Sciencemadness Discussion Board

Sodium silicates and Wikipedias sodium/silicate ratios

Fulmen - 25-10-2020 at 02:21

I was thinking of making some sodium silicate following NurdRages recipe (sodium hydroxide + crystal cat litter).

However, I then stop by Wikipedia where they talk about SiO2:Na2O weight ratios of 2:1 to 3.75:1. This makes no sense at all. other sources mention a standard "N-grade" with a 3.22 ratio. What gives?



[Edited on 25-10-20 by Fulmen]

njl - 25-10-2020 at 06:16

There are several compounds that are do not have the same composition that are all referred to as silicate/silicates. Some are non-stoichiometric, I think the "N grade" might be one of them. SiO2 + NaOH will still give sodium silicate. I think he mentions in the video that there are multiple compounds with the same name.

draculic acid69 - 25-10-2020 at 21:59

Can celite be used as a silica source?

Fulmen - 25-10-2020 at 23:37

@njl:Yes, that's the problem. How do I figure out what ratio the "N-grade" is?

MidLifeChemist - 26-10-2020 at 05:58

what do you want to use the Sodium Silicate for?

Fulmen - 26-10-2020 at 07:53

That's none of your f'ing business;-)

I actually have several uses for it, but right now I'm looking into binders used for sand casting. But this is about the quartz/sodium oxide-ratio that seems to be the most common way to describe these compounds.

[Edited on 26-10-20 by Fulmen]

Bedlasky - 26-10-2020 at 07:54

If you want sodium silicate solution, just buy water glass.

Fulmen - 26-10-2020 at 08:36

Jeeebus f'ing crud. If you can't contribute, then shut the hell up! If I wanted to buy sodium silicate I would have done it rather than starting this thread. And it still won't answer the main question. If I have, say 10% metasilicate, and need the 3.22 "N-grade", what do I do?

njl - 26-10-2020 at 09:13

What is 10% metasilicate? 10% solution in water? Maybe you need to contribute too. Some cursory googling says that sodium metasilicate is Na2SiO3.

PQ Corp datasheet: "Sodium silicate glass composition can be designated as: Na2 O • (SiO2)x – where x is the ratio of the components and falls in the practical range from 0.4 to 4.0."

So metasilicate represents x = 1 (Na2O has a similar mass to SiO2 so the ration is 1:1)
You want Na2O • (SiO2)x where x = 3.22
Try adding stoichiometric SiO2 to your metasilicate solution.

Like I said before, some things called "silicates" are non-stoichiometric compounds where there isn't necessarily a convenient equation. Sigma lists a silicate solution with the composition listed as a percent of the solution:

https://www.sigmaaldrich.com/catalog/product/sigald/338443?l...

MidLifeChemist - 26-10-2020 at 10:50

Quote: Originally posted by Fulmen  
That's none of your f'ing business;-)

I actually have several uses for it, but right now I'm looking into binders used for sand casting. But this is about the quartz/sodium oxide-ratio that seems to be the most common way to describe these compounds.

[Edited on 26-10-20 by Fulmen]


Thanks. I was asking because I've used a couple of different versions to make chemical gardens, and the Nurdrage recipe worked the best. Unfortunately I can't answer your exact question.

Fulmen - 26-10-2020 at 11:03

Sorry for the snarky replies, but let's look at the stats here: First a reply that basically confirms / recaps the question. Next is someone asking a tangentially related question. Then a question about use before the classic "just buy it". It's the last one that really pissed me off, if there is one answer that's counter to the whole idea behind SM it must be that.

Which PQ data sheet did you find that in? I looked at this: https://www.pqcorp.com/docs/default-source/msds/pq-corporati... and it's not there.

Let's assume that the wikipedia page is right about the various compounds covered by the generic "silicate":
Sodium metasilicate - Na2SiO3, Sodium orthosilicate - Na4SiO4 and Sodium pyrosilicate - Na6Si2O7. All these have a SiO2:Na2O-ratio of 1:2 - 1:1.

Then I looked up the Merck datasheet for "waterglass".
It lists the composition as Sodium trisilicatesolution - Na2O7Si3, which would have a SiO2:Na2O-ratio of 2.9.

A simple typo would explain a lot. If we correct "The ratio can vary between 2:1 and 3.75:1" to read "between 1:2 and 3.75:1" it would make a lot more sense.

Fulmen - 28-10-2020 at 03:20

Yeah, it's just a simple typo. Using the cheap kitty litter silica gel I had little problem dissolving the 3:1 ratio to a 37 w/w% and a density of 1.35. That's pretty close to the "N-grade".

Bedlasky - 28-10-2020 at 06:11

Quote: Originally posted by Fulmen  
Sorry for the snarky replies, but let's look at the stats here: First a reply that basically confirms / recaps the question. Next is someone asking a tangentially related question. Then a question about use before the classic "just buy it". It's the last one that really pissed me off, if there is one answer that's counter to the whole idea behind SM it must be that.


