is it possible 925 sterling silver powder

[kurtak]

Arrrrg - just spent about 3 hours posting a reply - had several other tabs open & went to close some of those tabs - accidently closed the tab for the reply I was working resulting in loosing all my work

Right now not even going to try to retype it all - Arrrrg

Kurt

 

[kurtak]

Everything is rated for 3000PSI.
For proof of concept, we hooked it up with a small home pressure washer, rated at 1.6 GPM at about 1000PSI.

To my surprise, it did a very nice job, with about 20% of the melt being above 2mm in size. Here's the result:

Sam - per the bold print - 2 mm in size is about 10 mesh (which is not a true powder)

When classifying "powder" - powder starts at about 80 mesh (80 mesh considered as "course" powder & fine powder starting at about 120 mesh - very fine at about 200 mesh - micro fine at about 300 mesh)

with your set up (roughly speaking) about how much powder at say 100 mesh & finer do you get ?

Kurt

 

[kurtak]

Ok - yesterday I messed up & lost what I spent three hours working on for a post - so will try again today

How does the atomizer power head that I and Sam have posted pictures of work

It works by high pressure water spray hitting the molten metal & busting the molten metal into small/fine particles (or a shear factor)

How small/fine particles the molten metal will bust into depends on a number of factors

1) Pressure - pressure is the force that does the busting apart of the metal when it (pressure) hits the metal - higher pressure means more force - more force means more effective busting --- less pressure in turn means less force which in turn means (edit to add word less here) effective busting

2) Disbursement of water delivered by the high pressure spray - this is determined by the nozzles orifice size as well the angle of the "water fan" coming out the nozzle with both effecting the shear factor

Orifices size has an effect on the size of the water droplets coming out the orifice (under pressure) smaller droplets have more energy then larger droplets --- fan angle - a large fan distributes the water AND energy over a larger area then a small fan

3) Angle at which the spray hits the molten metal as the molten metal passes through the spray also effects shear

4) Water volume (GPM) - there needs to be enough water in combination with the three above factors to optimize shear

5) Rate (speed & amount) of molten metal poured through the spray

All of these things have a direct effect on particle size produced by the shear energy to bust the metal according to system design

Regardless of system design - you are not going to get 100% of a given particle size (as in 100% of 50 mesh, 100 mesh, or 200 mesh, 300 mesh)

Reather - the system design will only determine the percentage of course - fine - ultra fine particles produced by the system

Sam was good enough to provide us pics of his system using a 1000 PSI 1.6 GPM pressure washer

Sam's system - though certainly doing a good job of "busting" the metal it also shows a relatively high percentage of course particle size

Here is a pic of the end product using a system with more pressure & more GPM (3000 - 3500 pressure delivering 6.8 - 7.5 GPM)



This pic is a bit deceiving because as you can see it is wet so the particles are clumped together making it look like it is much courser then it actually is

I have another pic of the same material dried but it's in a "paper" document (instead of a document on my computer) & I don't have a scanner to scan it & download it

Based on that picture (of the dry material) it is producing a large percentage of true powder ranging from course (80 mesh) to ultrafine (300 minus mesh)

The bottom line being (as already said) no matter the system - you will get a range of particle size - so sifting will be required if you are after a "classified" particle size --- and again the system will (at least to some degree) determine percentage of course to fine to ultrafine

One more note - regardless of the system - you will have some metal that goes through as "over size" (greater in size then powder) percentage of that will again be determined by the system design &/or the 5 above points

This post was to provide info concerning the principle behind producing metal powder with a pressure washer

My next posting will be to provide more details on actual design of the system

Kurt

 

[orvi]

Very interesting informations given. Thanks for everybody

 

[kurtak]

Currently very busy with other things I must get done - will get back to this ASAP

That may not be until this weekend

Kurt

 

[kurtak]

Sorry I have not got back to this yet - I will get back to it this weekend though

Edit to add; - during the week I only have time for "short" answer/replies

This is a long answer/info/reply thing

Kurt

 

[capitano9VII]

I will start working as soon as possible to make a prototype. i have doubts about which nozzle should i use. 1 kilo sample requested. need to know nozzle diameters. I'm looking for articles but There is no clear information. I will try to find out by doing a trial run.

 

[Cryogaijin]

Aside from being a bit lossy, would a ball-mill work?

 

[capitano9VII]

Aside from being a bit lossy, would a ball-mill work?

This method works for pure silver. Not suitable for alloys. And I don't think it's suitable for micron sizes.

 

[kurtak]

I will start working as soon as possible to make a prototype. i have doubts about which nozzle should i use. 1 kilo sample requested. need to know nozzle diameters. I'm looking for articles but There is no clear information. I will try to find out by doing a trial run.

