Sök:

Sökresultat:

131 Uppsatser om Sulphide mineral - Sida 1 av 9

Mikroskopering av opaka faser - en studie från Skyttgruvan, Falun.

In nature there are about 4,500 minerals identified. These can roughly be divided into two groups, opaque phases and non-opaque phases, with the exception that some opaque phases also may act as a non-opaque phase in different circumstances. The division is made on the basis of the optical properties. Opaque phases are nontransparent, which means that a different type of microscope must be used. A conventional microscope uses transmitted light while the microscope for opaque phases or the ore microscope uses reflected light.

Studie och riskanalys av sulfidleror i Uppsala stad

Most of the city of Uppsala rests on postglacial clay with a varying content of sulphur. The sulphur occurs naturally in the clay in reduced form as sulphide and the clay is for that reason usually called ?sulphide clay?. Excavation during construction activities gives rise to large amounts of excavation material, of which the sulphide clay is a considerable part.When the clay is exposed to air and water, an oxidation of the sulphides occurs which may produce an acid leachate and the mobilisation of heavy metals bound in the clay or underlying material. The aim of the work has been to improve our understanding of the behaviour of sulphide clays and produce a basis for risk assessment in the future handling of excavation material with high sulphide content.

Mineral composition of New Zealand monofloral honeys

The objective of this study was to determine the mineral content in ten New Zealand monofloral honeys, in order to distinguish whether New Zealand monofloral honeys are a good source of minerals compared to honeys from other parts of the world. The ten monofloral honeys were collected from a local honey factory (Airborne Honey Ltd, Leeston), Clover, Honeydew, Kamahi, Manuka, Nodding Thistle, Rata, Rewarewa, Tawari, Thyme and Vipers Bugloss honeys were been investigated. The water content, water activity, pH, conductivity, colour and mineral content were evaluated. The water activity was averaged for all the ten New Zealand monofloral honeys and set to 0.59 aw, which indicates a high stability and long shelf life as a food stuff. A strong correlation between total mineral content, pH, conductivity and colour was obtained.

Mineral i jordens inre : Hur kristallstrukturer förändras med tryck

Jordens innandöme är uppdelat i flera olika delar, vilket beror på gravitationen och kemisk differentiering. Skillnaden i tryck, temperatur och kemi mellan jordens skorpa, mantel och kärna är en förklaring till varför mineral ändrar karaktär längre ner i jorden. Djupare ner i jorden ökar trycket, men också temperaturen. Ökat tryck gör att atomerna packas tätare, medan ökad temperatur å andra sidan gör att mineralen expanderar. Detta är en av anledningarna till varför det är så svårt att bestämma stabilitetsområden för mineral, det vill säga vid vilka tryck och temperaturer de är stabila.

Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam

Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of Sulphide minerals. When Sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as a complexing agent for heavy metals and in this way increase their mobility.

Sänkta sjöars inverkan på ytvatten i Västerbottens kustland : Samband mellan sänkningsnivåer och vattenkemi i sjöar på sulfidrika sedimentjordar

Lake lowering in sulphide-rich areas is currently a major environmental impact for surface water. This study focuses on whether there is a relationship between a gradient of lake lowering and surface water impacts in areas of sulphide-rich sediments, in order to better understand their contribution of heavy metals and sulfuric acid. Also, is it a reasonable method to use the reduced lake area in order to quantify the gradient? The survey was conducted by collecting water samples from reference lakes and lowered lakes from south to north in coastal areas within the county of Västerbotten. Water samples were then analyzed for TOC, pH, conductivity, anions, base cations, alkalinity, acidity, sulfate, Al, Cd, Fe, Mn, Cu, Zn and Pb.

Malmmineralogisk undersökning av Pb-, Zn-, Cu- och Ag-förande kvartsgångar i Värmskogsområdet, mellersta Värmland

AbstractPolymetallic (Pb-Zn-Cu-Ag-Au-Sb-As-Bi-Cd-Te-Se-Ge?) quartz veins occur in an area from Eidsvoll in southeastern Norway to west of LakeVänern in southwestern Sweden. They most likely formed during the waning stage of the c. 1 Ga Sveconorwegian orogeny. In Värmskog parish, Värmland county, several mineralized quartz veins of different types are known.

Mineraliseringar utmed REE-linjen i sydvästra Bergslagen

This paper briefly summarizes Bergslagen as a bedrock province in order to give background to the genesis and presence of REE-bearing minerals (short for Rare Earth Elements) in the region. These mineralizations mainly occur along the REE-line, a line aproximately a hundred kilometers in length between Norberg in the north and Nora in the south with a width of a few kilometers. Situated in the southwest of Bergslagen it is currently one of only a few places in Sweden where REE-bearing iron oxide mineralizations are potentially economically viable for mining. Ore microscopy has been conducted in order to characterize an ore sample from Myrbacksfältet, one of few sulphide rich iron oxide mineralizations within the REE-line. Additionally, an electron microscope analysis of a sample from Stålklockan, a suspected REE-bearing mineralization also within the REE-line was confirmed by EDS (short for Energy Dispersive Spectrum) analysis.

