Transcript
Industrial minerals Background in the schools’ colours
Industrial minerals • • • • • • • • • •
Chemical minerals Agricultural minerals Construction minerals Glas raw materials Fillers, Filters Pigments Abrasives Lubricants Refractory minerals
Chemical minerals
Laitoksen nimi 11/22/2016 3
Limestone, dolomite and lime Aggregates for construction Chemical applications: (CaO) lime production • Limestones: calcite and aragonite (CaCO3) - Biological sediment - Metamorphosed: marbels, carbonate rocks
• Dolomite CaMg(CO3)2 -
Dolomitization during diagenesis, hydrothermal (MVT) High calcium limestone >95% CaCO3 High magnesium dolomite >86% MgCO3 Marl a calcium carbonate-rich mud or mudstone which contains variable amounts of clays and silt. Other carbonate minerals such as aragonite, dolomite, and siderite may be present
- FOLK, R.L. (1959): Practical petrographic classification of limestones. — AAPG (Amer. Assoc. of Petrol. - Geologists) Bull., KV 43, pp. 1-38. Laitoksen nimi 11/22/2016 4
Limestone classification
Laitoksen nimi 11/22/2016 5
Calcining process 700-1100 oC ->CO2 is released - Quicklime CaO or dolomitic quicklime CaMgO2 - Adding water produces lime Ca(OH)2 or CaMg(OH)4 - (Impurities produce SO2-releases)
• Metamorhic limestones tend to disintegrate during burning low tumbling index, rotary kiln (with preheater) must be used somewhat greater CO2 emissions - the lower the limestone calcination temperature, the more reactive the produced quicklime
Laitoksen nimi 11/22/2016 6
Calcining kilns Two categories. • rotary kilns, vertical kilns • Both the types can be designed to use any of the solid, liquid or gaseous fuels. • Rotary kilns can be long kilns with straight rotary coolers while verticals kilns can be several types. Decrepitation index of limestone • a measure of its susceptibility to disintegration during calcination. Low value of decrepitation means low porosity the bed thus impeding the flow of the gases and reducing the kiln efficiency Rotary kilns also need limestone with good tumbling index.
Laitoksen nimi 11/22/2016 7
http://ispatguru.com/wp-content/uploads/2013/05/Preheater.jpg
Laitoksen nimi http://ispatguru.com/wp-content/uploads/2013/05/Preheater.jpg
11/22/2016 8
Lime use • Steel production as flux (2005 about 4 Mtons in USA) -
lowers melting temperatures removes impurities (to slag)
• Chemical reagent in (8Mtons in USA 2005) - Industrial processes and water treatment
• Environmental (6Mtons in USA 2005) - Lake liming, water treatment, AMD-remediation, a growing sector during the last 20 years
• Competes with use of - crushed limestone (environmental, water treatment) - Fly ash in construction purposes for example
• Constrained by energy price (transportation costs) - Sensitive to CO2-emission penalties and taxes Laitoksen nimi 11/22/2016 9
Salt Evaporites • Reef isolated basins • Rift evaporates (slowly spreading rifts) Danakil rift (Red Sea rifting) , Rhine graben • Salt domes isostatically uplifting salt deposits • Classical open pit and underground mines • Solution mining • Crushing, grinding, sizing+ removal of impurities -
Air jet separation Temperature increase and resin belt Steam recrystallization Vacuum pan salt Solar salt (seawater or brines) Laitoksen nimi 11/22/2016 10
Salt consumption
Since 1944 use of deicing salts have increased 22000%
“The aircraft de-icing market is expected to reach $1.30 billion by 2020, to register a CAGR of 5.18%”
Global markets?? In USA (source USGS) $ 1.6 billion 46 % brine, 36 % rock salt, vacuum pan 11 %, solar salt 7 % -
45 % of sales for chemical industry Chlorine and caustic soda manufacturing 30 % high-way deicing 10 % food processing 5 agricultural NaCl General industrial 3% CaCl (manufacrured from limestone and Other and exports 2 % salt) Water treatment 1 %
Laitoksen nimi 11/22/2016 11
Sulfur Sulphuric acid production - Superphosphatic fertilizers - Paper and pulp industry
Main sources: • Natural gas and crude oil (by product) - covers new production (expected to increase due to the need of fertilizers)
• Native S evaporites rarely in salt domes as cap rock bacterial processes (sulphate reducing bacteria) - Frasch process, solution mining by superheated steam/water (160 oC)
• Gypsum -
evaporates, cap rocks of salt domes
• Pyrite (marcasite, pyrrhotite) -
main source of sulfuric acid for e.g Finnish pulp industry Laitoksen nimi 11/22/2016 12
Fluorite Consumption 7.5 million tons/a: • Glass-production • Production of hydrofluoric acid -
basis of numerous chemical products UF6 Synthetic cryolite and aluminium production Hydrofluorocarbons HFC:s and hydrochlorfluorcarbons HCFCs • Refrigenators, propellant fluids
- Fluoropolymers
• Steel production • Flux
Laitoksen nimi 11/22/2016 13
Deposits Mined fluorspar deposits are associted with • Replacement Missisippi Valley Type (MVT) Lead-Zinc deposits - (Cave-in-Rock area in Illinois) (exhausted resources!)
