E-waste scrap in chemical to be processed

[DIY5050]

I think what all is left is just fiberboard, material, maybe mask, and tiny gold flecks, now that it is all filtered. Water does no harm to it, barely rinses anything. except the hcl. There's no precipitate what so ever.
Next time, I will be stripping the solder mask for sure if I do boards. I'll do some reading and see if I should strip then HCL for the tin/solder, or the other way around. Anyway it will be a few weeks at least before I start another batch.

 

[Yggdrasil]

No only boiled in HCL. There shouldn't be any tin left since I boiled everything in HCL before I started the AP and made a mess, just for the solder and tin. I will go filter it all and see what material I have left

That means you have only solids dispersed in solution.
Then you should stop your washes and dissolve it in the method of your choice.
If you continue to “grind” down your material by friction/washing, it will be even finer.
Dissolve it and drop it by SMB, Copperas or other preferred methods.

Edit for spelling

 

[bleachsicle]

No only boiled in HCL. There shouldn't be any tin left since I boiled everything in HCL before I started the AP and made a mess, just for the solder and tin. I will go filter it all and see what material I have left

If I may ask, what did the faint smell of nitric smell like to you? I am a beginner as well and I saw all of the fumes getting sucked out of my fume hood but still smelt something in the air. Almost smelt like chlorine

 

[Yggdrasil]

If I may ask, what did the faint smell of nitric smell like to you? I am a beginner as well and I saw all of the fumes getting sucked out of my fume hood but still smelt something in the air. Almost smelt like chlorine

That is NOx

 

[bleachsicle]

That is NOx

Ok. Should I have any concerns? Limited myself as much as possible and wore a gas mask. Not sure if it helped but just as a precaution. Gonna have to do more tests with my hood

I should mention that my fume hood is made out of a liquid IBC container. It may have stored chlorine type substance in the past. Could the container it's self be giving off the chlorine smell? I never smelt it before I started refining though

 

[DIY5050]

Ok. Should I have any concerns? Limited myself as much as possible and wore a gas mask. Not sure if it helped but just as a precaution. Gonna have to do more tests with my hood

I should mention that my fume hood is made out of a liquid IBC container. It may have stored chlorine type substance in the past. Could the container it's self be giving off the chlorine smell? I never smelt it before I started refining though

Yeah, NOx is distinctive from chlorine. What I notice is the round container, like my 55 gal drum creates a swirl. I am assuming yours is round. Either the inline fan, which in my case, is causing the swirling of air, or I am getting a tornado effect. kind of like the vortex you get stirring a glass of water. I redirected my airflow, drilled holes below my doors, and lowered the intake. It helped me finish. Although I wore a respirator, I only can trust it so much, even with acid filters. Before I opened airflow in the bottom, I did another smoke test, and found the rotation of the air on mine is right to left. If only the right door is open, it will escape the hood. If only the left door is open, the smoke tries to escape but gets sucked back in. I will be redesigning the ventilation, and try a venturi system. If the gases still circulate I will be scrapping the round container idea. I am thinking about scrapping the thing now and build a rectangular structure. I have a feeling this is just air flow vortex amplified by a round container. I also notice none of the professional fume hoods are round. It's a shame too. Mine has a concrete bottom, lit up perfectly, and took a lot of work to bend the lexan doors. I have 3 more weeks before I can refine anything again due to other activities, so I'll have time on that decision.

 

[bleachsicle]

Yeah, NOx is distinctive from chlorine. What I notice is the round container, like my 55 gal drum creates a swirl. I am assuming yours is round. Either the inline fan, which in my case, is causing the swirling of air, or I am getting a tornado effect. kind of like the vortex you get stirring a glass of water. I redirected my airflow, drilled holes below my doors, and lowered the intake. It helped me finish. Although I wore a respirator, I only can trust it so much, even with acid filters. Before I opened airflow in the bottom, I did another smoke test, and found the rotation of the air on mine is right to left. If only the right door is open, it will escape the hood. If only the left door is open, the smoke tries to escape but gets sucked back in. I will be redesigning the ventilation, and try a venturi system. If the gases still circulate I will be scrapping the round container idea. I am thinking about scrapping the thing now and build a rectangular structure. I have a feeling this is just air flow vortex amplified by a round container. I also notice none of the professional fume hoods are round. It's a shame too. Mine has a concrete bottom, lit up perfectly, and took a lot of work to bend the lexan doors. I have 3 more weeks before I can refine anything again due to other activities, so I'll have time on that decision.

It’s definitely a learning curve and the biggest part is to make sure we are safe!! I actually made my fume hood using a liquid IBC container and cut some plastic out of the middle and plastic welded it back together… it’s sort of a box shape but also very uneven walls (if you look it up on Google you can tell). Honestly thinking about just buying something like this from eBay: 35" Plastic Vented Fume Hood Enclosure | eBay


Or maybe even spend the extra cash and go with a fully working fume hood.

Good luck in your journey and stay safe!!

