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1
Content available Effect of ammonium sulfate on the sulfidation flotation of malachite
Liu C., Feng Q., Zhang G.
Archives of Mining Sciences
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2018
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Vol. 63, no. 1
139--148
EN
The effect of ammonium sulfate on the sulfidation flotation of malachite was investigated by micro-flotation tests, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) measurements. Micro-flotation results show that the sodium sulfide concentration and strring time are difficult to control on the sulfidation flotation of malachite. However, when ammonium sulfate was used, the detrimental effect of mixing time and high dosage of sodium sulfide on the sulfidization flotation of malachite can be efficiently eliminated. SEM results showed that sulfidized film on malachite in the presence of ammonium sulfate, and EDS analysis results showed that more S element absorbed and distributed equality on the malachite surface, which was agreed well with the macro-flotation results.
PL
Badano wpływ siarczanu amonu na przebieg procesu siarczkowania w trakcie flotacji malachitu przy wykorzystaniu badania mikroskopowego, mikroskopii elektronowej skanningowej (SEM) oraz pomiarów spektrometrycznych rozpraszania energii EDS. Testy mikroskopowe wykazały, że stężenie siarczku sodu i długość czasu mieszania są parametrami, które niezwykle trudno kontrolować w trakcie procesu siarczkowania towarzyszącemu flotacji malachitu. Z kolei przy zastosowaniu siarczanu amonu, udaje się skutecznie wyeliminować niekorzystne efekty związane z czasem mieszania oraz wysokimi stężeniami siarczku sodu w trakcie flotacji malachitu poprzez siarczkowanie. Wyniki mikroskopii skaningowej wskazują, że przy zastosowaniu siarczanu amonu powstaje cienki film siarczkowy na malachicie zaś pomiary spektrometryczne wykazały większe ilości zaabsorbowanej i bardziej równomiernie rozłożonej siarki pierwiastkowej S na powierzchni malachitu, co pozostaje w pełnej zgodności z wynikami uzyskanymi z badania procesu flotacji w skali makro.
2
Content available Role of sodium hexametaphosphate in flotation of a nickel ore
Feng B., Wang P., Lu Y., Feng Q.
Physicochemical Problems of Mineral Processing
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2016
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Vol. 52, iss. 1
170--181
EN
In this work, a role of sodium hexametaphosphate (SHMP) in the flotation performance of a nickel ore was studied and mechanism was discussed in detail. The results showed that the presence of lizardite interferes with the flotation performance of pentlandite. The adsorption of SHMP at the lizardite/solution interface and the removal of magnesium ions from lizardite surface overcompensated the positive charge on the lizardite particle, and made its zeta potential negative. The interaction between lizardite and pentlandite changed from attractive to repulsive in the presence of SHMP. Thus, the addition of SHMP made the mixed sample of pentlandite and lizardite more dispersed, and significantly reduced the adverse effect of lizardite on the flotation of pentlandite. However, when the content of lizardite in the mixed ore was increased, the effect of SHMP weakened. Therefore, in flotation of a nickel ore containing a large amount of lizardite (46% w/w), SHMP usage is not suitable at the roughing stage due to the fact that lizardite in the pulp will consume most of the SHMP, and hence the removal of lizardite slimes from pentlandite surface become impossible. Based upon the results, SHMP usage is found to be suitable at the cleaning stage to improve the grade of concentrate.
3
Content available Effect of pH on surface characteristics and flotation of sulfidized cerussite
Feng Q., Wen S., Zhao W., Liu J., Liu D.
Physicochemical Problems of Mineral Processing
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2016
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Vol. 52, iss. 2
676--689
EN
The effect of pH on surface characteristic and flotation of sulfidized cerussite was studied by micro-flotation tests, dissolution experiments, scanning electron microscopy (SEM) energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). The micro-flotation tests demonstrated that higher recovery of cerussite was achieved in acidic solutions than that in alkaline solutions. Despite the addition of high collector concentrations, cerussite flotation did not improved in alkaline solutions. The dissolution performance of sulfide-treated cerussite at different pH values indicated that the lead sulfide layer on the surface of sulfide-treated cerussite could exist in acidic solutions and it was more stable at acidic pH than in alkaline solutions. This finding was proved by the SEM-EDS and XPS analyses.
4
Content available Beneficial effects and mechanism of lead ion on wolframite flotation
Yang S., Qiu X., Peng T., Chang Z., Feng Q., Zhong C.
