Development of a Method of Secondary Use of Slags of Non‐Ferrous Metallurgy for Obtaining Mineral Fertilizers

In this study, extracts of metallurgical slags of the former lead plant in Shymkent and Zhezkent Mining and Processing Plant are used as a liquid mineral fertilizer for growing corn. Slag extraction was carried out by the method of chemical leaching with potassium sulfate and ammonia solution in hydrogen peroxide medium. Macro- and microelement analysis of extracts from slag was carried out. Among the obtained extracts, the slag extract of the second slag store of the former lead plant is the least toxic and the richest in macro- and microelements (27.605 Са 2+; 5.959 Mg2+; 423.751 Cu2+; 86.649 Zn2+; 5.567 Fe2+,3+; 22.652 Mn mg/L). The studied solution was diluted in the ratio of extract: distilled water 1:10 for the extract based on potassium sulfate and 1:200 for the extract based on ammonia and used to evaluate the initial development of seeds and yield of corn. Germination of seed corn and its development after 90 days did not differ from the control variant. The concentration of potentially toxic elements in the dry mass of the plant does not exceed the permissible concentration. The results showed the potential of safe application of this fertilizer in agriculture and rational utilization of industrial waste.