Enhanced separation of pyrite from oxidized coal by froth flotation using biosurface modification

Attia, Yosry A.; Elzeky, M.; Ismail, Mohd Nazari

doi:10.1016/0301-7516(93)90005-u

Cited by 41 publications

(21 citation statements)

References 4 publications

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“…Escherichia coli, a strain with hydrophobic properties, was found to act as collector for quartz (Farahat et al, 2008(Farahat et al, , 2009), on the other hand, strains with hydrophilic nature like Thiobacillus ferroxidans (Nagaoka et al, 1999;Attia et al, 1993), Thiobacillus thiooxidans (Chandraprabha and Natarajan, 2005) and Ferroplasma acidiphilum (Farahat et al 2010) were found to act as good depressants for pyrite. The surface properties of microbial cells including surface charge and hydrophobicity depend on the nutrition conditions and surrounding environment (Sharma et al, 2003).…”

Section: Introductionmentioning

confidence: 98%

Hydrophilicity of Ferroplasma acidiphilum and its effect on the depression of pyrite

Farahat

Hirajima

2012

Minerals Engineering

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Section: Introductionmentioning

confidence: 98%

Hydrophilicity of Ferroplasma acidiphilum and its effect on the depression of pyrite

Farahat

Hirajima

2012

Minerals Engineering

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“…This bacterium has also been used in removing pyrite from mixtures of sulfide minerals [62][63][64][65]. Acidithiobacillus ferrooxidans have frequently been used as an excellent pyrite depressant in coal flotation [66][67][68][69]. Bacillus polymyxa was used in the separation of sulfide minerals [70], iron ore flotation [71], for pyrite separation from oxide gangue minerals [72], and in the separation of galena from chalcopyrite [73].…”

Section: Biofrothersmentioning

confidence: 99%

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Khoshdast¹

2011

TOMPJ

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Abstract:The importance of frothers in flotation is widely acknowledged, particularly in terms of their role with respect to bubble size, and the stability and mobility of the froth phase. These factors play a significant role in the kinetic viability of the process, and the overall recovery and the grade that can be achieved from a flotation cell or circuit. About 60 years ago, Wrobel [1] presented a comprehensive review of flotation frothers, their action, properties and structures. However, during recent six decades flotation reagent technology has undergone considerable evolutions and innovations. The aim of the present review is to provide an updated, comprehensive database comprising recent developments in flotation frother technology as well as some historical aspects. Different types of flotation frothers are discussed regarding to their classifications, properties, and preparation methods. New classification schemes have been suggested in parallel with introducing new characterization criteria. New classes of frothers are actually conventional frothers modified by incorporating certain functional "group" or "atoms" into their molecular structure. Like particle surface modifiers, frothers are also influenced by biotechnology, leading to introducing a new class of frothers named as "biofrothers".

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“…These results represent pyritic sulfur contents as low as 0.13%, down from 1.59% in the feed. In another study, Attia et al (1993) reported that bacterial depression action on pyrite seems to be unaffected by the oxidation state of the pyrite surface.…”

Section: T Thiooxidans Leptospirillum Ferroxidans Andmentioning

confidence: 98%

Novel microorganism for selective separation of coal from pyrite and ash. Final report

Misra¹,

Smith²

1995

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In keeping with the main objective of the project, the separation of fine coal from ash and pyrite was conducted using a microorganism Mycobacterium phlei (M. phlei). The surface hydrophobicity and surface charge ofMycobacterium phlei and it's sonicated products (extracellular soluble fractions) were established using contact angle and electrophoretic measurements.Mycobacterium phlei was highly hydrophobic and point-of-zero charge was around pH 2. The hydrophobic character and negative surface charge of the microorganism above pH 2 were due to the presence of excessive fatty groups at the surface and corresponding carboxylate groups. In addition, soluble fractions derived from the cell exhibited the presence of varying amounts of fatty acids ranging from C,, -C,, carbon chain and phosphate groups.The surface chemistry analyses of coal, coal-pyrite, mineral pyrite and quartz were conducted. The adhesion of Mycobacterium phlei onto coal, coaliii .. ..e..,,-pyrite and quartz was measured as a function of pH and Mycobacterium phlei concentration. It was noticed that Mycobacterium phlei selectively attached to hydrophobic coal particles and did not attach to hydrophilic mineral fractions.Adhesion was strongly dependent on pH and maximum adhesion was observed in an acidic pH range of 3-4.On the basis of the detailed surface chemistry analysis, adhesion and contact angle measurements, a series of flocculation and flotation experiments were conducted. The experimental results showed that Mycobacterium phlei was an excellent flotation collector and flocculating agent. However, the soluble fkaction derived from Mycobacterium phlei by sonication was a better flotation collector and flocculating agent for fine coal than whole cells of Mycobacterium phlei. In order to selectively separate the coal-Myco bacterium phlei entities, a modified floc-flotation technique was used. At an optimized experimental condition, more than 70 percent pyritic sulfur and 60 percent of ash could be rejected with a combustible (clean coal) recovery of 90 percent. During this investigation, it was established that Mycobacterium phlei and more importantly it's sonication products had a strong potential to be used for selective flocculation and separation of fine coal from associated mineral matters.. . . The impurities occurring in coal may be classified broadly into those that form ash and those that contribute sulfur. From the standpoint of coal cleaning, both the ash-forming and the sulfur-containing impurities may be subdivided into two categories -inherent and extraneous. The inherent impurities are inseparably combined with the coal. The extraneous impurities are segregated and can be eliminated by the available cleaning methods.Sulfur occurs in coal in three different forms. It is present in organic compounds as part of the coal substance, as sulfides, generally pyrite or marcasite, and as sulfate. The amount of organic sulfur normally is not over 3%.The sulfates, mainly calcium and iron, rarely exceed a few hundredths...

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Enhanced separation of pyrite from oxidized coal by froth flotation using biosurface modification

Cited by 41 publications

References 4 publications

Hydrophilicity of Ferroplasma acidiphilum and its effect on the depression of pyrite

Hydrophilicity of Ferroplasma acidiphilum and its effect on the depression of pyrite

Flotation Frothers: Review of Their Classifications, Properties and Preparation

Novel microorganism for selective separation of coal from pyrite and ash. Final report

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