Yes you are right, I tried to say that the combined amount of Ni and Cu is about 1% in the slag they throw out. Of course it varies, I am sure it can be less such as 0.6 to 0.8% but sometimes slightly higher than 1% combined. Depending on the mine output, they sometimes treat some of this slag in their mill to recover some Ni and Cu from the slag. However, that is a small part of the total slag.  The point I tried to make is that 0.2 to 0.3% Ni and Cu is just not even close to being economic, in my oppinion you need at least 1% Ni, ideally closer to 1.5% Ni.