OneGuyFromBarlick

Tizer wrote: ↑14 Oct 2019, 10:33 Stone wool is made from volcanic rock, typically basalt or dolomite, an increasing proportion of which is recycled material in the form of briquettes.

[I have to take issue with their reference to dolomite. It isn't a volcanic rock, it's like limestone (calcium carbonate) but with some of the calcium replaced by magnesium which makes it a bit harder.]

chinatyke wrote: ↑14 Oct 2019, 12:16

Tizer wrote: ↑14 Oct 2019, 10:33 Stone wool is made from volcanic rock, typically basalt or dolomite, an increasing proportion of which is recycled material in the form of briquettes. [I have to take issue with their reference to dolomite. It isn't a volcanic rock, it's like limestone (calcium carbonate) but with some of the calcium replaced by magnesium which makes it a bit harder.]

Thanks Tiz. I think they have got their punctuation wrong and wouldn't have meant to suggest dolomite was volcanic:
Stone wool is made from volcanic rock, typically basalt, or dolomite...

Tizer wrote: ↑15 Oct 2019, 10:53

chinatyke wrote: ↑14 Oct 2019, 12:16

Tizer wrote: ↑14 Oct 2019, 10:33 Stone wool is made from volcanic rock, typically basalt or dolomite, an increasing proportion of which is recycled material in the form of briquettes. [I have to take issue with their reference to dolomite. It isn't a volcanic rock, it's like limestone (calcium carbonate) but with some of the calcium replaced by magnesium which makes it a bit harder.]

Thanks Tiz. I think they have got their punctuation wrong and wouldn't have meant to suggest dolomite was volcanic:
Stone wool is made from volcanic rock, typically basalt, or dolomite...

I agree with you China that the comma should be there so that dolomite isn't implied to be volcanic. But there's another issue here - do they really mean dolomite? It's calcium magnesium carbonate, it doesn't contain any silica, it's relatively soft and it dissolves in acid. it doesn't sound to me like the type of material for making mineral wool. Quite unlike basalt which contains quartz and other very hard and resistant minerals. When you heat dolomite it doesn't melt it decomposes into calcium oxide (quicklime) and its magnesium equivalent, magnesium oxide.I've looked beyond the EURIMA web site and find other mineral wool pages, e.g. the Knauf web site, saying almost exactly the same as the EURIMA page. It makes me wonder if they're all perpetuating a mistake. I wouldn't be surprised if they are confusing dolomite with dolerite which is similar to basalt in composition, structure and properties and is also volcanic in origin (to a precise geologist it is not truly volcanic but is an igneous intrusive rock - it's formed from magma squeezed along fissures and doesn't get blown out of a volcanic cone but a layman would probably call it volcanic). Geologists are forever troubled by the woolly nomenclature used in the masonry trade. Granite is a good example. In the stone trade any hard black stone gets called `granite' yet true granite is not black and not homogeneous. It's a very specific mixture of quartz, feldspar and mica with a characteristic appearance.

StoneRoad wrote: ↑15 Oct 2019, 18:44 I think that Dolomite should actually be Dolorite - another igneous rock like basalt.
https://en.wikipedia.org/wiki/Diabase
As has been said Dolomite is a sedimentary rock ...

Stanley wrote: ↑16 Oct 2019, 08:48 It would Gloria but while you were homing in China has upstaged you with the right answer, it's a frame for lacing up, spoking, trueing and balancing bicycle wheels. How could he do this to you.....

Gloria wrote: ↑16 Oct 2019, 08:54

Stanley wrote: ↑16 Oct 2019, 08:48 It would Gloria but while you were homing in China has upstaged you with the right answer, it's a frame for lacing up, spoking, trueing and balancing bicycle wheels. How could he do this to you.....