Abstract on the topic of graduation work
Content
- Introduction
- 1. Raw materials base of secondary nonferrous alloys
- 2. Collection and sorting
- List of sources
Introduction
The production of non-ferrous metals and alloys from primary raw materials is an expensive and time-consuming process, so many enterprises seek to return as much scrap as possible, containing the required components, into the working cycle. This allows significant savings in mining and smelting.
1. Raw materials base of secondary nonferrous alloys
Resources of waste of non-ferrous metals and alloys are a part of the fund of non-ferrous metals and alloys, which has passed into the category of waste by the time the fund is determined. At the same time, waste of non-ferrous metals and alloys means residues of non-ferrous metals and alloys generated in the production process (production waste), consumption and operation of machines and mechanisms (consumption waste or scrap) that have lost their original consumer properties.
Production waste - the remains of raw materials, materials, semi-finished products, formed during the manufacture of products and have completely or partially lost their original consumer properties. Consumption waste (scrap) - products and materials that have lost their consumer properties due to physical wear and tear.
Distinguish between recycled waste - a part of waste of non-ferrous metals and alloys intended for use in places of their formation and commercial waste - a part of waste intended for sale in the domestic market and for export. In this case, the secondary raw materials of non-ferrous metals mean only that part of the waste of non-ferrous metals and alloys, the reuse of which is technically possible and economically feasible.
In industrialized countries, the increase in the production of non-ferrous metals over the past decade was (in percent): aluminum - 16.0% (from secondary raw materials 13.0%); copper 6.0% (from secondary raw materials 30.0%); lead 8.0% (from secondary raw materials 15.0%); zinc 9.0% (from secondary raw materials 8.0%).
The consumers of non-ferrous metals are: transport and general machine building, aircraft and shipbuilding, electrical engineering, construction, chemical industry, agriculture. However, increasing the production of non-ferrous metals from ore raw materials is fraught with significant difficulties. The resources of waste of non-ferrous metals and alloys depend on the volume of consumption of non-ferrous metals and the completeness of their use in the manufacture of various products. The higher the metal utilization factor (CMR), the lower the waste yield.
Sometimes they use the concept of specific waste yield, which is understood as the amount of scrap and waste generated when a unit of non-ferrous metals is consumed.[1].
The main indicators of the formation and use of waste and non-ferrous metal scrap for various categories of consumers and types of products consumed are given in picture 1.1.
Picture 1.1 – RAT values in products and their service life (life cycle) in various industries
2. Collection and sorting
Resources of consumption waste (scrap). Machines, units, structures contain units and elements made of non-ferrous metals. Replacement of morally and physically obsolete products leads to the transition of these metals into consumption waste (scrap), while part of the metal is lost due to corrosion or physical wear, as well as due to incomplete collection of such waste.
Consumption waste resources are calculated by determining the annual investment of non-ferrous metals in the national economy and their service life in products. The service life of non-ferrous metals in various products ranges from 2 to 50 years[1].
Every year, each industrial enterprise irretrievably loses from ~ 15.0 thousand tons of aluminum and 10.0 thousand tons of copper, the main directions of losses of which are shown in picture 2.1.
Picture 2.1 – The main directions of losses of aluminum and copper, in percent
The larger the stock of non-ferrous metals, the greater the amount of generated scrap. This indicator is also influenced by the service life of products and parts (life cycle)[1].