Raymond Mill

What is a Raymond Mill?

Raymond mills, also known as Raymond grinding mills, are used to prepare various mineral and coal powders, such as raw ore, gypsum, and coal. They are primarily suitable for crushing and separating impurities from mineral materials in metallurgy, building materials, chemicals, and mining. They can crush calcine, bentonite, talc, gypsum, activated carbon, humic acid, clay, graphite, red iron oxide, soybean cake, compound fertilizer, rare earth elements, and other non-flammable and explosive materials with a Mohs hardness below 3 and a humidity level less than 6%.

Raymond mills are used in ore mining.

Mining is the primary application of Raymond mills. Mined ore is initially crushed in a jaw crusher and then fed by an elevator to a Raymond mill for further processing. For example, the ground limestone powder can be used directly in building block production or as a desulfurizer in the flue gas treatment system of thermal power plants. In ceramic factories, Raymond mills grind raw materials like feldspar and quartz to a fineness of around 200 mesh, ensuring a smooth, grain-free glaze. Pesticide factories use them to process bentonite carriers, ensuring that the active ingredient in the pesticide powder is evenly adhered to the surface.

Raymond Mill type

 

Traditional Raymond Mill

R-type Raymond mills are considered “traditional Raymond mills.” They utilize 3-5 grinding rollers suspended on a plum blossom frame, which revolve and rotate with the main shaft. The material is crushed between the rollers and the grinding ring, and a fan blows the powder to the analyzer for separation. Coarse powder is returned for re-grinding, while fine powder is collected by a cyclone collector. The entire system operates in a negative pressure closed circuit.

High-strength Raymond Mill

Based on a conventional Raymond mill, the roller assembly is replaced with a “high-pressure spring” pressurization system, increasing pressure by 1.2-1.4 times. Furthermore, the fan air volume is increased, and the analyzer blade angle is modified, resulting in a simultaneous increase in both output and fineness.

YGM Fine Powder Mill

The YGM fine powder mill utilizes a multi-layer ring roller + high-speed rotating disc grinding system, with a built-in multi-layer cage classifier. The speed and classifying wheel frequency are adjustable, enabling single-stage grinding to produce ultrafine powders ranging from 600-2500 mesh with a narrow particle size distribution and low iron content.

MTW European Raymond Mill

The MTW is Europe’s latest generation of trapezoidal mills. It replaces the traditional circular grinding chamber with a “curved scraper + curved air duct” structure. The grinding rollers and grinding rings form a curved contact surface, creating a wider and more uniform grinding zone. The integrated design of the fan, analyzer, and piping minimizes negative pressure loss, resulting in over 30% energy savings compared to traditional Raymond mills. It can also be directly connected to European standard dust removal systems.

How does a Raymond mill work?

The overall working process of a pulverizing mill (grinding material engineering): After large lump materials are crushed to the desired particle size by a jaw crusher, an elevator transports the material to a storage silo. A vibrating feeder then delivers the material evenly and continuously to the main grinding chamber for grinding. The ground powder is carried away by the fan airflow and classified by an analyzer. Powders that meet the required fineness requirements flow through the airflow through a pipe into a large cyclone collector for separation and collection. The powder is then discharged through a powder discharge pipe as the finished product.

How does a Raymond mill crush materials?

The raymond mill crushes materials by rotating a central shaft through a transmission mechanism. The upper end of the shaft is connected to a plum blossom frame, which houses a grinding roller assembly that forms a swinging fulcrum. The rollers not only rotate around the center, but also rotate around the grinding ring, while friction causes the rollers to rotate on their own.

The lower end of the plum blossom frame is equipped with a scraper system, which is located at the lower end of the grinding roller. During the simultaneous rotation of the scraper and the grinding roller, the material is shoveled and fed into the gap between the grinding roller rings to form a cushioning layer. The material layer is subjected to the outward centrifugal force (i.e., extrusion force) generated by the rotation of the grinding roller to crush the material, thereby achieving the purpose of powder making.

Raymond Mill air separation process

After grinding, the material is drawn into the main housing by a fan, which removes the powder. This powder is then separated by an analyzer above the grinding chamber. Excessively coarse material falls back into the grinding chamber for re-grinding. Material that meets the required fineness is then carried by the air to the large cyclone collector. After being collected, it is discharged through a powder discharge pipe and becomes the finished product.

The airflow is returned to the fan through the return air duct above the large cyclone. The airflow is circulated and flows under negative pressure. The increased air volume in the circulating airflow enters the small cyclone collector through the exhaust duct between the fan and main housing. Fine powder entrained in the airflow is collected, and the excess air enters the bag filter, where it is purified and discharged into the atmosphere.

Raymond Mill Installation

The Raymond mill can be installed on a concrete floor with a thickness of 80-100mm. Installation can begin after the concrete has solidified. The machine does not have anchor bolts, so please refer to the installation diagram. First, position the main unit as shown. Then, install the fan, cyclone separator, and connecting ducts. All connecting flanges must be sealed with rubber or foam plastic to prevent air leakage that affects production. Once installation and connections are complete, connect the power cord and test run the machine.