As I said I will post details for making the power head (donut) this weekend

typing up such a post with details takes time - LOTS OF TIME

I don't have that kind of time during the week - which is why I said I would do it this weekend

You have two options

you can experiment by trying to build one with the lack of details & off a couple pics in which case angles etc. etc. etc. will likely be wrong & need to rebuild

Or you can wait till I have the time (this weekend) to post the details --- & you can build it right the first time

If you are going to waste your time experimenting --- then there is no sense in me wasting my time to give you proper instructions

Keep in mind - that I am not being paid to help you here - so I am not working on your clock but rather on my clock --- which in turn means you simply have to wait until I have the free time to do so (which as I said would be this weekend)

It would be one thing if the instructions I have were on my computer where I could just copy & paste them here

But they are not on my computer - they are in "paper documents"

That means I have to go over them (a page at a time) & then hand type them here --- that takes a LOT OF TIME

Sorry if that all sounds rude - but I am working for free to try to help you --- so WAIT & I will give you the proper instructions --- it's only a couple more days that you have to WAIT for proper instructions to do it right THE FIRST TIME

Kurt

 

[capitano9VII]

As I said I will post details for making the power head (donut) this weekend

typing up such a post with details takes time - LOTS OF TIME

I don't have that kind of time during the week - which is why I said I would do it this weekend

You have two options

you can experiment by trying to build one with the lack of details & off a couple pics in which case angles etc. etc. etc. will likely be wrong & need to rebuild

Or you can wait till I have the time (this weekend) to post the details --- & you can build it right the first time

If you are going to waste your time experimenting --- then there is no sense in me wasting my time to give you proper instructions

Keep in mind - that I am not being paid to help you here - so I am not working on your clock but rather on my clock --- which in turn means you simply have to wait until I have the free time to do so (which as I said would be this weekend)

It would be one thing if the instructions I have were on my computer where I could just copy & paste them here

But they are not on my computer - they are in "paper documents"

That means I have to go over them (a page at a time) & then hand type them here --- that takes a LOT OF TIME

Sorry if that all sounds rude - but I am working for free to try to help you --- so WAIT & I will give you the proper instructions --- it's only a couple more days that you have to WAIT for proper instructions to do it right THE FIRST TIME

Kurt

I appreciate your effort. you helped me a lot. I will wait for you.

 

[cejohnsonsr1]

I see this keep popping up and wondering why? Making a mixture of powdered metals at a given ratio is child’s play. No more difficult than mixing flour for bread. The real question is why so much concern? It won’t be Sterling unless or until you melt it into an alloy and once you start that the only thing that matters is the weight and purity of the metals. The form is absolutely irrelevant.

 

[kurtak]

I see this keep popping up and wondering why? Making a mixture of powdered metals at a given ratio is child’s play. No more difficult than mixing flour for bread. The real question is why so much concern? It won’t be Sterling unless or until you melt it into an alloy and once you start that the only thing that matters is the weight and purity of the metals. The form is absolutely irrelevant.

Per the bold print --- you have missed the whole point of this thread - we are not talking about making sterling (which yes - would be made by taking 92.5% silver & 7.5% copper & melting it together resulting in the alloy of sterling silver (925 silver)

Rather - this thread is about taking sterling silver that is already the alloy (of 925 silver) & turning that alloy into powder

In other words - turn (actual) sterling into powder --- not make sterling from silver/copper powders

Why do you want to do that ?

Because - if you can turn actual sterling into a powder you can use that sterling powder for MANY things including but not limited to - 3D printing sterling objects - making sterling glazes - sterling paste type solder - sterling inks - or sterling powder coatings - etc. etc. etc.

So again (at the risk of repeating myself) we want to make sterling into a powder --- not take silver powder & copper powder & make it into sterling

Kurt

 

[kurtak]

Let's start with this ------

The more pressure you have, the finer the powder you make.

The point I am making here is that you can make a "proto type" using a small home use pressure washer - like the one Sam posted (For proof of concept, we hooked it up with a small home pressure washer, rated at 1.6 GPM at about 1000 PSI) --- but all that is going to do is prove the concept that a pressure washer will bust molten metal into small particle size - but we already know that this works

What this won't do is tell you how much actual powder can/will be made (which is the end goal) by operating at higher pressure & higher GPM in order to optimize production of powder

We already know a pressure washer will bust molten metal - but our goal is not to just bust metal - rather it is to optimize powder production - So IMO - it only makes sense to build for optimized powder production in the first place

Other wise all you are doing is building to prove what we already know --- & then re-building to optimize - what we already know

The power head I posted a pic of is built with that in mind (operate at higher pressure & higher GPM) for optimum powder production

Once this system is built - there are a few things you can alter (such as rate of the molten metal pour - orifice size - nozzle fan - ect.) to achieve your most desired output

With that said - I will next post the materials needed for building the power head/system I posted a pic of

Kurt

 

[capitano9VII]

