Classification of scrap iron and steel

Scrap steel can be divided into two categories according to its source. One is the scrap steel produced by the depreciation of scrap steel in all walks of life (hereinafter referred to as depreciated scrap steel). The other is the scrap steel produced in various production processes (referred to as productive scrap steel).

If subdivided, it can be divided into seven categories:

1. Part of the productive scrap steel is the scrap of goods used by various steel manufacturing terminals; This part is returned to iron and steel enterprises for re-smelting through market transactions. The other part is the returned scrap steel produced by various iron and steel enterprises, which is the leftover materials from workshops, factories and other production units in the production process, such as cutting heads, tails, casting slag, waste products, samples, steel scraps, scraps and so on. Productive scrap steel is characterized by good quality, high yield of molten steel, clear steel grade and clear chemical composition. Managing this part of scrap steel well is of great significance for reducing production costs. However, with the technical progress of various industries and the pursuit of energy saving and consumption reduction, and since the converter (electric furnace)+full continuous casting has been realized in iron and steel enterprises, the output has increased, the self-produced returned scrap steel has decreased, and the productive scrap steel has tended to decrease.

2. Agricultural scrap iron and steel Agricultural scrap iron and steel comes from various damaged agricultural facilities such as gates, dams, bridges, tools and appliances. Because China's agricultural modernization started late, underdeveloped and few. There are more waste cast iron and tool steel in agricultural scrap.

3. Scrap steel in infrastructure industry comes from a large number of scrap steel in infrastructure industry. Especially in recent years, with the development of railway construction, highway construction, municipal construction, industrial and civil buildings, there are more and more scrap steel in this area, and it is expected that the output will maintain a high level in the next 20 years. The scrap steel in this respect is of good quality, including all kinds of steel bars, corners, troughs and plates that have been dismantled, leftover materials of corners, troughs and plates used in the project, and obsolete construction equipment and tools. In recent years, with the increase of demolition efforts, more and more scrap steel has been removed from various buildings. Most of these scrap steels are ordinary carbon steel. Generally speaking, the amount of steel used in brick-concrete structures is small, ranging from {0} to 30 kg per square meter; The amount of steel used in frame structure construction is relatively large, and the amount of steel used per square meter is between 40 and 50 kilograms. 4. Railway scrap At present, China's railway construction is developing rapidly. With the great development of high-speed rail and EMU and the speed increase of railway, the original railway facilities are becoming more and more unsuitable. As a result, many railway facilities, such as locomotives, carriages and tracks, have been eliminated and scrapped. This part of scrap steel is of high quality, and most of it is heavy material. The recovery rate of molten steel is high. This part of scrap steel is a hot commodity of various iron and steel enterprises. With the development of railway industry, there will be more and more scrap steel in this area, which should attract the attention of scrap steel operators and users. Railway scrap includes carbon steel and alloy steel. 5. Mine scrap iron and steel China is rich in mineral resources, especially coal production ranks first in the world, coal reserves rank third in the world, and coal production has a long history. Therefore, a large number of scrap steel were eliminated in this respect. Coal mine is a high-risk industry, and the equipment is eliminated and updated quickly, which is also the place where more scrap steel is produced. Such as various hydraulic supports, roadway supports, transport vehicles, various mining machinery and tools, etc. This kind of scrap steel is also high quality scrap steel. Mine waste is characterized by heavy materials and alloy steel. 6. Civil scrap Civil scrap occupies a considerable proportion in the whole scrap market. But the quality is uneven, mostly light and small, easy to oxidize and rust, and the recovery rate of molten steel is low. For example, the skin of household appliances, steel furniture, office furniture, cooking stoves, kitchen utensils, water pipes, steel doors and windows, pedal tools, fitness equipment and beverage containers. In order to recycle civil steel scrap, it must be treated. For example, balers, shears and shredders are used to increase fluff density. In addition, early use is beneficial to reduce oxidation. Civil scrap steel should pay attention to all kinds of scrap steel containing zinc and tin, such as cans, cans and various cylinders. 7. Military scrap The quantity of military scrap is very small. In China, some outdated military weapons and equipment must be supervised by soldiers and destroyed in designated steel enterprises.