Started in 1980s, Zhengzhou Unique Industrial Equipment Co., Ltd (Unique Group) is already a famous manufacturer & developer of mining equipment like stone crushing & screening equipment and ore processing equipment in China. Our products scope mainly includes cone crusher, jaw crusher, impact crusher, sand making machine, vibrating screen, vibrating feeder, belt conveyor, stationary & mobile stone crushing plant, ball mill, magnetic separator and cement production line etc.
Aggregate Sources and Processing
¾-inch aggregate typically comes from natural stone (such as granite and limestone) or recycled building materials (such as crushed concrete blocks and bricks). The processing process mainly includes:
Crushing
First, the raw material (large stone or waste) is crushed in a crusher (such as a jaw crusher or cone crusher) to obtain smaller particles.
If the particles are still large after the initial crushing, secondary crushing (such as an impact crusher) is required to further refine the particle size.
Screening
The crushed mixed particles are screened by vibrating screens with a precisely set ¾-inch (19.05 mm) aperture.
During the screening process, particles smaller than ¾-inch pass through the screens, while particles larger than this size are returned to the crusher for re-crushing until they meet the required size.
Cleaning (Optional)
If the aggregate is used in applications requiring high cleanliness (such as concrete), a sand washer is required to remove surface impurities such as dirt and dust.
Key Equipment and Parameters
Crusher: Select according to the hardness of the raw material. A jaw crusher and cone crusher combination is often used for hard rock (such as granite), while an impact crusher can be used for soft rock (such as limestone) or recycled material.
Vibrating Screen: A 3/4-inch mesh is required to ensure that the aggregate particle size is within the range of 3/8-inch to 3/4-inch (approximately 9.5-19.05 mm) (a certain degree of tolerance is acceptable in actual projects).
Screening Efficiency: By adjusting the vibration frequency and mesh angle, the passing rate of appropriate aggregate is increased and the number of overly fine or coarse particles is reduced.
Application Scenarios and Precautions
Applicable Applications: 3/4-inch aggregate is commonly used in ordinary concrete, roadbed fill, asphalt mixtures, etc. Its particle size distribution must meet relevant standards (such as China GB/T 14685 and US ASTM C33).
Quality Control:
Avoid excessive mud content (generally ≤3%), as this will affect concrete strength. Check the particle shape and try to choose aggregates with fewer edges and corners and uniform grading to improve construction and work-ability.
