With the rapid development of domestic infrastructure construction, the demand for sand and aggregate is increasing. However, traditional sand and aggregate production enterprises generally face problems such as small production scale, low capacity, outdated technology, and serious environmental pollution. To meet market demand and achieve green and sustainable development, large-scale, intensive, and environmentally friendly sand and aggregate production lines have become an urgent need. The following will share a case study of a limestone manufactured sand and aggregate production line with a production capacity of up to 4000 t/h.

More Crushing and Sand Making Cases

I. Project Overview

This project uses limestone as raw material and adopts a production process of "two-stage impact crusher + vertical shaft impact crusher + four-stage screening + composite powder selection," successfully achieving a breakthrough in hourly production capacity exceeding 4000 t/h. The high-quality manufactured sand and aggregate produced are widely used in key provincial and municipal projects such as highways, subways, and super high-rise buildings, and have received widespread market recognition.

II. Process Introduction

Primary Crushing Stage

Based on the project's annual mining and processing volume and mine geographical conditions, two impact crushers with a single-machine hourly output of ≥2000t were selected as the primary crushing equipment. This equipment has a large crushing ratio, a small crushing area, and good particle shape after crushing, making it an ideal choice for producing high-quality manufactured sand and aggregate.

Secondary Crushing Stage

The secondary crushing equipment is mainly responsible for processing the oversized material after primary crushing and screening. Four impact crushers with a single-machine hourly output of ≥600t were selected. Through two-stage crushing (i.e., impact crusher (primary crushing) + impact crusher (secondary crushing) combination), the goal of high yield and good particle shape was achieved.

Sand Making Stage

The sand making equipment uses a vertical shaft impact crusher (sand making machine), which adopts the stone-on-stone working principle. In the high-speed rotating turntable, the stones collide and break each other, forming rounded, well-graded manufactured sand. This equipment has high sand making efficiency and stable product quality.

Mud Removal Process

The mud removal process uses a roller screen for screening. Through the conveying, rolling, and loosening action of the rollers, the mud content and methylene blue value are effectively controlled. Screening Process

The aggregate screening process utilizes a circular vibrating screen, which boasts high screening efficiency and large processing capacity, making it suitable for large-particle screening and large-scale production. For manufactured sand screening, a high-frequency screen is used, with a screen vibration frequency of 4000–4200 r/min, effectively improving screening efficiency.

III. Conclusion

Through the combination of impact crushers, vertical shaft impact crushers, circular vibrating screens, high-frequency screens, and composite powder selection processes, this project successfully achieved large-scale, intensive, and environmentally friendly production goals. The manufactured sand and aggregate produced have good particle shape, reasonable gradation, and low methylene blue value, meeting the high-quality requirements of key engineering projects. In the future, we will continue to dedicate ourselves to the research and innovation of sand and aggregate production technology, contributing to the green and sustainable development of my country's sand and aggregate industry.