I have used every size of glass vessel for refining, including glass lined reactors. And glass is great, but it does have a nasty little habit of breaking. And unless you are a large refinery that can afford it, any practical sized glass vessel starts getting pricey. I often use a 4 liter beaker as a go to vessel. This size (4L) can hold a digestion of about 15 ounces at it's half full operating level. last I priced them a 4 liter flask from a reputable source (meaning it really is borosilicate glass) was about $100 each.
Glass has a distinct advantage of being able to be heated directly on a hot plate. (with secondary containment of course)
But in the real world of refining where it is necessary (or convenient) to process lots in bulk. For example, a customer shipped you 20 pounds of material and you want to process it as 1 lot because you don't have a month to play with it in small enough quantities to fit in a 4 liter beaker. This is where plastic containers come in. And the most ubiquitous plastic container I can think of is the 5 gallon bucket. (19 liter for all of you members across the pond)
The first thing someone will say is "What about if I need heat?" I often heat 5 gallon pails using one of these.
http://www.thecarycompany.com/pail-...MI566YwLzs2gIVBFqGCh0k5QBFEAYYASABEgLlPPD_BwE
They get the acid hot enough that the reaction will progress nicely. They will not boil the liquid but if it was full of water for example, so you could put your hand in to see how hot it is, it will be hot enough that you won't keep your hand in there for long.
Plastic buckets do get scratched and gold sticks in the little scratches and you won't get out 100% of the gold, but really the amount that remains in the bucket is minimal and I routinely clean buckets with aqua regia when they get dirty. That gold is all recovered!
Plus there are all sorts of devices to make the ubiquitous 5 gallon pail more useful. One I like in particular are gamma seal lids. These are screw on lids that fit tightly, are inexpensive, and allow you to store spent solutions without corrosive fumes eating up your shop.
The one thing you should do if you are going to use 5 gallon pails is remove the handle. Why? They make it convenient to lift them when they're full, why remove them? When you least expect it they will break because they are usually metal and they corrode. And the plastic handles are made of a thin plastic that tends to get brittle and break as well. The last thing you need is spilling a bucket full of pregnant acid because the handle snapped.
Buckets will get brittle in time from the exposure to the acid so when they start to get brittle you need to replace them, but I will bet the farm that in the time that it takes a 5 gallon bucket to get brittle enough to replace it, you will have broken some glass beakers and replaced them as well.
If your goal is high purity, plastic will work as well, but if you're going to do a second precipitation from a large lot, it is easy to transfer the sponge to a glass beaker and work in the beaker.
So, back to the original question, Glass or Plastic? I, without hesitation, will vote for both!
