The halt will remain in place until the start of normal trading on Friday, October 25, 2019, or when an announcement is made to the market, whichever occurs earliest.
IBG's securities last traded at 1.7 cents, down from 2.1 cents in mid-September.
New managing director
In September the company appointed experienced commercial and corporate executive Michael Jardine to the role of managing director.
The new managing director said: “I am very pleased to be taking on this role at a key stage in Ironbark’s development journey and am excited by the challenge of helping build what will be a world-class zinc mine.”