Fluoride Action Network

Hexafluorosilicic acid. Lithium Australia denies using toxic chemicals to develop technology

Source: Australian Mining | March 9th, 2017 | By Ben Creagh
Location: Australia
Industry type: Mining Industry

Lithium Australia wants to bust a myth that a process it is developing for lithium recovery uses toxic reagents.

The Perth-based company is developing a technology called Sileach, a hydrometallurgical process aimed at enhancing the recovery of lithium from hard rock.

Lithium Australia managing director Adrian Griffin said there had been “a lot of speculation about its 100 per cent owned Sileach process” incorporating the use of hydrofluoric acid (HF).

The speculation stems from a recent announcement by Lithium Australia takeover target, Lepidico, which is currently the subject of $23.8 million bid.

Lithium Australia has previously stated it is using halogen chemicals to develop Sileach, which Lepidico believes is a “broad definition” and “does not clearly identify the reagents used in the process”.

“As Lithium Australia has not referred to its process as a ‘chloride process’, which would employ hydrochloric acid, Lepidico holds considerable concern that Lithium Australia is evaluating a process that utilises fluoride-based reagents, which may be highly toxic and difficult to commercialise on occupational health and safety grounds,” Lepidico said in a statement.

In response, Griffin commented: “There is speculation that Sileach uses very toxic reagents, in particular HF.”

“We can tell you Sileach does not use HF and the main fluorine product produced is hexafluorosilicic acid which is commonly used as a source of fluoride for fluoridation of domestic water supplies – if you think that is dangerous, you had better stop drinking water.”

ANSTO Minerals – a division of the Australian Nuclear Science and Technology Organisation – has been conducting pilot testing of the process.

Prior to commissioning the pilot plant, ANSTO conducted a thorough investigation of the processes and safety aspects and approved operation based on negligible HF risk, according to Lithium Australia.

“Lithium Australia has undertaken all Sileach pilot tests under the most stringent safety conditions and has monitored for HF and, as predicted by ANSTO, found that negligible quantities are produced during processing,” Griffin continued.

“Independent safety investigations have concluded that operating with hot sulphuric acid is a much greater hazard than the risk of HF in the Sileach process.”

The proposed bid for Lepidico involves one Lithium Australia share for every 13.25 shares of the target.

• Original article online at https://www.australianmining.com.au/news/lithium-australia-denies-using-toxic-chemicals-develop-technology/