Difference between Wet Grinding and Dry Grinding

In the fiercely competitive powder industry, the quest for refined materials has surged among customers, steering the sector toward nanopowder development. The traditional single processing method is rendered obsolete in this evolving landscape, presenting a new challenge for enterprises: the preparation of nanopowder. Powder preparation essentially involves grinding for fineness dispersion, with wet and dry grinding as the two primary methods. Dry grinding is exemplified by the ball mill, while bead mills are popular in wet grinding.

Features of Dry Grinding

Dry grinding employs physical and mechanical methods to achieve nanometer fineness in powder materials. This pioneering technology, initially applied to material grinding and decomposition, boasts advantages such as a short production cycle, simplified post-processing, and lower costs. However, challenges like powder agglomeration, difficulty in achieving fine grades, and potential temperature rise during grinding present notable drawbacks.

Features of Wet Grinding

Conversely, using a dry mill for powder grinding leads to a sharp temperature rise due to the introduction of substantial energy. Addressing challenges like explosion protection and temperature control, wet grinding technology comes to the forefront, overcoming issues that dry grinding cannot resolve. While wet grinding allows for obtaining smaller particles, including nano-scale particles, it comes with a longer production cycle, more intricate post-processing, and higher costs.

Distinguishing Factors

Dry grinding limits water content to below 4%, while wet grinding suspends raw materials in a liquid carrier stream with added dispersants. Wet grinding proves advantageous in food processing, where higher moisture content aids dust control. However, it generally consumes more energy than dry operation, leading to increased equipment wear.

Choosing the Right Grinder

For less stringent grinding requirements and enhanced cost-effectiveness, a dry grinder may be suitable. In contrast, most chemical companies prefer wet grinding due to its effectiveness. Wet grinding machines come in vertical and horizontal variants, with horizontal grinders dominating the market due to superior sealing properties, low gravity influence, and minimal dust generation.

Grinder Classification

Grinders, adopting diverse grinding methods, include basket grinders, mass grinders, and ultra-fine grinders. Each type caters to specific production materials and processing requirements, reflecting the absence of a precise standard due to their unique characteristics.

Conclusion

The challenge of obtaining sub-micron powders through mechanical dry grinding, coupled with the high cost of chemical powdering, positions wet grinding as a vital method for preparing ultrafine powders. The practical application underscores that there’s no absolute difference between the advantages and disadvantages of the two methods. Choosing the appropriate treatment method depends on the product characteristics and economic considerations.