According to the last announcement the smelters are expected to leave Durban today (12th May) via Singapore then through to Kupang.
From what I have looked up it will take around 26-27 days to arrive in Singapore from Durban. This is on the Maersk website (has a joint venture with company that owns Themba dry cargo).
Then it will take a further 3-4 days to ship from singapore to Kupang.
Not sure how long they will stay in transit for once arriving in Singapore?
So possibly excpecting arrival of smelters to Kupang around 11th, 12th, 13th of June.