Don't be hypersensitive. Next time take a deep breath and count to ten, than you insult all members in theme. Your reaction is excessive. You just disgracing yourself.

Fulmen - 28-10-2020 at 09:20

Wow, you're really committed to being a useless prick aren't you? Just for the record:I KNOW HOW TO FUCKING BUY STUFF, OK? That wasn't the point.

Please, please, PLEASE go fuck yourself.

unionised - 28-10-2020 at 10:21

Quote: Originally posted by Fulmen  
That's none of your f'ing business;-)


[Edited on 26-10-20 by Fulmen]

Well.... there's a reason why Wiki talks about sodium silicates with a variety of different Na : Si ratios.
They are for different things.
Your contention that "This makes no sense at all."
is simply wrong.
It makes perfect sense- to those who know anything about sodium silicates.

And, you can't sensibly expect any guidance on what ratio to aim for unless you tell us what you plan to do with it.

Obviously, if you aren't prepared to give us the information we need in order to help, and you don't understand the wiki page, then the only option left is fo you to buy the damned stuff- as sold for whatever purpose you want.

Yet, when someone said that, you got all shouty.
so, perhaps you would care to, as you so delicately put it,
Please, please, PLEASE go fuck yourself.


Fulmen - 28-10-2020 at 10:43

1. There WAS an error on the Wikipedia page (the 2:1-3.75:1 should be 1:2-3.75:1). This conflicted with the examples given which were all in the 1:2 to 1:1 range. The NurdRage video also specified a 1:1-ratio.
2. I never asked for which ratio to use, how to make it or even if I should make it or buy it. And for the record I can't simply buy it, the only stuff available is of unknown composition and usually watered down to an unknown concentration. And usually at a price that borders on criminal.


MidLifeChemist - 28-10-2020 at 10:46

Quote: Originally posted by Fulmen  
Wow, you're really committed to being a useless prick aren't you? Just for the record:I KNOW HOW TO FUCKING BUY STUFF, OK? That wasn't the point.

Please, please, PLEASE go fuck yourself.


Personally I find Bedlasky's comments very useful as I always learn something from them. If you disagree, you may have better luck suggesting acts that are physically possible, assuming he is not a mangrove killifish disguising themselves as some form of chemist.

Fulmen - 28-10-2020 at 12:46

Re-reading my first post I see I wasn't too clear on defining the problem. I'm sure I'm not the only one who has that: Pondering on something for so long you forget that others haven't. You wanna kick me around for that, be my guest. But if you're having problems understanding the question, why not ask a follow-up? Or just ignore it. Honestly, either is fine.

But "Just buy it"? In here? This is the one place where people should know better. Sometimes it's not about getting the stuff, it's about understanding, achievement or even boredom. Or it's all about getting the stuff, and buying isn't an option. Not everything is available to everyone, everywhere at a reasonable cost. Again, do I need to explain this in here?

To be fair, sometimes buying is the only sensible option. If so, try to explain why. In my not-so-very-humble opinion, this one was well withing the DIY range. And I think it's reasonable to assume NurdRage agrees with me on this :D

j_sum1 - 28-10-2020 at 15:04

[modding]
This is feisty enough. We can treat each other nicely here. That's at you, Fulmen.
[/modding]

I understand your problem, Fulmen. Or at least I think I do. I attempted to make waterglass a few weeks back. I used kitty litter and followed Nurdrage roughly. My problem was that I had no idea of the specs of the kitty litter silica gel. How hydrated is it out of the box? What particular silicate is it? What is its composition? That made weighing the stuff pretty pointless.
I ended up with a thick, slightly cloudy alkaline solution. It did not make a good crystal garden. And it was not useful for the project I had planned – In retrospect, sodium silicate was the wrong approach anyway.
Added to the confusion was the loose terminology surrounding the word "silicate" in any reading that I did. I am sure if I had dug harder I may have got there. Progect abandoned in favour of another approach.

J.

Fulmen - 28-10-2020 at 15:17

I know, I know. I'm in a bad mood these days, and unhelpful answers ain't helping much. But I still maintain that "just buy it" should be grounds for banning :mad:

What threw me off was the use of low-ratio examples (and not just on Wikipedia), leading me to believe that it had to be rich in sodium oxide. After all, we're talking about dissolving quartz here. It's pretty amazing to see so much silica dissolve in a bit of lye. I stopped at 3:1, but with more aggressive heating I'm sure I could dissolve a fair bit more.

woelen - 28-10-2020 at 23:38

@Fulmen: Being in a bad mood should be NO reason to be rude to other members. Next time when you are in a bad mood, simply don't post, and wait for the next day before you proceed!

Fulmen - 28-10-2020 at 23:50

Sure, fine. But dumb-ass answers like "just buy it" IS a good reason to be rude.

Bedlasky - 29-10-2020 at 10:27

Fulmen: You are really mad person. You behave like just an insulted little kid. If you can just insult others, you better shut up. You just womit the same shits over and over and over. I won't waste energy on you next time. You not worth it.