Method and device for loading fibers contained in a fibrous suspension with calcium carbonate

Abstract

In a method and device for loading the fibers that are contained in a fiber stock suspension with calcium carbonate by way of a chemical precipitation reaction, calcium oxide and/or calcium hydroxide are added to the fiber stock suspension. In order to trigger the precipitation reaction at least partially liquid carbon dioxide is injected into the reactor thereby ensuring the transformation of the starting substance calcium dioxide or calcium hydroxide into the reaction products calcium carbonate and water. The carbon dioxide can be added in an exclusively liquid state or partially in a liquid state and partially in a gaseous state.

What is claimed is:  
     
         1 . A method for loading fibers in a fiber stock suspension with calcium carbonate by way of a chemical precipitation reaction, comprising the steps of: 
 adding at least one of a calcium oxide and a calcium hydroxide to the fiber stock suspension;    injecting an at least partially liquid carbon dioxide into a reactor; and    transforimig said at least one of calcium oxide and calcium hydroxide into a plurality of reaction products including calcium carbonate and water.    
     
     
         2 . The method of  claim 1 , wherein said at least partially liquid carbon dioxide is exclusively liquid carbon dioxide.  
     
     
         3 . The method of  claim 1 , wherein said at least partially liquid carbon dioxide includes a gaseous liquid carbon dioxide.  
     
     
         4 . The method of  claim 3 , further including the step of adjusting both a reaction temperature in said reactor and a crystalline form of the calcium carbonate through a ratio of a volume of said liquid carbon dioxide to a volume of said gaseous carbon dioxide.  
     
     
         5 . The method of  claim 1 , further including the step of regulating a reaction temperature in said reactor via a differential pressure P Δ =P CO2 −P R  between said liquid carbon dioxide and a reaction space in said reactor.  
     
     
         6 . The method of  claim 5 , wherein said differential pressure P Δ  is approximately between 0 bar and 100 bar.  
     
     
         7 . The method of  claim 5 , wherein said differential pressure P Δ  is approximately between 1 bar and  50  bar.  
     
     
         8 . The method of  claim 1 , further including the step of achieving a rhombohedral crystallite form of the calcium carbonate by keeping a reaction temperature in said reactor no greater than 45° C.  
     
     
         9 . The method of  claim 1 , further including the step of achieving a scalenohedron crystallite form of the calcium carbonate by keeping a reaction temperature in said reactor greater than 45° C.  
     
     
         10 . The method of  claim 1 , further including the step of cooling down said carbon dioxide by relieving said carbon dioxide into said reactor thereby creating an at least partially solid carbon dioxide.  
     
     
         11 . The method of  claim 1 , wherein said at least partially liquid carbon dioxide is injected into said reactor through a valve.  
     
     
         12 . A device for loading a plurality of fibers that are contained in a fiber stock suspension with calcium carbonate by way of a chemical precipitation reaction, comprising: 
 at least one first adding element through which at least one of calcium oxide and calcium hydroxide are added to the fiber stock suspension;    a reactor connected to said at least one first adding element; and    at least one second adding element connected to said reactor; said at least one second adding element through which at least partially liquid carbon dioxide is injected into said reactor in order to trigger a precipitation reaction, thereby transforming said at least one of calcium oxide and calcium hydroxide into a plurality of reaction products including a calcium carbonate and water.    
     
     
         13 . The device of  claim 12 , wherein said at least partially liquid carbon dioxide is exclusively liquid carbon dioxide.  
     
     
         14 . The device of  claim 12 , wherein said at least partially liquid carbon dioxide includes a gaseous liquid carbon dioxide.  
     
     
         15 . The device of  claim 14 , wherein both a reaction temperature in said reactor and a crystalline form of the calcium carbonate are adjusted through a ratio of a volume of said liquid carbon dioxide to a volume of said gaseous carbon dioxide.  
     
     
         16 . The device of  claim 12 , wherein a reaction temperature in said reactor is regulated via a differential pressure P Δ =P CO2 −P R  between said liquid carbon dioxide and a reaction space in said reactor.  
     
     
         17 . The device of  claim 16 , wherein said differential pressure P Δ  is approximately between 0 bar and 100 bar.  
     
     
         18 . The device of  claim 16 , wherein said differential pressure P Δ  is approximately between 1 bar and 50 bar.  
     
     
         19 . The device of  claim 12 , wherein a rhombohedral crystallite form of the calcium carbonate is achieved by keeping a reaction temperature in said reactor no greater than 45° C.  
     
     
         20 . The device of  claim 12 , wherein a scalenohedron crystallite form of the calcium carbonate is achieved by keeping a reaction temperature in said reactor greater than 45° C.  
     
     
         21 . The device of  claim 12 , wherein said carbon dioxide is relieved into said reactor cooling said carbon dioxide thereby creating an at least partially solid carbon dioxide.  
     
     
         22 . The device of  claim 12 , wherein said at least partially liquid carbon dioxide is injected into said reactor through a valve.