Physicochemical Problems of Mineral Processing
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2016
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Vol. 52, iss. 2
855--873
EN
In this study the effects and mechanism of lead ions influence on wolframite flotation with benzohydroxamic acid (BHA) were studied through micro-flotation, adsorption experiments, zeta potential measurements, logarithmic concentration diagram, and X-ray photoelectron spectroscopy. It was observed that lead ions could significantly enhance the recovery of wolframite in flotation and adsorption density of collector BHA onto the wolframite surface. The results showed that Pb existed in the forms of lead ion, monohydric lead, and lead hydroxide at the water-wolframite interface respectively, at three pH ranges. They increased the zeta potential of wolframite. However, the zeta potential of wolframite was still negative, resulting in repulsive electrostatic force to anionic collector BHA. Combining with XPS spectra, it revealed the chemisorption of BHA onto the wolframite surface. In addition, PbO or Pb(OH)2 was observed on the wolframite surface due to the reaction between lead ions and wolframite. These reaction products increased the adsorption site of BHA on the wolframite surface because Pb-hydroxamate was found on the wolframite surface.
5
Content available Recovery mechanisms of sericite in microcrystalline graphite flotation
Li H., Ou L., Feng Q., Chang Z.
Physicochemical Problems of Mineral Processing
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2015
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Vol. 51, iss. 2
387--400
EN
Sericite is the main contaminant of concentrate in commercial microcrystalline graphite ore flotation. It was necessary to identify its recovery mechanisms so that the appropriate solution can be selected. In this study, the influence of sericite on flotation selectivity of microcrystalline graphite ore and its recovery mechanisms were investigated. Artificial mixtures flotation test suggested that sericite seriously reported into concentrate leading to poor flotation selectivity of microcrystalline graphite ore. However, the aggregation/dispersion behavior of artificial mixtures indicated that a large repulsive energy existed between sericite and microcrystalline graphite particles at pH 7.4, and sericite was not likely to report into graphite concentrate by slime coating. The results obtained from contact angle measurements and a technique of Warren showed that the floated sericite reached the froth via a combination of both entrainment and entrapment mechanisms, not via true flotation.
6
Content available Investigation of leaching kinetics of cerussite in sodium hydroxide solutions
Feng Q., Wen S., Wang Y., Zhao W., Deng J.
Physicochemical Problems of Mineral Processing
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2015
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Vol. 51, iss. 2
491--500
EN
The leaching kinetics of cerussite in alkaline medium was investigated with respect to experimental variables such as sodium hydroxide concentration, temperature, particle size and stirring speed. The results showed that leaching reagent concentration and reaction temperature exerted significant effects on the extraction of lead, whereas particle size and stirring speed exhibited a relatively moderate effect on the leaching rate. The leaching process followed the kinetic law of the shrinking core model, and the dissolution rates were controlled by the surface chemical reaction with an apparent activation energy value of 43.79 kJ/mol. A corresponding dissolution kinetic equation was also proposed to describe the dissolution reaction. The results indicated that sodium hydroxide could be used as an effective leaching reagent for extracting lead from cerussite.
7
Content available Relationship between flotation and Fe/Mn ratio of wolframite with benzohydroxamic acid and sodium oleate as collectors
Yang S., Feng Q., Qiu X., Gao Y., Xie Z.
Physicochemical Problems of Mineral Processing
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2014
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Vol. 50, iss. 2
747--758
EN
Several studies revealed that flotation of wolframite changes with different Fe/Mn ratios, but they did not reach a consensus. This relationship in the presence of benzohydroxamic acid (BHA) and sodium oleate (NaOl) as collectors was studied in this paper through comparison of probability distribution curve of wolframite with different Fe/Mn ratios between the raw ore and the flotation concentrate, the pure mineral flotation and solution chemistry of flotation. The results showed that wolframite with high Fe/Mn ratio showed higher flotation with BHA as a collector while the flotation behavior of wolframite was completely opposite with NaOl as a collector. Besides, the calculations of chemical equilibrium in the solution were plotted as ΔG°-pH graphs. The results revealed that the flotation of wolframite may be determined by the interaction between BHA and ferric(II) ion or between NaOl and manganous ion. From the perspective of collector mixture, the results also explain the high collecting capability of the BHA/NaOl collector mixture, which can be defined as “functional complementation”.
