Aggregates play a filling and framing role in concrete. They are loose particles and improve the durability and stability of concrete.

According to the source, they are divided into natural, artificial and recycled;

According to the particle size, they are divided into coarse aggregate and fine aggregate;

According to the density, they are divided into ordinary aggregate and light aggregate.

Particles with a particle size between 0.15 and 4.75 mm are called sand, while particles between 4.75 and 9.0 mm are called stone. In view of the decreasing natural sand and stone resources, the artificial sand and stone market is booming. Using mechanical equipment, slag, rock, waste, etc. can be processed into sand and stone aggregates of the required particle size.

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Aggregate production process

The selection of aggregate production line is an important part of modern aggregate mine production. The complete production line consists of four major systems: feeding system, crushing and sand making system, screening system, and sorting system.

1. Pretreatment

The main task of this stage is to pre-crush the bulk materials of the sand and gravel aggregate ore by hammering. At the same time, the debris that is not suitable for crushing, such as waste wood and plastic, is sorted and removed. In addition, the primary magnetic separation is also carried out to remove the waste iron in the aggregate to prepare for the subsequent processing steps.

2. Crushing and sand making

First, the raw materials are evenly fed into the jaw crusher through a vibrating feeder for primary crushing. The jaw plate moves to crush the large pieces of sand and gravel aggregate into smaller particles. The coarsely crushed materials are transported to the transfer pile by the conveying equipment. Subsequently, the materials are finely crushed and shaped using a sand making and shaping machine, and the processed sand and gravel aggregates have uniform particle sizes.

3. Primary screening

In this stage, a circular vibrating screen is used to screen the coarsely crushed concrete aggregate to obtain 0-40mm blocks and crushed materials below 5mm. Among them, 5-40mm coarse aggregate can be directly used for C15-C20 concrete production, while fine aggregate is transported to the transfer pile for subsequent processing.

4. Secondary crushing and screening

The secondary crushing uses a ball mill to crush the fine aggregate again. Then the secondary screening is carried out to divide the aggregate into 5-20mm specifications. These high-quality recycled aggregates are suitable for C25-C30 concrete production. The tertiary screening further subdivides the fine aggregate of 0.15mm-5mm and the fine powder below 0.15mm.

Common aggregate production line configuration

Generally speaking, the configuration of the aggregate production line needs to be combined with the user's working conditions, hourly production, finished product particle size, energy consumption and other requirements. Common equipment combinations of aggregate production lines:

1, jaw crusher + cone crusher + sand making machine + auxiliary equipment (feeder, conveyor, elevator, etc.);

2, jaw crusher + impact crusher + sand making machine + auxiliary equipment;

3, hammer crusher + high-efficiency fine crusher + impact sand making machine + auxiliary equipment.