Method for preparing fibers contained in a pulp suspension

Abstract

A method for one of preparing fibers contained in a pulp suspension and preparing coating color for coated papers including the steps of providing fibers in a suspension form having a predefined solids concentration; loading the fibers with a precipitation product; grinding the fibers with the precipitation product to thereby produce precipitation product particles having a dimension. The dimension being from approximately 0.05 μm to 5 μm. With an additional step of producing crystalline precipitation product particles using the precipitation product particles in an online process directly in a stock preparation line.

1 . A method for one of preparing fibers contained in a pulp suspension and preparing coating color for coated papers, comprising the steps of: 
 providing fibers in a suspension form having a predefined solids concentration;    loading said fibers with a precipitation product;    grinding said fibers with said precipitation product to thereby produce precipitation product particles having a maximum dimension from between approximately 0.05 μm to 5 μm; and    producing crystalline precipitation product particles using said precipitation product particles in an online process directly in a stock preparation line.    
     
     
         2 . The method of  claim 1 , wherein said online process utilizes at least one of a cleaning device, a HC cleaner, a first mixing device, a first static mixer, a lime slaking device a press, a press, a screw press, a belt press, a balancing reactor, a crystallizer, a further mixing device, a further static mixer, a CO 2  supply device, an additional CO 2  recovery device, a CO 2  heater, a chemical bleaching agent addition, and a press water tank.  
     
     
         3 . The method of  claim 2 , wherein press water is used as dilution water on a crystallizer side of a papermaking machine.  
     
     
         4 . The method of  claim 2 , wherein said online process utilizes said further mixing device that is used for a fine adjustment of the pH of the pulp suspension, said fine adjustment of the pH being in a range from between 6 and 8.  
     
     
         5 . The method of  claim 2 , wherein said first mixing device is used for mixing milk of lime into the pulp suspension.  
     
     
         6 . The method of  claim 2 , wherein said online process utilizes said cleaning device to prevent contamination that occurs during the method, said contamination being heavy materials including sand, stones and pieces of metal.  
     
     
         7 . The method of  claim 2 , wherein said online process utilizes said CO 2  recovery system to supply at least some of the CO 2  needed by the method.  
     
     
         8 . The method of  claim 1 , wherein said precipitation product is calcium carbonate.  
     
     
         9 . The method of  claim 1 , wherein said precipitation product particles are of a rhombohedral form with a cube size range from about 0.05 μm to about 2 μm.  
     
     
         10 . The method of  claim 1 , wherein said precipitation product particles are of a scalenohedral form with a length in a range from approximately 0.05 μm to 2 μm and a respective diameter in a range from approximately 0.01 μm to 0.5 μm.  
     
     
         11 . The method of  claim 1 , wherein said solids concentration of the pulp suspension is in a range from approximately 5% to 60%.  
     
     
         12 . The method of  claim 11 , wherein said range is from approximately 10% to 35%.  
     
     
         13 . The method of  claim 1 , wherein said loading step includes adding at least one of calcium carbonate, calcium oxide and calcium hydroxide to the pulp suspension, a precipitation being initiated by treating the pulp suspension with carbon dioxide.  
     
     
         14 . The method of  claim 13 , wherein said calcium hydroxide is added to the pulp suspension in liquid form.  
     
     
         15 . The method of  claim 13 , wherein said calcium hydroxide is added to the pulp suspension in dry form.  
     
     
         16 . The method of  claim 13 , wherein said carbon dioxide is added to the pulp suspension at a temperature in a range from approximately −15° C. to 120° C.  
     
     
         17 . The method of  claim 16 , wherein said temperature is in a range from 20° C. to 90° C.