Sökning: "pyrite"

Visar resultat 1 - 5 av 70 avhandlingar innehållade ordet pyrite.

1. 1. Quantification of mineral weathering rates in sulfidic mine tailings under water-saturated conditions

   Författare :Magdalena Gleisner; Docent Roger Herbert; Professor Emeritus Rolf Hallberg; Dr. Magnus Land; Professor Patrick Crill; Mats Åström; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mine tailings; pyrite; sulfides; weathering; oxygen availability; Acidithiobacillus ferrooxidans; Earth sciences; Geovetenskap;

   Sammanfattning : Tailings are a fine-grained waste product produced during the metal recovery process. Tailings consist mostly of different silicates but also sulfides (e.g. pyrite), since 100 % metal recovery is not possible. LÄS MER

3. 2. Nanomagnetic and Micromagnetic Properties of Rocks Minerals and Sulphide Oxidation Products

   Författare :Erik Eneroth; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; physical geography; Geology; multi-domain; single-domain; ilmenite; magnetite; maghemite; hematite; pyrite; marcasite; fysisk geografi; Geologi;

   Sammanfattning : Magnetic and related properties of rocks and products from oxidation of sulphide minerals have been investigated with magnetisation measurements (rocks and oxidation products), magnetic force microscopy (rocks), scanning electron microscopy (rocks and oxidation products), transmission electron microscopy (oxidation products), Mössbauer spectroscopy (oxidation products) and powder X-ray diffraction (oxidation products). The investigations have shown the following: During thermal oxidation of pyrite (cubic FeS2) and marcasite (orthorombic FeS2) in air, nano-crystals of a-Fe2O3 and g-Fe2O3 were formed. LÄS MER

4. 3. Seismic-Reflection and Seismic-Refraction Imaging of the South Portuguese Zone Fold-and-Thrust Belt

   Författare :Cedric Schmelzbach; Christopher Juhlin; Laust Pedersen; Hans Thybo; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Dip-moveout; Prestack time migration; Crooked-line geometry; Traveltime tomography; Inversion; Seismic velocity; IBERSEIS profile; Variscan orogeny; Iberian Pyrite Belt; Geofysik; Earth sciences; Geovetenskap;

   Sammanfattning : The South Portuguese Zone (SPZ), which host world-class massive sulphide deposits, forms the southern fold-and-thrust belt of the Iberian Variscan orogeny. This thesis focuses on seismic-reflection and seismic-refraction processing efforts on a subset of the IBERSEIS deep seismic-reflection data set aiming at resolving the SPZ upper crust in high resolution. LÄS MER

5. 4. Vattenfysikalisk-kemiska och bottenfaunaförhållanden i ett norrländskt vattendrag påverkat av utsläpp från sulfidmalmbrytning och anrikning

   Författare :Bertil Brånin; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mining; metals; pollution; stream; physicochemical; invertebrates and diversity index;

   Sammanfattning : Gruvbrytnings- och anrikningsverksamheten av komplexa zink-och kopparsulfidmalmer orsakar på flera håll i Västerbottens län vattenföroreningsproblem. För att studera effekterna av utsläppen i recipienten, har undersökningar och utvärderingar gjorts av de fysikalisk-kemiska och biologiska förhållandena i Vormbäcken 1971 - 1975. LÄS MER

7. 5. Sulphide oxidation and geochemical processes in mine tailings

   Författare :Lena Alakangas; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : The generation of acid mine drainage (AMD) from oxidation of sulphide- bearing waste is a world wide problem, due to low pH levels and the release of metals to recipients. It is therefore important to understand the fundamental geochemical processes occurring in mine waste. LÄS MER