• lime stone stones resulting from precipation as fluorspar - from f-hydrothermal fluids from granitic intrusions F - from F-containing groundwater (infiltration through a F-bearing rhyolite dome) (Potomosi, Mexico)
F-bearing magmatic rocks not common in geological history • Rapakivi granites and their volcanic equivalents • Some extensional settings associated with f-bearing volcanics
Laitoksen nimi 11/22/2016 14
Criticality of fluorspar resources • Global reserves 240 million tonnes - no shortage foreseen - Replacement of CFC:s and HFC:s have made markets stagnant or decreasing
• So why is fluorspar considered critical both by EU and USA? - Dependence on imports in EU and USA - No “domestic” production or limited production (although ore potential exist) in EU some production in Spain, No mining in USA
• World production • China 62 %, Mexico 17 %
Laitoksen nimi 11/22/2016 15
Agricultural minerals
Laitoksen nimi 11/22/2016 16
Phosphate • P is essential for all life on the planet - The world consumption of phosphorus pentoxide will steadily increase - For technical and economical reasons the possibilities for the recycling phosphorus are very limited.
Phosphate rock is used fertilizers and animal feed supplements • Phosphate rock cannot be replaced • The global phosphorus rock resources abundant - Resources to produce fertilizers have been estimated to be available for the next 300-400 years
• The global supply of phosphorus is dominated by few countries, none of which are European. - Only in Finland a small scale production - s. Over 90 per cent of all phosphorus is currently imported into the EU. - Since 2013 a "critical raw material of EU" which is a subject to a higher risk of supply interruption .
,
Laitoksen nimi 11/22/2016 17
Phosphate ores Global production • Sedimentary phosphorite deposits
P = 0.44 * P2O5 P2O5= 2.3 * P Apatite = 2.4 *P2O5; P2O5= 0.42 * Apatite
- 90 % production and 95 % of known reserves - P2O5 in ore 20-30 %, in the concentrate 30-34 % • Replacement of apatite by francolite makes concentration more difficult • Cd-concentrations high over 60 ppm
- Marocco, USA, China
• Apatite bearing intrusions - P2O5 in ore 4-7 %, in concentrates 35-40 % - Cd-concentrations typically low, < 1 ppm
• Alkaline intrusives, carbonatites, and gabbros - Russia, S-Africa, Brasilia, Finland, Canada, Zimbabwe - Alkaline intrusions in Kola-peninsula a major source (Russia)
• Guano-deposits largely exhausted
Sedimentary phosphate deposits • Biological activity • Continental shelf or slope with limited flux of clastic sediment 1. Up welling cold oceanic currents bringing phosphate bearing deep waters - Deposits can be found where deep water shales grade to shallow water carbonates
2. Phosphate carrying river flows into estuarine areas • Inter bedded phosphorous layer (fish bones, teeth, plankton shells) interbedded with chemical sediments (cherts, dia-atomic layers) and shales • Mineralogical changes during burial improve ore grade - Wave action and sorting - Pellets and phosporitic oolite - recrystallisagtion
Laitoksen nimi 11/22/2016 19
Depositional environments tectonic setting Long (paleo) shorelines of continental margins • Oceanic currents • Tectonic processes Past climatic conditions (different from present) USA: Permian age depostis boundary of N-American plate (Florida) Miocene deposits in small deposits along continental margin N-W Africa (Marocco) continental marging in self formed during separation of Africa-S-America and Africa-Europe
Laitoksen nimi 11/22/2016 20
Laitoksen nimi 11/22/2016 21
Alkaline rocks in Finland and in Kola Penisula
Laitoksen nimi 11/22/2016 22
Potash “Potash is any of various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, which refers to plant ashes soaked in water in a pot, the primary means of manufacturing the product before the industrial era. The word potassium is derived from potash” (Wikipedia) - Sylvite, carnallite, “bittern salts” - Evaporites deposited in restricted basins
