Meanwhile, magnetite miners are appealing to the Government for exemption from the proposed tax.
The issue was discussed yesterday in Perth with the Government's policy transition group, lead by BHP Billiton's Don Argus and Mr Ferguson.
The executive director of the magnetite network, Megan Anwyl, says the value of this particular type of iron ore before it's processed is too low.
"Iron ores are different. We say that magnetite should be exempt from the tax on the basis that the Government is talking about taxing the value as it comes out of the ground," she says.
"There's very little value to magnetite ore as it comes out of the ground. It's only after the very expensive, intense processing that it acquires some value."