Consistency of leaching & electrolytic refining processes

[alercah]

I was looking to write a description for an electrowinning cell, and I discovered that the electrolytic refining processes don't really match up with reality:

• The leaching cell is used to upgrade ore chunks to crystals.
• The leaching cell is also used to create ferrous and cupric slurries, which are then put into the electrowinning cell to turn them into "anode seedling", which is a fluid requiring crystallisation.
• Molten sodium hydroxide electrolysis, used to produce sodium in an electrolyser, is also, according to Wikipedia a form of electrowinning. This process seems similar enough to the electrolysis of molten salt that I would hazard the latter is called electrowinning as well?
• Some electrolysis recipes allow the explicit recycling of electrodes. For salt/chlorine processes, an electrode is necessary. Saltwater electrolysis cannot use an electrode. Water electrolysis recipes have their speed doubled when electrodes are used.
• Sodium sulfate can be made in an electrolyser. (an oversight?)
• A lot of the refining processes that lead to ingots, that consume anodes, are actually electrolytic but take place in a chemical furnace. Sometimes we make the cathodes in a chemical furnace then fire them into ingots in a blast furnace, other times we make the anodes in a blast furnace then process them to ingots in a chemical furnace. I assume the distinction is whether the metal is supposed to come from leached solution (as in zinc), or from purifying an impure anode (as in copper). The step that consumes the acid is actually leaching, possibly with subsequent electrolysis in the same step.

Based on light research, the actual processes are:

• Leaching is a process by which desirable metals are dissolved out of a solution.
• Electrowinning refers to recovery of metals from a solution by electrolysis, causing them to coat an electrode (usually the cathode).
• Whether or not an electrode would dirty depends on the specific process.
  • In refining ores, the cathode will be of the desired metal to begin with and will embiggen during the electrolysis; the anode will be the raw material and will be consumed.
  • In water electrolysis, if the water is impure, there may be some deposition on the cathode which would require cleaning or replacement. The anode might erode too if it can deposit on the anode, as I understand it?
  • Pure water electrolysis shouldn't have this as the electrodes remain pure---except that you can't actually reasonably electrolyse it because it's not conductive. So I'm very uncertain here.
  • I'm unsure about molten salt (or sodium hydroxide, if we added it) electrolysis but it appears to me that since the sodium doesn't actually accumulate on the electrodes, those shouldn't have cleaning/replacement either.
  • I'm also unsure about the electrolysis to produce sodium hydroxide in the first place, but looking at the chemicals involved, my guess is it's just electrolysing the water so it should be the same as water?
  • I was linked [https://pubs.rsc.org/en/content/articlelanding/2014/ra/c3ra46630b#!divAbstract] in regards to water electrolysis but haven't read it in detail.

In effect, we have at least five different processes, all of which can reasonably be called electrowinning:

• Leaching raw ore crystals (the most tenuous, but how else do we get them out of solution?).
• The ferrous/cupric refinement path.
• Molten sodium electrolysis.
• Ore -> ingot refining via cathodes.
• Ore -> ingot refining via anodes.

I feel like these ought to be unified a little. Some other thoughts:

• The ferrous/cupric steps don't really make much sense. It appears that the "anode seedling" was originally supposed to be "anode sludge" i.e. the byproduct from electrowinning, which is mostly ignored in other processes (it cannot even be said to be the slag from sorting crystals, because that comes from the sorter, not the electrowinning cell). But also, we do the leaching and electrowinning. I think the most sensible thing here is that this is supposed to be electrorefining, where the impurities are electrolysed out of solution, as opposed to electrowinning, where the pure metal is electrolysed out?
• Cathodes produced from electrolysis should be pure and meltable directly rather than needing to be turned into ingots. So processing cathodes to ingots seems largely a step for convenience to avoid melting the ingots? Also both electrolytic ore -> ingot refining processes should require ingots as cathode seeds.
• Crystalising raw ore crystals should probably actually be in a crystalliser.

[LovelySanta]

A long wall of text to dissect...

• The leaching cell is used to upgrade ore chunks to crystals.
• The leaching cell is also used to create ferrous and cupric slurries, which are then put into the electrowinning cell to turn them into "anode seedling", which is a fluid requiring crystallisation.

Leaching in itself is a 2 step process. First you add a strong acid to dissolve the wanted product, the remainder that does not get dissolved are the impurities, in angels simplified to slag. The next step is to crystallize this ore/acid mixture into a high purity crystal.

For simplicity this is done in 1 building, like it is done in practice. For the ferrous and cupric, only the dissolving step is done, because after that it first has to be filtered and anodized before it can be crystallized, which are some intermediate steps. For this reason it's done in multiple buildings.

