# Ideas for bulk filtering leach liquor in the field ?



## CO-WYO-Peter (May 16, 2022)

I am interested in ways to bulk filter on the cheap up to 60 gallons at a time; does anyone have practical experience? 

At lab scale I used a Büchner funnel and it worked well. However I am trying to figure out how to do it in the field effectively. Decanting doesn’t seem to work well - there seems to be some colloids in solution.

I tried filtering through pvc , socks , paper towels, funnels and seems to not work really well. 

Any thoughts would be appreciated.


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## speed (May 17, 2022)

I would probably be thinking about some kind of single pass centrifuge. The kind of thing you use to clean oils.


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## Martijn (May 17, 2022)

Please explain 'in the field' 
Is there a catch basin? Is the waste treated or 'released' in the field?


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## CO-WYO-Peter (May 17, 2022)

Martijn said:


> Is there a catch basin? Is the waste treated or 'released


Of course containment and treatment. Looking for answers not eco virtue signaling.


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## kurtak (May 17, 2022)

Wick filtering "may" be a good option

Don't have time to post more today but will "try" to post something in the next day or two

Kurt


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## Yggdrasil (May 17, 2022)

kurtak said:


> Wick filtering "may" be a good option
> 
> Don't have time to post more today but will "try" to post something in the next day or two
> 
> Kurt


Wick filtering is good and inexpensive, but if speed is important its not always the best.
Then again speed may exclude filtering quality and the other way around.


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## Yggdrasil (May 17, 2022)

What is most important to you, speed or quality? As Martijn said, do you have a plan for the solids or the liquids depending on what you call waste?


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## kurtak (May 18, 2022)

Yggdrasil said:


> Wick filtering is good and inexpensive, but if *speed* is important its not always the best.
> Then again speed may exclude filtering quality and the other way around.


The speed of filtering depends a great deal on the solids being filtered (course, fine, ultra fine)

Example; - vacuum filtering - say you are filtering (&/or washing) silver crystals from your silver cell "fill" your buchner funnel with crystals from the cell - pour wash water in - most of the water will run right through (gravity) - you only need to turn the vacuum on to get more complete de-watering & that will happen in a heart beat

Now lets do the same thing with silver cement - water will still flow through (gravity) but much slower & de-watering under vacuum takes a "bit" longer

Now lets try to filter a solution that has a small but fair amount of ultra fine solids (like stannic tin) it only takes a very thin layer of stannic tin to build up on the surface of the filter paper & the filtering slows to a drip, drip, drip whether gravity or vacuum - it can/will take *hours* to filter just a couple liters of solution - a drip at a time with a relatively small amount of solids to be filtered --- in fact in this case - vacuum will suck the ultra fine solids so tight on the filter paper that it can/will be slower then gravity --- you are better served to let gravity do it's work & & then turn on the vacuum at the very end to finish complete de-watering of the solids

This holds true no matter your method of filtering

For filtering "large" volumes of solutions - outside of having a filter press - wick filtering works very well

Here is a very good discussion we had about it back in 2017









Wick filter


This guy surely was once on the forum. He copied my wick filter. See 4:53 on video. https://www.youtube.com/watch?v=yxviTLVjvDQ




goldrefiningforum.com





Kurt


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## kurtak (May 18, 2022)

Some more pics of my wick filter set up

Pic 1 - wick installed through bung hole

pic 2 - wick bunched/packed around bung hole

pic 3 - filter installed

pic 4 - filter at work

pic 5 - shows filter vessel set at just "a bit" of an angle

pic 6 - solids pulled from filter vessel & set out in sun to dry 

Kurt


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## snoman701 (May 18, 2022)

Do you have a pump? 

If so, filter socks.


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## kurtak (May 18, 2022)

besides type solids (course, fine, ultra fine) the other thing that needs to be asked is amount of leach solution to amount of solids (solids/solution ratio)

That can make a difference on filtering method - especially on LARGE batch

Kurt


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## snoman701 (May 18, 2022)

Kurt....is that an old blanket as the disposeable layer?


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## RennVin (May 19, 2022)

I have a question on this topic. 
I have seen lixivant with a great deal of fine solids in suspension that have passed through coarse filtration pass into cartridge filters and tighter situations that have clog rapidly. 
Is there a simple way to settle these fine particles and colloids; perhaps with a fining/settling agent(protein or otherwise) that would compact solids and ease filtration.


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## CO-WYO-Peter (May 21, 2022)

kurtak said:


> Some more pics of my wick filter set up
> 
> Pic 1 - wick installed through bung hole
> 
> ...


Kurt this is awesome - thanks for sharing.


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## Yggdrasil (May 21, 2022)

snoman701 said:


> Kurt....is that an old blanket as the disposeable layer?


To me it looks like towels, might be wrong though
I used some cheap thin cloth from a market and braided PP rope as wick. 
It worked superbly.


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## kurtak (May 22, 2022)

RennVin said:


> Is there a simple way to settle these fine particles and colloids; perhaps with a fining/settling agent(protein or otherwise) that would compact solids and ease filtration.


