Elsevier

Minerals Engineering

Volume 156, 1 September 2020, 106474
Minerals Engineering

Selective flotation of apatite from micaceous minerals using patauá palm tree oil collector

https://doi.org/10.1016/j.mineng.2020.106474Get rights and content

Highlights

  • Pataua oil trees are abundant in the Amazon region.

  • Pataua oil has no significant industrial application.

  • Pataua oil collector shows selectivity between apatite and micaceous minerals.

  • Low pataua oil collector concentration is required to achieve selectivity.

  • Pataua oil collector can improve sustainability in the mining industry.

Abstract

Micaceous minerals are commonly found in phosphate ores, representing a challenge to selectively recover apatite. Aiming at identifying new flotation reagents for the separation of apatite from micaceous minerals, this study investigates the floatability of apatite, biotite and phlogopite in the presence of patauá oil-based collector. The chemical and mineralogical composition, electrokinetic properties and floatability of apatite, biotite and phlogopite in the presence of patauá fatty acid salts, as well as the reagent synthesis and adsorption mechanism were investigated in this work. The collector was successfully synthesized and showed a 90% selectivity gap between apatite and micaceous minerals in microflotation tests, at neutral and alkaline pH. The formation of calcium dicarboxylate was indicated to be the collector adsorption mechanism for apatite, whereas a less significant interaction with interlayer cations exposed during comminution was pointed as the adsorption mechanism for biotite and phlogopite.

Introduction

Phosphate ores are an important, non-renewable and currently irreplaceable source of phosphorous for application in the agriculture sector (Bada et al., 2013, Fang and Jun, 2011, Horta et al., 2016, Yang et al., 2017), as phosphorus is one of the fertilizers’ most important macronutrients for plants, necessary for increasing their productivity and, therefore, ensuring a stable global food supply (Cao et al., 2015, Chen and Graedel, 2015). In fact, currently 80% of the phosphate ores mined worldwide is used to produce phosphoric acid, which is an input in the production of fertilizers (Al-Thyabat et al., 2012, Mohammadkhani et al., 2011).

Apatite is the main valuable phosphorus-bearing mineral in phosphate ores, whereas the non-valuable minerals are mostly carbonates (e.g.: calcite and dolomite) and silicates (e.g.: quartz, chert, clays, feldspar and mica) (Liu et al., 2017, Mohammadkhani et al., 2011, Sis and Chander, 2003).

The phosphate ores are usually classed as low (12–16% P2O5), medium (17–25% P2O5) or high grade (26–35% de P2O5) reserves (Mohammadkhani et al., 2011). The main Brazilian phosphate deposits are located in the Alto Paranaíba Igneous Province, in the States of Goiás (Catalão) and Minas Gerais (Araxá and Tapira), and present low grade, which vary from 5 to 15% P2O5 (Albuquerque et al., 2012, Zhang et al., 2006). Carbonates and quartz are typically the gangue minerals in these deposits (Hanumantha Rao et al., 1989, Peng and Gu, 2005), although micas also appear in significant amounts in these mineral assemblages, being one of most abundant non-carbonate minerals in carbonatites (Giebel et al., 2019). Phlogopite is one of the main gangue minerals in Goias phoscorites (Albuquerque et al., 2012, Cordeiro et al., 2010, Zhang et al., 2006), whereas biotite and muscovite are present in Minas Gerais deposits (Brod et al., 2001, Seer and de Moraes, 2013). Phlogopite and biotite were also identified in Brazilian deposits of minor importance, as Itataia (Albuquerque et al., 2012) and Morro da Mina (Leal Filho et al., 1993).

Micas are a group of minerals which present perfect cleavage in one direction, forming sheets. In this group, the minerals also have a crystalline structure consisting of 2:1 layers (tetrahedral: octahedral) which present a negative structural charge due to the substitutions of Si4+ ions by Al3+ in the tetrahedral layers or Al3+ by Mg2+ or Fe2+ in the octahedral layers (Parks, 1975, Reynolds, 1980). The charge compensation occurs via electrostatic bonds with the cations in between the aluminosilicates layers (Loh and Jarvis, 2010, Parks, 1975).

