Quarry Waste: Chances of a Possible Economic and Environmental Valorisation of the Montorfano and Baveno Granite Disposal Sites

G A Dino,M Fornaro,A Trentin

doi:10.1155/2012/452950

Abstract

The Montorfano and Baveno granite ore bodies are located in the Lake District (VCO-NE Piedmont). They were and are still quarried as dimension stones, with a consequent production of a huge volume of “waste.” In 1995, an Italian company (GMM S.p.A) decided to invest in the valorisation of granite quarry waste as a secondary raw material. An in situ geological prospecting was carried out in order to evaluate the characteristics of the material and the thickness and volume of the useful disposal sites that could be used (by means of geophysical surveys). As a consequence of the field work, the amount of quarry waste was estimated as nearly 2 Mm3. Chemical analysis was carried out on 75 granite samples, in order to individuate the Fe2O3 grade: from 1.321–2.593% of the original waste to 0.160–0.228% after the “dry process” treatment. Three different detailed maps that show the typology, the locations, and the quality distribution of the material in the dumping areas have been drawn up.

Highlights

The main quarry disposal sites, the subject of the present research, are located in two different areas: the Sengio and Ciana Tane-Pilastretto dumps, which are located on the southern slope of the Montorfano Massif, while the Braghini site pertains to Monte Camoscio, on the right side of the Toce River (Ossola Valley) (Figure 1)
The two granitic plutons belong to the Hercynian Magmatic belt, which is located between the Ivrea-Verbano zone and the Serie dei Laghi unit
The Mottarone-Baveno pluton is mainly formed by two different varieties of granite: a pink granite, a historically famous ornamental stone, which has been quarried in the district over the last centuries, and a white granite, which represents the prevalent volumetric variety in the pluton, and which is no longer quarried

Summary

Geological Setting

The main quarry disposal sites, the subject of the present research, are located in two different areas: the Sengio and Ciana Tane-Pilastretto dumps, which are located on the southern slope of the Montorfano Massif, while the Braghini site pertains to Monte Camoscio, on the right side of the Toce River (Ossola Valley) (Figure 1). The Permian granites, Graniti dei Laghi, consist of nonmetamorphosed to weakly metamorphosed rocks [1, 2] and constitute an elongated SE-NW batholith, between the Biella-Valsessera and Val d’Ossola zones. This batholite is formed by singular plutons which develop a narrow contact aureole [3] in the Scisti dei Laghi and the Strona-Ceneri formation. The Montorfano pluton is formed by a medium-grained white granite and a small amount of a “green granite.” It is an episyenite consisting mainly of albite and chlorite. (iii) the Pogallo-Lago d’Orta fault, in the N-S direction, is in the western part of the pluton

Mining Context

Waste Valorisation

Quarry Dumps Rehabilitation

Findings

Conclusions