Geotechnical characteristics of tailings via lime addition

A method for treating tailings, comprising:

• obtaining tailings comprising clay and bicarbonates;
• combining at least a portion of the tailings with a first coagulant comprising calcium hydroxide to form a first mixture having a pH of at least 11.5 to no more than 12.0;
• combining a second coagulant comprising calcium hydroxide with the first mixture to form a second mixture having a pH of at least 12.0 and a soluble calcium level of no more than 800 mg/L, wherein the pH and soluble calcium level promote pozzolanic reactions to occur within the second mixture;
• and
• dewatering the second mixture to produce a product having a shear strength that increases over a period of time of at least two days to be at least 1.5 kilopascals.

A system for treating tailings, comprising:

• a mixer or inline mixing area configured to
• receive (i) tailings comprising clay and bicarbonates and (ii) a coagulant comprising calcium hydroxide, and
• mix the tailings and coagulant to form a first mixture comprising a pH of at least 12.0 and a soluble calcium level of no more than 800 mg/L;
• and
• a dewatering device configured to dewater the mixture to produce a product having a shear strength that increases over a period of time of at least two days to at least 1.5 kilopascals.