# Types of material I would refine



## goldsilverpro (Nov 21, 2014)

I dragged out the old incomplete list I made of PM bearing scrap that appeared on the 1st GRF thread I ever posted on. I broke it into 3 categories, based on my general subjective ideas of profitability - yellow (stuff that I would likely refine), pink (stuff that I might refine), and no color (stuff that I wouldn't refine - I would only assay and sell). All, of course, would depend on quantity, value, and what I had to pay for it. With all, there could be exceptions.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=53&t=95


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## g_axelsson (Nov 21, 2014)

Nice list, just curious why is sterling silver or gold teeth better than karat gold? Is it because of the competition?

Göran


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## Anonymous (Nov 22, 2014)

Great list.

I could add a few bits to the IT list if it wouldn't be considered presumptuous Chris?

Jon


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## its-all-a-lie (Nov 22, 2014)

g_axelsson said:


> Nice list, just curious why is sterling silver or gold teeth better than karat gold? Is it because of the competition?
> 
> Göran




I was wondering the same thing, seems like karat would be one of the best materials to refine in terms of metal return as well as profit, atleast in my opinion.


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## goldsilverpro (Nov 22, 2014)

spaceships said:


> Great list.
> 
> I could add a few bits to the IT list if it wouldn't be considered presumptuous Chris?
> 
> Jon


Great, Jon. PM me your list. Photos or links to photos would be nice.


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## goldsilverpro (Nov 22, 2014)

its-all-a-lie said:


> g_axelsson said:
> 
> 
> > Nice list, just curious why is sterling silver or gold teeth better than karat gold? Is it because of the competition?
> ...


My subjective list was about stuff I would actually refine and make a good profit on. If I were a small to medium sized refiner doing karat gold, I truly believe it would be more profitable and faster, in most cases, to lock in the price, melt, drill, assay, ship, and receive money (say, 99.5%). If I built another refinery, the first things I would setup would be a crucible melting furnace, fire assay, and a makeshift fume hood. Just with that, I could sample, buy, and sell almost anything. The only times I would refine karat gold would be if I were very small (maybe) or very large. If I were only doing about 5 oz/week, I might refine it myself just because I enjoy doing it.


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## Westerngs (Nov 23, 2014)

One good reason for a small to medium scale refiner to refine their own material would be if you can make a product other than pure metal bullion, especially if you can find a niche product.

There is very little profit to be made from refining, the profits come from making specialized products.

Of course, it is not necessary to refine your own material to make a product, you can always melt-assay-sell, then buy pure metals or pre-made alloys out of which to make your product, but you lose money at every transaction, which, if you are efficient are refining, can be saved.

Refiners often pay x days after receipt of material. They therefore have lease-fee-free use of your material for those days. If they are efficient, those days can be used to turn metal over, in some cases 2-3 times or more, saving a lot of money on lease fees.


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## bigbaud (Nov 24, 2014)

Router dust?


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## g_axelsson (Nov 24, 2014)

bigbaud said:


> Router dust?


Dust from rounding the edges of circuit boards. If there are gold plated fingers on the edge the dust will contain gold.

Göran


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## justinhcase (Nov 24, 2014)

Thank you for the complete list.
I am impressed with the number of option's you have in your aria.
There not being any real manufacturing in South West England not meany are available to me locally.Nevada having such a long history with Au production and California with Silicon Vally must be a duck shoot. 
Unfortunately in the U.K. almost all sources are imported in very small quantity's. 
And between the Tax man needing an accurate account of all expenditures and profit and the new precursors and poisons unit or the CBRNE unit that came on line this year 
You do not need a licence for the substances currently in your possession. But If you are not set up as a trading business by 3 March 2016, you will need a licence even for the substances in your possession.
So in order to operate with out a special home office licence you have to be able to demonstrate to a supplier that you need the substances for the purposes of your trade, business or profession at that current time.
So now any one who want's to actively refine in any capacity has to be set up as a business or spend month's inline trying to gain a licence form central government,which if you have tried before as I have know's that is a hard road to go down. 
So in the U.K. you are considered business even if you are just finding your feet the moment you start to buy and sell any noble metals beyond that you happen to have by chance..
But more options mean better chance of success.


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## goldsilverpro (May 18, 2015)

Westerngs said:


> One good reason for a small to medium scale refiner to refine their own material would be if you can make a product other than pure metal bullion, especially if you can find a niche product.
> 
> There is very little profit to be made from refining, the profits come from making specialized products.
> 
> ...


