The influence of modifiers obtained from silicon production waste on the morphological form of graphite in gray cast iron was evaluated. Experimental melts were performed to study the effect of nanomodifiers. Series of ten samples were obtained, in each of which one sample was a control sample without the use of an experimental modifier. The other nine samples of each series were obtained using the studied additives. Cast iron was smelted in an induction furnace of the IST-0.6/0.4 brand, with a capacity of 500 kg. The conducted researches included: determination of the chemical composition of cast iron; determination of the hardness of samples using the Brinell method; tensile testing of samples; study of the macro-and microstructure of gray cast iron. The graphite phase in the modified cast iron was obtained using our proposed modifiers and is represented by vermicular graphite. The mechanisms of graphite formation using the suggested modifiers are considered.