Ann: Avebury Nickel Project - Mineral Resource Estimate, page-32

from the MYL resource estimate...

"A small portion of nickel concentrate produced during the period of operation contained arsenic levels which reached unsaleable levels. It is assumed that production scheduling, blending, and processing strategies will enable the sale of future concentrates. It is assumed that concentrate limits for deleterious elements will not change."

So they've made assumptions but there's no back up for the assumptions.

A con which can't be put on a ship because of high As is a problem

A con which can't be sold because of high As, may ironically, be less of a problem if it can be blended with another con to cut the As grade. In Taiwan, OZ Minerals blended and may still blend high uranium, high copper cons with low uranium, high As cons from South America to create a blend which the Chinese would buy.

20% + is a high grade nickel con so maybe the same could happen, if it can be put on a ship.

If 2000ppm As is a limit chuck some tailings in to drop the As grade.