In-Depth Survey Report of Silica Flour Dust during Packing, Transfer and Shipping at Ottawa Silica Company, Ottawa, Illinois

摘要

A visit was made to the Ottawa Silica Company, Ottawa, Illinois to evaluate innovative control methods used to keep the exposure of workers to silica-flour (14808607) dust at a minimum. Silica sand ore was pumped as a wet slurry from the quarry to a processing building where it was washed and sized on stationary wet screens. Exhaust ventilation was provided at each packer station and consisted of several collection points. Water was injected into the product at each filler spout to reduce the emission of dust from silica-flour products. Sonic sprayers were installed at three strategic locations. Water was sprayed on top of the bags to remove dust from the valve area near the fill spouts. Water was sprayed at the transfer point both upward and downward on the bags to remove dust. At the transfer point from the declining conveyor to the horizontal transfer conveyor, water was sprayed from both sides to wash the sides of the bags. The authors recommend the use of respiratory protection in all work areas, as a preventive measure when dust control measures fail. Good local control ventilation is needed. Proper ventilation design requires both sufficient air movement and the development of effective flow patterns.