An agitator impeller arrangement for dispersing gas into a slurry of solids and liquid, the arrangement comprising - a rotating shaft having an upper end which is connected to a rotating means, and a free lower end, the rotating shaft having a central axis (x) which is the axis of rotation, and - an impeller connected coaxially and centrally in relation to the central axis (x) to the lower end of the rotating shaft, said impeller having -- a horizontal circular hub disc connected centrally and horizontally to the lower end of the rotating shaft, and -- a plurality of agitating blades mounted radially and equally spaced to the circular hub disc, each agitating blade comprising + a lower vertical dispersion blade located below the plane of the circular hub disc parallel to the radius of the circular hub disc, said vertical dispersion blade having a straight vertical outer edge being close to a periphery of the circular hub disc, an inner edge which is close to the axis of rotation (x)) and a rounded edge curving with a radius r between the outer edge and the inner edge, + an upper vertical dispersion blade located above the plane of the circular hub disc and parallel to the radius of the circular hub disc, and + an inclined suspension blade located radially outside the periphery of the circular hub disc, at a first angle (α) in relation to the vertical direction and below the plane of the circular hub disc, characterized in that the agitating blade is one integral piece of metal plate, the lower vertical dispersion blade, the upper vertical dispersion blade and the inclined suspension blade being bent from a single metal plate blank. - a rotating shaft having an upper end which is connected to a rotating means, and a free lower end, the rotating shaft having a central axis (x) which is the axis of rotation, and - an impeller connected coaxially and centrally in relation to the central axis (x) to the lower end of the rotating shaft, said impeller having -- a horizontal circular hub disc connected centrally and horizontally to the lower end of the rotating shaft, and -- a plurality of agitating blades mounted radially and equally spaced to the circular hub disc, each agitating blade comprising + a lower vertical dispersion blade located below the plane of the circular hub disc parallel to the radius of the circular hub disc, said vertical dispersion blade having a straight vertical outer edge being close to a periphery of the circular hub disc, an inner edge which is close to the axis of rotation (x)) and a rounded edge curving with a radius r between the outer edge and the inner edge, + an upper vertical dispersion blade located above the plane of the circular hub disc and parallel to the radius of the circular hub disc, and + an inclined suspension blade located radially outside the periphery of the circular hub disc, at a first angle (α) in relation to the vertical direction and below the plane of the circular hub disc, characterized in that the agitating blade is one integral piece of metal plate, the lower vertical dispersion blade, the upper vertical dispersion blade and the inclined suspension blade being bent from a single metal plate blank. -- a horizontal circular hub disc connected centrally and horizontally to the lower end of the rotating shaft, and -- a plurality of agitating blades mounted radially and equally spaced to the circular hub disc, each agitating blade comprising + a lower vertical dispersion blade located below the plane of the circular hub disc parallel to the radius of the circular hub disc, said vertical dispersion blade having a straight vertical outer edge being close to a periphery of the circular hub disc, an inner edge which is close to the axis of rotation (x)) and a rounded edge curving with a radius r between the outer edge and the inner edge, + an upper vertical dispersion blade located above the plane of the circular hub disc and parallel to the radius of the circular hub disc, and + an inclined suspension blade located radially outside the periphery of the circular hub disc, at a first angle (α) in relation to the vertical direction and below the plane of the circular hub disc, characterized in that the agitating blade is one integral piece of metal plate, the lower vertical dispersion blade, the upper vertical dispersion blade and the inclined suspension blade being bent from a single metal plate blank.