They (whoever) probably think there's too big an element of risk doing anything with it, and disturbing all the arsenic which is still crusted inside.
Mind you, the (now truncated) chimney on the arsenic works at Bissoe, has still got visible arsenic in the flue, as has the Wheal Busy calciner and others.
HSE regs being what they are, they would no doubt recommend bringing in a Hazmat team and setting up a 2 mile exclusion zone around it.
Failing that, a couple of chaps with cotton wool plugs in their nostrils would suffice.
"You Chinese think of everything!"
"But I''m not Chinese!"
"Then you must have forgotten something!"