• Water soluble+ cave and pillar, continuous miners -
Stability Shallow mining Mining expected to icrease Exploration in Australia, Ethiopia, Brazil Laitoksen nimi 11/22/2016 23
Nitrates and ammonia Nitrates are commonly included as a “agricultural minerals” Atacama nitrate deposit/ Chilean saltpeter -
one of the dryiest places on earth,
• Few meter thick crust layer along hill sides of valleys -
(halite, Na-sulphates + evaporates tend to form playas)
Since WW I, Haber-Bosch-process is used to make ammonia from natural gases and air to replace nitrate mining
Laitoksen nimi 11/22/2016 24
Construction minerals
Construction minerals • Cement -
3.6 billion tons about $ 3 billion used 3000 years, but comprises also “high tech” R&D-today
• Aggregates crushed stone sand and gravel
-
• Light aggregates -
natural light aggregates volcanic deposits: pumice, scoria • “manmade” light aggregates o o o o
Perlite Fat clay, mixtures of clay and vermiculite, vermiculite Recycled concrete or slags
Cement raw materials Limestone and lime are main raw materials for cement also • see previous slides Sustainability issues: • Emissions (CO2) • Dust and noise • Need to replace soil and gravel aggregates by crushed rocks
Laitoksen nimi 11/22/2016 27
Cement markets Global markets of cement production
Consumer prise index Steel production
Laitoksen nimi 11/22/2016 28
Construction mineral trade Aggregate and construction materials is global business China imports sand, exports cement
Laitoksen nimi 11/22/2016 29
Aggregates
Laitoksen nimi 11/22/2016 30
Aggregate consumption • Cement raw material • Construction material that has its own mechanical and mineralogical requirements • Geographically unevenly distributed - Regional shortages
• Supply of ail road ballast, asphalt aggregates, and dense construction materials particularly challenging • So called hard rocks have certain advantages compared to sedimentary rock areas
Laitoksen nimi 11/22/2016 31
Sand and gravel aggregates Fluvial Glacio-fluvial Eolian Suitable sand and gravel resources limited Cement production moving towards rock aggregate use?
22.11.2016 32
Mafic igneous rocks as aggregates - Can provide high-strength, wear-resistant and density required in certain important applications • Rail road ballast • Asphalt pavement • Dense materials for e.g. bridge engineering
• Result from partial melting of the upper mantle of the Earths crust • Include Fe_Mg-rich silicates -
Mechanical stiffness Moderately high hardness Dense Bound chemically to bitumen
Kuva: GTK/Paavo Härmä
Bowen’s reaction series
Page 33
Intrusive rocks Gran Felsic Granite Granodiorite Quartzdiorite Diorite Gabro (+ subclasses) Peridotite (+ subclasses
Acid rocks
Gr dr
Qzdr intermediate Mafic
Dior
Ultramafic
Peridoti te
Basic rocks
Gabr o
Volcanic rocks • Basic (low-silica) magmas commonly erupt on the surface as lava flows or small and less violent pyroclastic eruptions building cinder cones. - due to their lower viscosity and low content of water (volatile components)
• Form basalts (or andesites) which are eruptive counterparts of gabbro and diorite - Basaltic lavaflows can be large, good or excellent aggregates known as trap rock
• Cinder cones can comprise loose material - Ready to be excavated, comprise in geologically young areas valuable sources of aggregates
Dykes - Represent intrusion channels for magma - Cooled faster than intrusive rock but slower than volcanic rocks - In sedimentary rock areas, swarns of diabases particularly, can comprise regionally important sources of aggregates
Diabases (dolerites) can comprise particularly good aggregate material
Page 36
Sedimentary rocks Sedimentary rocks cover a majority of earths continental crust • Limestones and sandstones are therefore used extensively in construction. Commonly because no better material is available - Bitumen containing sandstones may comprise good aggregate materials for road construction.
