Patent ID: 8506822

Claim:
A process of concentrating an aqueous suspension of solid particles comprising mineral particles, the process comprising the steps of: (i) adding at least one organic polymeric flocculant to the suspension thereby, wherein said organic polymeric flocculant is a nonionic or anionic polymer having an intrinsic viscosity of at least 4 dl/g, (ii) forming flocculated solids, and (iii) allowing the flocculated solids to settle forming a layer of solids and a more concentrated suspension, wherein an effective amount of an agent is applied to the suspension prior to or substantially simultaneously with adding the organic polymeric flocculant and/or the organic polymeric flocculant is added to the suspension in a vessel and the agent is applied to the suspension in the same vessel, wherein the agent is a free radical agent, and wherein the free radical agent brings about a reduction in yield stress of the layer of solids at least 10% below the yield stress of a layer of solids at an equivalent solids content without the addition of the free radical agent, and an increase in aqueous liquid released from said layer, wherein the free radical agent is tertiary butyl hydro peroxide, sodium sulphite, sodium bisulphite, sodium persulphate, sodium perborate, sodium nitrite, or sodium percarbonate.