Halloysite
{{Short description|Aluminosilicate clay mineral}}
{{Infobox mineral
| name = Halloysite
| image = Halloysite variety Indianaite Hydrous Aluminum silicate Bedford, Lawrence County, Indiana 2770.jpg
| imagesize =
| alt =
| caption =
| category = Phyllosilicates
Kaolinite-serpentine group
| formula = Al2Si2O5(OH)4
| molweight =
| strunz = 9.ED.10
| system = Monoclinic
| class = Domatic (m)
(same H-M symbol)
| symmetry = Cc
| unit cell = a = 5.14, b = 8.9,
c = 7.214 [Å]; β = 99.7°; Z = 1
| color = White; grey, green, blue, yellow, red from included impurities.
| habit = Spherical clusters, massive
| twinning =
| cleavage = Probable on {001}
| fracture = Conchoidal
| tenacity =
| mohs = 2–2.5
| luster = Pearly, waxy, or dull
| streak =
| diaphaneity = Semitransparent
| gravity = 2–2.65
| density =
| polish =
| opticalprop = Biaxial
| refractive = nα = 1.553–1.565
nβ = 1.559–1.569
nγ = 1.560–1.570
| birefringence = δ = 0.007
| pleochroism =
| 2V =
| dispersion =
| extinction =
| length fast/slow =
| fluorescence =
| absorption =
| melt =
| fusibility =
| diagnostic =
| solubility =
| impurities =
| alterations =
{{cite web|url=http://www.mindat.org/show.php?id=1808&ld=1&pho=|title=Halloysite: Halloysite mineral information and data.|publisher=mindat.org}}{{cite web|url=http://webmineral.com/data/Halloysite.shtml|title=Halloysite Mineral Data|first=Dave|last=Barthelmy|publisher=webmineral.com}}
}}
Halloysite is an aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. Its main constituents are oxygen (55.78%), silicon (21.76%), aluminium (20.90%), and hydrogen (1.56%). It is a member of the kaolinite group. Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals. It can occur intermixed with dickite, kaolinite, montmorillonite and other clay minerals. X-ray diffraction studies are required for positive identification. It was first described in 1826, and subsequently named after, the Belgian geologist Omalius d'Halloy.
Structure
Halloysite naturally occurs as small cylinders (nanotubes) that have a wall thickness of 10–15 atomic aluminosilicate sheets, an outer diameter of 50–60 nm, an inner diameter of 12–15 nm, and a length of 0.5–10 μm.{{Cite book |last1=Saharudin |first1=Mohd Shahneel |last2=Hasbi |first2=Syafawati |last3=Nazri |first3=Muhammad Naguib Ahmad |last4=Inam |first4=Fawad |title=Advances in Manufacturing Engineering |chapter=A Review of Recent Developments in Mechanical Properties of Polymer–Clay Nanocomposites |date=2020 |editor-last=Emamian |editor-first=Seyed Sattar |editor2-last=Awang |editor2-first=Mokhtar |editor3-last=Yusof |editor3-first=Farazila |chapter-url=https://link.springer.com/chapter/10.1007/978-981-15-5753-8_11 |series=Lecture Notes in Mechanical Engineering |language=en |location=Singapore |publisher=Springer |pages=107–129 |doi=10.1007/978-981-15-5753-8_11 |isbn=978-981-15-5753-8|s2cid=226833413 }} Their outer surface is mostly composed of SiO2 and the inner surface of Al2O3, and hence those surfaces are oppositely charged. Two common forms are found. When hydrated, the clay exhibits a 1 nm spacing of the layers, and when dehydrated (meta-halloysite), the spacing is 0.7 nm. The cation exchange capacity depends on the amount of hydration, as 2H2O has 5–10 meq/100 g, while 4H2O has 40–50 meq/100g. Endellite is the alternative name for the Al2Si2O5(OH)4·2(H2O) structure.[http://www.webmineral.com/data/Endellite.shtml#.WQfoVqKLmUk Endellite]. Webminerals
Owing to the layered structure of the halloysite, it has a large specific surface area, which can reach 117 m2/g.{{cite book|author=Yang, Y. Zhang|author2= J. Ouyang|title=Nanosized Tubular Clay Minerals - Halloysite and Imogolite|volume=7|pages=67–91|doi=10.1016/B978-0-08-100293-3.00004-2|chapter=Physicochemical Properties of Halloysite|series=Developments in Clay Science|year=2016|isbn=9780081002933}}
Formation
File:Halloysite nanotubes TEM.jpg
File:Ru-intercalated halloysite nanotubes 2.jpg catalytic nanoparticles]]
The formation of halloysite is due to hydrothermal alteration, and it is often found near carbonate rocks. For example, halloysite samples found in Wagon Wheel Gap, Colorado, United States are suspected to be the weathering product of rhyolite by downward moving waters. In general the formation of clay minerals is highly favoured in tropical and sub-tropical climates due to the immense amounts of water flow. Halloysite has also been found overlaying basaltic rock, showing no gradual changes from rock to mineral formation.{{Cite journal|last=Papke |first=Keith G. |year=1971 |title=Halloysite Deposits in the terraced Hills Washoe County, Nevada |journal=Clays and Clay Minerals |volume=19 |issue=2 |pages=71–74 |doi=10.1346/CCMN.1971.0190202 |bibcode = 1971CCM....19...71P |s2cid=98464074 }} Halloysite occurs primarily in recently exposed volcanic-derived soils, but it also forms from primary minerals in tropical soils or pre-glacially weathered materials. Igneous rocks, especially glassy basaltic rocks are more susceptible to weathering and alteration forming halloysite.
