Limestone Grinding Project (0.5 TPH, 80 Mesh)
This small-scale limestone grinding project is designed to meet the local construction needs of a rural area in Shanxi Province, China, where large-scale industrial projects are limited and small-scale construction materials are in high demand. The project focuses on processing limestone into 80-mesh powder with a production capacity of 0.5 TPH, supplying local villages and small construction sites with raw materials for mortar, small concrete products, and road base construction. It not only addresses the shortage of local construction materials but also creates employment opportunities for local residents, promoting rural economic development.
The raw limestone used in the project is sourced from a small local quarry, with a CaCO₃ content of 80-85%, which is suitable for low-grade construction applications. The raw limestone arrives at the project site as 50-100mm lumps, which are first crushed to 10-20mm using a small jaw crusher (PE250×400), a compact and easy-to-operate machine suitable for small-scale production. The crushed limestone is then sorted manually to remove large impurities such as rock fragments and clay, ensuring the feed material is clean and uniform.
Due to the small production scale and limited investment, the project uses a small Raymond mill (YGM-210), which is compact, low-cost, and easy to maintain. The Raymond mill features 3 grinding rollers, a grinding ring, and a small fan with a 15 kW power rating, operating at a rotational speed of 28 rpm. The 10-20mm limestone particles are fed into the mill manually, where they are ground between the rotating rollers and grinding ring into fine powder.
Hot air is blown into the Raymond mill using a small hot air fan, drying the powder and carrying it to a simple air classifier. The classifier is set to separate particles finer than 80 mesh (180 μm); coarser particles are recycled back to the mill for regrinding. The 80-mesh limestone powder is collected by a small pulse bag filter, which has a dust collection efficiency of 99%, ensuring dust emission meets local environmental requirements (dust emission ≤15 mg/m³).
The project is designed to be low-cost and easy to operate, with a total investment of only 800,000 yuan, including equipment purchase, workshop construction, and raw material procurement. The operation requires only 5 local workers, who are trained to operate the crusher and Raymond mill, creating stable employment opportunities. The 80-mesh limestone powder is sold directly to local construction teams and small concrete product factories, with a stable market demand. In mortar production, the powder improves the workability and strength of mortar, while in road base construction, it enhances the compactness and durability of the road surface. The project has a payback period of 1 year, providing a sustainable income source for local residents and supporting the development of rural infrastructure.
