Comment by cinntaile | Hacker News Reader

Comment by cinntaile | Hacker News Reader

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I found the following quote:

> RheEnergise said it invented the new high-density fluid, known as R-19. Chief executive Stephen Crosher told Professional Engineering that the liquid is a fine-milled suspended solid in water, with low viscosity and low abrasion characteristics. The base material is used in oral medication applications, in a similar way that chalk is used as a bulking agent for pills and tablets. He said the raw materials are common and available, including in the UK, and the fluid could either be manufactured on-site or at a depot. [0]

Maybe someone knowledgeable about oral medication applications has any idea.

[0] https://www.imeche.org/news/news-article/high-density-pumped...

After looking up mining slurry densities limestone is 2.7x the density of water. Calcium carbonate (limestone) is also used for filler in some medications. I'm pretty sure its just limestone slurry.

It is more like that is a sort of drilling mud (bentonite possibly additioned with baryte ):

https://en.wikipedia.org/wiki/Bentonite

https://en.wikipedia.org/wiki/Drilling_mud

Bentonite is also used in medicine (dermatology).

Interesting! I wonder how the economics work out wrt aging of the liquid, abrasion (low abrasion != no abrasion)... and of course how environmentally friendly it is to dispose of.

It seems hardly worth it to use a specialized fluid for "only" a 2.5x density multiplier, on first glance.

I wonder if it's kaolin?

My first guess was some form of alginate.

An organic compound would not have the density.

Alginate is probably not as dense as a suspension of kaolin, and also being an ionic polymer, there's no need for a surfactant or dispersant to stabilize it. Also it is probably way more expensive.

Kaolin apparently has a specific gravity of 2.16–2.68, so it doesn't seem to be dense enough on its own unless the ratio of kaolin:water is extremely high? Good guess though!

Probably just silica? It would be non-toxic and maybe dense enough.

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