초록 ▼

Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second f

Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second filtrate including oxalic acid, recycling the second filtrate to the pulp prior to the bleaching step, and transferring the first filtrate to the bleached pulp.

대표청구항 ▼

1. A process for bleaching a metal-containing pulp, said process comprisinga) combining said metal-containing pulp with an aqueous stream that includes oxalic acid; b) removing water thereby providing a treated pulp and a first metal-containing filtrate; c) bleaching said treated pulp with ozone the

1. A process for bleaching a metal-containing pulp, said process comprisinga) combining said metal-containing pulp with an aqueous stream that includes oxalic acid; b) removing water thereby providing a treated pulp and a first metal-containing filtrate; c) bleaching said treated pulp with ozone thereby providing a bleached pulp and said oxalic acid; d) transferring said first metal-containing filtrate to said bleached pulp; e) washing said bleached pulp thereby providing a washed bleached pulp and a second metal-containing filtrate including said oxalic acid; wherein said aqueous stream comprises at least a portion of said second metal-containing filtrate.