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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus
Examples ofphosphorus in food additives
Cola
Backing powder
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus
from Greek:
(φως = light,
φορέω = carry)
Phosphorus
• was discovered by Henning Brand, a German pharmacist and alchemist
• he was searching for the Philosopher’s Stone, concentrating urine by evaporation
• white phosphorus was formed after calciningthe residue under exclusion of air
• white phosphorus showed an unique property phosphorescence (glowing in the dark)
• http://www.youtube.com/watch?v=GIGOF_In9BM&feature=related
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus
Phosphorescence
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus White phosphorus
• was first used as a drug due to it’s unique property
• is highly flammable and pyrophoric (self-igniting)
• was used for fabrication of matches
• fire bombs and other weapons (additive to napalm)
• highly toxic
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
WhitePhosphorusin weapons
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
WhitePhosphorus
http://youtu.be/QaUIFZCCHiE
White phosphorus is the least stable, most reactive, more volatile, less dense and most toxic of all allotropes of phosphorus
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus Red phosphorus
• Crystalline and amorphous modifications in a density range of 2.0 – 2.4 g/ccm are know as red phosphorus
• Is formed from white phosphorus by heating to 260°C for several hours under exclusion of air
• is highly flammable when combined with strong oxidants safety matches
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
RedPhosphorus
http://www.youtube.com/watch?v=CsvSUAwq0uM&list=LPGstqDNdS354&index=9&feature=plcp
Red phosphorus is less reactive than the white allotrope, and it is not toxic.
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphorus
Black phosphorus
• 3 crystalline and 1 amorphous modification with a density of 2.69 g/ccm
• Is formed from white or red phosphorus under high pressure
• It is gray-black and the structure resembles to that of graphite
• Has semiconductor properties
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate ore
Phosphorus is the 11th most abundant element in the lithosphere occurring as phosphate commonly as an inorganic mineral phase or as an organic molecule.
Phosphate rock is the only economic source for P
• Marine sedimentary phosphorite formed on continental shelves by oceanic upwelling of cold water enriched in nutrients (North Africa, W-USA, Mexico, Brazil, China, Vietnam)
• Deposits formed by disintegration of phosphoriterocks and reworking in sea and streams (Florida)
• Magmatic resources: magnetite-apatite (Kiruna) apatites from nepheline syenite (Khibiny, Kola) pyroxenite and carbonatite (Palabora, SA)
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate ore
Phosphorite
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate rockMorroco
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate ore Minor sources include:
• Guano: thick accumulation of bird excreta reacting with limestone (Christmas Island, Nauru)
• Aluminous phosphates from weathering of phosphate rock with local significance (Senegal)
• Recycling product: slag (Thomas converter)
• Earlier is CH: ground bones, but also marls and sandy layers (Gault, Gemsmättlischichten)
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Guano
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Another source of phosphorus
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate minerals
Apatite (Fluorapatite)
From Greek “apatao” = I’m misleading
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate minerals
Autunite
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate minerals
Turquoise
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate minerals
Nearly 400 phosphate compounds are known, but only few control phosphate concentration in natural systems
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate exploitation Phosphate mine, Negev
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate exploitation
Phosphate miningin Togo
Photo: Alexandra Pugachevskaya
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate exploitation
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
• Open pit mining methods with walking draglines (Florida)
• Coal mining-like techniques with blasting and removal by dragline/shovel (Morocco, Tunisia)
• Underground methods for steeply dipping deposits include room-and-pillar (North Africa)
• Sub-level open stoping (Kola Penninsula)
• Washing, crushing, sizing and flotation is common in order to increase BPL to 60 – 88%
• Magnetic separation to remove iron minerals
• Slurries need screening and hydrocycloning to remove clay prior to flotation (Florida)
Phosphate exploitation
Phosphorus contentGrade of commercial phosphate rock is usually defined in terms of its phosphorus pentoxide (P2O5) content.
The phosphorus concentration in phosphate rock is also commonly expressed in terms of tricalcium phosphate Ca3(PO4)2 known in the trade as "Bone Phosphate of Lime" or BPL. This term originated when tricalcium was thought to be the main constituent of bone and phosphate rock.
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate rock production
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate ore
80% sedimentary origin
17% igneous rocks and their weathering prod.
