Tongli raw material HPGR Introduction

Tongli High Pressure Grinding Roller (HPGR) is a type of modern and energy-efficient comminution technology used for reducing the size of various ores and minerals especially cement raw material and clinker through high-pressure interparticle crushing. It's often used as an alternative to traditional grinding methods. The main function of an HPGR is to apply high pressure to the feed material, causing it to undergo interparticle breakage rather than traditional grinding mechanisms, which involve impact and abrasion. This interparticle breakage leads to a more energy-efficient process and can result in improved product quality with a reduction in overgrinding. HPGRs are particularly suitable for hard and abrasive ores.

Raw material high pressure grinding roller structure

Tongli HPGR consists of two counter-rotating rolls with diameters ranging from a few centimeters to several meters, depending on the application. The rolls are typically made of wear-resistant materials to withstand the high pressure and abrasion. The rolls are equipped with a variety of surface configurations, such as studs or grooves, which help to grip and compress the feed material as it passes between the rolls.

Grinding Rollers: The central component of an HPGR is the pair of counter-rotating rolls. These rolls are typically made of wear-resistant materials and have a specific surface pattern or texture to help grip and compress the feed material.

Frame and Bearings: The rolls are mounted within a sturdy frame, which also contains the bearings that support the rolls' rotation. These bearings are subjected to significant forces and pressures, so they need to be designed to withstand these conditions.

Hydraulic System: HPGRs operate by exerting high pressure on the feed material between the rolls. A hydraulic system is used to apply and control this pressure. It consists of hydraulic cylinders that push the rolls together and maintain the desired pressure level during operation.

Feed Chute: The feed chute is where the material to be processed is introduced into the HPGR. It guides the material between the rolls and ensures a consistent and controlled feed.

Drive System: The rolls are driven to rotate in opposite directions by a drive system. This system can include motors, gearboxes, and other components that provide the necessary torque and rotational speed.

Control System: A sophisticated control system is used to manage and regulate the operation of the HPGR. It monitors factors such as pressure, feed rate, roll speed, and other parameters to optimize the crushing process and ensure efficient operation.

Discharge Conveyor/bucket elevator: After the material has been processed through the HPGR, a discharge conveyor is used to transport the crushed material away from the equipment for further processing or handling.

Design principles of raw material high pressure grinding roller

High Pressure: The rolls exert significant pressure on the feed material, causing it to be crushed or ground between the rolls. This pressure creates microcracks in the ore particles, making them more susceptible to subsequent grinding processes.

Particle Size Reduction: HPGRs are commonly used as a final stage of ore comminution before ball milling or other grinding methods. The technology is capable of producing finer product sizes compared to conventional crushers or mills.

Energy Efficiency: HPGRs generally consume less energy per ton of processed material compared to traditional grinding methods, which can lead to cost savings and reduced environmental impact.

Liberation of Valuable Minerals: The microcracks created by the high pressure help in liberating valuable minerals from the ore matrix, making them more accessible for downstream extraction processes.

Reduced Water Usage: HPGRs can reduce the need for water in the grinding process, which is beneficial in regions with water scarcity or where water conservation is important.

Specifications of raw material high pressure grinding roller

Note: * Diameter refers to the grinding roller inner diameter.

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Industry Knowledge extension

What is the application of high-pressure grinding roller HPGR?

Cement Industry: HPGRs have found applications in the cement industry for grinding clinker and raw materials.

Ore Crushing: HPGRs are commonly used to crush ores and minerals to a finer size before further processing. This can enhance the efficiency of downstream processes like grinding, flotation, and leaching.

Diamond Liberation: In the diamond industry, HPGRs are used to liberate diamonds from the ore matrix, as diamonds are very hard and require specialized methods for extraction.

Iron Ore Pellet Feed Preparation: HPGRs can be used to prepare the pellet feed by reducing the size of iron ore concentrates before balling or pelletization.

Copper Ore Processing: HPGRs are employed in copper ore processing to improve the liberation of copper minerals and reduce the energy consumption of downstream grinding processes.

Gold Ore Processing: In some gold mining operations, HPGRs are used to reduce the particle size of gold-bearing ores to enhance the efficiency of gold recovery methods.

What is the difference between high pressure roller press and ball mill?

High Pressure Grinding Roller (HPGR) and ball mills are both commonly used comminution equipment in the mining and minerals processing industry. However, they operate on different principles and have distinct advantages and disadvantages.

Principle of Operation:High Pressure Grinding Roller (HPGR): HPGRs use two counter-rotating rolls to exert high pressure and compress the material being processed. This pressure causes inter-particle breakage and helps to create microcracks within the material, enhancing its overall comminution. HPGRs are more efficient in terms of energy consumption compared to traditional grinding methods. A ball mill is a rotating cylinder filled with steel balls that grind the material to a fine powder. As the ball mill rotates, the balls 'cascade' and crush the material between themselves and the inner walls of the cylinder.

Particle Size Reduction Mechanism:The main mechanism of particle size reduction in HPGRs is the application of high pressure, which causes inter-particle breakage and generates a more uniform product with fewer fines compared to traditional grinding methods. The microcracks produced also expose more surface area for subsequent leaching or further processing.

Particle size reduction in ball mills occurs mainly due to impact and attrition between the balls and the material being ground. The size reduction achieved by ball mills tends to be more heterogeneous, with a wider range of particle sizes produced.

Product Quality:HPGRs tend to produce a more uniform product with fewer fines, which can be advantageous for downstream processes such as leaching or flotation. The microcracks produced during HPGR grinding can also improve the liberation of valuable minerals from the ore matrix. Ball mills can produce a wide range of particle sizes, which can be beneficial for some applications but might require additional processing steps to achieve the desired product quality.

Maintenance and Wear:HPGR: The wear on HPGR rollers and lining materials can be significant due to the high pressure and forces involved. Maintenance and replacement of worn components can be more challenging and costly. Ball mills experience wear on the grinding media and liners, which can also require regular maintenance and replacement. However, the maintenance procedures for ball mills are generally more straightforward compared to HPGRs.