An apparatus for simultaneous grinding and froth flotation of at least one crude mineral and/or pigment, comprising a) a vessel suitable for containing grinding media , a flotation gas, a collector agent and at least one crude mineral and/or pigment; b) an agitation unit rotatably mounted in vessel ; c) drive means connected to agitation unit for agitating the grinding media and the at least one crude mineral and/or pigment to grind the at least one crude mineral and/or pigment into at least one ground mineral and/or pigment; d) a charge system connected to vessel comprising i. a crude mineral and/or pigment feed , ii. a collector agent feed , and iii. a flotation gas inlet ; e) a discharge system connected to vessel comprising i. a sieve suitable for separating the froth from the ground mineral and/or pigment, and suitable for preventing that grinding media is discharged to the ground mineral and/or pigment, wherein the sieve is a vertical circumferential discharge screen being mounted on top of vessel , ii. a product collecting zone suitable for collecting the ground mineral and/or pigment, iii. a froth collecting zone , which is arranged on top of sieve and product collecting zone , and iv. a froth redirecting zone , which is arranged around the circumference of the stirring shaft of agitation unit and on top of sieve and product collecting zone . a) a vessel suitable for containing grinding media , a flotation gas, a collector agent and at least one crude mineral and/or pigment; b) an agitation unit rotatably mounted in vessel ; c) drive means connected to agitation unit for agitating the grinding media and the at least one crude mineral and/or pigment to grind the at least one crude mineral and/or pigment into at least one ground mineral and/or pigment; d) a charge system connected to vessel comprising i. a crude mineral and/or pigment feed , ii. a collector agent feed , and iii. a flotation gas inlet ; i. a crude mineral and/or pigment feed , ii. a collector agent feed , and iii. a flotation gas inlet ; e) a discharge system connected to vessel comprising i. a sieve suitable for separating the froth from the ground mineral and/or pigment, and suitable for preventing that grinding media is discharged to the ground mineral and/or pigment, wherein the sieve is a vertical circumferential discharge screen being mounted on top of vessel , ii. a product collecting zone suitable for collecting the ground mineral and/or pigment, iii. a froth collecting zone , which is arranged on top of sieve and product collecting zone , and iv. a froth redirecting zone , which is arranged around the circumference of the stirring shaft of agitation unit and on top of sieve and product collecting zone . i. a sieve suitable for separating the froth from the ground mineral and/or pigment, and suitable for preventing that grinding media is discharged to the ground mineral and/or pigment, wherein the sieve is a vertical circumferential discharge screen being mounted on top of vessel , ii. a product collecting zone suitable for collecting the ground mineral and/or pigment, iii. a froth collecting zone , which is arranged on top of sieve and product collecting zone , and iv. a froth redirecting zone , which is arranged around the circumference of the stirring shaft of agitation unit and on top of sieve and product collecting zone . <EOS>