Lafarge Canada Inc., St. Constant, Quebec Like many other cement plants, the Lafarge Canada St. Constant facility experienced problems with the obstruction of the grates (partition openings) inside its ball mills. The traditional method of cleaning the grates generated substantial noise and created an extremely hot working environment, since the fans of the bag houses had to be locked up. Another method of cleaning the grates required workers to wear protective leather clothing and other safety equipment from head to toe. A team was formed to develop a new method to clean the grates safely, and the idea of a "hydraulic extractor" was created. Several attempts were made and a hydraulic specialist was called in to build a reliable and safe tool. The final design is made from a simple combination of a strong hook, a hydraulic cylinder, a pump, and a pressure regulator. The obstructions (or punchings) are pulled from the grates and, most importantly, captured inside the almost noiseless tool. Therefore, workers are not required to wear full-body protection, and fans can be used to bring in fresh air.