The awards presentation was part of the Precious Metals Investment Symposium, which is in Perth for the first time.
When presenting the award to Plimer, conference organiser Kerry Stevenson read out a letter of congratulations from Plimer's colleague, Hancock Prospecting chair Gina Rinehart.
Plimer urged the industry to rally against environmentalists and said it continued to be a pleasure of his to get letters from "nutters".
The ‘Gavin Thomas' Mining Award, named after the late Kingsgate Consolidated boss, went to retiring Gold Road Resources managing director Ian Murray.
An emotional Murray said one of his best decisions in life was emigrating to Australia.
Murray, who is chairman of new float Helios Gold, will be focusing on a career as a non-executive director.
"As a managing director I could add value to one company - as a non-executive director I can add value to many companies," he said.
G4S International Logistics managing director Julian Haskard won the ‘Maggie' Bullion Award for outstanding customer service to the precious metals sector.
The event also included the unveiling of heavily guarded specimens recovered from RNC Minerals' Beta Hunt mine at Kambalda last month.