Limestone is a common and important material in the crushing and sand making industry, widely used in building materials and industrial raw materials. Limestone crushing and sand making lines are widely distributed, with typical hourly outputs ranging from 100 tons to thousands of tons. The following will take a 1000-ton-per-hour aggregate line as an example to detail the equipment selection, process flow, production line layout, and dust control aspects of a sand and gravel aggregate line for reference.

Limestone Crushing Production Line

Limestone Characteristics and Distribution

The main component of limestone is calcium carbonate (CaCO3), with a specific gravity generally around 2.7 (specific gravity of the stone, not bulk density). It has medium hardness and low abrasiveness. Limestone is widely distributed in 29 provinces, municipalities, and autonomous regions in China, including:

Shaanxi Province: Reserves of 4.9 billion tons, the largest in the country.

Anhui Province, Guangxi Zhuang Autonomous Region, and Sichuan Province (including Chongqing Municipality): Reserves of 3.4-3 billion tons each.

Shandong, Hebei, Henan, Guangdong, Liaoning, Hunan, and Hubei: Reserves of 3-2 billion tons each.

Heilongjiang, Zhejiang, Jiangsu, Guizhou, Jiangxi, Yunnan, Fujian, Shanxi, Xinjiang, Jilin, Inner Mongolia, Qinghai, and Gansu: Reserves of 2-1 billion tons each.

Beijing, Ningxia, Hainan, Tibet, and Tianjin: Reserves of 500-200 million tons each.

Equipment Selection: Based on the characteristics of limestone and production requirements, the commonly used crusher combinations are mainly as follows:

Jaw crusher + impact crusher

Jaw crusher + cone crusher + shaping machine

Hammer crusher + impact crusher

Taking an existing limestone mine of a cement plant as an example, a production line with a processing capacity of 1000t/h was designed, with a soil removal ratio of 10%, and finished aggregate specifications of 20-31.5mm (18%), 10-20mm (25%), 5-10mm (17%), and 0-5mm (25%).

A two-stage crushing scheme was selected, namely a combination of a jaw crusher and an impact crusher. The main characteristics of this combination are good product particle size, low stone powder content, low total investment and energy consumption, moderate maintenance and operating costs, and moderate environmental impact from noise and dust.

Main Equipment:

Primary Crusher: One jaw crusher with a processing capacity of 680-880 t/h (200mm discharge opening), and an installed power of 250 kW.

Secondary Crusher: Four impact crushers with a processing capacity of 300-350 t/h (40mm discharge opening), each with an installed power of 250 kW.

Screening Equipment: Primary screening uses four 3YKR3075 circular vibrating screens, and secondary screening uses two 2YKR3075 circular vibrating screens.

Aggregate Storage: Storage is achieved using four 16-meter steel silos, with a bulk loading machine underneath for shipment.

Conveying Equipment: Belt conveyors and bucket elevators are used for lumpy materials, while chain conveyors are used for powdery materials.

Process Flow

The process flow includes the following units:

Primary aggregate crushing and conveying

Aggregate desoiling, screening, and conveying

Secondary aggregate crushing and conveying

Primary aggregate screening and conveying

Secondary aggregate screening and conveying

Finished aggregate storage and shipping

Powder conveying and bulk handling

Compressed air station and pipeline network

Weighing system

Water supply and treatment unit

Electrical automation system

Spare parts and maintenance center

A limestone crushing and sand making production line requires reasonable equipment selection and a carefully designed process flow. By selecting suitable crusher combinations and supporting equipment, efficient production and full utilization of resources can be achieved. We hope this article will provide you with useful reference when designing and constructing a limestone crushing and sand making production line.