 

[Martijn]

If I may ask, what did the faint smell of nitric smell like to you? I am a beginner as well and I saw all of the fumes getting sucked out of my fume hood but still smelt something in the air. Almost smelt like chlorine

An old diesel engine smells like faint NOx.

 

[DIY5050]

Just follow up I have finished processing the material. What little is left I now have stored in the bottom of a test tube, that I can't fully drain. I should have just put it in the stock pot to extract later when there is something to salvage. I can add this to another batch if and when I decide to process another round. Thanks for all your help my friends.

 

[DIY5050]

It's so nice to have an actual copy of Hoke's book. I can't read computer screens, hurts my head. The price of a paperback is far superior to printing it from the PDF. The preface and forward has good information too, just FYI.
I tore out my fume system with a lot of mistakes. In-line fan, 90 degree piping, and a poor choice of a vessel are lessons learned. I am so close to finishing my new hood, I can't wait. Room pressure is another important lesson to learn. Don't pull more air out than you can put in. I'm uploading my pics. The blower I have was my inline, and that POS is going in the trash. Mail has had the new blower out for delivery for 2 days not. We will see. Anyway, I have a venturi going at the top, and I will use the old piping for the intake of outside air, so I can keep the fume hood at a lower pressure than my shed. I live in the south, and need my AC going. Outside is my fume wash tank which works. All the piping is now bends now too. Any pointers from here would be nice.
Thanks

 

[Martijn]

It's so nice to have an actual copy of Hoke's book. I can't read computer screens, hurts my head. The price of a paperback is far superior to printing it from the PDF. The preface and forward has good information too, just FYI.
I tore out my fume system with a lot of mistakes. In-line fan, 90 degree piping, and a poor choice of a vessel are lessons learned. I am so close to finishing my new hood, I can't wait. Room pressure is another important lesson to learn. Don't pull more air out than you can put in. I'm uploading my pics. The blower I have was my inline, and that POS is going in the trash. Mail has had the new blower out for delivery for 2 days not. We will see. Anyway, I have a venturi going at the top, and I will use the old piping for the intake of outside air, so I can keep the fume hood at a lower pressure than my shed. I live in the south, and need my AC going. Outside is my fume wash tank which works. All the piping is now bends now too. Any pointers from here would be nice.
Thanks

Does the inside of your venturi look like this?
https://goldrefiningforum.com/threads/fume-hood-venturi.10979/post-339473Theoretically the vaccuum inlet point should be right at the narrow point, or just after, for the best vacuum. further behind the point where the pipe has expanded, there still is a lower pressure than in the supply pipe, but less or no vacuum, just flow, which can draw air along, but not that good.
Venturi Flow Equation and Calculator

I also feel the narrow part of your venturi is too narrow compared to the diameter of your fan. It will have to work hard to get any flow after the venturi. The restriction causes a pressure drop, powering the venturi, but also lessens the flow. This lower flow is then divided over the larger pipe diameter again. So it's a balance of vacuum vs flow to get optimum efficiency.

I made one by inserting a conical plastic cup in a Y-connector, where the narrow part is about half the size of the pipe. Bottom taken out obviously.
More flow in the main pipe may not result in a deeper vacuum, but may result in more flow from your hood, which is what you want.

Martijn.

 

[DIY5050]

Does the inside of your venturi look like this?
https://goldrefiningforum.com/threads/fume-hood-venturi.10979/post-339473Theoretically the vaccuum inlet point should be right at the narrow point, or just after, for the best vacuum. further behind the point where the pipe has expanded, there still is a lower pressure than in the supply pipe, but less or no vacuum, just flow, which can draw air along, but not that good.
Venturi Flow Equation and Calculator

I also feel the narrow part of your venturi is too narrow compared to the diameter of your fan. It will have to work hard to get any flow after the venturi. The restriction causes a pressure drop, powering the venturi, but also lessens the flow. This lower flow is then divided over the larger pipe diameter again. So it's a balance of vacuum vs flow to get optimum efficiency.

I made one by inserting a conical plastic cup in a Y-connector, where the narrow part is about half the size of the pipe. Bottom taken out obviously.
More flow in the main pipe may not result in a deeper vacuum, but may result in more flow from your hood, which is what you want.

Martijn.

Thanks Martijn, I will be replacing the fan with a blower with a 4 inch exhaust. I agree the 6" is too much and I am leaking air through the fan. The 2 inch pipe you see is going through the adapter and stopping in the middle of the T (4 inch pipe at fume hood inlet) maybe a little past mid point. Should my hood inlet be 2 inches as well, and put more the 2 inch past the hood?

 

[Martijn]

I would place the reducer as far as possible inside the T to minimize the length of greater flow resistance of the smaller pipe. Look at the picture in the other thread i posted. The narrow reducing part is right before the nozzle.
This also helps the airflow expanding after the nozzle and creating the vacuum.

