiol collectors behave in the presence of a monovalent cation versus a polyvalent cation. Bench-scale froth flotation tests were conducted using a Cu-Ni-PGM ore from the Merensky Reef. The results have shown that the divalent cation, Ca2+, resulted in higher %Cu and %Ni recoveries at all collector mixtures compared to the monovalent cation, Na+. The concentrate grades were, however, slightly compromised, as slightly more gangue reported to the concentrate in the presence of Ca2+. This behavior is attributed to the effect of polyvalent cations on bubble coalescence and froth stability.

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Fabrication of monodisperse polypyrrole/SBA-15 composite for the selective removal of Cr(Ⅵ) from aqueous solutions

New Journal of Chemistry ◽

10.1039/d1nj00717c ◽

2021 ◽

Author(s):

Liang Wang ◽

Peng Gao ◽

Mengxin Liu ◽

Ziqing Huang ◽

Shixia Lan ◽

...

Keyword(s):

Aqueous Solution ◽

Aqueous Solutions ◽

Adsorption Process ◽

In Situ Polymerization ◽

Selective Removal ◽

Factors Affecting

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...

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Laboratory Tests on Engineering Properties of Wind-Blown Sand

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.706 ◽

2012 ◽

Vol 170-173 ◽

pp. 706-709

Author(s):

Zhao Lin Jia ◽

Shu Wang Yan ◽

Zhi Liang Huo

Keyword(s):

Water Content ◽

Laboratory Tests ◽

Fine Sand ◽

Engineering Properties ◽

Grain Composition ◽

Factors Affecting ◽

Compaction Curve ◽

Main Factors ◽

Dry And Wet Conditions ◽

Compaction Properties

By means of laboratory tests and theoretical calculation, the physical, mechanical properties and compaction mechanism of the wind-blown sand are studied to deal with the problem of how to use the wind-blown sand as roadbed materials. It is revealed that water content doesn’t affect the compressibility and the shear strength of the wind-blown sand obviously and the wind-blown sand can be compacted both in dry and wet conditions. The compaction curve of the ordinary fine sand is consistent with that of wind-blown sand and the main factors affecting the compaction properties are the grain composition, water content and compaction work.

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