Scrap iron and steel according to its source can be divided into two categories, one is the society of all walks of life due to depreciation of scrap iron and steel (referred to as depreciation of scrap iron and steel). The other category is in a variety of production process of iron and steel scrap (referred to as productive iron and steel scrap).
Subdivision can be divided into seven categories:
1, production scrap iron and steel
Production scrap iron and steel is part of the various use of steel to manufacture end-use commodities of the edge of the scrap; this part of the market through the transaction back to the steel enterprises for smelting again. The other part is the return of the steel enterprise self-produced scrap iron and steel, is the enterprise internal production units such as, workshop, branch in the production process down the edge of the residue such as: cut head, cut tail, casting residue, scrap, samples, scraps, scraps, and so on. Productive scrap iron and steel is characterized by: very good quality, high steel yield, clear steel, chemical composition is clear. Good management of this part of the scrap iron and steel for reducing production costs has an important meaning. However, with the technological progress of various industries and the pursuit of energy saving and cost reduction, as well as iron and steel enterprises to realize the converter (electric furnace) + all continuous casting since the material rate increased, self-produced back to the reduction of iron and steel scrap, productive iron and steel scrap tends to reduce the trend.
2. Agricultural scrap iron and steel
Agricultural scrap iron and steel from the damage to a variety of agricultural facilities such as gates, dams, bridges, utensils, implements, etc., due to the modernization of China's agriculture started late, is still underdeveloped, less. Agricultural scrap steel in the waste cast iron, tool steel more.
3. Capital construction scrap iron and steel
Scrap iron and steel from the capital construction industry in larger quantities, especially in recent years, with the development of railroad construction, highway construction, municipal construction, industrial and civil construction, more and more scrap iron and steel in this area, is expected in the next 20 years will be maintained in the output of higher quantities. Scrap iron and steel from this area is of better quality, with varieties of demolished steel bars of various types, corners, slots, plates, engineering corners, slots, plates of scraps, elimination of end-of-life construction equipment and industrial appliances. In recent years, with the increase in the amount of demolition, all kinds of building demolition of scrap iron and steel more and more. This part of the scrap steel is the vast majority of ordinary
Carbon steel.
Generally speaking, the brick structure of the building with a small amount of steel, steel per square meter in the }0}-30kg; frame structure of the building with a larger amount of steel, steel per square meter in the 40^-50kg.
4. Railway scrap iron and steel
Currently, China's railroad construction is developing rapidly, with the high-speed railways, rolling stock, railroad speed up the development of the original railroad facilities with which more and more incompatible. Therefore, the elimination of many railroad facilities, such as locomotives, carriages, tracks and so on.
This part of the scrap iron and steel quality is superior, the vast majority of heavy material. And the chemical composition is clear, high steel recovery rate. This part of the scrap iron and steel is the steel enterprises of the sought-after goods. With the development of the railroad business, this aspect of the scrap iron and steel will be more and more, should cause the scrap iron and steel operators and users of attention. Scrap steel from the railroad has carbon steel and alloy steel.
5. Mining scrap iron and steel
China is rich in mineral resources, especially coal production ranks first in the world, coal storage capacity ranks third in the world, the history of coal production is longer, therefore, this aspect of the elimination of scrap iron and steel down a lot. Coal mine is a high-risk industry, the equipment out of the update faster, the same is also more scrap iron and steel production. For example, a variety of hydraulic support, roadway support, transportation vehicles, a variety of mining machinery and equipment. This kind of scrap iron and steel is also high-quality scrap iron and steel. Mining scrap steel is characterized by heavy material, alloy steel.
6. Civilian scrap iron and steel
Civilian scrap iron and steel in the entire scrap iron and steel market occupies a considerable proportion. However, the quality varies, the vast majority of light material and small material, easy to oxidize and rust, the steel recovery rate is low. For example, the outer skin of home appliances, steel-made tables and chairs furniture, office furniture, stoves, kitchen utensils, water and sewage pipes, steel doors and windows, foot tools, fitness equipment, beverage containers. To better recycle the use of civil scrap iron and steel must be civil scrap iron and steel processing. For example, use balers, shears, crushers to increase the pile density. In addition, use as soon as possible to reduce oxidation, turn unfavorable into favorable. Civilian scrap steel should pay attention to a variety of scrap steel containing zinc, tin, such as cans, can boxes, a variety of cylinders.
7. Military scrap iron and steel
Military scrap iron and steel in smaller quantities. In our country some of the elimination of end-of-life military weapons and equipment in the destruction must be supervised by military personnel, and to the designated steel enterprises to destroy.