Dust Control Handbook for Industrial Minerals Mining and Processing

Some specialty grinding operations purchase damp granular minerals and dry them before theyare fed into the milling process. Regardless, all the process equipment involved in preparing andfeeding the grinding mill have their respective dust collection systems.The most important consideration for dust control within a grinding/classification/productstorage circuit is dust containment, and the second is dust collection. All of the materialconveying equipment related to a milling or grinding circuit must be enclosed. In addition, alltransfer points must be fully enclosed.Design and Work Practices to Minimize Dust Exposure from MillingThe following design and work practices can serve to reduce operator exposure to airborne dustaround milling operations.Grinding circuit equipment must be tightly closed and maintained under a slight negativepressure 100 percent of the operational time by a dust collection system. This means thatany air leakage will flow into and not out from the equipment, keeping the dustcontained.Sampling points must be designed so that when the access doors are opened, the milledmaterial stays inside. All sample and inspection doors should be installed at least 45degrees off the vertical or greater, with horizontal doors being preferable for easy accessand lower risk of spillage (see Figure 4.14).Figure 4.14. Sampling doors located on top of a collection/transfer point to prevent leakage.124 Crushing, Milling, and Screening