The National Institute for Research into Aquatic Habitats (Nirah) will see the former Quest pit near Stewartby village transformed.
The council insisted that this is "vital" to bring jobs and growth to an area where industry is declining. But the plans have been criticised by animal rights activists.
The county's development control committee has aired concerns over site access and traffic management. It will consider revised plans before full permission is given.
Cabinet member for planning and economic growth John Scott explained: "Nirah is central to our long-term jobs and growth strategy."