I know and respect the big refinery Westerngs works for and I know he's been there quite awhile in a technical capacity. They make a lot of PM products and I've bought from them a couple of times - 999.8+ Ag wire, if I recall. Outside of Sel-Rex, none of the 32 refineries I worked or consulted for made any sort of product from the PMs other than, maybe, an occasional order of shot or casting grain. I guarantee you they made money on the refining - of course, many of them took a little off the top. Once you know how to do all the technical stuff well, profitability in a PM refinery is mainly dependent on 2 things: 
(1) The types of scrap you decide to process. Gotta be based on profits. 
(2) Definitely known available sources for these types of scrap, in necessary quantities.

If I were to start another small to medium refinery (I've been thinking about it), I would first look at the colored scrap list I posted that started this thread and try to find the easiest, most profitable, available, safe, somewhat local, hopefully stuff I have run in volume before, stuff I like to do and fits my situation types of scrap. With my particular experience and knowledge, I would definitely process aircraft scrap at some point and would do a big search/network thing to find out exactly where it is located. I would possibly buy gold filled from the gold buyers and good sorted CPUs, pins, fingers, etc. from people and small companies that scrap out electronic stuff. I know I could pay more than, say, boardsort, for the good stuff. Doesn't take long for word to get around. I would also do a lot of certain types of silver scrap. Much of it sits around or sells for a song. Most people don't want to mess with it. Just got to find out where it is (locating where any type of scrap is is always #1). Everything is assayed, of course.

After gaining some momentum, I would think about expanding things. I would locate reps around the country that would, for a fee, find the types of scrap I want. They're out there, somewhere. If I were to do other types of electronic scrap, it would only be manufacturing scrap - I like scrap before it's been assembled. Lots of reps in that industry.

Just my present take on a few things. I might do everything differently.

Chris


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## glaucodobrasil (Jun 24, 2015)

goldsilverpro said:


> Westerngs said:
> 
> 
> > One good reason for a small to medium scale refiner to refine their own material would be if you can make a product other than pure metal bullion, especially if you can find a niche product.
> ...



That's good to know I'm not going crazy with my plan by listening it from a very experienced guy. That is exactly what I'm doing, and I'm just refining my first 150 computers. I'm a bit curious about the airplane things. I know places around where I can find some airplane scrap... will take a look soon!

Tks for the list, it's awesome!


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## alexxx (Jun 5, 2016)

I like this topic a lot.

Really curious to know more about your opinions & experience on Silver scrap.

Since there's a lot of Sterling jewelry, silverware & coins available almost anywhere, how do you guys are turning a profit out of it ?

Simply buying, melting, assaying and selling OR refining the material to profit from the other PMs carried with the silver ?

Let's say someone can play with a Sterling feedstock of 100 to 200 lbs per month acquired for 80% spot, what would be your strategy ?


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## modtheworld44 (Jun 5, 2016)

alexxx said:


> I like this topic a lot.
> 
> Really curious to know more about your opinions & experience on Silver scrap.
> 
> ...



alexxx

If that was the position I was in,this is how I would do it.

(1) First and foremost,would be to seek out and find me a wealthy dedicated silver hobby collector that is willing to pay over spot,for fine pure silver shot,ingots,and crystals.When I had that secured by paper contract then and only then would I move forward.

(2)I would draw up a second contract for my supplier,that would insure 100-200 pounds a month and give him 85 percent for doing so.Contract would be for a minimum of 5 years time and the option to extend it to 10 years after that.

(3)Build two silver cells from 18/8 stainless steel.The first cell would be big enough to hold an electrolyte that contains five of the pounds dissolved in it.This cell would be used to remove the majority of impurities,by running it at the prescribed electrochemical series.I would melt all 95 remaining pounds into shot and run it through the cell.The second cell would be to get the silver into the high fines pure form.I would make this one big enough to hold twenty pounds of the previous cells crystals digested in the electrolyte.I would then melt the remaining weight of previous cells crystals into shot.

(4)I would then find me a power supply that could provide 12v 100amps for the second cell.Then I would start the cell and start prepping the next hundred pounds.

This is how I would do it,you may or may not agree with my method but this is what it would take for me to take on such an endeavor.Thanks in advance.



modtheworld44


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## 4metals (Jun 5, 2016)

Ok Mod, so you want to start with a cell around 10 gallons of electrolyte? At 60 grams per liter? Are you suggesting running the entire 100 pounds through it? That would give you a solution when you are done with a bit over 100 grams per liter of copper and it will produce silver to feed your second cell.

