Crushing Coal Gangue for Sulfur Recovery – Roll Crusher Solution Crushing Solutions

Coal gangue is a solid waste generated during coal mining and washing, containing a certain amount of pyrite. Through crushing, separation, and other processes, sulfur concentrate can be extracted from coal gangue for producing sulfuric acid and other chemical products. In the sulfur extraction process, the full liberation of pyrite from gangue is the key to determining sulfur concentrate grade and recovery rate, and the liberation effect largely depends on particle size control at the front-end crushing stage. Hua Sheng Ming’s two-stage crushing solution – toothed roll for primary crushing and hydraulic roll for fine crushing – is designed around the core objective of “full liberation and controlled over-grinding,” and has been proven effective in coal gangue comprehensive utilization projects in Guizhou, Shanxi, Shaanxi, and other regions.

coal gangue

Core Challenges in Coal Gangue Sulfur Extraction Crushing

Coal gangue sulfur extraction has three core requirements for the crushing stage:

Full Liberation with Controlled Fines

Pyrite crystals are embedded in the gangue matrix. The goal of crushing is to separate them along natural bonding surfaces, rather than shattering the ore into powder. Traditional impact crushers operate at high speed, easily pulverizing pyrite crystals that have not yet been liberated, reducing mineral liberation and affecting downstream separation performance.

Adaptability to Moist Materials

Coal gangue often contains moisture and clay during mining and stockpiling, with significant moisture content fluctuations. Traditional crushers with screens are prone to clogging, requiring frequent shutdowns for cleaning and severely affecting continuous production.

Precise and Adjustable Discharge Size

Different beneficiation processes require different feed sizes – gravity separation typically requires discharge below 3cm, while flotation requires finer feed conditions. Crushing equipment needs flexible particle size adjustment capabilities.

coal gangue crusher

Hua Sheng Ming Solution: Toothed Roll for Primary + Hydraulic Roll for Fine Crushing

Hua Sheng Ming’s two-stage crushing solution – toothed roll for primary crushing and hydraulic roll for fine crushing – has been proven effective in coal gangue comprehensive utilization projects in Guizhou, Shanxi, Shaanxi, and other regions.

Primary Crushing – Toothed Roll Crusher

The toothed roll crusher operates on the low-speed shearing and compression principle. Two toothed rolls rotate in opposite directions, gripping and splitting the coal gangue. The two rolls act like a rotating grizzly screen – material meeting the size requirement passes directly through the roll gap, preventing re-crushing and thus reducing over-grinding and roll tooth wear. The screenless design allows direct discharge after crushing, with high tolerance to moisture content, fundamentally eliminating clogging issues.

Fine Crushing – Hydraulic Roll Crusher

The hydraulic roll crusher operates on the inter-particle compression principle. Two rolls rotate slowly in opposite directions, applying sustained compressive force to the coal gangue, causing pyrite crystals to separate along natural bonding surfaces. This gentle compression crushing method effectively prevents over-grinding, ensures mineral liberation, and provides uniformly sized feed for downstream magnetic separation or flotation.

The hydraulic gap adjustment system supports online roll gap adjustment, allowing discharge size to be flexibly controlled according to subsequent process requirements. The hydraulic retraction protection device automatically retracts when encountering unbreakable material such as tramp iron, then resets after discharge, ensuring continuous production.

Coal gangue crusher production site

Process Configuration

The “two-stage crushing + magnetic separation” process is a proven route validated in multiple projects:

1. Primary Crushing: Toothed roll crusher reduces coal gangue to below 30mm

2. Fine Crushing: Hydraulic roll crusher further reduces to below 3mm

3. Magnetic Separation: Magnetic separator extracts sulfur concentrate from the material

The fine crushing size below 3mm effectively improves the liberation degree of pyrite from gangue, providing ideal feed conditions for downstream flotation or magnetic separation, and is the critical prerequisite for improving sulfur concentrate grade and recovery rate.

Conclusion

In sulfur extraction from coal gangue, the key to the crushing stage lies in achieving full liberation of pyrite from gangue while controlling over-grinding. Hua Sheng Ming’s two-stage crushing solution – toothed roll for primary crushing and hydraulic roll for fine crushing – addresses high-moisture clogging issues with the screenless toothed roll design and achieves gentle liberation and precise particle size control with the roll crusher, providing a proven crushing solution for coal gangue sulfur extraction projects.