Hooker Chemicals & Plastics Corporation

Willard A Fuller

Earl A Schilt

Theodore H Dexter

Harold deVere Partridge

A cellulosic pulp and bleaching process is described. The process integrates two cycles, one is a digestor liquor cycle and the other is a sulfur cycle. The digestor liquor cycle comprises the steps of digesting a fibrous cellulosic feed to form a pulp, separating the pulp and bleaching it in at least one stage with chlorine dioxide, evaporating and burning the remaining waste liquor to form a smelt, dissolving the smelt to form a green liquor and utilizing the green liquor, after recausticizing, as at least a portion of the feed stock for the digestor step. The sulfur cycle of the present invention utilizes a portion of the green liquor of the digestor liquor cycle. The green liquor is carbonated to form a bicarbonate which is then stripped of H.sub.2 S. The H.sub.2 S is converted into H.sub.2 SO.sub.4 and utilized as a feed stock to a chlorine dioxide generator. The chlorine dioxide generator utilizes H.sub.2 SO.sub.4 as feed stock and produces Na.sub.2 SO.sub.4 as a by-product. The Na.sub.2 SO.sub.4 by-product from the chlorine dioxide generator is furnaced in common with the evaporated waste pulping liquor from the digestor liquor cycle to form a common smelt, which is dissolved to form a green liquor, a portion of which is used in the sulfur cycle and a portion of which is used in the digestor cycle.

Kraft mill recycle process

A flowable, non-caking aqueous slurry of sodium chlorate and sodium chloride having a weight ratio of sodium chloride to sodium chlorate between about 0.55 and 0.65, and, more preferably, about 0.59, is described. The slurry contains a solid phase essentially entirely of sodium chloride. The slurries contain from about 28 to about 33% by weight sodium chlorate, from about 15 to about 21% by weight sodium chloride, and from about 45 to about 58% by weight water. The slurries are produced by forming an initial aqueous solution of sodium chlorate and sodium chloride containing from about 28 to about 50% by weight sodium chlorate and from about 0 to about 14% by weight sodium chloride and subsequently adding sufficient sodium chloride to obtain a slurry containing from about 28 to about 33% by weight sodium chlorate, from about 15 to about 21% by weight sodium chloride, and from about 45 to about 58% by weight water.

Stable non-caking aqueous slurry of sodium chlorate and sodium chloride

There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate a reducing agent, and a mineral acid are reacted in a vessel, and the salt crystals are separated from the generator crystal slurry.

Production of chlorine dioxide

An improved process is provided for the production of chlorine dioxide and chlorine wherein an alkali metal chlorate and a strong acid selected from the group sulfuric acid, hydrochloric acid, phosphoric acid, and mixtures thereof are circulated and reacted in an integral forced circulation crystallizing reaction evaporator comprising in vertical disposition: a. an upper crystallizing evaporation chamber having a substantially vertically disposed cylindrical partition which divides at least the lower portion of the reaction evaporation chamber into a first and second substantially concentric cylindrical sections; B. a heat exchange chamber, and C. a lower pump chamber, having a pump means disposed therein to provide forced circulation of fluids within the reaction evaporator. An aqueous slurry of alkali metal salt of the strong acid is withdrawn from the lower portion of the pump chamber and chlorine dioxide, chlorine, and water vapor are withdrawn from the evaporation chamber.

Process for the production of chlorine dioxide

An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and a mineral acid are reacted in a single vessel, and the resultant alkali metal salt is converted to a more desirable salt in a metathesis column by reaction with an appropriate acid or an alkaline earth or alkali metal, chloride.

Production of chlorine dioxide with product slurry metathesis

There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate, and hydrochloric acid are reacted in a vessel, and the salt crystals are separated from the generator crystal slurry.

An improved process for the treatment of precipitator catch wherein the catch is slurried with water, sufficient carbon dioxide is added to convert the sodium carbonate present to sodium bicarbonate, and sodium chloride is separated from the sodium sulfate and sodium bicarbonate.

Kraft mill recovery system

An improved process for the treatment, separation, and utilization of precipitator catch wherein treated precipitation catch is separated by countercurrent washing in a column.

An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and sulfuric acid are reacted in a single vessel, and the resultant alkali metal sulfate converted to alkali metal chloride in a metathesis column by reaction with hydrochloric acid.

There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate, and a mineral acid are reacted in a single vessel, and the salt crystals separated from the generator crystal slurry.

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Grand Island, NY, United States of America

Willard A Fuller