Dust Control Handbook for Industrial Minerals Mining and Processing

WORK PRACTICES TO MINIMIZE DUST EXPOSURESFROM BAGGING AND PALLETIZINGThe following list of best practices should be considered by operations wishing to minimizerespirable dust exposures to workers performing bagging and palletizing.Use slides or chutes whenever possible to minimize the distance that product free-falls inopen areas.Keep floors as clean as possible to minimize dust liberation as forklifts/tow motors travelaround the area transporting bag material and other items.Maintain the work area such that there are no sharp edges at bag drop-off locations,turning points, and/or conveyor lines that could tear bags of product material.Maintain material flow cut-off valves at bagging machines to minimize product dribblefrom fill nozzles/fill chutes.Determine the optimal bag construction and bag valve type for the material beingprocessed and bagging machine being used.Minimize product blowback and product "rooster tail" during bag filling and ejectionfrom the fill station. Both of these dust sources can also cause extensive dusting on theoutside of bags, as well increase the overall demand on the LEV system.Consider using ventilated filling spouts as discussed in the "Dual-Nozzle BaggingSystem" section to remove product from the fill nozzle and bag valve areas after bagfilling is completed.Slow bag filling rates when necessary to minimize the amount of product blowback.Carefully place loaded bags onto pallets. Throwing or dropping bags onto conveyors orpallets increases the potential for dust generation and/or bag breakage.Use a hydraulic lift table to minimize dust generation and MSDs to workers during bagloading onto pallets by keeping the loading height at knuckle height as described in the"Semi-Automated Bag Palletizing Systems" section. This allows for a push-pullventilation system to more effectively capture any dust generated during bag palletizing.Use dust-free empty bags manufactured to Flexible Intermediate Bulk Container (FIBC)standards. Many reusable FIBC bags are returned with clean interiors, but dust is oftentrapped in the fabric on the bag exterior. This dust is then expelled during handling of thebag.Store all empty bags in a clean environment and keep them covered to prevent dust fromsettling on them.When tying or sealing the spout of a filled FIBC bag, the operator should always hold theflexible loading spout away from his or her breathing zone to minimize the escaping dust.Avoid positioning the bag operator or the bag palletizer between any dust source and thepickup point of an LEV system. When this is not done, dust will be drawn directly overthe worker, significantly increasing the worker's dust exposure.Consider using a mechanically assisted bag handling system to prevent dropping filledbags onto pallets. These systems also greatly reduce the potential for workers developingMSDs.Consider the use of a bag cleaning device prior to bag palletizing, as discussed in the"Bag and Belt Cleaning Device" section. Mechanical brushes and air nozzles can be184 Bagging