MPR Refractories Ltd. Manufactures Coke Oven Gunning Mixes. MPR Refractories Ltd. Is an ISO 9001:2008 certified company. MPR Refractories Ltd. Offers Slide Gate Plates, Collector Nozzles, Ladle Nozzles, Porous Plugs, Tundish Nozzles, Well Block for Porous Plugs, 90 K Mortar, 95 H Castable, Tundish Boards, Packing & Sealing Compounds, etc. The Coke Oven Gunning Mixes are used for heating fine cracks in Coke Oven Wall, Head. These are used at roof and ascension pipe.