Patent ID: 8262851

Claim:
An alkaline peroxide mechanical pulping process comprising the steps of: (a) preconditioning a lignocellulosic chip material by adding chemical stabilizers selected from the group consisting of diethylene triamine pentaacetic acid (DTPA), ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), silicate and MgSO 4 to a non-compressive digester containing the lignocellulosic chip material to be preconditioned in the presence of liquor to achieve a liquor to wood ratio in the digester of between about 0.5:1 to about 5:1 to form a preconditioned liqnocellulosic chip material; (b) discharging the preconditioned lignocellulosic chip material from the digester without the use of a screw mechanism to a fiberizer, and mechanically breaking apart the preconditioned lignocellulosic material in the fiberizer to obtain a fiberized lignocellulosic material; (c) washing the fiberized lignocellulosic material, (d) feeding the washed fiberized lignocellulosic material to a high consistency refiner; (e) treating the washed and fiberized lignocellulosic material with alkali peroxide chemicals for a time and under conditions sufficient to obtain a pulp therefrom; (f) retaining the pulp in a high consistency tower for a time sufficient to allow chemical reactions to complete; and thereafter (g) transferring the pulp from the high consistency tower to downstream processes and recovering the pulp therefrom.