Often as is the case with halloysite found in Juab County, Utah, United States the clay is found in close association with goethite and limonite and often interspersed with alunite. Feldspars are also subject to decomposition by water saturated with carbon dioxide. When feldspar occurs near the surface of lava flows, the CO2 concentration is high, and reaction rates are rapid. With increasing depth, the leaching solutions become saturated with silica, aluminium, sodium, and calcium. Once the solutions are depleted of CO2 they precipitate as secondary minerals. The decomposition is dependent on the flow of water. In the case that halloysite is formed from plagioclase it will not pass through intermediate stages.
Locations
A highly refined halloysite is mined, then processed, from a rhyolite occurrence in
Matauri Bay, New Zealand.[https://web.archive.org/web/20100214023625/http://www.minerals.co.nz/html/main_topics/resources_for_schools/industrial_minerals/indmin_cs_halloysite.html CASE STUDY: Halloysite Clay]. minerals.co.nz{{cite journal|url=http://ccm.geoscienceworld.org/content/25/1/1|title=Mineralogy and geology of the Maungaparerua halloysite deposit in New Zealand|journal=Clays and Clay Minerals|first1=H. H.|last1=Murray|first2=C.|last2=Harvey|first3=J. M.|last3=Smith|date=1 February 1977|volume=25|issue=1|pages=1–5|bibcode=1977CCM....25....1M|doi=10.1346/CCMN.1977.0250101|s2cid=129310746|url-access=subscription}}{{cite web|url=http://www.reciprocalnet.org/recipnet/showsampledetailed.jsp?sampleHistoryId=21742&sampleId=27344589|title=Common molecules sample 50642 |publisher=Reciprocal Net}}Lyday, Travis Q. (2002) [http://minerals.usgs.gov/minerals/pubs/country/2002/nzmyb02.pdf The Mineral Industry of New Zealand]. minerals.usgs.gov Annual output of this mine is up to 20,000 tonnes per annum.'Global Occurrence, Geology And Characteristics Of Tubular Halloysite Deposits.' I. Wilson and J. Keeling. Clay Minerals, Vol 51, 2016. pg 309-324.
One of the largest halloysite deposits in the world is Dunino, near Legnica in Poland.{{Cite journal|last1=Lutyński|first1=Marcin|last2=Sakiewicz|first2=Piotr|last3=Lutyńska|first3=Sylwia|date=2019-10-31|title=Characterization of Diatomaceous Earth and Halloysite Resources of Poland|journal=Minerals|language=en|volume=9|issue=11|pages=670|doi=10.3390/min9110670|bibcode=2019Mine....9..670L|issn=2075-163X|doi-access=free}} It has reserves estimated at 10 million tons of material. This halloysite is characterized by layered-tubular and platy structure.
The Dragon mine, located in the Tintic district, Eureka, Utah, US deposit contains catalytic quality halloysite. The Dragon Mine Deposit is one of the largest in the United States. The total production throughout 1931–1962 resulted in nearly 750,000 metric tons of extracted halloysite. Pure halloysite classified at 10a and 7a are present.Patterson, S., & Murray, H. (1984). Kaolin, refractory clay, ball clay, and halloysite in North America, Hawaii, and the Caribbean region. Professional Paper, 44-45. doi:10.3133/pp1306
Applications
Commercial
Uses of the halloysite produced at the Matauri Bay deposit in New Zealand include porcelain and bone china by manufacturers in various countries, particularly in Asia.