Yes - they are called flocculants - they use different flocculants depending on solution Ph (basic, neutral, acidic, very acidic)

Kurt


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## kurtak (May 22, 2022)

snoman701 said:


> Kurt....is that an old blanket as the disposeable layer?


Yes - *old* blankets - I used to buy storage units & many of them (storage units) had garbage bags full of clothing & bedding so I had LOTS of blankets --- I found that blankets made out of the material electric blankets are made of work best but any old blanket will work & for that matter old sheets will work but it better if you double or triple them

Go to your local thrift store - they always have blankets (&/or sheets) that are not good enough to put out on their selves for sale which they will sell very cheap as "rag bags" (same thing with towels for the wicks) 

You can reuse both the liner (blanket) & the wick (towel) multiple times with this setup - however - with reuse you will start getting "some" solids going through to the catch barrel - but very VERY little - most (if not all) of which will be settled in the bottom of the catch barrel by the time the wick is done wicking (wick stops dripping)

The most important thing to keep in mind when setting this filter up (& getting best filter results) is "packing" the "wet" towel (wick) around the dung hole to make a good "seal" around the bung hole - other wise solids that pass through the blanket liner/filter will go out the bung hole & "ride" on the surface of the wick to the catch barrel resulting in in "more" solids going to the catch barrel (still not a "lot" but more)

Ultimately - like any kind of filtering - it comes down to what is being filtered (course, fine, ultrafine solids) - or solid to liquid ratio (lots of liquid little solids - or - lots of solids little liquid) - amount being filtered (1 liter or 20 liters or more) - are you filtering leaches containing PMs or filtering solids from waste treatment - etc. etc. etc.

It all begs the question of what type/process of filtering is going to get you to your end filtering result ???

What's going to best serve your filtering needs - a colander with a couple restaurant coffee filters to remove most of the solids (because you have a "lot" of solids) & then a Charman plug to filter ultra fines that passed the coffee filters - or just a Charman plug to filter a solution with just "some' ultra fines ???

Do you want ultra clear like before precipitation - or are "some" solids acceptable like hydroxide waste treatment ???

Then there is the question of do you need to get most/all the chem out of the solids - or not ???

Then - depending on the situation - what system/method works best - gravity, wicking, vacuum, pressure ??? 

All questions that need to be answered when it comes to filtering as they all (systems/methods) will be employed at some point in time in the course of refining --- as I am sure you fully understand snowman  

In other words - this is just a "general discussion" post about filtering


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## RennVin (May 22, 2022)

kurtak said:


> Yes - they are called flocculants - they use different flocculants depending on solution Ph (basic, neutral, acidic, very acidic)
> 
> Kurt


Kurt, thanks for clarifying.
Are there any particular flocculants that you’ve used and like for low Ph leaches at scale. By scale I mean 80 to 100L of process solution. 
We are taking measures to screen to <100 micron prior to cartridge filtration and ultimately cementation.


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## kurtak (May 22, 2022)

CO-WYO-Peter said:


> I am interested in ways to bulk filter on the cheap up to 60 gallons at a time; does anyone have practical experience?
> 
> At lab scale I used a Büchner funnel and it worked well. However I am trying to figure out how to do it in the field effectively. Decanting doesn’t seem to work well - there seems to be some colloids in solution.
> 
> ...


So - after posting my last post - it begs the questions -----------

What are you filtering CO-WYO-Peter ???

Leach from something like leaching ore &/or something else ???

Solids from waste treatment like hydroxides &/or carbonates &/or copper cemented with iron (&/or for that matter silver/gold/PGMs cemented with copper) ???

Is what you are filtering a lot of solids & a little liquid or a lot of liquid & only some solids ???

Are the solids course, fine, ultrafine &/or combination ??? 

Do you need to get most/all the chem out or not ???

Kurt


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## kurtak (May 22, 2022)

RennVin

When I was full time refining the flocculant I used for acidic solutions I got from an aluminum anodizing plant that I did a lot of contract work for - I never needed a lot of it for my refining work so they would just give me a small bottle of it when I needed it - I don't remember the particulars on it any more

Lou & Deano have both mentioned & recommended a company called Tramfloc for flocculants -----------









Polymers for Water and Wastewater Treatment


Polymers for Wastewater Treatment | emulsion breakers, super absorbent polymers, metal remediation, dechlorination and defoamers




tramfloc.com





So you can contact them & explain your situation to them & they will likely recommend some of their different products & send you (likely free) "samples" for you to try to determine which product works best for you

Kurt


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## RennVin (May 22, 2022)

kurtak said:


> RennVin
> 
> When I was full time refining the flocculant I used for acidic solutions I got from an aluminum anodizing plant that I did a lot of contract work for - I never needed a lot of it for my refining work so they would just give me a small bottle of it when I needed it - I don't remember the particulars on it any more
> 
> ...


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## RennVin (May 22, 2022)

Kurt, thank you. I appreciate the information. I will run it down with the manufacturers. This was very helpful.


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