As a minimum P2O5 grade of 30% is required for producing phosphoric acid, phosphate ores usually required concentration, which is achieved using flotation (Abouzeid, 2008, Azizi and Larachi, 2018, Cao et al., 2015). In phosphate flotation systems, vegetable oil based fatty acids and their salts are the most common collectors (Brandão et al., 1994, Filippov et al., 2019, Sis and Chander, 2003). These collectors are used to recover apatite in alkaline pH and depressors are used to reduce the flotation of non-valuable minerals (Filippova et al., 2018, Zhang et al., 2006). In these conditions, fatty acids are ionized and the carboxyl group reacts with calcium ions, at the apatite surface and in solution, producing the non-soluble calcium carboxylate (Filippova et al., 2018, Jong et al., 2017). Worldwide, tall oil (a by-product of the paper industry) is the main source of the fatty acids used in flotation plants (El-Shall et al., 2004, Guimarães et al., 2005, Sis and Chander, 2003), although the substitution by alternative vegetable oil sources, e.g.: rice, soy bean and grape, is a growing trend currently observed, particularly in Brazil (Cao et al., 2015, Guimarães et al., 2005). In fact, the investigation on alternative vegetable oil sources has been encouraged by tall oil price increases due to paper recycling (Sis and Chander, 2003). Sources recently investigated are: linseed (Linum usitatissimum) (Brandão et al., 1994), babaçu (Orbignya phalerata) (Oliveira et al., 2005), buriti (Mauritia flexuosa), inajá (Attalea maripa), açaí (Euterpe oleracea), passion fruit (Passiflora edulis), andiroba (Carapa guianenses), Brazil nut (Bertholletia excelsa) (Costa et al., 2011), jojoba (Simmondsia chinensis) (Al-Thyabat et al., 2012), coconut (Cocos nucifera) (Albuquerque et al., 2012), macaúba (Acromia aculeata) (Silva et al., 2015a), pequi (Caryocar brasiliense) (Silva et al., 2015b), and patauá (Oenocarpus bataua) (De Oliveira et al., 2019).

Patauá palm trees are found in the Amazon forest in Brazil, French Guiana and Peru. Typically, the fatty acid profile obtained from patauá palm tree oil is similar to that of tall oil as it presents large amounts of unsaturated fatty acids, mainly oleic acid (>40%) (Balick and Gershoff, 1981, Guimarães et al., 2005, Montúfar et al., 2010). This profile is desired as unsaturated fatty acids are reported to exhibit greater collecting power over apatite (Brandão et al., 1994, Guimarães et al., 2005). The presence of unsaturation in the fatty acid structure not only results in greater solubility (Brandão and Poling, 1982), but it also promotes a partial polymerization between the molecules adsorbed onto the mineral surface, resulting in a mixed film of high stability and hydrophobicity (Brandão, 1988). In the Brazilian phosphate beneficiation plants, the replacement of tall oil by other vegetable oils with similar fatty acid profile is already a consolidated practice (Guimarães et al., 2005). Patauá oil collector has also been reported as a potential collector for phosphate ore flotation, being selective to separate apatite from quartz and calcite at neutral and alkaline pH conditions. Fundamental tests demonstrated that, using low collector concentrations, adsorption took place preferably onto apatite surface. The performance rendered by Patauá oil collector also showed to be greater than that of sodium oleate, as lower dosages of the former reagent was required to achieve selectivity, which indicates lower reagent consumption (De Oliveira et al., 2019). In the Brazilian phosphate beneficiation plants, the replacement of tall oil by other vegetable oils with similar fatty acid profile is already a consolidated practice (Guimarães et al., 2005).

