Lynas Malaysia today touted the potential commercialisation of its neutralisation underflow residue (NUF) waste, including its application as a soil ameliorant to enhance crop productivity and construction.
However, the local arm of the Australian rare-earth mining firm made no mention of the potential risks highlighted by an executive review committee on Lynas, such as the increase in heavy metal levels through the use of Condisoil, a commercial product based on Lynas’ NUF waste.
The committee had warned that even though the increase in heavy metal levels was within a permissible amount, accumulation could happen under mass use.
Lynas Malaysia general manager (radiation safety, regulation and compliance) Ismail Bahari, in a statement today, said Lynas' NUF is "magnesium-rich synthetic gypsum which is non-radioactive, non-toxic and non-hazardous and is chemically equivalent to the material which is imported into Malaysia".
He pointed out that Malaysia imports more than 1 million tonnes of gypsum annually at a cost of around RM128 million to be used as cement, plaster and fertiliser.
"Lynas Malaysia has agreed on a NUF action plan with the government and regulators, which includes commercialisation options.
"Research and development have identified various applications for NUF and Lynas have been approached by companies in Malaysia regarding commercial use of the NUF material," it said.
Ismail also quoted Universiti Putra Malaysia professor Dr Shamshuddin Jusop as saying that Lynas' NUF is a "good soil ameliorant for low fertility soil and to enhance crop productivity" and "can also be used commercially as a gypsum replacement in the construction industry".
"The government has stated its commitment to the circular economy, which includes recycling and utilising local resources.
"It is therefore timely to ask why we are importing significant quantities of gypsum material when it is produced locally by Lynas," said Ismail.
The statement made no mention of any flip side of the residue’s potential commercialisation.
Lynas’ rare-earth processing plant in Gebeng, Kuantan produces two kinds of waste, namely radioactive water leach purification (WLP) residue and non-radioactive NUF.
Last September, the government had commissioned an evaluation of Lynas’ plant, which was carried out by an executive committee led by academic Mazlin Mokhtar.
According to the committee’s report, while NUF was effective in improving agriculture productivity, tests on oil palms and padi plantations found an increase in heavy metal levels in oil palm tissue and padi harvests, albeit within a permissible amount.
"Even though it is claimed that the radioactivity in Condisoil was reduced to a level below 1Bq/g, looking at the projects on a mass scale and tonnes of Condisoil being used, there is concern that heavy metal and concentration of naturally occurring radionuclides will accumulate leading to grave risks (risiko yang merbahaya)," said the report.
With regard to construction, the report noted that the NUF-based material was strong and stable when tested under wet conditions.
However, the report said that the production of Condisoil (1:3:6 ratio of WLP, NUF, and natural soil) led to "an increase in the plasticity character, causing instability for the purpose of infrastructure construction".
The full evaluation report can be read here.