Dan Stumbea

Universitatea Alexandru Ioan Cuza Iasi, Geologie, Faculty Member

Followers

Following

Co-author

Mentions

Public Views

Phone: +40232201464
Address: 20A, Carol I Blvd.

less

David Seamon

Kansas State University

Armando Marques-Guedes

UNL - New University of Lisbon

Dr.Subramaniam Karuppannan

Open University Malaysia (OUM),

AMAR DHERE

University Of Pune'S AFFILIATED INDIRA COLLEGE OF COMMERCE AND SCIENCE, PUNE

Md. Khairul Alam

Murdoch University

Shivaji Chaudhry

Indira Gandhi National Tribal University, Amarkantak , India

Dr Rehan Dastagir

International University Of Business Agriculture and Technology(IUBAT)

Alexandru Badarau

Babes-Bolyai University

Sibel Pamukcu

Lehigh University

Roger Saint-Fort

Mount Royal University

Interests

Uploads

Papers by Dan Stumbea

A Critical Approach to Ti in the Biotite Geothermometer. Case Study on Biotites from Pegmatites of Romania

Acid Mine Drainage-Related Products in Negoiul Românesc Quarrying Waste Deposits (Călimani MTS., Romania)

The tailings ponds from the Fundu Moldovei mine field (Suceava County, Romania). A preliminary study

Waste of the Straja Valley Tailings Pond (Suceava County, Romania). Geochemical Properties and Environmental Risks Related to Wind-Driven Removal

Carpathian Journal of Earth and Environmental Sciences

The tailings of Straja Valley waste deposit consist mainly of minerals resulting from the metalli... more The tailings of Straja Valley waste deposit consist mainly of minerals resulting from the metallic ores and their host schist of Lesu Ursului mining field (primary minerals). Additionally, secondary minerals produced through the weathering of the first ones were identified (Na-and Pb-jarosite, Mg-copiapite, gypsum, alunite, apjohnite, and goethite). Two grain-size classes were separated namely coarse grains (CG) (size larger than 0.25 mm) and fine grains (FG). The descriptive statistic data showed that the geochemical properties of the waste depend on its location on the tailings pond, abundance of the soluble fraction (in close relation with secondary hydrated sulfates) and, to a lesser extent, the waste grain size. Principal Component Analysis (PCA) carried out on geochemical data revealed the following patterns of waste: (i) pyrite-rich tailings from the waste beach are frequently fine-grained and have a higher Cu content; (ii) while the coarse-grained waste is rich in silicates, it also contains secondary minerals that trap Pb (Na-jarosite, Pb-jarosite, gypsum); (iii) if the silicate-rich tailings are controlled by quartz, they are coarse-grained and depleted in secondary minerals; (iv) the fine-grained silicate-rich waste also contains secondary minerals (e.g., Na-jarosite, Mg-copiapite, gypsum, alunite, and clay minerals) that collect Pb, Al, Mg, Ca, and Na in their structure. The environmental risks related to wind-driven transport of waste during long drought periods can be presumed as following: (i) mechanical pollution with quartz and chemical pollution with Pb, Zn, Cd trapped in sphalerite ± galena, Pb-jarosite, Mg-copiapite, goethite, apjohnite, and clay minerals, when wind exceeds 7.3 m/s; (ii) pollution with fine-grained pyrite (and Cu, Zn, Cd within) or secondary minerals that accumulate Pb and As (Pb-jarosite, Mg-copiapite, apjohnite, and goethite), when the wind speed is less than 7.9 m/s.

Geochemistry of Waste from the Tailings Pond of Pârâul Cailor, Fundu Moldovei Metallogenic Field, Romania

The waste of the tailings pond has a yellowish appearance, over 70-80 wt% consisting of fine and ... more The waste of the tailings pond has a yellowish appearance, over 70-80 wt% consisting of fine and very fine particles. The dominant minerals are quartz, sericite, chlorite and pyrite, while sphalerite and biotite occur accidentally. Translucent crystal grains of presumed hydrated sulfates were identified as well. The pH is very low (mean of 3.1), as well as the abundance of the soluble fraction (mean less than 2.0wt%). Across the surface of the waste deposit, four sectors with specific geochemical properties were identified, using statistical analyses: (1) the northern and southern edges of the horizontal surface (C2), where the waste is the most susceptible to be removed and transported either by wind or by runoff; (2) the flat, horizontal sector C1, rich in Al, Mg, Mn, and K, where especially the silt and clay particles accumulate; (3) the sector C3 which overlaps the watercourse of the temporary stream, the latter being the main vector of mechanical and chemical removal and transport of waste towards the surrounding areas; (4) the sector C4, the richest in toxic trace elements, related especially to primary sulfides, less mobile because of their higher specific weight. The relation between this geochemical distribution and other properties of the tailings (e.g., mineralogy, grain size, abundance of soluble fraction, pH) suggested that the sectors C2 and C3 present the highest risk to the environment.

The Flanks of the Dealul Negru Tailings Pond (Fundu Moldovei) – Pollution Risk Factors

Preliminaries on pollution risk factors related to mining and ore processing in the Cu-rich pollymetallic belt of Eastern Carpathians, Romania

Environmental Science and Pollution Research, 2013

The present study focuses on the mineralogical and geochemical patterns of mining and ore-process... more The present study focuses on the mineralogical and geochemical patterns of mining and ore-processing wastes from some occurrences in the Eastern Carpathians; its aim is to identify the main factors and processes that could lead to the pollution of the environment. In this respect, the following types of solid waste were investigated: efflorescent salts developed on the surface of rock blocks from a quarry, ore-processing waste from two tailings ponds, and salt crusts developed at the surface of a tailings pond. The potential risks emphasized by these preliminary investigations are the following: (1) the risk of wind-driven removal and transport of the waste from the surface of tailings ponds, given that fine grains prevail (up to 80 %); (2) the risk of tailings removal through mechanical transport by water, during heavy rainfall; (3) the appearance of hydrated sulfates on the rock fragments from the mining waste, sulfates which are highly susceptible to the generation of acid mine drainage (pH<4); (4) the high amount of toxic elements (Pb, Cd, Cu, Zn, As, etc.) that acid mine drainage leachates contain; and (5) the development of a salt crust on the flat, horizontal surfaces of the waste deposit, due to this very shape. Statistical data regarding the amount of both major and minor elements in the tailings have revealed two statistical populations for nearly all the toxic metals. This suggests that, beyond the effect that the tailings have upon the environment through their mere presence in a given area, there are alleged additional factors and processes which intensify the pollution: the location of the waste deposit relative to the topography of the area; the shape of the waste deposit; the development of low areas on the surface of the deposit, areas which favor the appearance of salt crusts; and the mineralogy of efflorescent aggregates.

Directory

Dan Stumbea

Uploads

Papers by Dan Stumbea

Log In