公开(公告)号：US10858782B2

公开(公告)日：2020-12-08

申请号：US16462570

申请日：2017-12-15

申请人： Kemira Oyj

发明人： Matti Hietaniemi ,  Rosa Carceller ,  Asko Karppi ,  Joonas Likander ,  Jyri Välimäki

IPC分类号： D21C9/18 ,  D21C5/02 ,  D21H21/10 ,  D21H17/45 ,  D21H23/04 ,  C02F1/54 ,  C02F11/125 ,  C02F11/147 ,  C02F11/126 ,  C02F103/28

摘要： A method is disclosed for dewatering of sludge from a pulp, paper or board making process, such as deinking sludge, including obtaining of an aqueous sludge including an aqueous phase and a fibre material suspended in the aqueous phase. The sludge is subjected to a pre-thickening step, where a first part of the aqueous phase is removed from the sludge and to a pressing step, where a second part of the aqueous phase is removed from the sludge, thereby obtaining a dry pressed sludge. Before or at the pre-thickening step a polymer composition having a charge density of at the most 1.7 meq/g, preferably at most 1.5 meq/g, more preferably at most 1.1 meq/g, is added to the sludge.

公开(公告)号：US11629459B2

公开(公告)日：2023-04-18

申请号：US16766718

申请日：2018-12-14

申请人： Kemira Oyj

发明人： Matti Hietaniemi ,  Jyri Välimäki ,  Joonas Likander ,  Rosa Carceller

IPC分类号： D21C5/00 ,  D21C5/02 ,  D21B1/32

摘要： A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.

公开(公告)号：US20200063340A1

公开(公告)日：2020-02-27

申请号：US16462570

申请日：2017-12-15

申请人： Kemira Oyj

发明人： Matti Hietaniemi ,  Rosa Carceller ,  Asko Karppi ,  Joonas Likander ,  Jyri Välimäki

IPC分类号： D21C9/18 ,  D21C5/02 ,  D21H21/10 ,  D21H17/45 ,  D21H23/04 ,  C02F1/54 ,  C02F11/147 ,  C02F11/126 ,  C02F11/125

摘要： A method is disclosed for dewatering of sludge from a pulp, paper or board making process, such as deinking sludge, including obtaining of an aqueous sludge including an aqueous phase and a fibre material suspended in the aqueous phase. The sludge is subjected to a pre-thickening step, where a first part of the aqueous phase is removed from the sludge and to a pressing step, where a second part of the aqueous phase is removed from the sludge, thereby obtaining a dry pressed sludge. Before or at the pre-thickening step a polymer composition having a charge density of at the most 1.7 meq/g, preferably at most 1.5 meq/g, more preferably at most 1.1 meq/g, is added to the sludge.