Last week I was dealing with a question on metamorphism about the reaction between calcium carbonate (limestone) and sand (silicon dioxide) to produce calcium silicate CaSiO3. This must be wollastonite. But I finally got to climb to climb the slag bank at Barrow yesterday and I am wondering if this is largely artificial calcium silicate.
The layers in it look like lava flows or some of the banded volcaniclastic sediments in the Lakes. The pieces I picked up with very light and full of holes like pumice. Essentially, in steel making there is sand in the ore still. It is not pure haematite. To get rid of the sand, it is reacted with limestone. Both iron ore and limestone were readily available around Barrow. So calcium carbonate and silicon dioxide could indeed get to react. There is more information
here and
here.
The views were so good that I could see Snowdonia, the Isle of Man and Scotland. In the picture above looking up the Duddon, the Scafells are in the distance.
