The waste slag materials from metallurgical plants contain calcareous materials, such as blast furnace (BFS) and converter slags (CS) of the Chelyabinsk Metallurgical Plant. However, the widespread use of these materials is limited by the presence of harmful impurities in their composition that can have a negative effect on soils and plants. The aim of our research is to study the effect of liming of soddypodzolic soils with metallurgical slags on the pHKCl value and the composition of the wash water. In a model experiment on columns, the migration ability of alkali metals from soils of light granulometric composition was studied after using two phases of steelmaking waste as a lime material. Research results indicate that the ameliorative properties of BFS and converter slags were different. When liming with BFS slag, a month after composting, the pHKCl value increased to 5.1 units. Studied soil from the category of "strongly acidic" moved to the category of "weakly acidic". When liming with the converter slag, the pHKCl value of the soil increased from 4.1 to 4.7 (the soil from the "strongly acidic" category moved to the "medium acidic" category). With an increase in the period of washing, the pH of the infiltration water increases. In the treatments with the use of BFS slag this increase was higher due to the continuing dissolution of ameliorants and the higher chemical activity of BFS slag. The liming led to intensive migration of alkaline earth metals. In the treatments limed with more soluble (chemically active) BFS slag, calcium losses were higher. Empirical estimation of alkaline earth metals leaching from the soil allowed to model the dynamics of the base migration. The dynamics of Ca and Mg migration from the soil were fundamentally different (content of Ca decreased, and of Mg increased). The dynamics of Ca migration from the soil limed with converter slag was most pronounced in comparison with the Ca dynamics for BFS slag and the Mg dynamics in all treatments.