Waste treatment system at Gold Refinery

[Gold.refinery]

You have a pH meter but it is not connected to a dosing pump?

Yep, dosing pump have ph meter, but very slowly.

 

[Gold.refinery]

The barometer tells you what pressure you are exerting. When the press does not leak from between the plates when waste is pumped through, note the pressure and that is what you set it to each time.

Is it enough that there is no leakage? I understood

Holy didn’t the salesman show you how to work the equipment?

I'm sorry

 

[Yggdrasil]

I'm trying to make a reply. I just don't know how.......

 

[4metals]

Like the cylindrical filter that came after the silver chloride filter and you did not like it. Is that right?

I did not like it where they placed it on your system, they tend to trap solution which you verified with a stannous test. Since the solution where they had the filter has dissolved gold in it it wasn’t good there. On the discharge from cemented solutions the solution has no value so a little trapped liquor is no issue but any fines which may be cemented values will be trapped.
Same filter, where they located it, bad because it traps liquid holding gold. Where I suggested it, good because it retains unsettled values you don’t want to lose.

 

[4metals]

According to your calculations, 500 pounds of hydroxide in a 55 gallon drum is obtained approximately after refining 560 kg of scrap, which is two months of operation.

The weight of hydroxides generated by any refining lot is totally dependant on the karat of the material. You said you started with 18 kt. material although it had cadmium which is odd. Anyway, a refiner processing 10 kt scrap will generate more hydroxides than a refiner processing 14 kt. So it is impossible to (well not impossible to but not worth the effort) figure out how many kilograms of scrap were processed to generate one full drum of dried and sifted hydroxides. And, all of the refiners I know of who process karat gold scrap process mixed scrap lots so the karat varies.

 

[Gold.refinery]

Start the stirring mixer and sprinkle the metabisulfite on the surface, it will darken as gold drops and may blow a little red until any remaining free nitric is consumed. Continue to add metabisulfite to the well mixing solution slowly allowing it to react before adding more. From time to time dip in a glass rod and test to be sure there is still gold in solution until you are experienced enough to notice the color shift from bright green to a dull green. When all of the gold is dropped and tested to confirm, shut the mixer and stir the mud to allow any pregnant acid under the mud to react. Agitate and test again. Now it is time to filter the acid into the funnel.

When adding smb we will turn on the scrubbers to absorb so2 gas.
But after filtering the solution into the second tank and getting the gold powder, the cement-copper operation in the next tanks will take several days. Definitely can not stay on the scrubbers day and night. Will the next so2 gas tanks be released into the workshop environment?

Of course we have an extra fan for ambient ventilation, but I do not think it is concentrated on top of each tank.
Each tank has a chimney to the scrubber, but no ventilation system.

 

[4metals]

From what you have said I take it you do not constantly run an exhaust over the tanks holding your acids or waste. Do you realize how corrosive the fumes coming off an open tank of spent aqua regia? Everything metal in your facility is slowly attacked by these almost imperceptible fumes. That’s the steel supports in most ceilings, I beams, anything not painted. And things often overlooked, like sprinkler tips in a sprinklered building. I had a client who chose not to protect his sprinkler tips and one let loose. Do you realize how much damage a 90 gallon per minute sprinkler tip can cause?

Even when you are not processing anything but the tanks contain liquids you should have air moving through those ducts. You can shut off the scrubber pumps and controllers but keep the air moving. What I prefer for general exhaust is a tee in your exhaust so one way goes through the scrubbing circuit and the other goes to a direct venting blower. By switching the flow you can go through a scrubber or bypass it.

But after filtering the solution into the second tank and getting the gold powder, the cement-copper operation in the next tanks will take several days. Definitely can not stay on the scrubbers day and night. Will the next so2 gas tanks be released into the workshop environment?

These can safely go through the bypass and run while you are not there safely as no reactions are actively outgassing.

But after filtering the solution into the second tank and getting the gold powder,

I take this to mean you get the gold sponge as it drops out of the precipitating tank before the liquid gets to tank 2. Is this correct?