I am confused by what you mean by this


> This cell would be used to remove the majority of impurities,by running it at the prescribed electrochemical series.



What is the prescribed electrochemical series?

And your second cell will be around 40 gallons, again at 60 grams per liter? With the feed for the second cell coming from the first pre-treatment, you will produce a solution which will have a long life.


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## Lou (Jun 5, 2016)

A break down cell is what we call 'em.


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## modtheworld44 (Jun 5, 2016)

4metals said:


> Ok Mod, so you want to start with a cell around 10 gallons of electrolyte? At 60 grams per liter? Are you suggesting running the entire 100 pounds through it? That would give you a solution when you are done with a bit over 100 grams per liter of copper and it will produce silver to feed your second cell.
> 
> I am confused by what you mean by this
> 
> ...



4metals

The sizes and per liters sound good to me on all accounts.
Here is the link for the google search I just did for electrochemical series,there's images of the charts I'm referring to.I'll have to go find the video that goes with it,give me a day or two to track it down.I should still have it bookmarked hopefully.Thanks for the calculations and for your time.

P.S Almost forgot to add this- https://www.google.com/?gws_rd=ssl#q=electrochemical+series

modtheworld44


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## modtheworld44 (Jun 5, 2016)

Lou said:


> A break down cell is what we call 'em.



Lou

Thanks you taught me something else new for today.I hope you don't mind me using that from now on.



modtheworld44


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## 4metals (Jun 5, 2016)

OK, I thought you were referring to some formulary which gives you the power to clean up the silver in a sort of electrowinning process but you just mean a typical breakdown cell. 

I don't typically use breakdown cells for sterling because the waste generated in the breakdown cell will be on a par with the waste generated running a cell until the copper gets to about 60 grams per liter. So the difference in waste is similar. The use of a breakdown cell is usually reserved for silver content in the 50% range, although if your goal is to run a high purity cell which will last a long time without copper contamination, a breakdown on sterling is more efficient than nitric dissolves and cementation.


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## modtheworld44 (Jun 5, 2016)

4metals said:


> OK, I thought you were referring to some formulary which gives you the power to clean up the silver in a sort of electrowinning process but you just mean a typical breakdown cell.
> 
> I don't typically use breakdown cells for sterling because the waste generated in the breakdown cell will be on a par with the waste generated running a cell until the copper gets to about 60 grams per liter. So the difference in waste is similar. The use of a breakdown cell is usually reserved for silver content in the 50% range, although if your goal is to run a high purity cell which will last a long time without copper contamination, a breakdown on sterling is more efficient than nitric dissolves and cementation.



4metals

I agree, normally for my 1 gallon cell I would do it your way as well.I was just going with fastest and most profitable way that I could see for the scenario,something that could be put into a continuous loop.In other words longer run times for production verses longer stop times for cleaning and electrolyte reclamation.So do you feel this would be viable for the scenario I out lined,with the end goal being high fines purity silver.Thanks in advance.



modtheworld44


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## 4metals (Jun 5, 2016)

Mod,

I made up a spreadsheet to crunch these numbers and if you take the small cell up to 120 g/l copper running .925 sterling, you should be able to pump out 2000 ounces of silver with under 1% copper in it as a contaminant. Less in the beginning and more at the end. Rinsing electrolyte from harvested cells is your friend. What is nice is 10 gallons of cell solution is easy to handle for cementing and waste treating, and depending on how fast you can push the 2000 ounces through you may need a few running. 

The "high grade" cell starting with the silver you made in the smaller cell will process 15 times as much silver of high purity before the 1% copper fouls the electrolyte. The foul electrolyte from the high grade cell will still function in the smaller cell to further raise the copper before changing it out. Less waste = more profit. 

Remember the second cell will function better if you add some copper to start as the feed silver will provide little.


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## goldsilverpro (Jun 6, 2016)

I most certainly would not make a silver cell from stainless or any other metal.


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## 4metals (Jun 6, 2016)

My first choice would be PVC and a stainless cathode. 

Interestingly there are members here who have had good luck using the 1 gallon stainless bowls though. But for a production deal, I would agree.


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## Lou (Jun 6, 2016)

I used plywood and titanium sheet as the cathode and made the boxes out of polypropylene and fiberglass rod for support.

I folded up the cathode and punched a hole in it and bolted the 000 wire lead in between some 1/2" copper bus bar. They ran well.

