CHEMICAL ADDITIVE FOR CEMENT ARTICLES Russian patent published in 2017 - IPC C04B22/08 C04B28/02 C04B111/20 

FIELD: chemistry.

SUBSTANCE: invention relates to composition of a chemical additive and can be used in production of construction materials. Chemical additive for increasing strength of cement products, containing acidic substances, which enter into exchange reaction with products of hydration of cement dough to form insoluble compounds, accelerating cement hardening process, additive used is spent hydrochloric acid etching solutions from steel rolling plants with density of 1.35 g/cm³, containing (wt%) 25.5–27.0 acidic substances in following ratio of components (g/l): hydrochloric acid – 15–17; iron (II) chloride – 320–330; iron (III) chloride – 11–13; water – 990–1,004.

EFFECT: technical result is reduction of toxicity of additives and high strength of articles with its use.

1 cl, 2 tbl