Granite, a hard rock with a Mohs hardness of 5-7, requires comprehensive consideration of multiple factors, including rock properties, production scale, product requirements, and economic benefits. Depending on the stage of the crushing process, primary crushing equipment can be categorized into three types: coarse crushing, secondary and fine crushing, and sand making. Each type of equipment has its own unique application scenarios and technical features.

Equipment Selection for the Coarse Crushing Stage

The coarse crushing stage primarily processes large lumps of rock and typically utilizes a jaw crusher. This type of equipment crushes rocks through the squeezing action between movable and fixed jaws, offering advantages such as a simple structure, easy maintenance, and high processing capacity. For high-hardness materials like granite, a deep-cavity jaw crusher is recommended, as it offers a higher reduction ratio and effectively reduces the load on subsequent equipment.

Equipment Optimization for the Secondary and Fine Crushing Stage

A multi-cylinder hydraulic cone crusher is recommended for the secondary and fine crushing stages. Compared to traditional single-cylinder cone crushers, the multi-cylinder design utilizes multiple hydraulic cylinders working in tandem, enabling more precise discharge control and iron overload protection. Its laminated crushing principle subjects the material to multiple compression and grinding cycles within the crushing chamber, resulting in a more uniform product particle shape and keeping the needle-like flake content below 15%.

Sand Production Equipment Configuration

If manufactured sand is to be produced, a vertical shaft impact crusher (VSI) is required for shaping. The VSI utilizes a "rock-on-rock" or "rock-on-iron" principle to achieve self-crushing and shaping of the material, producing high-quality manufactured sand with a well-graded and rounded particle shape. For granite sand production, the "rock-on-rock" operating mode is recommended to minimize wear on the iron.

Production Line Configuration Recommendations

In practice, a two-stage jaw crusher + cone crusher solution is suitable for small and medium-sized projects (with an output of less than 100 tons per hour). This offers lower investment costs and easier operation. For large production lines (over 500 tons per hour), it is recommended to add a cone crusher or impact crusher to create a three- or four-stage crushing system, such as a "jaw crusher + cone crusher + cone crusher" or "jaw crusher + cone crusher + impact crusher" combination. This allows for better control of the product particle size distribution. For particularly hard granite varieties (such as black gold sand), a shaping process can be added at the end, using a vertical shaft impact crusher to perform surface treatment on the finished product to improve the market competitiveness of the aggregate.