• Molten sodium hydroxide electrolysis, used to produce sodium in an electrolyser, is also, according to Wikipedia a form of electrowinning. This process seems similar enough to the electrolysis of molten salt that I would hazard the latter is called electrowinning as well?
• Some electrolysis recipes allow the explicit recycling of electrodes. For salt/chlorine processes, an electrode is necessary. Saltwater electrolysis cannot use an electrode. Water electrolysis recipes have their speed doubled when electrodes are used.

Both of these recipes you describe are done already in an electrolyzer. Since it's part of petrochem it's not done in an electrowinning. I do agree that electrowinning doesn't have a lot of uses so far...

The electrodes are not always used as a chemical interface but in the case of water it's used to pass a current through the water. With this the interface between the electrolyzer/water becomes better due to more surface contact and reduction of the bubble creation along the interfaces. (Search for "speed up hydrogen production in basic water electrolysis").

• Sodium sulfate can be made in an electrolyser. (an oversight?)

Looks like a chem plant to me?

• A lot of the refining processes that lead to ingots, that consume anodes, are actually electrolytic but take place in a chemical furnace. Sometimes we make the cathodes in a chemical furnace then fire them into ingots in a blast furnace, other times we make the anodes in a blast furnace then process them to ingots in a chemical furnace. I assume the distinction is whether the metal is supposed to come from leached solution (as in zinc), or from purifying an impure anode (as in copper). The step that consumes the acid is actually leaching, possibly with subsequent electrolysis in the same step.

There are 2 distinctions to be made here. For example in copper, the creation of the cathode is easy, but then it has to be put into a chemical solution to create ingots out of it. This means the cathode creation can be done in a blast furnace, but the ingot creation has to be done in a chemical furnace. On the other had, for example in gold, the creation of the anode is the difficult part which requires the acid, so this step is done in a chemical furnace. Then converting the anode into ingots is easy, and is done in a blast furnace. This also gives some variety in the different setups. to not having to build the same setup every time.

Based on light research, the actual processes are:

• Leaching is a process by which desirable metals are dissolved out of a solution.

"Leaching is a process by which desirable metals are dissolved and crystallized to leave behind impurities"

• Electrowinning refers to recovery of metals from a solution by electrolysis, causing them to coat an electrode (usually the cathode).

• Whether or not an electrode would dirty depends on the specific process.

  • In refining ores, the cathode will be of the desired metal to begin with and will embiggen during the electrolysis; the anode will be the raw material and will be consumed.
  • In water electrolysis, if the water is impure, there may be some deposition on the cathode which would require cleaning or replacement. The anode might erode too if it can deposit on the anode, as I understand it?

The anode will corrode over time due to giving off all the electrons, and will require cleaning, while the cathode will be "used" and require replacement (more frequently than the anode).

• Pure water electrolysis shouldn't have this as the electrodes remain pure---except that you can't actually reasonably electrolyse it because it's not conductive. So I'm very uncertain here.

Keep in mind that it's never fully pure and even if it was, electrolysis never happen with ideal faradaic efficiency, resulting in (competing) side reactions. This gets worse when the conductivity gets lower.

• I'm unsure about molten salt (or sodium hydroxide, if we added it) electrolysis but it appears to me that since the sodium doesn't actually accumulate on the electrodes, those shouldn't have cleaning/replacement either.
• I'm also unsure about the electrolysis to produce sodium hydroxide in the first place, but looking at the chemicals involved, my guess is it's just electrolysing the water so it should be the same as water?
• I was linked [https://pubs.rsc.org/en/content/articlelanding/2014/ra/c3ra46630b#!divAbstract] in regards to water electrolysis but haven't read it in detail.

In effect, we have at least five different processes, all of which can reasonably be called electrowinning:

• Leaching raw ore crystals (the most tenuous, but how else do we get them out of solution?).
• The ferrous/cupric refinement path.
• Molten sodium electrolysis.
• Ore -> ingot refining via cathodes.
• Ore -> ingot refining via anodes.

I feel like these ought to be unified a little. Some other thoughts:

Yes and no.. The difficult part is that we want to keep refining, petrochem and smelting separated. And because they are not all the same it requires some extra building, which is exactly intended.

• The ferrous/cupric steps don't really make much sense. It appears that the "anode seedling" was originally supposed to be "anode sludge" i.e. the byproduct from electrowinning, which is mostly ignored in other processes (it cannot even be said to be the slag from sorting crystals, because that comes from the sorter, not the electrowinning cell). But also, we do the leaching and electrowinning. I think the most sensible thing here is that this is supposed to be electro_refining_, where the impurities are electrolysed out of solution, as opposed to electrowinning, where the pure metal is electrolysed out?

