Home Page
   Articles
       links
About Us    
Traders        
Recipes            
Latest Articles
gold fever mr behemoth?
Page Previous  1, 2
 
Post new topic   Reply to topic    Downsizer Forum Index -> Reduce, Reuse, Recycle
Author 
 Message
dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Tue Nov 17, 15 12:03 pm    Post subject:  Reply with quote    

Behemoth wrote:
Theoretically possible. Processing sludge is messy and expensive though, particularly the incineration route. If you have poor quality sludge your basically trying to burn water.

This made me laugh:

". These tend to involve the use of powerful chemicals known as leachates that are used by industrial operations to extract metals from rock. While they can be toxic to ecosystems, in the controlled setting of a sewage plant they can be safely used without environmental risk. "

There is always risk and an STW is not a safe place to use them as they are not designed to do this. You could build an extraction plant alongside an STW.

Most large sewage works are now managed as power stations, processing the sludge to generate gas or heat, to generate energy and the ash goes to the construction industry. If someone wants to extract metals from it they can buy it if us. Maybe one day they will.

The Bradford works used to extract lanolin from the sewage and sold it to the cosmetics industry! Had to stop when the mills closed.


that is interesting,if one end product of treatment/energy extraction is ash the idea seems to be plausible to use that as ore if the "feed"is sufficiently rich from either industrial activity or domestic in places where precious metals are common.

the lanolin story is gross

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Tue Nov 17, 15 12:04 pm    Post subject: Reply with quote    

Behemoth wrote:
Theoretically possible. Processing sludge is messy and expensive though, particularly the incineration route. If you have poor quality sludge your basically trying to burn water.

This made me laugh:

". These tend to involve the use of powerful chemicals known as leachates that are used by industrial operations to extract metals from rock. While they can be toxic to ecosystems, in the controlled setting of a sewage plant they can be safely used without environmental risk. "

There is always risk and an STW is not a safe place to use them as they are not designed to do this. You could build an extraction plant alongside an STW.

Most large sewage works are now managed as power stations, processing the sludge to generate gas or heat, to generate energy and the ash goes to the construction industry. If someone wants to extract metals from it they can buy it if us. Maybe one day they will.

The Bradford works used to extract lanolin from the sewage and sold it to the cosmetics industry! Had to stop when the mills closed.


that is interesting,if one end product of treatment/energy extraction is ash the idea seems to be plausible to use that as ore if the "feed"is sufficiently rich from either industrial activity or domestic in places where precious metals are common.

the lanolin story is gross

Nick



Joined: 02 Nov 2004
Posts: 33696
Location: Hereford
PostPosted: Tue Nov 17, 15 4:35 pm    Post subject: Reply with quote    

Someone in the UK is doing this on a pre-commercial scale. I believe he makes a tidy packet on the side doing it whilst at work.

Mistress Rose



Joined: 21 Jul 2011
Posts: 8923

PostPosted: Wed Nov 18, 15 7:32 am    Post subject: Reply with quote    

There is a folk song I have heard called 'Down Below' about what can be found in the sewers. Even talks of a diamond being found.

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Wed Nov 18, 15 8:36 am    Post subject: Reply with quote    

Nick wrote:
Someone in the UK is doing this on a pre-commercial scale. I believe he makes a tidy packet on the side doing it whilst at work.


ummm interesting ,i think i need to do some reading.

Nick



Joined: 02 Nov 2004
Posts: 33696
Location: Hereford
PostPosted: Wed Nov 18, 15 8:37 am    Post subject: Reply with quote    

dpack wrote:
Nick wrote:
Someone in the UK is doing this on a pre-commercial scale. I believe he makes a tidy packet on the side doing it whilst at work.


ummm interesting ,i think i need to do some reading.


He also has a supply of dead circuit boards which he plunders, too.

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Wed Nov 18, 15 8:54 am    Post subject: Reply with quote    

circuit boards and components make quite a rich ore but the "easy" way of getting the metals separated from the plastics and minerals starts with burning them which is a very messy process(especially the way it is done third world style in an old wok).iirc the metal refiners who need to work within decent environmental controls have decided it is uneconomic to do it.

i had considered the direct mince and aqua regia route but that has a few issues with the fumes ,the side products,preventing runaway reactions when "randomly"nitrating a mixture of plastics,paper labels etc,waste disposal and the usual handling problems when messing about with nasty chemicals.

to receive the "ore"in a pre ashed form from a plant made for the job seems ideal.

Nick



Joined: 02 Nov 2004
Posts: 33696
Location: Hereford
PostPosted: Wed Nov 18, 15 9:18 am    Post subject: Reply with quote    

He's using Aqua Regia route.

Behemoth



Joined: 01 Dec 2004
Posts: 18995
Location: Leeds
PostPosted: Wed Nov 18, 15 11:35 am    Post subject: Reply with quote    

The best place to start recycling is the design and construction phase.

