Honest circuit board refining / PM recovery

[alloy2]

Tell us about your red light district and wife seeking adventures.

Bring cash.

[ragstoriches]

So is Tantalum and other rare earth elements lost in the process and just dumped as slag? Or is it sold to someone that removes other metals than the PMG's that were removed by the refineries? There still must be some value to the slag?

[alloy2]

So is Tantalum and other rare earth elements lost in the process and just dumped as slag? Or is it sold to someone that removes other metals than the PMG's that were removed by the refineries? There still must be some value to the slag?

Nothing goes to waste, if there were harmful elements left in the slag it could not be used as blasting media.

Like I mentioned in another recent thread, my recent study hydroxides and oxides can be returned into their previous metallic states.

https://en.wikipedia.org/wiki/Copper_slag

Copper slag is mainly used for surface blast-cleaning. Abrasive blasting is used to clean and shape the surface of metal, stone, concrete and other materials. ... The blasting media manufactured from copper slag brings less harm to people and environment than sand.

[ragstoriches]

So after the PM's are removed because of the copper, who removes the nickel. aluminum, tin, lead, etc.??? When you smelt a PC board, all those metals have to end up somewhere.

[alloy2]

So after the PM's are removed because of the copper, who removes the nickel. aluminum, tin, lead, etc.??? When you smelt a PC board, all those metals have to end up somewhere.

Combustible material, iron and aluminum would be removed beforehand, shaker table, eddy current separators.

Assuming we're dealing with shredded e-waste, the majority of which would be copper, this is melted into a copper rich anode with at lease 96% copper with the remainder being of a mixed species.

The copper anode is electronically refined in a copper parting cell, pure copper plates over to the cathode the impuritys fall to the bottom of the cell as slimes.

The cell slimes could be subjected to pyro-metallurgy, wet chemistry or a combination of both.

With wet chemistry.

Selective Precipitation Using pH

In this technique, pH is often used to control the concentration of the anion in solution, which controls which cations precipitate. The concentration of anions in solution can often be controlled by adjusting the pH, thereby allowing the selective precipitation of cations.

Its an interesting journey, wish i had started it earlier in life.

[alloy2]

Some elements are hydrophobic, like this diamond.

Diamonds when mined are passed over a grease table he diamonds stick to the grease everything else pass's over to trash.

Here's an interesting read on the Stillwater refinery who also add scrap automotive catalytic converters into the feedstock. https://www.911metallurgist.com/plat...ium-flotation/

Using a combination of hydroclassification, heavy-liquid separation, and magnetic separation, mineral samples were prepared to determine the mode of occurrence of the platinum-group metals and to obtain information for the formulation of a minerals beneficiation scheme.

Flotation Test Equipment & Procedure

The sample as received was approximately minus ¾-inch and was crushed to 100 pct minus 10-mesh with a cone crusher and rolls. The minus 10-mesh ore was mixed and sampled, and split in 30-lb (13.6-kg) lots as needed. Each 30-lb lot was crushed in rolls and screened on a Sweco vibrating screen to 100 pct minus 65-mesh.

The minus 65-mesh product was dry ground to the desired sieve size in a steel ball mill operating in closed circuit with a Sweco vibrating screen. The ground ore was mixed on a large rolling cloth, and the charges to be used for flotation tests were split out, weighed, and bagged.

Dry grinding was chosen for the final comminution step because of greater convenience than wet grinding in sizing, sampling, and handling of the product. In the course of the study, some flotation tests were made on wet-ground ore. Metallurgical results were similar to those obtained using dry-ground ore.


Both conditioning and rougher flotation were conducted in Denver No. 12 laboratory flotation cells having stainless steel impellers, stators, and tanks. Tests were made using 1,600- and 5,000-gram charges or ore.

The 1,600-gram tests were made in a 5.5-liter tank fitted with a 2-7/8-inch- diameter impeller and a 3-1/8-inch-diameter stator.

The 5,000-gram tests were made in a 10-liter tank fitted with a 3¾-inch-diameter impeller and a 4¼-inch-diameter stator. Impeller speed was 2,100 rpm in the 1,600-gram tests and 1,800 rpm in the 5,000-gram tests. To prepare cleaner concentrates, rougher concentrates from both 1,600- and 5,000-gram tests were conditioned and floated in a 2-liter stainless steel tank having an impeller mechanism operating at 1,800 rpm.


Pulp pH in all flotation tests was determined with a phenaphtazine indicator paper. The pH’s were checked with a Corning Digital 109 general-purpose pH meter.