关键词：
steel scrap
coated steel
removal rates
recycling
degredation
废钢
涂层钢
清除率
再循环
碎裂
Caustic solutions
Coating
Steel scrap
metal ions
REMOVAL RATE
coated steel bar
organic
Coated
undercutting
root pruning
Steels
摘要：
The demand for organic and metallic coated steels has risen dramatically over the past two decades. The future requirement to recycle large quantities of organic and metallic coated steels in an environmentally satisfactory manner through basic oxygen steelmaking (BOS) or electric are furnace (EAF) routes has been examined. The coating removal rates of different types of organic coated steel have been investigated over a range of different conditions. This research has been carried out with the aim of delaminating organic coatings using wet chemical treatments with and without the use of ultrasonics. Results indicate that successful coating removal using a caustic solution was due to a chemical attack of the coating. The acid reaction solution produced successful coating removal via an undercutting of the zinc substrate layer. Use of ultrasonics disintegrated the thinner coatings for both the caustic and acid reaction solutions. Ultrasonic use also initiated undercutting of the zinc layer when used with a caustic reaction solution. Plastisol was not chemically attacked by any reaction solution, nor disintegrated by the use of ultrasonics. The plastisol material required a thermal pretreatment to produce successful coating removal with the use of a caustic reaction solution. Base hydrolysis and the addition of metal ions were found to be unsuccessful in producing degradation of the plastisol. The data presented in this paper have led to the design and construction of a larger scale pilot plant. This work is currently in progress and is intended to be the subject of a future paper. The project as a whole contributes to environmental protection by providing a process route for removing coatings from coated steels, should this become necessary. (C) 1999 loM Communications Ltd.
欢迎来到三峡大学图书馆！
