2017年四川省岳池县第一中学高中英语 Module1 Life in the Future 第5课时学案 外研版必修4.docVIP

Period 5: Cultural Corner 学习目标： 1. 了解2. 树立跨文化交际意识 3. 掌握重点的用法 学习重点： 了解 学习难点： 掌握重点的用法 课前预习 使用说明与学法指导： 1. 树立跨文化交际意识 2. 15分钟之内完成 教材助读： Glass Recycling Glass has the least volatile pricing of all the post consumer recycling commodities. Composed of sand and potash; bottle glass is made from readily available and inexpensive raw materials. To be competitive, recycled glass must maintain a price that competes with these abundant raw materials. Traded as flint (clear), amber (brown), emerald (green) or mixed color broken glass. The price depends on the cleanliness and color of the recycled product. Clean flint cullet (another word for broken glass) is usually the most desirable form of recycled glass scrap. Mixed color broken glass with ceramics or stones mixed in it is the least desirable grade of cullet bringing the lowest price. Most Recyclers color sort and break or crush and screen bottles before selling their product. Modern, high production bottle manufacturing requires very clean and uniform feedstock. Over the past decade there has been a growth in the glass benefaction sector. These are intermediate processors that receive glass from recycling programs and run it through a series of steps to remove any contaminants (rocks, ceramics, metal caps, etc.) and provide a uniform feedstock to the bottle manufacturers. These preprocessor provide an excellent market for recycling programs that do not have the volume or ability to produce glass for direct mill delivery. Glass beneficiation plants use sophisticated optical sorting machines to separate the glass into the three color types. They may also x-ray the glass to detect any rocks or ceramics which are then removed. Magnets and eddy current separators are used to removed magnetic and non-magnetic metal contamination from caps and lids. The end product is a uniformly sized load of ground glass that is free of contaminants readily acceptable by bottle manufacturers. Lower grades of recycled glass that are too mixed o