The development of technologies for treatment of industrial wastes on the site that they are produced and their transformation after recycling in new qualitative materials is a project of the 21st century. For that purpose methods and technologies are developed which require a minimum quantity of energy and time. The main problem in the production of Fe-Ni is the waste product(Fe-Ni slag). More than about 1 millons tons of industrial wastes will be landfilled annually. The metallurgical Fe-Ni slag is a multi component system characterized by high percentage content of Si, Mg, Ca, Fe, and Mg-oxides due to the presence of glass phase(5～30%). This metallurgical slag can be also used as raw material for production of new materials useful for the other application. In this study, serpentine mineral and Fe-Ni slag were treated in a planetary ball mill, and the effect of grinding were studied on the crystalline structure, size distribution and metal extraction rate by sulfuric acid leaching. The crystalline peaks of the serpentine and Fe-Ni slag were gradually reduced with increase of grinding time, and after 120 min. The serpentine was turned into the amorphous phase. It was found that the extraction rate of the metals contained in the mineral and Fe-Ni slag by sulfuric acid was rapidly increased by the mechanochemical treatment. For the mineral treated for 240 min, Mg and Fe metal elements were extracted at 100% within 5min, while 83% and 58% of Ca and Al, respectively, were obtained within 10 min. 1. The leaching ratio of Mg was enhanced along with the acid-leaching temperature increase. 2. The leaching ratio of Mg was enhanced slag (2h) along with the acid-leaching time increase. 3. The leaching ratio of Mg enhanced slag (50%) along with the concentration increase. 4. The leaching ratio of Mg enhanced slag (1:6) along with the solid/liquid ratio increase. 5. The optimum operating conditions of the main process are established, that is, ore sample is ground for 1h by ball mill, calcined at 700℃ for 1h, and then mixed with 3mol/l H2SO4 and stirred an normal temperature. The solid/liquid ratio is 1:5 under the optimum operating conditions. The leaching ratio of magnesium oxide in Fe-Ni slag is up to 93%.