Features of the air compressor I have : 10bar 1150lt/m 10hp/7.5kW 240kg

 

[kurtak]

First & foremost - before we move forward with this build there needs to be a WARNING that goes with the build

This system is made to operate at VERY high pressure (3000 - 3500 PSI) - & it is made using welded fittings

Therefore - it is important that the welds be done by someone that is VERY GOOD in the field of stainless steel welding

Bad welds can & will result in failure of the power head --- at best that failure could be pin holes &/or cracks resulting in water spraying everywhere - &/or - at worst - the power head actually blowing apart resulting in serious injury to someone being hit by pieces of steel flying across the room

Bottom line - unless you are VERY GOOD at welding SS - do NOT build this yourself - pay a professional to weld it for you

It is a good idea (& i recommend) to have the welds X-rayed to insure there are no weak spots in the welds

--------------------------------------------------------------------------------------------------------------------

Pressure washer size 3000 psi @ 6.8 GPM - or - 3500 psi @ 7.5 GPM


The power head "donut" is made using (4) --- 304 SS - 3 inch - schedule 80 - 90 degree - weld type - short radius elbows like these (you do not want to use long radius elbows)

https://www.pipefittingsdirect.com/...e-80-304-stainless-steel-90-deg-weld-on-elbow
(1) --- 1/2" socket weld - class 6000 - threaded half coupling - 304 SS --- this is welded to the donut in order to connect the pressure washer hose to the power head donut - therefore this thread size needs to match the threads on the end of the pressure washer hose (or will have to use an adapter if the 1/2 coupling has different threads then the hose end threads)

You are looking for something like this except you want it to be 6000 class not 3000 class

https://www.steelsupplylp.com/sku/1...term=4580084407688201&utm_content=Ad group #1
(4) --- 1/4" socket weld - class 6000 - half coupling - 304 stainless (like in the above link) --- these are welded to the donut for screwing the nozzles into so actual thread size is determined by the thread on the spray nozzles

You do not want to use adapters in this case so make sure the treads of your half couplings & nozzles match

(4) treaded nozzles --- using 4 standard - size 2 - nozzles will deliver 1.7 GPM (per nozzle) at 3000 psi and 1.87 GPM (per nozzle) at 3500 psi.

Therefore - using 4 nozzles @ 3000 psi a pressure washer delivering 6.8 GPM is needed and at 3500 psi 7.5 GPM

WARNING --- you do NOT want to use quick connect nozzles --- use ONLY threaded nozzles

Spray pattern of the nozzles --- you want 7.5 degree flat fan spray pattern if possible --- but 15 degree works if you can't find the 7.5.

You will also need a piece of straight SS pipe - this pipe is placed in the center of the "donut hole" so needs to fit "down" into the donut hole --- this pipe protects the nozzles from molten metal. It is best to have the angled nozzles release their spray right at the end of the pipe. This protects the nozzles from accumulating little balls of frozen metal. It will still accumulate some from spray but minimal if the pipe protects it well.

So the length of this pipe well be determined by the measurement from the top of the donut to the bottom of the nozzles

This is enough for today & will at least get you started in what you need to look for to do this build

Will post more again tomorrow --- it is likely going to take a couple more days to post all the details for this build

Kurt

 

[cejohnsonsr1]

Per the bold print --- you have missed the whole point of this thread - we are not talking about making sterling (which yes - would be made by taking 92.5% silver & 7.5% copper & melting it together resulting in the alloy of sterling silver (925 silver)

Rather - this thread is about taking sterling silver that is already the alloy (of 925 silver) & turning that alloy into powder

In other words - turn (actual) sterling into powder --- not make sterling from silver/copper powders

Why do you want to do that ?

Because - if you can turn actual sterling into a powder you can use that sterling powder for MANY things including but not limited to - 3D printing sterling objects - making sterling glazes - sterling paste type solder - sterling inks - or sterling powder coatings - etc. etc. etc.

So again (at the risk of repeating myself) we want to make sterling into a powder --- not take silver powder & copper powder & make it into sterling

Kurt

I think I understand the question better now, but the answer is really still the same. And please believe me when I say I’m not trying to be facetious or adversarial. When you talk about a metal in powder form, it’s referred to as “elemental” because it is quite literally the atoms of the element(s) (in this case silver and copper) in pure form. Sterling is an alloy of those 2 metals in metallic form. To get to the elemental form you necessarily have to remove everything that isn’t the element in question. To get what you’re describing would require the ability to combine 2 elements in very precise ratios in quantities so small that you’d literally be counting atoms and then melting them in those quantities tens of millions of times per gram. I hope this is a better answer, though I’m sure it’s not the one you were hoping for. It’s just that elemental metals and alloys are mutually exclusive of each other by their very definition.

