Ammonium paratungstate (APT) producers in China are looking to cement markets to address the short-term challenges of APT slag disposal, Roskill learned at the Antaike Tungsten & Molybdenum Industry Forum, held in Xi’an in late June.
Tungsten ores frequently occur in association with arsenides and their processing into APT generates slags containing high levels of arsenic. Slag disposal has been an additional cost for many established APT smelters for years, but regulations in China were tightened up in August 2016 when APT slag was categorised as hazardous waste. This created new requirements for its handling and disposal.
One of the findings of the environmental inspections carried out in 2018 was that many APT producers were still in the process of upgrading their facilities to meet these new regulations. In addition, some producers had been forced to mothball facilities as they awaited licences for the handling and transport of slags to centralised recycling centres.
With APT prices now languishing at their lowest level since August 2017, some smelters are reluctant to pay the slag disposal fee and are instead opting to stockpile waste at their facilities. However, producers can only store waste on site for 12 months before it must be sent to an approved disposal facility—which is likely to see prices rise as producers move to cover their higher costs.
Roskill understands that in the short term, one solution for the slag stockpiles is to treat them to remove valuable metals and arsenic, then use the remaining material as filler in cement. Longer term, initial suggestions by the Academy of Environmental Sciences include technology to reduce molybdenum and arsenic in the APT feed material and controlling As in the smelting process.
Another suggestion is a government-administered indicator system to collect data on waste levels, requiring the input of smelters. Either way, the signals being sent from China are that environmental protections are here to stay, and, with them, higher costs for the tungsten industry.
Roskill’s Tungsten: Outlook to 2028 report was published in March 2019 and the first quarterly update is now available for subscribers.