Laboratory studies
- Halloysite is an efficient adsorbent both for cations and anions. It has also been used as a petroleum cracking catalyst, and Exxon has developed a cracking catalyst based on synthetic halloysite in the 1970s. Owing to its structure, halloysite can be used as filler in either natural or modified forms in nanocomposites. Halloysite nanotube can be intercalated with catalytic metal nanoparticles made of silver, ruthenium, rhodium, platinum or cobalt, thereby serving as a catalyst support.
- Halloysite has been evaluated for use in the sorption of CO2{{Cite journal|last1=Lutyński|first1=M.|last2=Sakiewicz|first2=P.|last3=Gonzalez|first3=M. a. G.|date=2014|title=Halloysite as Mineral Adsorbent of CO2 – Kinetics and Adsorption Capacity|url=http://yadda.icm.edu.pl/baztech/element/bwmeta1.element.baztech-1059065e-3ccb-4293-b319-41fa548227b0|journal=Inżynieria Mineralna|language=EN|volume=R. 15, nr 1|issn=1640-4920}} and CH4.{{Cite journal|last1=Pajdak|first1=Anna|last2=Skoczylas|first2=Norbert|last3=Szymanek|first3=Arkadiusz|last4=Lutyński|first4=Marcin|last5=Sakiewicz|first5=Piotr|date=2020-02-19|title=Sorption of CO2 and CH4 on Raw and Calcined Halloysite—Structural and Pore Characterization Study|journal=Materials|language=en|volume=13|issue=4|pages=917|doi=10.3390/ma13040917|issn=1996-1944|pmc=7078888|pmid=32092961|bibcode=2020Mate...13..917P|doi-access=free}}
- Due to its nanostructure, halloysite is used as the main nanostructured filler in multifunctional mixed matrix membranes (MMMs), opening up new possibilities in the separation of gaseous and liquid mixtures {{Cite journal |last1=Piotrowski |first1=Krzysztof |last2=Sakiewicz |first2=Piotr |last3=Gołombek |first3=Klaudiusz |date=2021 |title=Halloysite as main nanostructural filler in multifunctional mixed matrix membranes – review of applications and new possibilities |journal=Desalination and Water Treatment |url=https://doi.org/10.5004/dwt.2021.27873 |volume=243 |pages=91–106 |doi=10.5004/dwt.2021.27873|bibcode=2021DWatT.243...91P |s2cid=247830004 |url-access=subscription }} and water purification.{{Cite journal |last=Sakiewicz Piotr; Piotrowski Krzysztof; Boryn Dominika; Kruk Milena; Mscichecka Joanna; Korus Irena Barbusinski, Krzysztof |date=August 2020 |title=Zastosowanie sorbentu haloizytowego do usuwania syntetycznych barwników azowych Acid Red 27 i Reactive Black 5 z roztworów wodnych |url=https://sigma-not.pl/publikacja-127557-zastosowanie-sorbentu-haloizytowego-do-usuwania-syntetycznych-barwnik%C3%B3w-azowych-acid-red-27-i-reactive-black-5-z-roztwor%C3%B3w-wodnych-przemysl-chemiczny-2020-8.html |journal=Przemysl Chemiczny |volume=99 |issue=8 |pages=1142–1148 |via=Web of Science}}
- Besides supporting nanoparticles, halloysite nanotubes can also be used as a template to produce round well-dispersed nanoparticles (NPs). For example, bismuth and bismuth subcarbonate NPs with controlled size (~7 nm) were synthesized in water. Importantly, when halloysite was not used, large nanoplates instead of round spheres are obtained.{{cite journal |last1=Ortiz-Quiñonez |first1=J.L. |last2=Vega-Verduga |first2=C |last3=Díaz |first3=D |last4=Zumeta-Dubé |first4=I |title=Transformation of Bismuth and β‑Bi2O3 Nanoparticles into (BiO)2CO3 and (BiO)4(OH)2CO3 by Capturing CO2: The Role of Halloysite Nanotubes and "Sunlight" on the Crystal Shape and Size |journal=Crystal Growth & Design |date=June 13, 2018 |volume=18 |issue=8 |pages=4334−4346 |doi=10.1021/acs.cgd.8b00177 |s2cid=103659223 }}