Lou


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## Barren Realms 007 (Jun 6, 2016)

Lou said:


> I used plywood and titanium sheet as the cathode and made the boxes out of polypropylene and fiberglass rod for support.
> 
> I folded up the cathode and punched a hole in it and bolted the 000 wire lead in between some 1/2" copper bus bar. They ran well.
> 
> Lou



If you know someone whit the experience they can weld the poly tanks up for you.


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## Lou (Jun 6, 2016)

We have heat and ultrasonic welder at the plant for welds CPVC (our exhaust), PVDF (socket welds for nitric or Aqua Regia duty valves), and the polyolefins (low temp tanks, <50 C).

I made the box from plywood and marine epoxy. Works as well as any poly tank at much less of a price.

Our Mob cells are polypropylene.


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## Barren Realms 007 (Jun 6, 2016)

Lou said:


> We have heat and ultrasonic welder at the plant for welds CPVC (our exhaust), PVDF (socket welds for nitric or Aqua Regia duty valves), and the polyolefins (low temp tanks, <50 C).
> 
> I made the box from plywood and marine epoxy. Works as well as any poly tank at much less of a price.
> 
> Our Mob cells are polypropylene.



Marine epoxy. I need to do some searching on that unless you wold be willing to supply some link'sto some information on this.


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## 4metals (Jun 7, 2016)

I believe he means fiberglass resin, the vinyl ester resin holds up well in fabrication of hoods and scrubbers and large tanks.

Here is a comparison of epoxy resins and vinyl ester resins.
Advantages and Disadvantages

On a broad scale of viscosity, vinyl esters are midway between polyesters and epoxy resins, before adding styrene. Thinning affects workability and strength - 'thinning' reduced strength but makes it easier to brush or spray.

Vinyl esters are more tolerant of stretching than polyesters. This makes them more able to absorb impact without damage. They are also less likely to show stress cracking.

Vinyl ester has fewer open sites in its molecular chain. This makes it much more resistant to water penetration ('hydrolysis') which can cause osmotic blistering.

Vinyl esters shrink less on curing, which means that 'pre-release' of a laminate from a mold is less significant.

The cross bonding of vinyl esters is superior to that of polyesters. This means that vinyl esters bond to core materials much more effectively than polyesters and delamination is less of an issue.

Vinyl esters are less sensitive to ambient conditions (temperature and humidity) than are polyesters.

Vinyl esters are more expensive than polyesters though careful calculations are required to assess the cost impact for a significant build project such as a luxury yacht. This is because the relative strengths need to be factored in - you can use less vinyl ester to achieve a given strength.

PLus I like it from my surfboard building days!


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## Barren Realms 007 (Jun 7, 2016)

4metals said:


> I believe he means fiberglass resin, the vinyl ester resin holds up well in fabrication of hoods and scrubbers and large tanks.
> 
> Here is a comparison of epoxy resins and vinyl ester resins.
> Advantages and Disadvantages
> ...



Yea that would make sense now that he was talking about fiberglass resins.

Fiberglass held up good for the majority of the time and operations at our chemical plant. When heat is added to the fluids it seems to break down the resins faster though. so this would be one of the areas to consider when using fiberglass.


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## Lou (Jun 7, 2016)

No, both of you. I meant an actual epoxy not a polyester or vinyl ester (kind of a hybrid between the two really, so I see the confusion).

This should answer some questions:

http://www.masepoxies.com/file/About%20Epoxies%20.pdf

Not saying that either wouldn't work, which they would. Fluoridated "novolac" epoxies are perhaps the best in terms of corrosion resistance.


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## Barren Realms 007 (Jun 7, 2016)

Lou said:


> No, both of you. I meant an actual epoxy not a polyester or vinyl ester (kind of a hybrid between the two really, so I see the confusion).
> 
> This should answer some questions:
> 
> ...



Clarify the marine epoxy with an example please.


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## 4metals (Jun 7, 2016)

Lou,

With the vinyl ester resins I always used fiberglass chopstrand mat or cloth, actually both mat for the flat surfaces and cloth strips for the corners. 

Does the novolac epoxy require fabric? Actually the vinyl ester resin doesn't "require" fabric but it is much stronger with it. Novolac epoxies are the self leveling floor coating epoxies I use on refinery floors for containment purposes.


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## Lou (Jun 8, 2016)

https://www.amazon.com/AeroMarine-300-Epoxy-Resin-Gallon/dp/B0047R2C9Y?ie=UTF8&*Version*=1&*entries*=0

That's what I mixed and put over the wood and worked great. I put two or three coats down. Generally speaking, epoxies have more corrosion resistance than vinyl esters which have more corrosion resistance than polyesters (which are really susceptible to base hydrolysis).

