The current research is focused on the cooling of a hot moving steel plate by using air atomized spray cooling technique. A new type of coolant, Cu-Al LDH nanofluid, has been prepared and used for heat flux removal. Preparation method of nanofluid and its characteristics has been reported. The cooling effectiveness is reported in terms of cooling rate by varying the concentration of nanofluid in five levels. The results indicate that the cooling rate increases at very low concentration of LDH with respect to base fluid. However, beyond a certain concentration a decreasing trend of cooling rate has been observed. Abbreviations: CHF: Critical heat flux; HTC: Heat transfer coefficients; LDH:Layered double hydroxide; TEM: Transmission electron microscopy. © 2017 Taylor & Francis.