 

[4metals]

I should mention it is not recommended to
paint sprinkler tips. But a twice a year painting with molten candle wax (paraffin) will do the trick. It’s one of those things that it pays to do but those that do it never see the benefit because they never have a tip let loose from corrosion.

 

[Gold.refinery]

And things often overlooked, like sprinkler tips in a sprinklered building. I had a client who chose not to protect his sprinkler tips and one let loose. Do you realize how much damage a 90 gallon per minute sprinkler tip can cause?

What exactly do you mean by sprinkler?

 

[FrugalRefiner]

He's talking about automatic sprinkler heads used in buildings in case there is a fire. They're designed so that if there is a fire, the sprinkler head is turned on and sprays water throughout the room.

Dave

 

[4metals]

The biggest mess I have ever seen in a refinery was made by the sprinkler system going off due to a corroded tip.
The biggest loss I've ever seen in a refinery was due to having an unsealed concrete floor.
Both of which I always advise clients to do, coat the sprinkler tips, and seal the floor. But not everyone listens.

 

[orvi]

I am with 4metals on this 100%. If you are ever working with HCl or HNO3 anywhere, you mush have the fumehood running 24/7. And all the corrosive fumes must go through the fumehood - so all vessels bearing acids and acidic waste must be scrubbed. If you want to refine in nice clean rooms, not rusted and messy ones.

Chlorides, and espetially HCL (chloride, and also acidic) are promoters, or better said catalysts for corrosion. Seawater, using salt on the roads in the winter... All chlorides. And the iron is gone order of magnitude faster than in normal conditions. Even comparably acidic, but with different acid, say H2SO4 won´t be that bad as HCL.

You must protect everything in your shop from HCL fumes. For some time, nothing is obvious. It takes some time for the corrosion to appear, but when it accelerates, results are devastating. Precision scales, rebar in concrete, sink faucets, water pipes (often unnoticed and causing disstrous situations), doorframes... Everything. And it is often very difficult to stop it, because chlorides deposit on the material and promote further corrosion. And some things, you simply cannot wash.

If you cannot place everything into the fumehoods, best would be to concentrate the flow of air in the shop that way, it would go from the tanks straight to the some suction hose, leading to the exhaust motor/fan. So generally, any fumes possibly created have predetermined pathway, not affecting your expensive equipment and shop in general.

 

[AMS-Pro]

From what you have said I take it you do not constantly run an exhaust over the tanks holding your acids or waste. Do you realize how corrosive the fumes coming off an open tank of spent aqua regia? Everything metal in your facility is slowly attacked by these almost imperceptible fumes. That’s the steel supports in most ceilings, I beams, anything not painted. And things often overlooked, like sprinkler tips in a sprinklered building. I had a client who chose not to protect his sprinkler tips and one let loose. Do you realize how much damage a 90 gallon per minute sprinkler tip can cause?

Even when you are not processing anything but the tanks contain liquids you should have air moving through those ducts. You can shut off the scrubber pumps and controllers but keep the air moving. What I prefer for general exhaust is a tee in your exhaust so one way goes through the scrubbing circuit and the other goes to a direct venting blower. By switching the flow you can go through a scrubber or bypass it.

These can safely go through the bypass and run while you are not there safely as no reactions are actively outgassing.


I take this to mean you get the gold sponge as it drops out of the precipitating tank before the liquid gets to tank 2. Is this correct?

There is a nifty trick for this, that will still allow the power bill to stay on the lower side. At one of my clients properties, we took an old 42U Server Cabinet, filled it top to bottom with UPS (uninterrupted power supplies), and connected the exhaust fan system to it.

Whether it was just the power being shut off for the night to keep the bill lower, or in the instance of a power loss, in either case, the exhaust fans always had power. The cabinet should not be located in the refine/recovery room for obvious reasons, but it is not hard to run the power to the exhaust system in sealed piping. In most cases, you should be able to set this up right next your utility box (breaker box), and install an ATS (automatic transfer switch) for the power on the supply end to the UPS, this way, if it is because of a power loss, the cabinet gets isolated for fan use only, and excess power doesn't get fed back into a dead power grid.

