Indirect flotation process for manufacturing white pigment containing products

Process for manufacturing white pigment containing products, characterised in that said process comprises the following steps:

• a) providing at least one white pigment and impurities containing material;
• b) providing at least one collector agent selected from the group consisting of compounds of formula (1):
• wherein R2 is selected from the group consisting of:
• i) a direct bond,
• ii) a C1-C20, linear or branched, saturated or unsaturated hydrocarbon chain optionally substituted by one or more —OH group(s), a substituted alkylene radical wherein said alkylene radical is substituted by 1 or 2 —OH groups, an alkenylene radical having from 1 to 20 carbon atoms, and a substituted alkenylene radical, wherein said alkenylene radical is substituted by 1 or 2 methyl and/or methylene groups,
• iii) a cycloalkylene,
• iv) a cycloalkenylene and
• v) an arylene group
• R5 is a C1-C6 hydrocarbyl group,
• X is a leaving group,
• t is 0 or 1,
• p is an integer in the range from 1 to 15,
• QO is an alkyleneoxy group containing from 2 to 4 carbon atoms,
• q1, q2, q3, q4, are independently from each other an integer in the range from 1 to 20,
• R10 is independently from each other selected from the group consisting of R7 and R11, with the proviso that at least one of the R10 groups is R7 and at least one other of the R10 groups is R11, wherein
• R7 is selected from the group consisting of a hydrocarbyl group having 1 to 7 carbon atoms, an aryl or an arylalkyl group, a group of formula H—(OA″)v-, wherein v represents an integer of between 1 and 20 and A″O represents an alkyleneoxy group containing from 2 to 4 carbon atoms, HO(CH2)q— and a group of formula (2)
• wherein R8 and R9, independently from each other, are selected from among a hydrocarbyl group having 1 to 6 carbon atoms, or R8 and R9, together with the nitrogen atom to which they are linked form a 5-, 6- or 7-atom ring, optionally bearing one or more heteroatom(s) chosen from among oxygen, nitrogen or sulphur and wherein q is an integer in the range from 1 to 10
• R11 is R1-(G)y- wherein R1 is selected from the group consisting of a hydrocarbyl group having 8 to 24 carbon atoms and a group of formula R4—O-(A′O)w-T-, wherein R4 is a hydrocarbyl group having from 8 to 24 carbon atoms, w is an integer in the range from 0 to 20, A′O is an alkyleneoxy group having from 2 to 4 carbon atoms, T is an alkylene group having from 1 to 6 carbon atoms, y is an integer from 0 to 5, and G represents a group of formula (3):
• wherein
• B is selected from the group consisting of C1-C4 alkyl, aryl and arylalkyl group,
• s is 1, 2 or 3 and
• R5, X and t are as defined above,
• and the group (CH2)s is a spacer between the two nitrogen atoms to which it is linked,
• c) mixing said white pigment and impurities containing material of step a) and said collector agent of step b) in an aqueous environment to form an aqueous suspension;
• d) passing gas through the suspension formed in step c);
• e) recovering the white pigment containing product by removing the white pigment bearing phase from the aqueous suspension obtained after step d).