Method for treating an aqueous suspension of solid mineral particles containing between 5% et 60% by weight of solids relative to the total weight of said suspensions, arising from the extraction of ores, comprising the following steps: - we prepare a water-soluble polymer comprising: ∘ at least one non-ionic monomer selected from the group consisting of acrylamide; methacrylamide; N-monoderivatives of acrylamide; N-monoderivatives of methacrylamide; N,N-derivatives of acrylamide; N,N-derivatives of methacrylamide; acrylic esters; methacrylic esters; N-vinylformamide; and N-vinylpyrrolidone; ∘ at least one anionic monomer representing between 10 and 70 mol%, selected from the group consisting of monomers having a carboxylic functional group and salts thereof; monomers having a sulfonic acid functional group and salts thereof, monomers having a phosphonic acid functional group and salts thereof; ∘ at least one cationic monomer representing between 0.2 and 6 mol%, selected from the group comprising diallyldimethylammonium chloride, methacrylamido-propyl trimethyl ammonium chloride and acrylamidopropyl trimethyl ammonium chloride; - we add said water-soluble polymer to the aqueous suspension of solid particles into a thickener that already contains the suspension to be treated, or into a pipe transporting the aqueous suspension of solid particles to a thickener or into a pipe transporting the aqueous suspension of solid particles to a depositing area on which the treated suspension is spread with a view to its dehydration and solidification. - we prepare a water-soluble polymer comprising: ∘ at least one non-ionic monomer selected from the group consisting of acrylamide; methacrylamide; N-monoderivatives of acrylamide; N-monoderivatives of methacrylamide; N,N-derivatives of acrylamide; N,N-derivatives of methacrylamide; acrylic esters; methacrylic esters; N-vinylformamide; and N-vinylpyrrolidone; ∘ at least one anionic monomer representing between 10 and 70 mol%, selected from the group consisting of monomers having a carboxylic functional group and salts thereof; monomers having a sulfonic acid functional group and salts thereof, monomers having a phosphonic acid functional group and salts thereof; ∘ at least one cationic monomer representing between 0.2 and 6 mol%, selected from the group comprising diallyldimethylammonium chloride, methacrylamido-propyl trimethyl ammonium chloride and acrylamidopropyl trimethyl ammonium chloride; ∘ at least one non-ionic monomer selected from the group consisting of acrylamide; methacrylamide; N-monoderivatives of acrylamide; N-monoderivatives of methacrylamide; N,N-derivatives of acrylamide; N,N-derivatives of methacrylamide; acrylic esters; methacrylic esters; N-vinylformamide; and N-vinylpyrrolidone; ∘ at least one anionic monomer representing between 10 and 70 mol%, selected from the group consisting of monomers having a carboxylic functional group and salts thereof; monomers having a sulfonic acid functional group and salts thereof, monomers having a phosphonic acid functional group and salts thereof; ∘ at least one cationic monomer representing between 0.2 and 6 mol%, selected from the group comprising diallyldimethylammonium chloride, methacrylamido-propyl trimethyl ammonium chloride and acrylamidopropyl trimethyl ammonium chloride; - we add said water-soluble polymer to the aqueous suspension of solid particles into a thickener that already contains the suspension to be treated, or into a pipe transporting the aqueous suspension of solid particles to a thickener or into a pipe transporting the aqueous suspension of solid particles to a depositing area on which the treated suspension is spread with a view to its dehydration and solidification.