Elementkoncentrationer i gran utmed en markfuktighetsgradient :

One key factor in silviculture today is sustainability. In order to achieve sustainability it may be important to restore lost nutrients to the forest after clearcutting. In order to calculate the removal, you need to know how much of different elements you will find in different tree compartments. The aim of this study was to investigate if the concentration of elements in different tree compartments of spruce (Picea abies (L.) Karst) were related to the moisture conditions of the site. Five plots at Risfallet (60º 21´ N, 16º 13´ E), was placed along a moisture gradient in a 40- year spruce stand.

Malmmikroskopering - en studie av sulfidmineral från Långbantrakten, Bergslagen, Sverige

De sulfidgruvor belägna i Långbantrakten som studien behandlar ligger i den västra delen av Bergslagen utanför Filipstad i Värmlands län. Opaka mineral (malm) från två mindre mineraliseringar, Näset och Getberget, har studerats med malmmikroskop och mikrosond för att beskriva mineralogin i området. Båda områdena domineras av olika (Cu-Fe-Pb-Zn)-sulfider, i Näset av kopparkis (CuFeS2), blyglans (PbS) och zinkblände ((Zn,Fe)S) och i Getberget av blyglans, zinkblände, kubanit (CuFe2S3) och magnetkis (Fe1-xS). I Näset finns en del mindre frekventa mineral, två olika faser av Co-pentlandit (en nickelrik och en utan nickel), gedigen Sb och Bi, (Ni-Co)-sulfid, breithauptit (NiSb) och magnetkis. Kubanit är även ett viktigt mineral som speglar mineraliseringens bildning.

Mineralämnen i fullfoder : studier på 20 mjölkkogårdar i Halland

In 2003 the recommended phosphorus allowance for dairy cows in Sweden was lowered approximately 10 %. For a cow at a production level of 35 kg ECM it decreased from 0,40 to 0,36 % of dry matter. To investigate if the decrease has been implemented at farm level, analysis of following minerals; P, Ca, Mg, K, Na, S, Se, Cu, Mn and Zn was performed on the TMR at 20 farms in Sweden in the summer of 2004. The purpose was to describe the actual allowance of different minerals as compared to the new recommendations. One hypothesis was that the decrease in recommended allowance of phosphorus would lead to the need of new mineral feeds on the market.

Omkonservering av Vattendr?nkt L?der Analys och Metodutveckling f?r Vasaskeppets L?derartefakter

In the collections of the Vasa Museum, 100 leather objects have exhibited salt precipitations. The objects, that have previously been impregnated with PEG, have become deteriorated and fragmented due to the precipitations. During a previously conducted study it was established that the precipitations consisted of iron and sulphur. However, it was not established whether they occurred in the leather?s inner structure and no treatment plan was developed.

Traditionella och samtida bottenbj?lklag: med fokus p? isoleringsmaterialen

The survey aims to shed light on traditional and contemporary bottom floor frames, their construction and different insulating materials; mineral wool, wood shavings and charcoal. The purpose is to analyze and discuss the similarities and differences as well as the pros and cons with a focus on the construction and the different insulating materials. The work has been limited to comparing two different wooden floor frames. The first one is based on a real floor frame from an older building, this example is presented as the traditional floor frame in this study and are from around 1940. The other floor frame is presented as a contemporary floor frame and is based on wood building type descriptions and literature.

Slam ? en outnyttjad resurs i skogsbruket

Every year about 210 000 tones dry weight of sewage sludge is produced in Sweden. Most of the sludge is applied to agricultural land, plantsoil and landfill cover. Sewage sludge contains essential nutrients such as nitrogen and phosphorus. Nitrogen is limiting growth on solid ground in Sweden and can therefore be used as fertilizer to increase productivity. In order that the sludge can be spread to forest land it requires first a conversion of sludge to pellets, to make it more manageable.

Kvarnkretssimulering för test av styrsystem

This thesis has been carried out in autumn 2009 at Uppsala University for Boliden Mineral AB. Physical modelling has been used to model a comminution circuit. The model has then been linked to a PLC.When a concentrator is about to become operational Boliden Mineral AB have been looking for a way to test the PLC. The purpose of this report has therefore been to develop models for the subprocess in a concentrator and link these models to the PLC. The subprocess was a comminution circuit in Aitik36.

1 Nästa sida ->