Despite the studies conducted on the selective flotation of mica, such as muscovite and biotite from other silicate minerals in mica schist bed rocks (Hanumantha Rao et al., 1995, 1990), biotite and muscovite from Ca-bearing minerals (Filippov et al., 2012), and the significant number of studies on vegetable oil-based collectors for the flotation of apatite from calcite, dolomite, quartz and other non-valuable minerals (Al-Thyabat et al., 2012, Albuquerque et al., 2012, Brandão et al., 1994, Costa et al., 2011, De Oliveira et al., 2019, Oliveira et al., 2005, Silva et al., 2015a, 2015b), research on the use of fatty acids to separate apatite from micaceous minerals are scarce. In fact, most of siliceous minerals flotation studies are based on cationic collectors as the electrostatic mechanism is well understood to be efficient for this mineral class (Filippov et al., 2012, Hanumantha Rao et al., 1995, Hanumantha Rao et al., 1990, Peng and Gu, 2005). In this sense, based on previous study (De Oliveira et al., 2019), this work expands the study on the use of patauá palm tree oil as a phosphate collector, investigating the selective separation of apatite from the non-valuable biotite and phlogopite, commonly found in Brazilian phosphate deposits.

Section snippets

Materials

The apatite, biotite and phlogopite samples were purchased from Luiz Menezes Comércio e Exportação de Minerais Ltda (Belo Horizonte, Brazil). They had their size initially reduced using a hammer, were handpicked to separate impurities, and then pulverized using an agate mortar and pestle to obtain particles in the 212–45 µm size range for microflotation tests and smaller than 38 µm for zeta potential and infrared spectroscopy measurements. The 212–45 µm particle size range was used in the

Characterization

The XRD results were evaluated using the PANalytical X’Pert HighScore and the peaks compared with standards from the ICDD (International Centre for Diffraction Data) PDF-2 database released in 2010. These results, shown in Fig. 1, confirmed the mineral samples presented high purity, which was also confirmed by the WDXRF analyses (Table 1). It can be noted that the apatite sample presented high CaO and P2O5 content and the micas had high quantities of Al2O3 and SiO2, for their octahedral and

Conclusions

This study showed that a selective fatty acid salt collector for apatite flotation can be synthesized from patauá palm tree oil, an abundant vegetable oil source found in the Amazon region. The collector has great potential for application in the flotation of phosphate ores with significant micaceous mica content, whereas the use of patauá oil in the reagents industry can generate economic growth in the Amazon region. Bench flotation tests should be conducted with ore samples to further

CRediT authorship contribution statement

Juliana Angélica Evangelista de Carvalho: Conceptualization, Methodology. Paulo Roberto Gomes Brandão: Investigation. Andreia Bicalho Henriques: Supervision. Priscila Silva de Oliveira: Writing, Data analysis. Raul Zanoni Lopes Cançado: Validation. Gilberto Rodrigues da Silva: Reviewing, Editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors thank all who collaborated in this work and acknowledge the financial support from UFMG, Engineering School, PPGEM and CAPES / PROEX.

References (79)

  • M. Chen et al.

    The potential for mining trace elements from phosphate rock

    J. Clean. Prod.

    (2015)
  • P.F.O. Cordeiro et al.

    Mineral chemistry, isotope geochemistry and petrogenesis of niobium-rich rocks from the Catalão I carbonatite-phoscorite complex, Central Brazil

    Lithos

    (2010)
  • G.R. Da Silva et al.

    Surface characterization of microwave-treated chalcopyrite

    Colloids Surfaces A

    (2018)
  • G.R. Da Silva et al.

    The effects of microwave irradiation on the floatability of chalcopyrite, pentlandite and pyrrhotite

    Adv. Powder Technol.

    (2018)
  • J. Deng et al.

    Flotation separation of barite from calcite using acidified water glass as the depressant

    Colloids Surfaces A Physicochem. Eng. Asp.

    (2019)
  • G. Fang et al.

    Selective separation of silica from a siliceous–calcareous phosphate rock

    Min. Sci. Technol.