8
Content available Ontological multi-view failure modeling for ippd
Ren Y., Sun B., Feng Q., Zeng S.
Eksploatacja i Niezawodność
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2011
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nr 2
35-41
EN
Reliability engineering includes series of failure focused technology and management activities running throughout the entire product development cycle. Only these activities are effectively integrated and numerous relevant failure data is synthetically applied, the intent for progressively identifying failure and continuously improving reliability can be obtained. In current engineering practice, the reliability data and knowledge produced in different development phases cannot be efficiently shared and reused. There still exist difficulties in interoperating between different reliability activities. This paper establishes the failure ontology models that contain global failure ontology model, functional failure ontology model and hardware failure ontology model. In virtue of this ontology model, the reliability activities are seamlessly integrated into the integrated product and process development (IPPD). In this model, the evolution process of failure cognition during each development phases is considered. Base on this ontology model, a reliability engineering environment is constructed with the support of PLM (Product Lifecycle Management) platform to verify the ontology model's correctness and applicability.
PL
Inżynieria niezawodności zajmuje się prowadzeniem licznych działań w zakresie technologii uszkodzeń i zarządzania uszkodzeniami w ciągu całego cyklu rozwoju produktu. Stopniowa identyfikacja uszkodzeń oraz ciągła poprawa niezawodności jest możliwa tylko wtedy, gdy działania te zostaną skutecznie zintegrowane, przy syntetycznym uwzględnieniu szeregu istotnych danych dotyczących uszkodzeń. Obecna praktyka inżynieryjna nie pozwala na efektywną wymianę i ponowne wykorzystanie danych i wiedzy pochodzących z różnych faz rozwoju produktu. Ciągle jeszcze napotyka się trudności dotyczące interoperacyjności różnych działań ukierunkowanych na utrzymanie niezawodności. W artykule opracowano model ontologii uszkodzeń obejmujący modele ontologii uszkodzeń globalnych, funkcjonalnych i sprzętowych. Za sprawą tego modelu ontologicznego, działania niezawodnościowe stają się spójną częścią zintegrowanego rozwoju produktu i procesów (IPPD). Proponowany model uwzględnia ewolucję wiedzy na temat uszkodzenia w ciągu poszczególnych faz rozwoju. Na podstawie prezentowanego modelu ontologicznego stworzono środowisko inżynierii niezawodności oparte na platformie PLM (Zarządzanie Cyklem Życia Produktu) pozwalające zweryfikować poprawność i możliwość zastosowania omawianego modelu.
9
Content available remote Modyfikowanie gruntu dla wierceń głowicami typu EPB : równowaga właściwości funkcjonalnych i ekologicznych
Langmaack L., Feng Q.
Geoinżynieria : drogi, mosty, tunele
|
2006
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nr 2
34-39
PL
Maszyny EPB (Earth Pressure Balance) korzystające z dodatków do modyfikowania gruntu stają się coraz popularniejsze w świecie tunelowania. Ich konstrukcja pozwala na precyzyjne zrównoważenie parcia gruntu, zapobiegając niekontrolowanemu przepływowi wody gruntowej. Zdolność do zabezpieczenia równowagi ciśnień wraz z uwzględnieniem aspektów ekologicznych i toksykologicznych, należą do najważniejszych czynników decydujących o powodzeniu wiercenia maszynami TBM. Powodzenie użycia maszyn EPB - zwłaszcza przy gruntach spoistych oraz niejednolitych formacjach o znacznej porowatości, czy też w przypadku wysokiego poziomu wód gruntowych - zależy od dobrej inżynierii mechanicznej połączonej z wysoce efektywnymi dodatkami uzdatniającymi. Przykładami takich udanych połączeń są projekty tunelowe MetroSur w Madrycie, Toulouse Metro we Francji i tunel kolejowy w Rzymie.
EN
Earth Pressure Balancing (EPB) tunnel boring machines using soil conditioning additives have become more and more frequent in the world of tunnelling. Their ability to produce & secure the earth pressure equilibrium together with consideration on their ecological and toxicological aspects belongs to the most important factors of a successful TBM drive. The correct and effective use of soil conditioning additives is not always obvious. The success of EPB machines - especially in non-homogeneous, highly porous or adhesive ground conditions - depends on good mechanical engineering combined with highly effective soil conditioning additives. Examples of these successful combinations are Madrid MetroSur, Toulouse Metro and Rome Railway tunnel projects.
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