Mine waste rock often contains a small amount of valuable metals, so it has a certain pre-enrichment value. If the valuable metal in waste rock can be reused, the utilization rate of resources can be improved to a certain extent. In addition, waste rock also contains a large number of gangue minerals, such as carbonate and silicate, etc. These minerals have high strength and stable mechanical properties, which can be used as engineering filling or building materials, so as to realize the maximum utilization of waste rock.
1. Made Into Building Materials
According to the mechanical properties and stability of different waste rocks, the waste rocks can be made into materials such as sand and gravel aggregates, bricks, cement and concrete.
(1) Sand And Gravel Aggregate
Since most waste rocks have the characteristics of high strength and stable mechanical properties, waste rocks can be used to make sand and gravel aggregates. At this stage, the domestically adopted process is mainly to pulverize waste rock, and then through sieving to produce different types of sand and gravel aggregates.
(2) Brick Cement
The use of coal mine waste as building materials is in line with the country's policy of "saving energy and taking local materials" for the development of building materials. At present, the use of coal mine waste rock to produce non-burning bricks is a very promising technology. With the rapid increase in the amount of cement and the reduction of non-renewable resources such as limestone and clay, mine waste can also be used as raw materials for the production of cement.
Studies have shown that the addition of coal gangue can change the compressive strength, resistance and frost resistance of concrete. Therefore, coal gangue concrete is a promising building material. In addition to coal gangue, for iron ore waste rock, it is mainly mixed with iron tailings or iron ore tailings to make concrete.
The comprehensive utilization of waste rock not only avoids the hidden dangers of environmental pollution caused by waste rock storage, but also reduces the loss rate of resources and realizes the purpose of turning waste into treasure. Therefore, for the disposal of waste rock, it is recommended to maximize the utilization of useful minerals in the waste rock, and the extracted waste rock can be used for filling or making building materials.