Generation of active polysulphide with manganese and bismuth...

Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Treatment with particular chemical

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C162S029000, C423S562000

Reexamination Certificate

active

07867360

ABSTRACT:
Polysulphide produced by oxidizing white liquor includes both active and inactive components. “Active” polysulphide is the only component that increases pulp yield. The amount of active polysulphide formed when manganese oxides are used as catalysts in the generating process is increased by adding a co-catalyst. Adding bismuth compounds and, in particular, bismuth oxide as a co-catalyst increases the total amount of polysulphide formed with all the manganese oxides and increases the amount of active polysulphide produced particularly when using the lower manganese oxides. The co-catalyst also increases the number of cycles in which the most active catalyst, manganese dioxide, can participate before losing efficiency. Other elements in the same group and adjacent groups in the periodic table are active but these other elements are more soluble than bismuth and are toxic.

REFERENCES:
patent: 1900751 (1933-03-01), Baehr
patent: 3380931 (1968-04-01), Ryland
patent: 3470061 (1969-09-01), Barker
patent: 3838069 (1974-09-01), Kobayashi
patent: 3860479 (1975-01-01), Barker et al.
patent: 3928238 (1975-12-01), Koberstein et al.
patent: 4012280 (1977-03-01), Holton
patent: 4024229 (1977-05-01), Smith et al.
patent: 4075248 (1978-02-01), Marshall et al.
patent: 4290923 (1981-09-01), Mein et al.
patent: 4783545 (1988-11-01), Glaeser et al.
patent: 5082526 (1992-01-01), Dorris
patent: 6866748 (2005-03-01), Sundaram et al.
patent: 6963009 (2005-11-01), Leiber et al.
patent: 2002/0088576 (2002-07-01), Andoh et al.
patent: 2002/0192146 (2002-12-01), Sundaram et al.
patent: 2003/0157017 (2003-08-01), Sundaram et al.
patent: 2005/0072539 (2005-04-01), Van Heek et al.
patent: WO 97/19891 (1977-06-01), None
patent: WO 02/066373 (2002-08-01), None
Dowson et al., Studies in Qualitative Inorganic Analysis. Part XLIII, 1974, Mikrochimica Acta, 339-368.
“Carboxyl End Groups in Sulfate and Polysulfide Pulps” by B. Alfredsson et al, Department of Engineering Chemistry, Nr. 18, Sep. 30, 1963, pp. 703-706.
“Multi-Stage Polysulphide Pulping Processes” by D.W. Clayton et al, Pulp and Paper Magazine of Canada, Dec. 1967, pp. T619-T630.
“Sulphate Cooking With the Addition of Reducing Agents” by N. Hartler, The Central Laboratory of the Swedish Cellulose Industry, Stockholm, Sweden, Nr. 13, Jul. 15, 1959, pp. 468-471.
“Cooking Liquor Oxidation and Improved Cooking Technique in Polysulfide Pulping”, by P.A. Landmark et al, TAPPI, vol. 48, No. 5, May 1965, pp. 56A-58A.
“Hemicelluloses and Paper Properties of Birch Pulps”, by S.E. Pettersson et al, Svensk Papperstidning, 63, (1960), 762, 817, pp. 4-15.
“Factor Affecting Yield Increase and Fiber Quality in Polysulfide Pulping of Loblolly Pine, Other Softwoods, and Red Oak”, by N. Sanyer et al, TAPPI, vol. 47, No. 10, Oct. 1964, pp. 640-652.
“Some Aspects of the Chemistry of Polysulfide Pulping”, by A. Teder, Swedish Forest Products Research Laboratory, Stockholm, Sweden, Nr. 9, May 15, 1969, pp. 294-303.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Generation of active polysulphide with manganese and bismuth... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Generation of active polysulphide with manganese and bismuth..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generation of active polysulphide with manganese and bismuth... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2623787

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.