Benefits of Using Nano Ceramic Balls in the Second Stage of Grinding

In the modern era of industrial development, the mining and mineral processing sectors are constantly seeking innovative ways to optimize their operations. One area that has received significant attention is the second stage of grinding, where the choice of grinding media can have a profound impact on both the efficiency and cost-effectiveness of the process. The introduction of new nano ceramic balls as grinding media has emerged as a promising solution to address the challenges and opportunities in this crucial stage.

I. The Current State of Grinding in the Mining Industry

With the continuous exploitation and utilization of mineral resources over time, the nature of available ores has changed. The characteristics of "poor, fine, and complex" resources have become more prevalent, posing a significant challenge to the traditional methods of high-quality and high-efficiency production. In the context of the global push towards carbon peaking and carbon neutrality goals, the mining and dressing processes are under increasing pressure to achieve energy conservation and consumption reduction.

Mine grinding is a major energy-consuming operation, accounting for approximately 50% of the total energy consumption in a concentrator. This high energy demand not only impacts the operational costs but also has implications for the overall environmental footprint of the mining industry. Currently, the most commonly used grinding media in concentrators is steel balls. However, production practices have revealed several drawbacks associated with their use.

Steel balls are prone to causing over-crushing of the ore, which leads to the production of excessive fine particles. This not only reduces the efficiency of subsequent separation processes but also results in the loss of valuable minerals. Additionally, the use of steel balls introduces iron contamination into the ore, which can have a negative impact on the quality of the final product. The high energy consumption and noise levels associated with steel ball grinding are also significant concerns, both from an economic and environmental perspective.

II. The Emergence of Nano Ceramic Balls as a Viable Alternative

In recent years, the research and development of high-strength and high-wear-resistant nano ceramic balls have opened up new possibilities in the field of grinding media. Initially, ceramic ball grinding media found their application in vertical mills, and their success in this area led to further exploration of their potential in horizontal mills for fine grinding.

Nano ceramic balls offer several distinct advantages over traditional steel balls. Their unique physical and chemical properties make them an attractive option for improving the grinding process. One of the key benefits is their ability to reduce grinding energy consumption. The composition and microstructure of nano ceramic balls allow for more efficient transfer of energy during the grinding process, resulting in a significant reduction in the specific energy consumption.

III. Research Methodology and Experimental Setup

To evaluate the effectiveness of nano ceramic balls in the second stage of grinding, a comprehensive research study was conducted. The feed of the second stage ball mill in a customer's factory was selected as the research object. This allowed for a real-world assessment of the performance of different grinding media under actual operating conditions.

The study focused on comparing the grinding characteristics and magnetic separation tests of three different grinding media combinations: all-ceramic balls, all-steel balls, and a combination of ceramic balls and steel balls. The experimental conditions were carefully controlled to ensure accurate and reliable results. The grinding time was set at 3 minutes, the media filling rate was maintained at 36%, and the grinding concentration was held at 67%.

For the nano ceramic balls, a specific combination of different diameters was used, with a mass ratio of 50% : 30% : 20% for ϕ30 mm, ϕ25 mm, and ϕ20 mm balls. These were combined with ϕ20 mm steel balls in a mass ratio of 5 : 5. This particular combination was chosen based on previous research and preliminary testing to optimize the grinding performance.

IV. Results and Performance Analysis

The test results were highly encouraging and demonstrated the superiority of the nano ceramic ball - steel ball combination over traditional steel ball grinding media.

1. Improved Grinding Technical Efficiency

• The grinding technical efficiency was found to increase by 16.65 percentage points when using the nano ceramic ball - steel ball combination. This significant improvement can be attributed to the more efficient grinding action of the nano ceramic balls. Their hardness and wear resistance enable them to break down the ore particles more effectively, leading to a higher degree of liberation of valuable minerals. This, in turn, results in a greater proportion of the ore being ground to the desired size range, improving the overall efficiency of the grinding process.

2. Reduced Specific Energy Consumption

• The specific energy consumption was reduced by a remarkable 80%. This reduction is a direct result of the better energy transfer characteristics of the nano ceramic balls. They require less energy to achieve the same level of grinding compared to steel balls. This not only leads to cost savings in terms of energy consumption but also has a positive impact on the environment by reducing the carbon footprint associated with the grinding operation.

3. Lower Noise Levels

• The noise value decreased by 2.8 dB. This is an important aspect from an occupational health and safety perspective. The reduction in noise levels makes the working environment more comfortable for the operators and also reduces the potential for noise-induced hearing damage. The quieter operation of the grinding mill using nano ceramic balls can also have implications for the surrounding community, minimizing noise pollution.

4. Enhanced Magnetic Separation Efficiency

• The magnetic separation efficiency was improved by 9.65 percentage points. This is a crucial outcome as it directly impacts the recovery of iron minerals. The improved liberation of the minerals achieved through the use of nano ceramic balls results in a higher proportion of the magnetic minerals being separated during the magnetic separation process. This leads to a more efficient recovery of valuable iron minerals, increasing the overall profitability of the mining operation.

V. The Impact on Over-Crushing and Mineral Liberation

Using nano ceramic balls to partially replace steel balls in the second stage of fine grinding has a significant impact on over-crushing and the dissociation degree of iron minerals.

Over-crushing is a common problem with traditional steel ball grinding, where the ore is ground too finely, leading to the production of excessive slimes. This not only reduces the efficiency of subsequent separation processes but also results in the loss of valuable minerals. Nano ceramic balls, with their more controlled grinding action, are able to alleviate this problem. They break down the ore particles more selectively, reducing the production of fine slimes and improving the particle size distribution of the ground product.

The improved grinding action also leads to a higher dissociation degree of iron minerals. The more efficient transfer of energy and the better grinding performance of the nano ceramic balls result in a greater liberation of the iron minerals from the gangue. This is beneficial for the subsequent magnetic separation process, as it allows for a more complete recovery of the iron minerals.

VI. The Future Outlook and Potential Applications

The successful application of nano ceramic balls in the second stage of grinding holds great promise for the future of the mining industry. As the demand for high-quality minerals and the need for energy conservation continue to grow, the adoption of nano ceramic balls is likely to increase.

In addition to their use in the second stage of grinding, further research is being conducted to explore their potential in other stages of the mining process. There is also potential for the application of nano ceramic balls in other industries that require grinding and milling operations, such as the chemical and pharmaceutical industries.

The development of nano ceramic balls is an ongoing process, with researchers constantly working to improve their properties and performance. Future advancements may include further optimization of their composition to enhance their wear resistance and grinding efficiency, as well as the development of new manufacturing techniques to reduce production costs.

VII. Conclusion

The use of nano ceramic balls in the second stage of grinding offers a range of significant benefits, including improved grinding technical efficiency, reduced specific energy consumption, lower noise levels, and enhanced magnetic separation efficiency. These advantages make them a viable alternative to traditional steel balls and have the potential to revolutionize the grinding process in the mining industry.

As the mining industry continues to evolve and face new challenges, the adoption of innovative technologies such as nano ceramic balls will be crucial for achieving sustainable and efficient production. By reducing energy consumption and improving the quality of the final product, nano ceramic balls can contribute to the long-term viability and competitiveness of the mining sector.

For those interested in learning more about the application of ceramic balls in the fine grinding of ores, further information and application cases can be obtained by contacting the relevant experts or organizations. The future of grinding in the mining industry looks promising with the continued development and application of nano ceramic balls.