The recent decrease in Blast Furnace production as well as changes in raw materials and process conditions has produced an increase in the silicon and phosphorus contents in hot metal. This situation increases the probability of slopping and fume emissions during converter blowing because of the large volume of highly viscous slag. To carry out the silicon oxidation and dephosphorization steps, a double slag practice has to be used. The first slag is rich in silicon and phosphorus and has a low basicity. The first slag is removed. Then the second slag is formed; this low-viscosity slag is subject to the strong agitation created by a high decarburization rate. The second slag is characterized by higher CaO and phosphorus contents. These conditions yield a better dephosphorization at the end of the blow. In order to implement the double slag practice, the converter control system was modified. The changes included the design of the lance blowing pattern, the flux additions, the static control, and the logic of the gas collection and cleaning system. For a silicon content larger than 0.60% in the hot metal, the results show a significant reduction in the fume emissions and in slopping, a lower flux consumption, and open up the possibility of working with iron ore with higher phosphorus content.