TOTAL CHEMICAL COST SAVING AND COD REDUCTION THROUGH APPLICATION OF NEUTRAL DEINKING SYSTEM
Neutral or low-alkali deinking chemistry is of interest to many paper mills due to stringent economic and environmental pressures.Experiments on deinking and post bleaching process were carried out at both laboratory and field trial to evaluate brightness and residual ink of pulps under alkaline soap or low-alkali synthetic surfactant blend conditions. 100％ old newspaper (ONP) were pulped,floated and bleached with both deinking chemistries in series laboratory study at Kemira Shanghai R&D center.Compared with soap system,50-150 ppm lower residual ink and 2-2.5 point higher final brightness were achieved at low-alkali chemistry.The results also showed 0.5-1.0 point slightly brightness loses when eliminating or reducing NaOH and peroxide in pulper.However,the differences can always be compensated by post bleaching process because of better responsibility of the neutral deinked pulp in post peroxide bleaching. Neutral deinking system was proved total chemical cost saving and at least 20％ effluent COD reduction in several Kemira full scale trial of China DIP lines with similar or better ink release and floatation efficiency.In addition,lower system pH also provides better stickies control and less anionic trash in wet end. Nevertheless,neutral deinking technology is facing challenges in China.Instability of various furnish quality and more OMG or coated paper reuse with high ash and stickies content are big issues especially when using high foaming neutral deinking synthetic surfactants.Lower foaming surfactants or new surface chemistry are expected to be approaches in current flotation deinking system.
neutral deinking ERIC bleachability COD total chemical cost
TianxingWen
Kemira Shanghai R&D Center,Shanghai 201112,China
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
1401-1405
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）