Next Article in Journal
Fly Ash-Based Geopolymer Binder: A Future Construction Material
Next Article in Special Issue
Mineralogical and Geochemical Features of Cretaceous Bauxite from San Giovanni Rotondo (Apulia, Southern Italy): A Provenance Tool
Previous Article in Journal
Mineralogical and Geochemical Characteristics of Trace Elements in the Yongdingzhuang Mine, Datong Coalfield, Shanxi Province, China
Previous Article in Special Issue
Rare Earth Element Phases in Bauxite Residue
Open AccessArticle

Geochemical Characterization of Bauxite Deposits from the Abruzzi Mining District (Italy)

1
Dipartimento Scienze della Terra, dell’Ambiente e delle Risorse, Università di Napoli Federico II, Complesso Universitario di Monte Sant’Angelo, Via Cintia, 80126 Napoli, Italy
2
INGV—Osservatorio Vesuviano, Via Diocleziano 328, 80124 Napoli, Italy
*
Author to whom correspondence should be addressed.
Minerals 2018, 8(7), 298; https://doi.org/10.3390/min8070298
Received: 30 May 2018 / Revised: 8 July 2018 / Accepted: 10 July 2018 / Published: 12 July 2018
(This article belongs to the Special Issue Bauxite Deposits)
The Abruzzi bauxite district includes the deposits located on the Campo Felice plateau and those of the Monti d’Ocre, which had been mined in the first part of the 20th century. Bauxite is of the karst type, with textures ranging between oolitic and oolitic-conglomeratic, the latter suggesting a partial reworking of evolved lateritic soils. The high contents of Al2O3 and Fe2O3 (average values 53.76 and 21.76 wt %, respectively) are associated with the presence of boehmite, hematite, and minor goethite. SiO2 and TiO2 have average values of 7.79 and 2.75 wt %, corresponding to the presence of kaolinite, anatase and rutile. Among the minor so-called “bauxitophile” elements V, Co, Ni, Cr and Zr, the most enriched is Cr, with an average value of 0.07 wt %. Nickel has an average value of 210.83 ppm. Vanadium shows an average value of 266.57 ppm, whereas the average Co concentration is 35.89 ppm. The total rare earth elements (REE) concentration in the sampled bauxite sites is variable between ca. 700 and 550 ppm. Among REEs, the most abundant element is Ce, with Ce anomalies commonly associated with authigenic REE-fluoro-carbonates, probably produced after the REEs remobilization from primary detrital minerals and their precipitation in neo-formed phases during the bauxitization process. Scandium and Ga occur in small amounts (57 and 60 ppm, respectively), but geochemical proxies of their remobilization and uptake in neo-formed minerals (Fe- and Al-(hydr)oxides, respectively) have been observed. The mean Eu/Eu* and Al2O3/TiO2 ratios and the Ni-Cr contents of the Abruzzi bauxites suggest that the parent rock of these deposits was a material of acid affinity, likely corresponding to volcanic tephra or eolic loess-type sands. View Full-Text
Keywords: karst bauxite; rare earth elements; scandium; gallium; Abruzzi; Italy karst bauxite; rare earth elements; scandium; gallium; Abruzzi; Italy
Show Figures

Figure 1

MDPI and ACS Style

Putzolu, F.; Piccolo Papa, A.; Mondillo, N.; Boni, M.; Balassone, G.; Mormone, A. Geochemical Characterization of Bauxite Deposits from the Abruzzi Mining District (Italy). Minerals 2018, 8, 298.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop