I. Definition
Mineral sizers are a modern crushing solution capable of producing well-shaped finished products. Our company offers both primary and secondary mineral sizers, suitable for a wide range of minerals in primary, secondary, and tertiary crushing processes, such as coal, salt, gypsum, phosphate, limestone, bauxite, petroleum coke, lignite, trona, carbon anodes, oil sands, clay, shale, and more.
II. Core Components
The mineral sizer mainly consists of drive device, toothed roller, synchromesh gear, housing, base frame, lubrication device, running gear and so on. Below are detailed descriptions of three key parts: toothed rollers, synchronous gears, and low-speed end couplings.
1.Toothed Rollers
The rollers are divided into primary and secondary screening toothed rollers. The crushing teeth are designed for easy installation and removal, significantly reducing maintenance time and costs.
The primary sizer accepts feed material up to 1500mm and discharges particles smaller than 300mm. The crushing teeth are arranged in a unique spiral pattern. Made from wear-resistant and impact-resistant alloy steel, these crushing teeth are both durable and effective.
The primary screening rollers feature an innovative tooth design with deep spiral distribution, enhancing productivity. A pass-through chamber is formed between the two rollers and the side plate, which allows simultaneous screening and crushing of material.
2.Synchronous Gears
The primary sizer is equipped with synchronous gears at the end of the rollers. These gears are connected to the roller shafts using shrink-fit sleeves, ensuring consistent tooth engagement between the rollers. This configuration enforces crushing of large materials and guarantees uniform discharge particle size. 3.Low-Speed End Coupling
The type of low-speed end coupling is a self-aligning drum gear coupling. The coupling is our technical research and development team and the expert group of China University of Mining and Technology according to the working principle and characteristics of the mineral sizer joint research and development success, and applied for a national patent.
The coupling features edge-trimmed teeth and high-frequency quenching, along with a self-aligning function to correct for misalignment, enhancing torque transmission.
Both sides of the half-coupling incorporate shear safety pins made from custom-engineered materials. These have been rigorously calculated and field-tested for mechanical performance. If a roller becomes jammed, the excessive reverse force is instantly transferred to the safety pin, which shears off to disconnect the roller from the drive system, providing effective overload protection.
III. Working Principle
Mineral sizers use the combined forces of shear and tensile stress between the toothed rollers to crush material. The working process is explained in three phases: feeding, crushing, and discharge.
1.Feeding Stage
The mineral sizer features two inward-rotating toothed rollers, each fitted with replaceable crushing teeth. The most efficient feeding method is to use a plate feeder or screening equipment to deliver material at a controlled rate, allowing it to drop evenly into the crushing chamber between the rollers. The material size must meet the feeding requirements to prevent blockages from oversized lumps.
2.Crushing Process
Once the material enters from the top feed inlet, gravity guides it into the nip zone between the two rollers. The rotating rollers crush the material through the following three mechanisms:
Compression Crushing: As the material is drawn into the narrowing gap between the rollers, it is compressed by the roller surfaces. The opposing rotation creates centripetal compressive forces. When the internal stress exceeds the compressive strength of the material, it fractures.
Shear and Splitting: The staggered arrangement of the roller teeth forms shear surfaces. The tooth tips penetrate the material, applying both shearing and splitting forces. Tooth design significantly affects crushing performance—sharper teeth more easily penetrate and split the material, while broader teeth rely more on compression.
Grinding and Refining: Partially crushed particles may be further ground by the rotating teeth, refining them to meet the required particle size.
3.Discharge Stage
The crushed material is discharged through the gap between the rollers, driven by their rotation. By adjusting this gap, the output particle size can be controlled: a narrower gap yields finer particles, while a wider gap produces coarser material.
IV. Application Scenarios
Mineral sizers are widely used in mining industries for crushing coal, iron ore, manganese ore, and other metal ores, as well as non-metallic ores like phosphate, potash, gypsum, and limestone. They are also effective in secondary crushing during tailings recovery processes.
V. Summary
The working principle of mineral sizers is based on the shear and tensile forces generated between the toothed rollers. This modern crushing technology produces well-formed products. Our mineral sizers are built with high quality and professional support. Our comprehensive services are backed by experienced technical engineers and specialized tools to maximize your operational profitability.