Molten metal processing

Abstract

Processing apparatus and methods for introducing material into a molten metal are provided. The material is introduced through a tube, which leads into the molten metal flow between the exit from a chamber and the entry back into a chamber. Increased breaks for material injection and/or better material injection are provided as a result.

1 . Processing apparatus for molten metal, the apparatus including a chamber for the molten metal, a molten metal mover, an inlet leading from the chamber to the molten metal mover and an outlet leading from the molten metal mover to the chamber, a tube leading into the apparatus between the start of the inlet and the end of the outlet.  
   
   
       2 . Processing apparatus for molten metal, preferably according to  claim 1 , the apparatus comprising a tube, the tube leading to a location at which molten metal is provided in use, a gas permeable element being provided between the end of the tube at the location at which molten metal is present in use.  
   
   
       3 . Processing apparatus according to  claim 1  for introducing a gas to a volume of molten metal, the apparatus including a charge well into which solid metal to be melted is introduced, an electromagnetic pump, an inlet leading from the charge well to the pump, an outlet leading from the pump to the charge well, a tube leading into the outlet from the pump, the tube leading into the outlet at a location removed from the charge well.  
   
   
       4 . Processing apparatus according to  claim 3  in which the outlet form the charge well leads to the furnace and the metal then passes on to the pump.  
   
   
       5 . Processing apparatus according to  claim 1  for introducing solid metal to a volume of molten metal, the apparatus including a charge well into which solid metal to be melted is introduced, an electromagnetic pump, an inlet leading from the charge well to the pump and an outlet leading from the pump to the charge well, a tube leading into the outlet from the pump, the tube being provided in a wall of the charge well.  
   
   
       6 . Processing apparatus according to  claim 5  in which the outlet from the charge well leads to the furnace.  
   
   
       7 . Processing apparatus according to  claim 1  for melting metal or metal containing materials and/or for processing molten metal and/or for purifying molten metal and/or for distributing molten metal.  
   
   
       8 . Processing apparatus according to  claim 1  in which the tube leads into the apparatus between the end of the molten metal mover and the end of the outlet.  
   
   
       9 . Processing apparatus according to  claim 1  in which the tube is in contact with the chamber/charge well along at least a part of its length.  
   
   
       10 . Processing apparatus according to  claim 9  in which the tube is received within the wall of the chamber/charge well in a passage and the passage has an opening to the chamber/charge well along at least part of its length.  
   
   
       11 . Processing apparatus according to  claim 9  in which the passage is of circular cross-section with a portion cut away.  
   
   
       12 . Processing apparatus according to  claim 2  in which the gas permeable element is permeable to gas without being permeable to molten metal.  
   
   
       13 . Processing apparatus according  claim 1  in which the tube is connected to a source of material to be added to the molten metal.  
   
   
       14 . Processing apparatus according to  claim 2  the element having a porosity of between 5 and 20%.  
   
   
       15 . A method of introducing material into a molten metal, the method including providing apparatus including a chamber, providing molten metal within the chamber and circulating the molten metal through an outlet from the chamber to a molten metal mover and from the molten metal mover through an outlet to the chamber, the material being introduced through a tube which enters the apparatus between the start of the inlet and the end of the outlet.  
   
   
       16 . A method according to  claim 15  in which the method provides that gas leaves the tube through a gas permeable element and enters the molten metal, without molten metal entering the gas permeable element.  
   
   
       17 . A method according to  claim 15  in which the gas reacts with the metal or one or more constituent parts thereof and the reaction has completed before the gas reaches the end of the outlet and/or enters the chamber.  
   
   
       18 . A method according to  claim 15  in which the gas flow rate into the outlet and/or the distance between the location at which gas enters the outlet and the end of the outlet are controlled so as to ensure the reaction is completed and/or no gas is left and/or no gas bubbles are left by the time the molten metal leaves the outlet.  
   
   
       19 . A method according to  claim 15  in which the material is introduced as a solid.