From 500mm to 5mm – Hua Sheng Ming Roll Crusher in DRC Tin Ore Crushing

In the rock tin ore processing flowsheet, the selection of crushing equipment directly affects downstream grinding efficiency and cassiterite recovery. Cassiterite is a medium-hard but extremely brittle mineral. Traditional impact crushers tend to generate excessive over-grinding, causing fine cassiterite particles to be lost in downstream gravity separation circuits.A rock tin ore project in the DRC has successfully reduced 500mm run-of-mine ore to below 5mm through a three-stage crushing configuration, providing a reliable production practice for the “more crushing, less grinding” approach.

The project employs a 1149 vibrating feeder, a 750×1060 jaw crusher, two 300×1300 fine jaw crushers, two Hua Sheng Ming full-hydraulic 1200×1000 roll crushers, and a 2460 vibrating screen, forming a complete three-stage crushing and screening closed-circuit system.

rock tin ore roll crusher

Project Background

The DRC is rich in tin ore resources and is one of the world’s major tin-producing regions. The customer is a local mining company processing rock tin ore (primary cassiterite ore) with a feed size of 500mm. The final product is required to be below 5mm for downstream gravity separation operations.

Process Configuration

Stage 1 – Primary Crushing: The 1149 vibrating feeder evenly feeds the 500mm run-of-mine ore into the 750×1060 jaw crusher for primary crushing, reducing large ore blocks to a size suitable for secondary crushing.

Stage 2 – Secondary Crushing: Two 300×1300 fine jaw crushers operate in parallel, receiving the product from the primary crusher for further reduction. This parallel configuration shares the secondary crushing load, improves processing efficiency, and ensures continuous feed supply to the downstream roll crushers.

Stage 3 – Fine Crushing: Two Hua Sheng Ming full-hydraulic 1200×1000 roll crushers operate in parallel for the final fine crushing stage. The equipment operates on the inter-particle compression principle—two rolls rotate slowly in opposite directions, applying sustained compressive force to the material, causing the ore to fracture along mineral boundaries and natural textures. This approach achieves the target particle size while controlling over-grinding, with discharge size precisely controlled to below 5mm.

Screening Circuit: The 2460 vibrating screen classifies the product. Oversized material is returned to the roll crushers for re-crushing, forming a closed-circuit loop to ensure all final product meets specifications.

rock tin ore screening site

Key Equipment Advantages

The full-hydraulic 1200×1000 roll crusher belongs to Hua Sheng Ming’s large full-hydraulic roll crusher series, suitable for metal ore fine crushing and pre-grinding applications. Designed for the brittle nature of rock tin ore, the equipment offers several process advantages:

Low Over-grinding Rate: Static pressure compression replaces high-speed impact, effectively protecting brittle cassiterite and minimizing fine particle generation.

Precise and Concentrated Particle Size: The hydraulic system allows online roll gap adjustment, enabling precise control of discharge size to below 5mm with a narrow particle size distribution, providing uniform feed for downstream gravity separation.

Capacity Assurance: Two roll crushers operating in parallel ensure the required processing capacity while maintaining fine crushing performance.

Stable Operation: The screenless bottom design offers high tolerance to material moisture content, preventing clogging and accommodating clay-bearing materials that may accompany rock tin ore during crushing.

finished rock tin ore product

Process Configuration Logic

The three-stage crushing configuration fully embodies the “more crushing, less grinding” principle for tin ore processing. The jaw crusher handles primary crushing, the fine jaw crushers perform secondary crushing, and the roll crushers complete the final fine crushing stage. By enhancing fine crushing efficiency, the feed size to the grinding circuit is reduced from the conventional 10-20mm to below 5mm, significantly reducing downstream grinding load. Given the brittle nature of cassiterite, the gravity separation principle of “recover early, discard early” applies—controlling over-grinding at the crushing stage is the key to improving cassiterite recovery.

Conclusion

The three-stage crushing configuration at this DRC rock tin ore project validates the practical effectiveness of roll crushers in tin ore fine crushing. The Hua Sheng Ming full-hydraulic roll crusher replaces impact crushing with inter-particle compression, achieving the target particle size while controlling over-grinding, providing reliable equipment support for the “more crushing, less grinding” approach.