Abstract
	The possibility and efficiency of the leaching of Ni3S2 and ?-NiS in dilute nitric acid and hydrochloric acid solutions in the presence of activated carbon were investigated.
	Activated carbons were prepared from various types of coal. Influence of the addition of six various types of activated carbon on leaching rate was tested. In general, such an addition protects the retarding of Ni3S2 leaching in diluted nitric acid at 80°C, and considerably increases nickel extraction. Similar results were achieved for the leaching of ?-NiS in dilute hydrochloric acid solutions. 
	It was found that the leaching rate of nickel extraction for both sulphides increases depending on the capillary structure of activated carbon.