Some buyers have said they are shunning Rusal's metal, while others are securing price discounts at the same time as the industry negotiates supply deals for 2023.
Glencore put zinc sulphide operations at the Portovesme plant on care and maintenance in November 2021, but continued production of zinc recycling and lead.
Reuters sources say the exchange was planning to discuss banning new deliveries of Russian metal so its warehouses cannot be used to offload hard-to-sell stock.