In reply to CurlyStevo:
The location for the shaft is near Sneaton, about 3km south of Whitby. It is within the national park, but not in the area that I (having grown up a little further south) would consider "t' moor". It is mostly rolling farmland, with some forestry plantations.
To avoid any confusion, the potash is deep. The mine will be deep mining, not open cast. Most of the workings will be hidden deep underground. The shaft-head surface workings will be much smaller than is typical even for deep mines, as the potash will be brought out through a tunnel to Redcar (which is outside the national park). Plant trees around them and they probably won't be visible from anywhere much.
There is a long history and still a certain pride in deep mining in the north of England, mostly from the legacy of coal mining but there is also a deep potash mine about 15 miles away at Boulby. The development will bring 1000 jobs to the area. They are well worth having.
On balance, I would support this project, provided they take a few steps to minimise the visual impact of the surface workings inside the national park. I haven't looked into it enough to be sure that they have, but the fact that the planners approved it makes me think they probably did. These are the same planners who won't let you put PVC windows in your house in some areas of the park, as they are not in keeping with the image of the place.
Besides which, planning permission has been granted, the time for objections is a little bit past. The linked petition wants an inquiry, but I very much doubt an inquiry would overturn the planners decisions unless they find some new information. It looks to me like a waste of taxpayer money.