The quality sedimentary rocks as crushed rock varies substantially (some good materials can be found) • needs to be investigated carefully • design of mixes essential Examples of unusual materials in USGS
22.11.2016 37
Example: Approach to sustainable aggregate resource management USGS The use of (SARM) can help ensure an economically viable supply of aggregate. SARM techniques that have successfully been used include - protecting potential resources from encroachment; - using marginal-quality local aggregate for applications that do not demand a highquality resource; - using substitute materials such as clinker, scoria, and recycled asphalt and concrete;
And using rail and water to transport aggregates from remote sources.
22.11.2016 38
In Finland only about 3 % of studied outcrops suitable to railroad ballast or for asphalt in highly trafficked roads
Nordic ballmill test (abrasion susceptibility) 22.11.2016 39
Rock mineralogy and aggregate quality Mineralogy (minerals and their contents) are some main factors affecting the quality based on LA, AN • Presence of any sulfide minerals • Presence of soft minerals, particularly mica
22.11.2016 40
Mica content
AN<=10
AN<=15
AN<=20 22.11.2016 41
Grain size and aggregate quality
22.11.2016 42
Mineral contacts More complex the better
22.11.2016 43
Deformation Dynamic metamorphosis (induced by shearing)
22.11.2016 44
Metamorphosis Low metamorphic grade (low pressure and temperature) produces mica (chlorite, biotite, muscovite). High metamorphic grade favors recrystallization in stable conditions that leads to straight crystal contacts • medium grade, amphibolite facies probably best compromise? Hydrothermal alteration e.g. along faults can cause alteration of feldspars to fine mica (sericite, saussurite)
22.11.2016 45
Complexity of grain boundaries Grain-size Mica content Density (function of Fe-Mgsilicate content) - Note also Fe-Mg-silicates bind more efficiently to bitumen, which effects the performance of mafic rocks as asphalt pavement
LA
Geological trends
Nordic ball mill test
22.11.2016 46
Artificial and recycled aggregates • So called light aggregates - made by heating and melting suitable soil materials • Fat clays (Leca-gravel) • Perlite (volcanic tuffs with a perlitic texture)
• Crushed concrete - Binds CO2, readily available but in limited amounts - Will not be able to solve all sustainability issues
• Different types of slag materials (metallurgical waste) - E.g. Oktomurske eng. OKTO-aggregate • Slag material of ferro-chorimium production
22.11.2016 47
Glass minerals Examples of glass minerals Fluorite Pure quartz sands Feldspar (and feldspathoids, nefeline, syenite) Salt+limestone= Na-carbonate= soda ash Boron Strontium
22.11.2016 48
Refractory minerals • Minerals that hold their strength in high temperatures - Quartz Mp 1710 oC (dry conditions) and kaolin in firebricks.. - Alumosilicates: andalusite, kyanite, sillimanite - Wollastonite • lubricant
• Pyrophyllite • low reversible thermal expansion coefficient, low thermal conductivity, low density
22.11.2016 49
Example: a simple staple diagram 20 18
1. Quisque metus nunc
16 14 12 10 8 6 4 2 0
1
2
3
4
5
6
7
8
Here you may fill in a description for your picture or graph.
22.11.2016 50
Example: A SmartArt -graph Dolor sit amet:
Lorem ipsum: • lorem ipsum dolor sit • praesent sagittis elementum neque eu facilisis • in sit amet risus sem • integer congue nisl ut erat consequat eleifend in accumsan nis
• lorem ipsum dolor sit • praesent sagittis elementum neque eu facilisis • in sit amet risus sem • integer congue nisl ut erat consequat eleifend in accumsan nis
Here you may fill in a description for your picture or graph.
22.11.2016 51