If you can get a conical big plastic beaker and cut the bottom out, it will flow alot faster and create more suction imo.
This way you can attach a bigger pipe to the inlet and leave the two reducers out.
Tape up the edge of the beaker to get a tight fit and just push it in. Test how far to make it work best.
This setup you now have will also work, and you can test the flowrate with smoke of the different setups.
My simple venturi:

The cup inside is about at the position where I'm holding it and it works great for me.
Love your DIY work!

 

[Martijn]

And my piping diameter increases right after the venturi, which has a lower flow resistance. My outlet could be better.

 

[Brett Novak]

coming in a bit late, but, I'm gonna guess your "mud" is a nice thick green goop if you started with circuit boards.

It's epoxy. and it's a nightmare.

for PCB's, start with a 2 or 3 day soak in water and LYE. A bubbler in it will help as well. This will dissolve the epoxy silk screen crap, and leave about 90# of the gold traces intact

Then it's into a clean bucket of rinse water

Then put the PCB's in a suitable large bin with AP and bubble for a couple weeks. The gold foils will literally just come right off. The ones that don't float off will come off with a toothbrush or scruber of some sort. Add new HCL and Peroxide every 2 or 3 days and leave it covered in the sun if you can.

Then Rinse again in clean water.

Now comes the challenge. If you are working with POPULATED boards, be prepared to do some manual filtering of bigger crap compontns with tweezers. You;ll have caps, resistors, connectors and all sorts of junk in there. If you have A LOT of material go buy a cheap plastic cement mixer to wet tumble everything first. Or do it by hand.

AR the mostly clean stuff using normal procedure.

For the epoxy crap, now comes the fun. It will have gold in it. BUT - you need to boil it in acetone to remove as much as you can. This should get all of the epoxy in solution and then filter filter filter.

when you think it's clean enough, boil it again, filter, then do an AP processing on it.

 

[DIY5050]

coming in a bit late, but, I'm gonna guess your "mud" is a nice thick green goop if you started with circuit boards.

It's epoxy. and it's a nightmare.

for PCB's, start with a 2 or 3 day soak in water and LYE. A bubbler in it will help as well. This will dissolve the epoxy silk screen crap, and leave about 90# of the gold traces intact

Then it's into a clean bucket of rinse water

Then put the PCB's in a suitable large bin with AP and bubble for a couple weeks. The gold foils will literally just come right off. The ones that don't float off will come off with a toothbrush or scruber of some sort. Add new HCL and Peroxide every 2 or 3 days and leave it covered in the sun if you can.

Then Rinse again in clean water.

Now comes the challenge. If you are working with POPULATED boards, be prepared to do some manual filtering of bigger crap compontns with tweezers. You;ll have caps, resistors, connectors and all sorts of junk in there. If you have A LOT of material go buy a cheap plastic cement mixer to wet tumble everything first. Or do it by hand.

AR the mostly clean stuff using normal procedure.

For the epoxy crap, now comes the fun. It will have gold in it. BUT - you need to boil it in acetone to remove as much as you can. This should get all of the epoxy in solution and then filter filter filter.

when you think it's clean enough, boil it again, filter, then do an AP processing on it.

Hey Brett, yup it was definitely masking. I cleaned it up pretty good, I think. I will never do pins and board materials again together, and yes I will wash off the mask with Lye next time.

 

[DIY5050]

And my piping diameter increases right after the venturi, which has a lower flow resistance. My outlet could be better.

Thanks for the pointers. New blower arrived, and not it's time to fit a square peg into a round hole. I'm looking for cups or buckets to seal against the 4" piping and give it a try. Since Mardi Gras is half a year away, I guess it's buying big gulps at the 7-11.

 

[Martijn]

Use whatever is cheapest and functional. I do. Test this setup first to see a difference. You have it good to go once the new fan is attached.

 

[DIY5050]

So I have a question, how do you clean off the powder coat or paint on steel for the copper cementation. With the price of copper, and what people are asking of scrap, I plan on re-using my copper. It would be nice to be able to use the trash steel instead of it rotting in the landfill. Example, the sheet steel used in computer towers, amplifier covers and bottoms, painted piping, etc.
A lot of my motivation and want to get into precious metal refining was because of the trash thrown out in the USA's disposable economy. I grew up in a family that didn't waste things. Our commodes today give us no choice. Our "recycling," fallacy here is a sham people pay for to "feel good." Because there is little to no profit in most trash, we just ship it somewhere else, and call it recycling. It's disgusting.

 

[Yggdrasil]

So I have a question, how do you clean off the powder coat or paint on steel for the copper cementation. With the price of copper, and what people are asking of scrap, I plan on re-using my copper. It would be nice to be able to use the trash steel instead of it rotting in the landfill. Example, the sheet steel used in computer towers, amplifier covers and bottoms, painted piping, etc.
A lot of my motivation and want to get into precious metal refining was because of the trash thrown out in the USA's disposable economy. I grew up in a family that didn't waste things. Our commodes today give us no choice. Our "recycling," fallacy here is a sham people pay for to "feel good." Because there is little to no profit in most trash, we just ship it somewhere else, and call it recycling. It's disgusting.

Steel will cement out copper too.
Anything steel should be depopulated from the boards.