Feels like just making it more complicated than it is, also we don't want to go too realistic..

• Cathodes produced from electrolysis should be pure and meltable directly rather than needing to be turned into ingots. So processing cathodes to ingots seems largely a step for convenience to avoid melting the ingots? Also both electrolytic ore -> ingot refining processes should require ingots as cathode seeds.

Nothing has to be processed into ingots first.... You can perfectly make 'chunks' out of it and put that directly into an induction furnace. We chose to take ingots as an itermediate step as that's how it's easy to transport. Keep in mind that not everyone is doing ore -> plate directly but rather ore -> ingot and then combine ingots -> plates. So it make sense to have ingots as an extra step.

• Crystalising raw ore crystals should probably actually be in a crystalliser.

Like I mentioned before... We didn't want to introduce an extra step to first dissolve the ore and then putting it into a crystallizer, but rather combining both steps into 1.

[alercah]

Leaching in itself is a 2 step process. First you add a strong acid to dissolve the wanted product, the remainder that does not get dissolved are the impurities, in angels simplified to slag. The next step is to crystallize this ore/acid mixture into a high purity crystal.

I haven't found any references to leaching also referring to the crystallization step; can you refer to any? Most of the text I found seems to use leaching to refer only to the dissolution step, including dictionary definitions.

For simplicity this is done in 1 building, like it is done in practice. For the ferrous and cupric, only the dissolving step is done, because after that it first has to be filtered and anodized before it can be crystallized, which are some intermediate steps. For this reason it's done in multiple buildings.

Both of these recipes you describe are done already in an electrolyzer. Since it's part of petrochem it's not done in an electrowinning. I do agree that electrowinning doesn't have a lot of uses so far...

Yes and no.. The difficult part is that we want to keep refining, petrochem and smelting separated. And because they are not all the same it requires some extra building, which is exactly intended.

Why is this? Given that petrochem requires refining, it seems odd to me that petrochem shouldn't be allowed to use refining's buildings where it makes sense.

There are 2 distinctions to be made here. For example in copper, the creation of the cathode is easy, but then it has to be put into a chemical solution to create ingots out of it. This means the cathode creation can be done in a blast furnace, but the ingot creation has to be done in a chemical furnace. On the other had, for example in gold, the creation of the anode is the difficult part which requires the acid, so this step is done in a chemical furnace. Then converting the anode into ingots is easy, and is done in a blast furnace. This also gives some variety in the different setups. to not having to build the same setup every time.

Nothing has to be processed into ingots first.... You can perfectly make 'chunks' out of it and put that directly into an induction furnace. We chose to take ingots as an itermediate step as that's how it's easy to transport. Keep in mind that not everyone is doing ore -> plate directly but rather ore -> ingot and then combine ingots -> plates. So it make sense to have ingots as an extra step.

I don't follow the first quoted paragraph at all because these descriptions don't match the processes in either real-life or in Angel's Smelting. Copper for instance, is copper pellet -> copper anode -> copper ingot in Angel's. So there's no separate cathode -> ingot step in Angel's. And in reality, copper is considered smelted once it's been electrolysed to the cathode AFAICT, it's even traded on commodity markets. So I'm not sure why you say that refining the cathode into ingots requires more acid.

I was missing that some electrolytic processes electrolyse onto a pure-metal cathode directly, like with copper or gold, like [zinc]*https://www.911metallurgist.com/electrowinning-zinc/#:~:text=A%20simple%20and%20inexpensive%20method,from%20solutions%20containing%20fluoride%20ion.), where the cathode is of a different metal and so I can only assume that a further step is required to turn the metal into a solid. I'm not sure on those details, though.

So I think the processes mostly make more sense than I was thinking at first, and actually part of my idea is already incorporated (because copper cathodes are not a separate item but we just call them ingots instead, although on the other hand we do have separate gold cathode items that need to be blasted into ingots), but I still don't understand why all these electrolytic processes are happening in chemical furnaces rather than electrowinning cells.

Feels like just making it more complicated than it is, also we don't want to go too realistic..

The comment you're responding to about electrorefining was really a terminology thing more than anything else. The process makes more sense, I think, if you were to change that term without changing the complexity. Calling it an electrodeposition cell would be a term that works for both electrowinning and electrorefining.

[LovelySanta]

Leaching in itself is a 2 step process. First you add a strong acid to dissolve the wanted product, the remainder that does not get dissolved are the impurities, in angels simplified to slag. The next step is to crystallize this ore/acid mixture into a high purity crystal.

