Is coal gangue suitable for use as aggregate? What machines are available for processing coal gangue into aggregate?

Coal gangue is a blackish-gray rock with a lower carbon content and greater hardness than coal, formed alongside coal seams during the coalification process. Large quantities are discharged annually and often discarded, not only occupying vast tracts of land but also causing air pollution. However, it is actually rich in various valuable minerals. So, is coal gangue suitable for making crushed stone? How much do machines for processing coal gangue into crushed stone cost? Let’s take a detailed look.

Is coal gangue suitable for making crushed stone?

After being crushed and processed, coal gangue can be used as crushed stone in various fields, including road subgrades, brick-making raw materials, infrastructure construction, and industrial raw materials. To meet the required standards, the following conditions must be satisfied.

Common Crushing Value Standards for Aggregates

Concrete below C30: Sedimentary rock crushing value ≤16, metamorphic rock ≤20, igneous rock ≤30.

Concrete at or above C30: Sedimentary rock crushing value ≤10, metamorphic rock ≤12, igneous rock ≤13.

Precautions

Organic Matter Content: The organic matter content in coal gangue must be below 5%; otherwise, it may lead to increased brittleness and insufficient strength.

Physical Properties: Coal gangue has a lower density than bluestone and exhibits uneven hardness; particle size must be controlled through screening.

What Machines Are Used to Process Coal Gangue into Aggregate?

Coal gangue is a solid waste product generated during coal mining and coal washing. Based on its primary mineral composition, it can be classified into claystone, sandstone, carbonate, and aluminosilicate types. With a Mohs hardness of 3–7, jaw crushers, hammer crushers, and double-roll crushers are the most suitable choices among the various crushing equipment available. The specific choice requires a comprehensive consideration of factors such as the moisture content of the coal gangue, expected output, finished product size requirements, budget, and operating environment.

01 Jaw Crusher

Utilizing the principle of compression crushing, this machine prevents clogging even with large feed sizes. The deep, well-designed crushing chamber effectively increases throughput. Optimized motion parameters allow crushing to begin in the upper part of the chamber, while the large downward stroke achieves a higher crushing ratio. The discharge opening features a wedge-type adjustment mechanism, ensuring adjustable and uniform final particle size. Equipped with a flywheel structure, it reduces equipment vibration for smoother operation. The integrated design of the motor base and main unit facilitates easy installation and saves space.

02 Hammer Crusher

This crusher primarily relies on high-speed rotating hammers to impact and crush material, eliminating the need for a primary crushing stage and enabling the simultaneous crushing of both large and small materials into the desired shape. By changing the chamber type, it can flexibly switch between coarse, medium, and fine crushing. The barless design allows it to effectively process wet materials and coal gangue while preventing blockages. The forming zone is equipped with an impact plate featuring an adjustable gap; material smaller than the gap size is discharged directly, preventing over-crushing, thereby increasing production capacity and reducing the proportion of fine powder output.

03 Double-roll Crusher

Suitable for coal gangue with a particle size of 30 mm or less, it can directly enter the crushing stage after iron removal and impurity removal, eliminating the need for additional gangue removal processes and simplifying the coal preparation workflow. The equipment uses two counter-rotating rollers to crush material through compression. It offers advantages such as a compact footprint, high crushing ratio, uniform output particle size, and low over-crushing rate. The drive system is equipped with dual motors, providing stronger power to enhance crushing efficiency while reducing energy consumption and production costs, making it suitable for medium and fine crushing operations.

(Technical parameters and other data mentioned in this article are subject to change with product upgrades. Click on the website’s customer service to obtain the latest equipment specification sheet.)

Henan OCP operates on a self-production and direct-sales model. The company implements strict screening of raw materials during production and continuously upgrades and refines its technology, ensuring reliable quality. You are welcome to visit the factory at any time for an on-site inspection. We also have a dedicated technical team responsible for on-site installation, commissioning, and technical training to ensure stable long-term operation. For specific pricing on coal gangue processing machines, please consult online, and a manager will be available to assist you.