None of them require fabric or prepregs but pretty much all of them can be employed with them to make a composite having properties better than the individual components (resin and filler).

Self-leveling has to do with their viscosity when employed (be it from the precursors, as most of these are two or even three part and not UV-catalyzing, or from fillers like alumina), not whether it's a novolac--although you're spot on that all novolac's are quite viscous due to hydrogen bonding of phenol functionalities, steric effects etc. I consider novolac an arcane term mostly related to the precursors, which are aromatics like substituted cresols often made from destructive distillation of I'm guessing, pine lignin. They are quite chemically resistant and are usually very highly cross linked, which act like bridges to the other part of the structure. 

The degree of flexibility (along with most of its physical properties) in a coating has much to do with the way the molecules interact with each other, such as bond strength/length, whether or not the material is cross linked, presence of pendant groups that may entangle with one another. While this discussion as to the differences in epoxy resins vs polyester and polyvinyls can be very complicated, I'll try and sum up the main difference:

An epoxy is not a polyester--epoxies form by the ring opening of an epoxide (which is a stressed cycloether) and have entirely different linkages and polymerization mechanism.

A polyester, say Nylon, is by taking a polyol, in this case a diol and reacting it with a di-acid (or acyl/aryl halide) in a polyesterification. This is a condensation reaction and water (or HCl, if an acyl halide as in the case of Nylon) is produced as a product. 

While I do work in precious metals, I did go to school for polymer and materials science  and my little sister works in the R&D department at Sherwin Williams doing Protective and Marine Coatings as a chemist--she really has a lot more real-world expertise than I do.


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## 4metals (Jun 8, 2016)

Interesting Lou, thank you for the link.

The first hood I ever made was plywood with resin painted on, pretty thick actually but no fabric. It lasted until it was moved to a new building and the jostling cracked some of the seams. I would probably have never noticed except for the fact that the seams that cracked were on the bottom perimeter and functioned for spill containment, and the leak was in the front where it dripped, of course, on my shoes, so I noticed it. (Actually the wife noticed it, I always had a knack of burning holes through clothes!)

Since then I always used fabric. 

Maybe you could get a recommendation from little sis for a (spray on?) coating to transform relatively inexpensive metal blowers into something that has a fighting chance with refining hood exhaust. Now that is something a lot of our members would benefit from. I mean Sherwin Williams goal is to cover the earth. We can help do it one refining hood at a time!


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## Lou (Jun 8, 2016)

I know what we used for our steam table at work and it's holding up to aqua regia vapor. We put it over SS316L:

Two coats of Sherwin Williams DuraPlate II epoxy. They can even put it over plywood. That was her recommendation.


Anyway, the most important thing of any coating is the surface preparation. Period end of story. Don't have a good surface for it to adhere onto, it's going to spall. Some things are more tolerant than others but substrate preparation is paramount.


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## Barren Realms 007 (Jun 8, 2016)

4metals said:


> Interesting Lou, thank you for the link.
> 
> The first hood I ever made was plywood with resin painted on, pretty thick actually but no fabric. It lasted until it was moved to a new building and the jostling cracked some of the seams. I would probably have never noticed except for the fact that the seams that cracked were on the bottom perimeter and functioned for spill containment, and the leak was in the front where it dripped, of course, on my shoes, so I noticed it. (Actually the wife noticed it, I always had a knack of burning holes through clothes!)
> 
> ...



Back many years ago we had a 4" steel pump that we had to keep going till we got a hastaloy pump in for the process circuit if my memory serves me right. We were able to find a ceramic that we were able to pain onto the inside of the pump to make it last till we got the new pump in. That might be an option you could check into.


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## Lou (Jun 8, 2016)

If you went from steel to Hasty B or X I'm guessing it was caustic service. The ceramic was probably zirconia--very base resistant and acid resistant.


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## Barren Realms 007 (Jun 8, 2016)

Lou said:


> If you went from steel to Hasty B or X I'm guessing it was caustic service. The ceramic was probably zirconia--very base resistant and acid resistant.



It was B that we were waiting to come in to replace the existing pump. And it wasn't caustic. Were were producing zinc chloride and zinc bromide from plating wastes. They were using HCL & HBR acids to leach the zinc out of the plating wastes. It might have been a zirconia base ceramic I'm not sure because at that time I was not involved in the refining field and didn't pay as much attention to the make up of the ceramic coating make up as I would do now days.


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