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Wet Pan Mill - Mineral Processing

Why Do Wet Pan Mills Remain Popular?

Throughout the long history of mineral processing, the wet pan mill, as a classic piece of equipment, has consistently held a central position in small and medium-sized gold, silver, lead-zinc, and other ore processing plants. It is not the most technologically advanced equipment, but its unique structure, low cost, and reliable performance make it an irreplaceable choice in specific scenarios. Unlike large ball mills that prioritize high throughput, wet pan mills focus more on flexibility, return on investment, and applicability to a wide variety of minerals.

Gold grinding machine structural diagram

Working Principle and Core Structure

The wet pan mill, also known as a wet grinding mill or gold mill, is a wet grinding device that utilizes the principle of roller grinding.

Brief Description of Working Principle

The core of the equipment consists of grinding rollers and a grinding pan. The motor drives the grinding pan to rotate through a reducer, driving the two heavy grinding rollers placed on it. The rollers use their own weight and centrifugal force to roll, compress, and grind the material on the grinding pan. During the grinding process, continuously added water mixes with the minerals to form a slurry, which acts as a lubricant and coolant, and also facilitates subsequent separation and extraction.

Main Components

1. Frame and Base: Provides stable support.

2. Grinding Pan: The core component that holds the material, usually lined with wear-resistant steel.

3. Grinding Rollers: Made of high-manganese steel or special alloy, these are the main grinding media.

4. Transmission System: Includes the motor, reducer, and gears, providing power.

5. Feeding and Discharge Devices: Control the entry and exit of materials, enabling continuous or intermittent operation.

Outstanding Advantages of Wet Pan Mills

Based on our 20 years of manufacturing and service experience, we have summarized several core advantages of wet pan mills, which are the reasons for their popularity in the market:

1. Low Investment Cost and Simple Maintenance: The simple structure means the purchase cost is far lower than ball mills with the same processing capacity, and it is easy to operate and maintain, requiring minimal technical skills from operators.

2. Suitable for various minerals: Not only widely used for free gold recovery in gold mines (can be used as an alternative to small ball mills or amalgamation machines), but also suitable for fine grinding of various metal ores such as silver, lead, zinc, iron, and molybdenum, especially suitable for ores with low hardness.

3. Combines grinding and mixing functions: While grinding, it can fully mix minerals, water, and reagents, creating favorable conditions for subsequent processes such as cyanidation and flotation.

4. Small footprint and flexible configuration: Very suitable for mines with complex terrain, small scale, or dispersed operations. It can be used inpidually or multiple units can be connected in parallel to increase capacity.

5. Environmentally friendly working environment: Wet operation effectively suppresses dust, improves the working environment, and meets environmental protection requirements.

Gold grinding machine customer site

Practical Application Cases: Successful Practices Confirm Value

Among our many clients, a case from West Africa is quite representative. The client owns a medium-sized hard rock gold mine with medium ore hardness and uneven particle size distribution. Initially, the client considered investing in a large ball mill, but was limited by budget and site constraints.

We recommended a solution using two 1200-type wet grinding mills in parallel, and configured the corresponding classification and recovery system. After equipment installation:

• Grinding particle size: stably reached over 85% at -200 mesh, meeting the requirements for cyanide leaching.

• Recovery rate: Gold leaching rate was stable at around 92%.

• Return on investment: The equipment investment was recovered within 6 months through increased production and cost savings. The client particularly appreciated its low failure rate and the fact that local workers could operate it proficiently after simple training.

Equipment Selection and Matching Recommendations

When choosing a wet grinding mill, comprehensive consideration should be given to ore properties, capacity requirements, and budget.

How to choose a model?

Models are usually indicated by the grinding disc diameter (e.g., 1100, 1200, 1300, 1500, etc.). The larger the disc diameter, the stronger the processing capacity. It is recommended to conduct small-scale beneficiation tests to determine the optimal feed particle size, pulp concentration, and expected capacity for accurate model selection. H3 Common Supporting Equipment

To form an efficient production line, wet grinding mills often work in conjunction with the following equipment:

1. Jaw Crusher: Used for primary crushing, providing the mill with feed material of suitable particle size.

2. Spiral Classifier/Hydrocyclone: ​​Forms a closed-circuit system with the mill to control the finished product particle size and improve efficiency.

3. Shaking Table/Centrifugal Gold Separator: Used for gravity separation to recover coarse gold from the ground ore slurry.

4. Agitation Tank/Leaching Tank: Used for subsequent chemical gold extraction processes such as cyanide leaching.

Frequently Asked Questions (FAQ)

1. What are the main differences between a wet grinding mill and a ball mill?

Wet grinding mills belong to the roller mill type of grinding, primarily using compression and shear forces. They are better suited for processing ores of medium or lower hardness that require selective grinding, and have lower investment and operating costs. Ball mills primarily use impact and grinding forces, have a larger processing capacity, and produce a more uniform particle size. They are suitable for large-scale, continuous production plants, but have higher investment and maintenance costs.

2. What is the lifespan of the grinding rollers? Is replacement complicated?

The lifespan of the grinding rollers varies depending on the ore hardness, grinding fineness, and material. Our high-manganese steel reinforced rollers, when grinding medium-hardness gold ore, typically last for 6-12 months. The replacement process is relatively simple and can usually be completed by two skilled workers within a few hours.

3. How hard of an ore can a wet grinding mill process?

It is best suited for processing ores with a Mohs hardness of 7 or less, such as most gold ores and lead-zinc ores. For extremely hard ores (such as quartzite), the grinding efficiency will decrease, and wear will increase. In this case, a more economical crushing solution or a multi-stage grinding process should be considered.

The wet grinding mill is a classic, practical, and cost-effective piece of equipment in the field of mineral processing. For small and medium-sized mining projects with dispersed resources, limited capital, or those seeking rapid commissioning, it is often the wisest starting point. As a manufacturer with 20 years of extensive experience, we not only provide reliable equipment but also share comprehensive process knowledge to help you make the best decisions.

Perfect after-sales service

Baichy Heavy Industry provides professional on-site guidance for installation, training of workers, and other services to ensure that customers can use the equipment smoothly.

The company has a complete after-sales service system, which can provide customers with timely technical support and equipment maintenance services to ensure the long-term stable operation of the equipment.

To prevent the rights and interests of customers from being infringed, Baichy Heavy Industry reminds customers: please contact our customer service staff through the official website of Baichy Heavy Industry , or add WhatsApp: 15093222637 ; or send an email to: [email protected] , we will get in touch with you as soon as possible and provide you with the most professional service in the industry.

Baichy Heavy Industry

Baichy Machinery is a factory supplier of mining machinery, mainly focusing on stone crushers, powder grinding mills, and mineral beneficiation plants. We can offer you a free design and completed solutions according to your project.

Baichy Heavy Industry has grown into a high-tech mining equipment comprehensive enterprise, integrating R&D, manufacturing, sales, and after-sales service, Passing ISO9001:2015 quality management system certifications. The main products are mobile jaw crushing plants, construction waste crushing plants, PE jaw crushers, VSI sand-making machines, Symons cone crushers, single-cylinder hydraulic cone crushers, PCX high-fine crushers, grinding mills, ball mills, and full sets of beneficiation equipment with an excellent level.