The contribution deals with a new original technology of obtaining the very pure silicon dioxide (SiO2) and magnesium chloride MgCl2 from secondary serpentinite mineral raw material stored in the waste heaps in Dobšiná. In the part of these heaps there are residues of carcinogenic components of chrysolitic asbestos. The processing includes the physical modification of raw materials and their hydrometallurgical processing. The mentioned technology can be ranked among the environmental technologies.