- Halloysite is also used to purify water, e.g. from two azo dyes were removed from aq. solutions. by adsorption on a Polish halloysite from Dunino deposit.{{Cite journal|last=Sakiewicz|first=Piotr|date=2020-08-17|title=Zastosowanie sorbentu haloizytowego do usuwania syntetycznych barwników azowych Acid Red 27 i Reactive Black 5 z roztworów wodnych|url=https://sigma-not.pl/publikacja-127557-2020-8.html|journal=Przemysł Chemiczny|language=en|volume=1|issue=8|pages=48–54|doi=10.15199/62.2020.8.5|s2cid=225354676|issn=0033-2496|url-access=subscription}}
- Halloysite have many advantages and reported as a nanocontainer.{{Cite journal|last=Azmi Zahidah|first=Khairina|date=2017-09-19|title=Benzimidazole-loaded Halloysite Nanotube as a Smart Coating Application|url=https://www.researchgate.net/publication/320142351|journal=International Journal of Engineering and Technology Innovation|language=en|volume=7|issue=4|pages=243–254|issn=2226-809X}}{{Cite journal|last=Azmi Zahidah|first=Khairina|date=2017-05-19|title=Halloysite Nanotubes as Nanocontainer for Smart Coating Application: A Review|url=https://www.sciencedirect.com/science/article/pii/S0300944017301030|journal=Progress in Organic Coatings|language=en|volume=111|issue=C|pages=175–185|doi=10.1016/j.porgcoat.2017.05.018 |issn=0300-9440|url-access=subscription}}
- Halloysite can also be used to produce porous silicon nanotubes as anode materials for Li-ion batteries through the selective etching of aluminium oxide and thermal reduction.{{Cite journal|last1=Yeom|first1=S. J.|last2=Lee|first2=C. M.|last3=Kang|first3=S.|last4=Wi|first4=T.-W.|last5=Lee|first5=C.|last6=Chae|first6=S.|last7=Cho|first7=J.|last8=Shin|first8=D. O.|last9=Ryu|first9=J.|last10=Lee|first10=H.-W.|date=2019-11-01|title=Native void space for maximum volumetric capacity in silicon-based anodes|journal=Nano Letters|volume=19|issue=12|pages=8793–8800|doi=10.1021/acs.nanolett.9b03583|pmid=31675476 |bibcode=2019NanoL..19.8793Y |s2cid=207834252 }}
- As a nanofiller in nanocomposite e.g. thermoplastic polyurethane acting on the mechanical, physicochemical and biological properties.{{Cite journal |last1=Mrowka |first1=Maciej |last2=Szymiczek |first2=Malgorzata |last3=Machoczek |first3=Tomasz |last4=Lenza |first4=Joanna |last5=Matusik |first5=Jakub |last6=Sakiewicz |first6=Piotr |last7=Skonieczna |first7=Magdalena |date=November 2020 |title=The influence of halloysite on the physicochemical, mechanical and biological properties of polyurethane-based nanocomposites |url=https://ichp.vot.pl/index.php/p/article/view/92/ |journal=Polimery |volume=65 |issue=11/12 |pages=784–791 |doi=10.14314/polimery.2020.11.5|s2cid=228942877 |doi-access=free }}
Chemistry and mineralogy
Typical chemical and mineralogical analyses of two commercial grades of halloysite are:'Positive Outlook For Kaolin In Ceramics' F. Hart, I. Wilson. Industrial Minerals, April 2019. Pg.28
| class="wikitable collapsible"
! Product name !! Premium !! Yunnan |
| Country
| New Zealand || China |
|---|
| Area
| Northland || Yunnan |
| | || |
| SiO2, %
| 49.5 ||42.7 |
| Al2O3, %
| 35.5 ||37.0 |
| Fe2O3, %
| 0.29 ||0.10 |
| TiO2, %
| 0.09 || <0.05 |
| CaO, %
| - || - |
| MgO, %
| - || - |
| K2O, %
| - || <0.05 |
| Na2O, %
| - || <0.05 |
| LOI, %
| 13.8 || 19.8 |
| | || |
| Halloysite, %
| 92 || 99.1 |
| Cristobalite, %
| 4 || - |
| Quartz, %
| 1 || 0.1 |
References
{{Reflist|30em|refs=
}}
{{Phyllosilicates}}
{{Clay minerals}}
{{Authority control}}