    (2011)
  • L.O. Filippov et al.

    Selective flotation of silicates and Ca-bearing minerals: The role of non-ionic reagent on cationic flotation

    Miner. Eng.

    (2012)
  • L.O. Filippov et al.

    The role of a fatty alcohol in improving calcium minerals flotation with oleate

    Colloids Surfaces A

    (2019)
  • I.V. Filippova et al.

    Synergetic effect of a mixture of anionic and nonionic reagents: Ca mineral contrast separation by flotation at neutral pH

    Miner. Eng.

    (2014)
  • I.V. Filippova et al.

    Effect of calcium minerals reactivity on fatty acids adsorption and flotation

    Colloids Surfaces A Physicochem. Eng. Asp.

    (2018)
  • M.E. Fleet

    Infrared spectra of carbonate apatites: ν2-Region bands

    Biomaterials

    (2009)
  • R.J. Giebel et al.

    A model for the formation of carbonatite-phoscorite assemblages based on the compositional variations of mica and apatite from the Palabora Carbonatite Complex, South Africa

    Lithos

    (2019)
  • R.C. Guimarães et al.

    Reagents in igneous phosphate ores flotation

    Miner. Eng.

    (2005)
  • K. Hanumantha Rao et al.

    Flotation of phosphatic material containing carbonatic gangue using sodium oleate as collector and sodium silicate as modifier

    Int. J. Miner. Process.

    (1989)
  • Y. Hu et al.

    Interactions of amphoteric amino phosphoric acids with calcium-containing minerals and selective flotation

    Int. J. Miner. Process.

    (2003)
  • K. Jong et al.

    Flotation mechanism of oleic acid amide on apatite

    Colloids Surfaces A Physicochem. Eng. Asp.

    (2017)
  • S. Joseph-Soly et al.

    Effects of Eh and pH on the oleate flotation of iron oxides

    Miner. Eng.

    (2015)
  • R.F. Jung et al.

    Adsorption, precipitation, and electrokinetic processes in the iron oxide (Goethite)-oleic acid-oleate system

    J. Colloid Interface Sci.

    (1987)
  • J. Kou et al.

    Fatty acid collectors for phosphate flotation and their adsorption behavior using QCM-D

    Int. J. Miner. Process.

    (2010)
  • L.S. Leal Filho et al.

    Process mineralogy studies for optimizing the flotation performance of two refractory phosphate ores

    Miner. Eng.

    (1993)
  • M.J. Lerma-García et al.

    Authentication of extra virgin olive oils by Fourier-transform infrared spectroscopy

    Food Chem.

    (2010)
  • X. Liu et al.

    Effect and mechanism of phosphoric acid in the apatite/dolomite flotation system

    Int. J. Miner. Process.

    (2017)
  • Y. Lu et al.

    Carboxyl Stretching Vibrations of Spontaneously Adsorbed and LB-Transferred Calcium Carboxylates as Determined by FTIR Internal Reflection Spectroscopy

    J. Colloid Interface Sci.

    (2002)
  • A.G. Merma et al.

    On the fundamental aspects of apatite and quartz flotation using a Gram positive strain as a bioreagent

    Miner. Eng.

    (2013)
  • M. Mohammadkhani et al.

    Double reverse flotation of a very low grade sedimentary phosphate rock, rich in carbonate and silicate

    Int. J. Miner. Process.

    (2011)
  • C.L. Owens et al.

    Apatite enrichment by rare earth elements : A review of the effects of surface properties

    Adv. Colloid Interface Sci.

    (2019)
  • K. Quast

    The use of zeta potential to investigate the pKa of saturated fatty acids

    Adv. Powder Technol.

    (2016)
  • R.K. Rath et al.

    Studies on adsorption of guar gum onto biotite mica

    Miner. Eng.

    (1997)
  • H. Schulz et al.

    Identification and quantification of valuable plant substances by IR and Raman spectroscopy

    Vib. Spectrosc.

    (2007)
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