Nick



Joined: 02 Nov 2004
Posts: 33696
Location: Hereford
PostPosted: Wed Nov 18, 15 12:19 pm    Post subject: Reply with quote    

Behemoth wrote:
The best place to start recycling is the design and construction phase.


From a global perspective, yes.

However, if you're a site manager with a degree in chemistry, a stack of waste, a massive chemistry set, someone else's budget, an enquiring mind and no supervisor on site, Chris' office/lab is a close second.

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Wed Nov 18, 15 12:41 pm    Post subject: Reply with quote    

yep get the planning correct and the result follows

the aqua regia route does seem to be the best way to get noble metals into solution and therefore recoverable.

teflon here we come

afaik the stuff eats incaloy and hastaloy so my metals of choice are a non starter,glass is too probably too fragile for industrial scale,i spose there are suitable ceramics but teflon coating seems a promising option.

my next thought is how to transfer batch tech into a continuous process with as much recycling of reagents as possible and acceptable waste protocols.

spose something a bit similar to the engineering of thorp without the obvious extra problem they have might work.different chemistry but basically a similar process chain .
mixed solid,dissolve the metals,neutralise,collect the bits you want ,repackage the waste.

it cant be as difficult as never being able to maintain the plant unless you use a robot:lol:

Mistress Rose



Joined: 21 Jul 2011
Posts: 8923

PostPosted: Thu Nov 19, 15 6:59 am    Post subject: Reply with quote    

You can't design all electronic components to be recycle friendly. I used to work in the industry and just at the basic board level then there were PCBs which were generally copper and gold with some intervening nickel or similar on plastic, thick film, which is a mixture of glass and metal printed onto ceramic, and thin film which is a thin layer of gold and nichrome plated up and again on ceramic or glass. Then you get the plating and base metal on the legs of components, solders etc.

I am sure it is quite possible to extract the metal from this, which is a potentially rich ore, and then refining them into individual metals, but an interesting chemical challenge to start, and then you have to make it economic. From the point of recycling, it is certainly worth while, but making it economic is another thing.

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Thu Nov 19, 15 10:14 am    Post subject: Reply with quote    

separating the metals can be as simple as burning them in a bone ash dish ,cupellation has been used since the bronze age ,the oxidisable stuff burns and the dish absorbs the oxides leaving very pure gold (99% +).i have done this with scrap 9ct and got it well above 22 ct.burning zinc out of yellow 9ct is a bit nasty and 9ct redish has a bit of a problem with copper "freezing" on the edges of the liquid gold if the temp isnt quite high enough ,this requires a bump in temp and some stirring to get the copper back in "solution" so as it oxidises.

the roman way to get precious metals(silver) from lead uses a series of crucibles at decreasing temps and a ladle to move the liquid stuff towards cool( using the principle causing the copper problem above)and moving the solid bits back to the hottest part of the series and repeating the process until the centre pot is very pure silver.im not sure if there is evidence of from viking scandinavia of them using this method but the silver in viking decorative work and hack silver "coinage"is often 99% so they definately had some good refining methods.

etc etc .

once one starts to play with acids to make solutions ,chelating agents,cyanide and electricity the possible isolations are such that most metals can be seperated.

if we are considering gold,platinum,palladium,rhodium etc etc the economics are such that a fair bit of effort will still turn a nice profit

avoiding poisoning the staff and locals is probably the biggest problem

Mistress Rose



Joined: 21 Jul 2011
Posts: 8923

PostPosted: Fri Nov 20, 15 7:06 am    Post subject: Reply with quote    

The cost of the different metals will decide whether it is economic Dpack, and as you say there are various methods of separation and refining, but the health and safety is of paramount importance.

I hadn't heard about the silver refining. I knew that gold was separated by removing all the dross at high temperature, and that quite a lot of this would have been other metals as oxides.

dpack



Joined: 02 Jul 2005
Posts: 33033
Location: yes
PostPosted: Fri Nov 20, 15 8:45 pm    Post subject: Reply with quote    

there are chemical followed by electro chemical ways to isolate gold (and other noble metals)from a mix as well.

the mercury amalgam method has some merit for concentrating from a mostly not metal "ore"(especially as the mercury can be recycled) but it does take up quite a few metals so there is still the refining/seperation to do.

Post new topic   Reply to topic    Downsizer Forum Index -> Reduce, Reuse, Recycle All times are GMT
Page Previous  1, 2
Page 2 of 2
View Latest Posts View Latest Posts

 

Archive
Powered by php-BB © 2001, 2005 php-BB Group
Style by marsjupiter.com, released under GNU (GNU/GPL) license.
Copyright 2004 marsjupiter.com

<-- -->