Metallmangel i fokus

på TOD: Metal Minerals Scarcity and the Elements of Hope

Grei oversikt over problemet, halter på noen punkter (slide 16 f.eks. sier egentlig ingenting; OK Europas andel av verdens gruvedrift har falt dramatisk siden 1850 men so what?, den totale mengden gruvedrift har jo skutt i taket), og kunne godt gått litt dypere inn i materien synes jeg... men verdt å få med seg, og mye bra i diskusjonen etterpå, som vanlig... selv om Neil1947 begynner å irritere meg, han slenger ut mengder av halvrelevante fakta og stiller spørsmål i øst og vest, ofte motsier han seg selv fra kommentar til kommentar... aner ikke hva den egentlige agendaen hans er, men det virker som han er ute etter å skape mest mulig forvirring. Jeg har sluttet å lese kommentarene hans; men han klarer - merkelig nok - å provosere fram mange interessante svar. Her er ett av dem, fra metalman:

As regards total energy usage in mining, let me add a comment. If it costs several hundreds of millions to billions of dollars to construct a new open pit copper mine in, say, a remote area of the high Andes, how much of this is represented by the cost of energy needed to build roads, railroads, generating plants, a company town, the physical plant of the mine, and so on, and then to strip off millions of tons of barren overburden, before you get out your first ton of ore and first pound of copper concentrate waiting to be shipped to a smelter in China or Japan? Far more than most people would imagine, would be my guess. And I'm sure that with more time most of us could think of dozens of other energy costs involved in mining. I'd guess that a new technology such as heap leaching would have only a small affect on the total amount of those energy costs, although copper leaching does allow lower grade ores to be processed, at the cost of no longer producing by-product molybdenum and silver or gold.

Grunnen til at jeg uthevde den siste setningen er at heap leaching i en annen diskusjon ble brukt som bevis for at hele teorien om at energikostnaden for metallutvinning øker med tiden er feil.

Noen utdrag fra artikkelen:

Slide 7
A typical critique on stating that we are running into metals scarcity is the notion that you will find 300 times more ore as you lower the ore grade with a factor of 10. This misses the point that you need much more energy to keep extracting the same amount of metal. Even when the ore grade is more or less stable (example: copper over the last few decades), you still need increasingly more energy to extract the same amount of copper because you have to dig deeper and handle ever more quantities of solids to get to the ores. Of course lower ore grades aggravate the situation and increase energy expenditures much more because of the amounts of solids which have to be processed to keep up the production rate of concentrated metal.

Slide 11
A typical critique on stating that we are running into metals scarcity is the notion that the free market (the laws of demand and supply) will upgrade parts of the resources or the resource base into reserves once reserves start to get tight. This has seemed to be true for decades when there was cheap and abundant energy available. However with energy scarcity, the big lower part of the graph in figure 11 is out of reach (red crossed lines). We should also let go of the notion that vast amounts of rich ore deposits lie waiting somewhere to be discovered (red crossed lines), see slide 12.

Slide 19
The consequences of metals scarcity will be serious. Not only various established sectors like machining and the chemical industries will be affected. Especially the promising “new” sectors will be hit hard. For example there are no satisfactory substitutes available yet for essential and already scarce metals for efficient and mass-produced solar cells, permanent-magnet drives/generators (wind mills, hybrid cars, electric cars), catalysts, fuel cells, batteries and various electronic devices (telecommunication, displays/ touch screens/ plasma screens, micro-electronics).
Without a shift from scarce to less scarce metals, a large-scale transition towards a more sustainable economy doesn’t stand a chance. Moreover metals scarcity aggravates energy scarcity because the energy sector is one of the largest metals consumers. This applies to the whole chain from exploration, production, storage and distribution up to conversion into the desired forms of energy.

(mine uthevinger) Ikke egentlig noe nytt her altså... men en bekreftelse av at metallmangel er et problem, og at det er en gjensidig forsterkende vekselvirkning mellom energi og metallutvinning.

En kommentator hevder at dette ikke er tilfelle fordi vi tross alt har karbon-nano-rør som leder strøm bedre enn kobber og veier tiendeparten... men han blir raskt skutt ned: karbon er sprøtt og egner seg ikke til strømdistribusjon over litt avstand, og nanorør er svært dyre/energikrevende å produsere...

Energi er og blir nøkkelen.