Sodium Benzoate as Promoter in the Soap Flotation of Phosphate Minerals

In the present study we show that sodium benzoate substantially improves the efficiency of Soap LDO collector in the flotation of phosphate minerals.
&#xa

2,2-Dichloro-N-(4-chloro­phenyl­sulfon­yl)­acetamide

In the crystal structure of the title compound (N4CPSDCAA), C8H6Cl3NO3S, the conformations of the N—H and C=O bonds in the SO2—NH—CO—C group are trans to each other, similar to those observed in 2,2-dichloro-N-(phenyl­sulfon­yl)­acetamide (NPSDCAA), 2,2-dichloro-N-(4-methyl­phenyl­sulfon­yl)acetamide (N4MPSDCAA) and N-(4-chloro­phenyl­sulfon­yl)-2,2,2-trimethyl­acetamide (N4CPSTMAA), with similar bond parameters. The –SNHCOC– unit in N4CPSDCAA is essentially planar and makes a dihedral angle of 79.67 (5)° with the benzene ring, comparable to 79.75 (8)° in NPSDCAA, 81.02 (5)° in N4MPSDCAA and 82.2 (1)° in N4CPSTMAA. The mol­ecules in N4CPSDCAA are linked into layers parallel to the (001) plane by inter­molecular N—H⋯O hydrogen bonds

2,2,2-Trimethyl-N-(phenyl­sulfon­yl)­acetamide

The N—H and C=O bonds of the SO2—NH—CO group in the title compound, C11H15NO3S, are anti to each other. The asymmetric unit contains two independent mol­ecules. The benzene rings form dihedral angles of 83.19 (8) and 76.01 (10)° with the mean planes of the C2NOS fragments. The mol­ecules are linked into chains parallel to the b axis by inter­molecular N—H⋯O hydrogen bonds

N-(3,5-Dichloro­phen­yl)benzamide

The conformation of the H—N—C=O unit in the title compound, C13H9Cl2NO, is trans, similar to the conformation observed in N-(3-chloro­phen­yl)benzamide, N-(2,3-dichloro­phen­yl)benzamide, N-(2,4-dichloro­phen­yl)benzamide, N-(2,6-dichloro­phen­yl)benzamide and N-(3,4-dichloro­phen­yl)benz­amide. The amide group makes dihedral angles of 14.3 (8) and 44.4 (4)° with the benzoyl and aniline rings, respectively, while the benzoyl and aniline rings form a dihedral angle of 58.3 (1)°. The mol­ecules are linked by N—H⋯O hydrogen bonds into infinite chains running along the c axis

N-(2-Chloro­phen­yl)-2-methyl­benzamide

In the structure of the title compound (N2CP2MBA), C14H12ClNO, the conformations of the N—H and C=O bonds are trans to each other. Furthermore, the conformation of the N—H bond is syn to the ortho-chloro group in the aniline ring and the C=O bond is syn to the ortho-methyl substituent in the benzoyl ring, similar to what is observed in 2-chloro-N-(2-chloro­phen­yl)benzamide and 2-methyl-N-phenyl­benzamide. The amide group makes almost the same dihedral angles of 41.2 (14) and 42.2 (13)° with the aniline and benzoyl rings, respectively, while the dihedral angle between the benzoyl and aniline rings is only 7.4 (3)°. The mol­ecules in N2CP2MBA are packed into chains through N—H⋯O hydrogen bonds

N-(4-Bromo­phenyl­sulfon­yl)-2,2,2-tri­methyl­acetamide

The conformations of the N—H and C=O bonds in the SO2—NH—CO—C group of the title compound (N4BPSTMAA), C11H14BrNO3S, are trans to each other, similar to what is observed in N-(4-chloro­phenyl­sulfon­yl)-2,2,2-trimethyl­acet­amide (N4CPSTMAA) and 2,2,2-trimethyl-N-(4-methyl­phenyl­­sulfon­yl)acetamide (N4MPSTMAA). The bond para­meters in N4BPSTMAA are similar to those in N4CPSTMAA, N4MPSTMAA, N-aryl-2,2,2-trimethyl­acet­amides and 4-bromo­benzene­sulfonamide. The benzene ring and the SO2—NH—CO—C group in N4BPSTMAA form a dihedral angle of 82.8 (1)°, comparable with the values of 82.2 (1)° in N4CPSTMAA and 71.2 (1)° in N4MPSTMAA. N—H⋯O hydrogen bonds form a centrosymmetric ring characterized by an R 2 2(8) motif

N-(2-Chloro­benzo­yl)-4-methyl­benzene­sulfonamide

In the title compound, C14H12ClNO3S, the C=O bond is syn to the Cl substituent in the adjacent benzene ring. The C—S—N—C torsion angle is −80.6 (6)°. The chloro­benzoyl ring is disordered and was refined using a split model [occupancy ratio 0.537 (3):0.463 (3)]. In the crystal, mol­ecules are linked by pairs of N—H⋯O(S) hydrogen bonds, forming inversion dimers

2-Methyl-N-(3-methyl­phen­yl)benzamide

In the structure of the title compound (N3MP2MBA), C15H15NO, the conformation of the N—H bond is anti to the meta-methyl substituent in the aniline ring and that of the C=O bond is syn to the ortho-methyl substituent in the benzoyl ring, while the conformations of the N—H and C=O bonds are anti to each other. The bond parameters in N3MP2MBA are similar to those in 2-methyl-N-phenyl­benzamide, N-(3,4-dimethyl­phen­yl)benzamide and other benzanilides. The amide group, –NHCO–, makes a dihedral angle of 55.2 (7)° with the benzoyl ring, while the dihedral angle between the two benzene rings (benzoyl and aniline) is 36.2 (1)°. N—H⋯O hydrogen bonds give rise to infinite chains running along the b axis of the crystal structure

N-(3-Methyl­benzo­yl)benzene­sulfonamide

The asymmetric unit of the title compound, C14H13NO3S, contains three independent mol­ecules in which the dihedral angles between the sulfonyl and benzoyl benzene rings are 83.3 (2), 84.4 (2) and 87.6 (2)°. In the crystal, mol­ecules are linked into chains running along the a axis via N—H⋯O hydrogen bonds

N-(4-Chloro­phen­yl)-2-methyl­benzamide

In the structure of the title compound, C14H12ClNO, the N—H and C=O bonds are trans to each other. Furthermore, the C=O bond is syn to the ortho-methyl group in the benzoyl ring, similar to what is observed in 2-methyl-N-(4-methyl­phen­yl)benzamide and 2-methyl-N-phenyl­benzamide. The amide linkage (–NHCO–) makes dihedral angles of 36.9 (7) and 46.4 (5)° with the aniline and benzoyl rings, respectively, while the dihedral angle between the benzoyl and aniline rings is 83.1 (1)°. In the crystal structure, mol­ecules form chains running along the b axis through N—H⋯O hydrogen bonds