This invention relates to a method for treating chemical paper pulp comprising a step of treating the pulp with ozone followed by a step of alkaline extraction, in which alkaline extraction takes place in the presence of magnesium ions (Mg.sup.2+).

This invention relates to a method for treating chemical paper pulp comprising a step of treating the pulp with ozone followed by a step of alkaline extraction, in which alkaline extraction takes place in the presence of magnesium ions (Mg.sup.2+).

Apparatus (200) for the treatment of one or more substrates comprising a treatment chamber configured to receive a liquid medium and one or more substrates; a supply of a treatment gas comprising ozone; and one or more conduits to convey said treatment gas to a bubble generator (41) wherein said bubble generator is operable to form bubbles of said treatment gas in said liquid medium, wherein the apparatus comprises a multiplicity of solid particles (46). A method of treating one or more substrates, the method comprising agitating said one or more substrates in a treatment formulation comprising a multiplicity of solid particles, a liquid medium and bubbles of ozone.

Apparatus (200) for the treatment of one or more substrates comprising a treatment chamber configured to receive a liquid medium and one or more substrates; a supply of a treatment gas comprising ozone; and one or more conduits to convey said treatment gas to a bubble generator (41) wherein said bubble generator is operable to form bubbles of said treatment gas in said liquid medium, wherein the apparatus comprises a multiplicity of solid particles (46). A method of treating one or more substrates, the method comprising agitating said one or more substrates in a treatment formulation comprising a multiplicity of solid particles, a liquid medium and bubbles of ozone.

According to an example aspect of the present invention, there is provided a method of improving the reactivity and processability of cellulose in order to utilize cheap and easily available raw material and obtain excellent performance for biomaterial manufacturing.

A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material in the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.

A method for treating pulp through oxygen delignification and ozone bleaching is disclosed. The method uses a modified oxygen recovery unit which separates a mixture of oxygen and ozone thereby generating a stream of ozone and a stream of oxygen; feeding the stream of oxygen to an oxygen delignification unit; feeding a pulp to the oxygen delignification unit; feeding the stream of ozone to an ozone bleaching unit; feeding the delignified pulp to the ozone bleaching unit; and recovering the delignified and bleached pulp.

A method for treating pulp through oxygen delignification and ozone bleaching is disclosed. The method uses a modified oxygen recovery unit which separates a mixture of oxygen and ozone thereby generating a stream of ozone and a stream of oxygen; feeding the stream of oxygen to an oxygen delignification unit; feeding a pulp to the oxygen delignification unit; feeding the stream of ozone to an ozone bleaching unit; feeding the delignified pulp to the ozone bleaching unit; and recovering the delignified and bleached pulp.

A recycled pulp that is reusable sanitary products is efficiently manufactured by recovering pulp fiber from used sanitary products containing the pulp fiber and a polymer absorbent. The method of the present invention comprises: a step applying a mechanical force to the used sanitary products in an aqueous solution containing a polyvalent metal ion or an acidic aqueous solution with a pH of 2.5 or lower and thus degrading the used sanitary products into the pulp fiber and other materials; a step separating the pulp fiber from the mixture of the pulp fiber and other materials that has been formed in the degradation step; and a step treating the pulp fiber thus separated with an ozone-containing aqueous solution with a pH of 2.5 or lower.

A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material In the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.