I'm not new to handling metals, I've operated & still am running a foundry for over a decade now but refining is very new territory for me.
Some of our equipment should crossover and we have the space to operate, so our curve to entry should be reduced but very importantly, we have access to feed-in material providers and precious metal buyers are all at hand and well-established within our existing network.
Some of the equipment we have are as follows:
- Induction melting equipment
- Melting furnaces
- Extraction and ventilation set up and in place.
- XRF device
We take in a lot of gold that is alloyed with palladium, with the palladium price so high in recent years, it will be of large benefit if I can separate these to begin with.
My basic question is where to start with the chemicals and various other hardware, trying to be smart with it in terms of being able to scale up quickly if needs be. Any pointers to specific threads would be a great help at this stage.
We have about 300 square feet of space we can utilize at the beginning, with more that can be added if we go further along.
For us, the goal will be to get up and running at a reasonable cost and timescale, I suspect the learning curve will be steep enough, but we're willing to learn on our feet and put in the extra effort to meet the end goal of offering a homegrown solution for refining material, which isn't being offered currently.
Hi.
Welcome here
if you want some information about actual processes and actual refining of precious metals, you are in the right place here. Many experienced members and even professionals with decades of experience in real refining business.
In many terms, you have better start to the "refining" as many other members here. From what you said, you are established in the "(s)melting" business. If that is true, that means you can afford to buy basic equipment to somehow kickstart the learning and optimization process.
Owning induction furnances and XRF gun is a must for quick and reliable work around precious metals, and this will give you big advantage over others who lack these ones. From my personal experience, lacking these two is major drawback for majority of members here, which want to somehow scale up their operation.
It gives you confidence to know what you produced (XRF) and induction speeds everything up (if we compare it to ordinary electric/gas furnance, mainly if we are talking about platinum group metals).
But to start doing anything with hydro-chemistry and refining,
you will need to have a working reliable fumehood. There are numerous guides on the forum how to build one, but you are in a different situation as majority of hobby-guys here and some vague looking plywood construction simply wouldn´t work for you, as you must probably comply regulations and stuff. Good modular hoods can be made from 1 m3 HDPE plastic vats (IBC container), so if you can have some DIY built, this can be way to go for few bucks. If this is not an option, I would try to contact your partners and look for any industry auctions or marketplaces to buy some regular hood second-hand. Aim for ones that do not have sheet metal construction, as these will disintegrate from fumes in short time.
My questions are:
1. How much you are familiar with basic inorganic chemistry and redox reactions in general ? I am asking because now you will enter the "hydro" chemistry, not "pyro" chemistry. They have some things in common, but from my point of view, hydrometallurgy can be more difficult to understand. Chemistry of gold and silver is fortunately quite simple, but palladium and other platinum group metals chemistry (PGMs) isn´t.
2. Do you have access to buy basic inorganic chemicals in bulk ? Mainly speaking about nitric acid, as in EU, this is controlled substance and you need to have license to purchase it. Other "must have" chems that you will need are hydrochloric acid, sodium hydroxide, sodium metabisulfite, and speaking of palladium - probably dimethylglyoxime (DMG), ammonium chloride and formic acid (these do not need to be in bulk, kilo/liter of these for start is more than enough, for DMG, probably 100g is OK).
3. Describe the grades of typical feedstock (at least in general). Is it metallic, powder/ingots/mixed scrap, how much gold/palladium/silver it has, what are base metal constituents of it (espetially important is presence of "troublesome" metals like tin, bismuth or lead) etc.
4. What is appeoximate scale of the operation, assuming you have already gained the needed experience/know the processes etc. In other words, if everything will go nice and smooth, what is your target scale of processing. Hundreds of grams of feed, few kilos/month, hundreds of kilos/month etc... This will determine and justify the use of various equipment as well as different processes used to minimize work and ammount of waste generated.
5. Do you have the some waste management already established for liquid waste, or good contacts for waste disposal site, where you can dispose waste you will produce ? Thing is, your waste would most probably be acidic heavy metal chloride/nitrate solutions. And many companies charge hefty fees for this kind of waste. It would be good to know beforehand what are the rates applied for different kinds of waste - because it will eventually be produced, and in large quantities as you will scale up. Because waste treatment can be done by yourself, but it adds additional work and chemicals, so it need to be considered beforehand if it is financially OK to just pass it to the waste management company and pay for it.
Most important thing now is to get familiar with chemistry (if you already are, good for you) of the precious metals of your interest (Ag,Au, Pd) and also with redox chemistry in general. You will definitely encounter some problems during your journey, and theoretical knowledge of the processes will help you many many times resolving peculiar situations that can and will happen to you.