 

[cejohnsonsr1]

I think just a little further elaboration is in order. You can dissolve Sterling and have a solution that is the correct ratio of the 2 metals, but at that point you no longer have Sterling. You have a solution containing 2 elements. You can precipitate the silver and leave the copper in solution, or you can precipitate both (see the reactivity series of metals), but again, you won’t have Sterling. You’ll have a mixture of 2 metals in the ratio required to alloy them back into Sterling. What you have described would require that every 925 atoms of silver remain bonded to 75 atoms of copper during precipitation. There is no such method. Again, I’m not trying to give you a hard time. I see what you’re trying to do and there may be some way to accomplish your end goal, but this isn’t it and I hate to see you waste your time,effort and money on something that can’t work when you could possibly direct your energy to something that could work. And I wish you good luck in the endeavor.

 

[Yggdrasil]

I think just a little further elaboration is in order. You can dissolve Sterling and have a solution that is the correct ratio of the 2 metals, but at that point you no longer have Sterling. You have a solution containing 2 elements. You can precipitate the silver and leave the copper in solution, or you can precipitate both (see the reactivity series of metals), but again, you won’t have Sterling. You’ll have a mixture of 2 metals in the ratio required to alloy them back into Sterling. What you have described would require that every 925 atoms of silver remain bonded to 75 atoms of copper during precipitation. There is no such method. Again, I’m not trying to give you a hard time. I see what you’re trying to do and there may be some way to accomplish your end goal, but this isn’t it and I hate to see you waste your time,effort and money on something that can’t work when you could possibly direct your energy to something that could work. And I wish you good luck in the endeavor.

I think you need to reread.

No one is talking about dissolved metal here, we are talking about melted metal in an alloy form.
And he want to make it into a micron sized powder as uniform as possible for some application.
Maybe 3D printing or soldering as Kurt said.
Only his customer know.

 

[kurtak]

As I said yesterday --- "you have missed the whole point of this thread" --- & it is still clear you have missed the whole point - in fact you are not even understanding what is being discussed here

We are NOT talking about breaking metal down to it's "individual" elemental atoms

Rather we are talking about breaking metal down to an ultra fine (micron size) powder

That process (although not actually breaking the metal to "individual" atoms) is called atomizing (or atomization)

The system for doing this is called an atomizer

In this system/process - atomizer/atomizing/atomization is NOT a reference to "individual" atoms - but rather a reference to a particle micron(s) in size

Example; - a 400 mesh particle of metal is about 37 microns in size - a 37 micron particle of metal will have MANY atoms in it - if the original (large piece) of metal that the 400 mesh particle came from was sterling or brass (an alloy) then that 400 mesh particle will also be sterling or brass

I think just a little further elaboration is in order. You can dissolve Sterling and have a solution that is the correct ratio of the 2 metals

Correct/true

, but at that point you no longer have Sterling. You have a solution containing 2 elements.

Correct/true

You can precipitate the silver and leave the copper in solution, or you can precipitate both

Correct/true

(see the reactivity series of metals),

I am FULLY aware of the reactive series

but again, you won’t have Sterling.

Correct/true

You’ll have a mixture of 2 metals in the ratio required to alloy them back into Sterling.

Correct/true

What you have described would require that every 925 atoms of silver remain bonded to 75 atoms of copper

Correct/true

during precipitation.

This is where you are wrong because we are not trying to precipitate metals from a solution

Rather - we are trying to turn an existing alloy into micron size particles of that alloy

In the industry - that is called atomization & it is done with a system called an atomizer

There is no such method

Wrong again - it is in fact - a method/process used in industry !!!

. Again, I’m not trying to give you a hard time. I see what you’re trying to do

Wrong again - you don't see at all what I am trying to do !!!

and there may be some way to accomplish your end goal

Correct - here is a link to accomplishing this very goal - in the industry of metal atomization

https://www.sugino.com/site/water-atomization-equipment-e/
And another link - in the industry

https://www.stewardmaterials.com/products/atomized-powders/

, but this isn’t it

So wrong again - because what I am doing - is in fact it !!!

and I hate to see you waste your time,effort and money on something that can’t work

Therefore - because it DOES work - I am certainly not wasting anything - because what I am doing is passing on the actual info - that in industry - is called metal powder atomization - done with what (in industry) is called a metal powder atomizer

when you could possibly direct your energy to something that could work.

So my energy is in fact directed to something already proven to work

And I wish you good luck in the endeavor.

Therefore - no luck - what so ever - involved - because it is already a proven industrial process/method

In other words --- in the industry (of making micron size metal particles) the words - atomization - atomizing - atomizer is NOT a reference to actual individual atoms - but rather a reference to a process of making ultra fine - micron size - metal powders

That can be done with pure metal - OR - with alloys of metals

You can buy atomized metal powders on ebay - including (but not limited to) stainless steel - which is an alloy

atomized metal powder | eBay

Kurt