Abstract: The invention relates to an improvement in a method of regenerating alkaline or alkaline earth metal oxides or hydroxides from solution particularly in delignification processes wherein a suitable transition metal such as ferric oxide is burnt with the solution to produce a mixed oxide that is subsequently treated in hot water to regenerate the alkaline or alkaline earth metal oxide or hydroxide and precipitate the transition metal oxide. The improvement controls the presence of fines in the transition metal oxide to maintain these at an acceptable level in the fluidized bed combustion zone. This is achieved by contacting the fines with spent liquor from a delignification process. The invention also provides for the pelletization of the fine material of the transition metal oxide and spent delignification liquor can be used as a binder in the formation of such pellets.

Abstract: A twin wire papermaking machine which has a multichambered suction dewatering device located over the forming wires downstream from the forming roll. The dewatering device deflects the forming wires into a concave path to aid in formation and dewatering.

Abstract: A method of utilizing kraft black liquor by converting the black liquor to "green liquor" and then oxidizing the green liquor with air in the presence of a quinone compound or spent liquor from the kraft process, the soda semi-chemical process or the neutral sulfite semi-chemical process as a catalyst. A marked improvement in the rate of oxidation is obtained. The thus oxidized green liquor is then able to be used as part at least of the digestion liquor in the NSSC process.

Abstract: In the regeneration of alkaline liquors as used in paper pulping, a mixed oxide compound of an alkali or alkaline earth metal oxide and an oxide of Ti, Fe, Co, Ni, or Mn is formed by burning black liquor. The burning step is carried out in a fluidized bed. The mixed oxide product is washed in cold water and subsequently treated with hot water to precipitate the oxide of Ti, Fe, Co, Ni or Mn and enable recovery of the alkaline solution for recycling.

Abstract: A process for the delignification of lignocellulosic material is described wherein the lignocellulosic material is cooked with an alkaline or neutral sulphite pulping liquor, and there is added to the pulping liquor at least 0.001% by weight of an additive compound or mixture of additive compounds selected from quinones and hydroquinones.

Abstract: A delignification process using amine cooking liquors which also contain a quinoid or hydroquinoid compound. The process also encompasses a pretreatment step using the quinoid or hydroquinoid compounds.

Abstract: A process for the delignification of .Iadd.softwood .Iaddend.lignocellulosic material is described wherein the lignocellulosic material is cooked with .[.an alkaline or.]. .Iadd.a .Iaddend.neutral sulphite pulping liquor, and there is added to the pulping liquor at least 0.001% by weight of an additive compound or mixture of additive compounds selected from quinones and hydroquinones.