 

[4metals]

rebar in concrete

I know a refiner in the south who bought a new building to build and move his refinery. He had to repair the building he was vacating and he quickly realized it was cheaper to buy it and take it down than to repair it. The hidden culprit, aside from the rust falling off every bit of steel superstructure, was the almost non existent rebar which had corroded away invisibly beneath the concrete. Small cracks in the concrete slowly allowed corrosive fumes to get to the iron rebar.

 

[Shark]

Several years ago the plant where I worked decided to clean all the concrete floors and walls and paint them. Being so nasty someone decided to spray them with concrete cleaner called muriatic acid and leave it over the weekend. Luckily the equipment was stainless steel along with all the exposed piping. The steel joists and some retainers had to be painted afterwards due to heavy rusting. This was a bleaching facility for bleaching cloth that normally housed 50 gallon barrels of commercial powdered bleach. It could have been a lot worse than it was.

 

[Palladium]

I should mention it is not recommended to
paint sprinkler tips. But a twice a year painting with molten candle wax (paraffin) will do the trick. It’s one of those things that it pays to do but those that do it never see the benefit because they never have a tip let loose from corrosion.

Back when i used to do Lowes construction we had to paint the ceiling. Walmarts too!
There are about 2,000 heads in a store. We used to cover them with aluminum foil so they didn't get paint on them. But as luck would have it a couple always got missed and painted. The fire marshal would fail them for inspection and lets not even talk about what the plumber will charge you to replace them. $250 a piece counting the head. I was cleaning one off one time and popped the head! Talk about a shower! Alarms going off. Fire department shows up. It got ugly! lol

When i built my house a few years back i actually installed a commercial sprinkler system in my house. Insurance rates are VERY favorable.

Fans run 24/7/365 in my shop.

 

[4metals]

Fans run 24/7/365 in my shop

The only shops I know of that don’t do this are shops that close down for vacation and then any solution left in the shop has a pretty snug fitting lid. And one of those shops says the first day back from vacation none of the ladies in the office want to come back because of the smell!

 

[orvi]

Several years ago the plant where I worked decided to clean all the concrete floors and walls and paint them. Being so nasty someone decided to spray them with concrete cleaner called muriatic acid and leave it over the weekend. Luckily the equipment was stainless steel along with all the exposed piping. The steel joists and some retainers had to be painted afterwards due to heavy rusting. This was a bleaching facility for bleaching cloth that normally housed 50 gallon barrels of commercial powdered bleach. It could have been a lot worse than it was.

Concrete cleaner called muriatic acid... Nice
Altough HCL is fast in wrecking anything metallic, even stainless steel... Chlorine is whole another level AR fumes of chlorine mixed with NOCL and NO2 are somewhere in between HCL and HCL/Cl2.

Not to mention issue chlorides vs. concrete. Calcium chloride is even better de-icing agent than regular salt - yet it is not used on roads, and specifically pavements. Even low percentage of CaCl2 in NaCl for de-icing roads will be much much more effective than plain NaCl - but it is hardly used anywhere - because it wreck concrete very fast (it is also more expensive, but for the effect well worth extra money). Because of the solubility of CaCl2, it could penetrate the concrete to the significant depth and mess up the whole structure of Ca-silicate matrix = concrete start to crack and fall down of wall.
Not the thing you want from the structure which should hold the roof above you

 

[Gold.refinery]

Working with chemicals, Toxic gases, causes Cancer, Menial level of work, High energy consumption, Corrosion of metals, High risk, Low profit.
in 2022, What are we looking for?

 

[4metals]

Calcium chloride is even better de-icing agent than regular salt - yet it is not used on roads, and specifically pavements. Even low percentage of CaCl2 in NaCl for de-icing roads will be much much more effective than plain NaCl - but it is hardly used anywhere - because it wreck concrete very fast (it is also more expensive, but for the effect well worth extra money).

I live in the woods in rural Pennsylvania. The road I live on is a dirt road and in the summer it is quite dusty. The “fix” to the dust issue is calcium chloride spread on the roads to control the dust. Multiple treatments over the course of the summer assure that our cars rust out in 4 years.