Technical Reformations Of Pulp And White Water Flocculation In Secondary Fiber Pulping Process

Papermaking industry plays a decisive role in the national economy and the society request,of which more than 50%use of waste paper fiber resources.Papermaking with waste paper is an important achievement in the development of modern paper industry,is an important part of recycle economy that sustains social sustainable development,which can save resources,protect the ecology,reduce energy consumption and reduce pollution effectively.On the one hand,papermaking technology with waste paper has been very mature after decades of development,however,there are also many problems that have been difficult to solve,such as problems of sticky have been plagued modern papermaking enterprises.On the other hand,as the public’s need for a better life,the increasing awareness of environmental protection,the demands of the higher demands on the living environment and the working environment,the state environmental protection department also increasingly stringent requirements on the clean production process and environmental protection in various industries.As one of the eight major industries in China,the papermaking industry has continued to be controlled strictly by the state environmental protection department.With the continuous emergence of new technologies and new ideas,in the face of the national environmental protection requirements and market competition,for modern papermaking enterprises,to combine new technologies,new ideas,new equipments on the existing business problems existing production line by technological optimization and technological transformation to solve production and operation problems,to achieve efficiency,energy saving and so on,is not only very feasible and necessary,but also an inevitable trend of continuous development of enterprises in the fierce market competition.Because of the ink,sticky and other impurities in the waste paper have a greater impact on the paper production process and quality,the removal of impurities in waste paper pulp and white water purification is of great significance to papermaking technology with waste paper.This paper introduced that the technical reformation on waste papermaking line,including adding flotation equipment to the old corrugated containerboard(OCC)pulp production process,which is mainly used to remove the stickies in the OCC pulp,and adding large shallow air flotation equipment to treatment of the white water,so as to improve the cleanliness of white water and reduce the adverse effect of excessive accumulation of impurities on the production system during the recycling of white water.Combined with experimental datas and operation datas for statistical analysis after the tracking of technical reformation,and evaluated objectively the effect of the technical reformation.The results showed that,the flotation equipment can help to remove 34.49%stickies and 37.65%ashes on the OCC long-fiberpulp,and can help to remove 47.17%stickies and 30.82%ashes on the OCC short-fiberpulp;the removal rate of stickies was 77.47%for the scum of long-fiber pulp and was 60.12%for the scum of short-fiber pump through the tail fine screen.The breaking time decreased 4.12 hours per monthwhen producing coated paper,the efficiency increased from 90.49%to 91.93%,the A-class products increased about 0.31%,the number of the stickies which on the surface of paper reduced 7.71/M2 on average,the number of customers’ complaints which because of sticky decreased by 3.38 times per month,the amount of compensation decreased by ￥52,000 per month,above all,it can create￥5,183,200 of economic benefitsevery year,the payback period will be less than 3.5 years.It is showed that adding flotation equipment to the OCC pulp production process has obvious effect for removal of paste impurities like stickies.In addition,the effect is obvious after the white water was treated by the shallow air flotation equipment,the removal rate of solid substrate(SS)was 97.9%andChemical Oxygen Demand(COD)decreased by 48.6%on average,to reduce the excessive accumulation of impurities in the white water recycling cycle,reducing the reuse of excess water and white debris in the slurry cleanliness of the adverse effects on the benefits of white water reuse.The technical transformation conducive to the removal of sticky and other impurities,to improve the paper machine operating rate,improve the quality of production,resulting in a good economic benefits after technical reformation,it is pointed out that,adopting flotation technology to the OCC pulp production process and treating white water by the shallow air floatation equipmentis an effective way to improve the cleanliness of OCC pulp.