I haven't found any references to leaching also referring to the crystallization step; can you refer to any? Most of the text I found seems to use leaching to refer only to the dissolution step, including dictionary definitions.

Wikipedia has some links and just looking at some papers... It seems to go hand in hand, as the disolving step on it's own is 'useless'

For simplicity this is done in 1 building, like it is done in practice. For the ferrous and cupric, only the dissolving step is done, because after that it first has to be filtered and anodized before it can be crystallized, which are some intermediate steps. For this reason it's done in multiple buildings.

Both of these recipes you describe are done already in an electrolyzer. Since it's part of petrochem it's not done in an electrowinning. I do agree that electrowinning doesn't have a lot of uses so far...

Yes and no.. The difficult part is that we want to keep refining, petrochem and smelting separated. And because they are not all the same it requires some extra building, which is exactly intended.

Why is this? Given that petrochem requires refining, it seems odd to me that petrochem shouldn't be allowed to use refining's buildings where it makes sense.

It's the other way around... Refining is standalone (no notion of petrochem), so it doesn't have access to petrochem, so refining can't use petrochem buildings, however petrochem can use refining buildings (like petrochem is using the liquifier).

There are 2 distinctions to be made here. For example in copper, the creation of the cathode is easy, but then it has to be put into a chemical solution to create ingots out of it. This means the cathode creation can be done in a blast furnace, but the ingot creation has to be done in a chemical furnace. On the other had, for example in gold, the creation of the anode is the difficult part which requires the acid, so this step is done in a chemical furnace. Then converting the anode into ingots is easy, and is done in a blast furnace. This also gives some variety in the different setups. to not having to build the same setup every time.

Nothing has to be processed into ingots first.... You can perfectly make 'chunks' out of it and put that directly into an induction furnace. We chose to take ingots as an itermediate step as that's how it's easy to transport. Keep in mind that not everyone is doing ore -> plate directly but rather ore -> ingot and then combine ingots -> plates. So it make sense to have ingots as an extra step.

I don't follow the first quoted paragraph at all because these descriptions don't match the processes in either real-life or in Angel's Smelting. Copper for instance, is copper pellet -> copper anode -> copper ingot in Angel's. So there's no separate cathode -> ingot step in Angel's. And in reality, copper is considered smelted once it's been electrolysed to the cathode AFAICT, it's even traded on commodity markets. So I'm not sure why you say that refining the cathode into ingots requires more acid.

I was missing that some electrolytic processes electrolyse onto a pure-metal cathode directly, like with copper or gold, like [zinc]*https://www.911metallurgist.com/electrowinning-zinc/#:~:text=A%20simple%20and%20inexpensive%20method,from%20solutions%20containing%20fluoride%20ion.), where the cathode is of a different metal and so I can only assume that a further step is required to turn the metal into a solid. I'm not sure on those details, though.

So I think the processes mostly make more sense than I was thinking at first, and actually part of my idea is already incorporated (because copper cathodes are not a separate item but we just call them ingots instead, although on the other hand we do have separate gold cathode items that need to be blasted into ingots), but I still don't understand why all these electrolytic processes are happening in chemical furnaces rather than electrowinning cells.

I may have mixed up my anode and cathode words up... So the anodes are easy to produce, such as copper. Those anodes have to be put in a chemical solution to create ingots out of it. Cathodes on the other had, for example in gold have the other issue. Creating the cathodes for it is hard, requires some acid to be succesfull, but then converting the cathodes to ingots is easy. In both cases, the step with the acid is done in the chemical furnace and the other one in a blast furnace. So anodes are made in a blast furnace and then converted in a chemical furnace to ingots, while cathodes are made in a chemical furnace and converted in a blast furnace to ingots.

Feels like just making it more complicated than it is, also we don't want to go too realistic..

The comment you're responding to about electrorefining was really a terminology thing more than anything else. The process makes more sense, I think, if you were to change that term without changing the complexity. Calling it an electrodeposition cell would be a term that works for both electrowinning and electrorefining.

Oh I see what you mean now... However electrodeposition seems more like a term for creating metal coatings (aka electroplating) to me than anything else... And since it's not so widely used in angels.. I'm not that concerned about it. I would rather look into some other uses for it...

[adoa]

I am not 100% sure what we are supposed to be doing about this. Renaming of entities? Reference to realistic processes in text descriptions?

[Pezzawinkle]

I think this is more related to the creation of the wiki (booktorio stuffs) for angels mods. Again, making the smelting processes more realistic (even in case of localisation) is minor.