Remainder: residual sedimentary, guano
Economically produced phosphate ore contains 20 – 30% P2O5
World production peaked at 166 million tons of phosphate rock 1988, subsequently falling back to ca. 140 million tons but has increased again:
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate rock production
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Use of phosphates
Phosphate rich fertilizers used to dramatically increase global agricultural production
http://www.stonegateagricom.com/s/Videos.asp
Cereals are estimated to account for 55% of fertilizer use worldwide; wheat 20%, corn 14%, rice 13%, barley 4%
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphate fertilizers
• Single superphosphate (SSP)
• Triple superphosphate (TSP)
• Diammonium phosphate (DAP)
• Monoammonium phosphate (MAP)
• Ground phosphate rock
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphoric acid • Finely ground phosphate rock is mixed with water and treated with sulfuric acid. The basic reaction is:
Ca5(PO4)3F + 5H2SO4 + 10H2O 5CaSO4 · 2H2O + 3H3PO4 + HF
• Hydrogen fluoride reacts with silicates to fluorosilicic acid
SiO2 + 6HF H2SiF6 + 2H2O
• Formation of 1 ton of P2O5 as wet process acid consumes 3.3 – 3.4 t of phosphate rock (70% BPL)
• By-products include 1.7 t phosphogypsum
• High content of P, F, Cl, U, Th, REE requires this gypsum to be treated as waste
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphoric acid
Phosphoric acid is the largest inorganic acid produced and consumed by value (and only second to sulfuric acid in terms of volume).
• Fertilizer
• Feedstock of phosphates and fertilizers
• Cattle feed additives
• Food additives
• Detergent additives
• Acid cleaners
• Hardener for paints and varnish
• Synthetic rubber
• Etc……..
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Prices
Phosphate rock grade expressed as %P2O5 or as BPL (Bone Phosphate of Lime)
%P2O5 x 2.185 = %BPL
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Key element Phosphorus is a unique element:
• A key element in many physiological and biochemical processes
• An essential nutrient for all life forms
• Converts energy to a usable form for food and fiber
• Uptake by most living organisms from natural waters
But,
• Low solubility of phosphate minerals
P is a limiting element for animal and plant productivity
• (Historically: overcome by recycling of manure)
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphates
Adenosine Triphosphate (ATP); energy gain when end phosphate is released to form ADP
A phosphate group is attached when a cell needs to store energy.
molecular “rechargeable battery”
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphatecycle
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Phosphates in the environment
• Increase of phosphate content in sewage due to use of phosphate based detergents eutrophication of rivers and lakes
• Ban of phosphate base detergents in Switzerland (since 1985) caused a reduction of 70% of phosphate input
• Agricultural phosphate release to natural waters usually cannot be attributed to leaching of fertilizers
• But rather to increased use of phosphate-rich manure
• Phosphate-rich manure is mainly a consequence of feeding with off-site produced cattle feed
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Limited resources
2007 estimation:the supply of phosphorus may last only 345 years
Other estimates forecast a "peak phosphorus" in 30 years reserves will be depleted in the next 50 to 100 years
http://www.youtube.com/watch?v=Y17HqUsaoj8&feature=related
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Cleantech
Separation of urine from solid using No-mix toilets
Urine accounts for 1% of total wastewater but contains 80% of nutrients
“The Europeans are certainly leading the way in this area, in Switzerland trials with NoMix toilets have been quite successful. Apparently the majority of the Swiss people interviewed said they had no problem with it, even the men, who had to sit down to spend a penny!”
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Fertilizer from incinerated sewage sludge
• Use of sewage sludge as fertilizer is not allowed in Switzerland (since 2008)
• Sewage is incinerated and disposed in landfills
• 40 – 90 g P per kg ash from incinerated sewage sludge 6100 t P in Switzerland per year
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Source: BSH Umweltservice AG, Sursee
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Source: BSH Umweltservice AG, Sursee
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Source: BSH Umweltservice AG, Sursee
Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Source: BSH Umweltservice AG, Sursee
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Applied Mineralogy and Non-Metallic Resources I Phosphorus and phosphate
Results:
The large-scale production test at the decommissioned incineration plant in Bern has show:
• Sewage sludge ash is a source for phosphorus
• Recycling rate with LEACHPHOS procedure is ca. 90%
Further:
• A mono incineration plant was built in Werdhölzli, Zürich and is in operation
• The sewage sludge of all waste water treatment plants in Kt. Zürich incinerated there
• The sewage sludge ash is currently disposed in Teuftal Kt. Bern
• Production of phosphoric acid is from sewage sludge ash is more likely than production of fertilizer (for legal reasons)
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