AU601823B2

AU601823B2 - A process for the flotation of fillers from circulating waters in paper manufacture

Info

Publication number: AU601823B2
Application number: AU13069/88A
Authority: AU
Inventors: Klaus Hornfeck; Wolfgang Dr. Von Rybinski
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1987-07-16
Filing date: 1988-03-14
Publication date: 1990-09-20
Anticipated expiration: 2008-03-14
Also published as: DK136388D0; EP0302166A1; YU47188A; PL271189A1; DE3723500A1; JPS6433292A; CS272785B2; YU45490B; FI881183A; AU1306988A; NO880697D0; DK136388A; FI881183A0; NO880697L; CS166288A2; HUT53031A

Description

ir 601823 S F Ref: 44800 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: 0 ~1 Complete Specification Lodged: Accepted: Published: Class Int Class Jhi c, ntims the arncndments mae iunder ;A -ry and is correct for prinlir g Priority: Related Art: Name and Address of Applicant: Henkel Kommanditgesellschaft Henkelstrasse 67 Dusseldorf FEDERAL REPUBLIC OF GERMANY auf Aktien Address for Service: 44r Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: A Process for the Flotation of Fillers from Circulating Waters in Paper Manufacture The following statement is a full description best method of performing it known to me/us of this invention, including the 5845/3 LL _ii~ I D 7970 1. water-soluble salts of trivalent metal ions are added to the circulating water so that pH values of 4.5 to 9 are established and 2. the circulating water is floated after addition of to 100 g anionic surfactants per m 3 circulating water.

C C C C C a wai t an C C C C c r t V Il~iil i i 1 I i 1 This invention relates to a process for the flotation of fillers from circulating waters in paper manufacture and to the use of water-soluble salts of trivalent metal ions for the flotation of fillers from circulating waters in paper manufacture.

Large quantities of water are used in paper manufacture, for example for suspending the fibrous materials and auxiliaries, for dissolving other auxiliaries (dilution) or as 00 1 sealing water, cooling water or boiler feed water. Accordoooo oo a 10 ingly, papermaking factories are among the largest industrial 0 00 0 °0 users of water. However, the demand for fresh water is O0 greatly reduced by recirculation (Ullmanns Encyclopadie der 0000 o000 technischen Chemie, 17, 577 et seq (1979) Sw To guarantee uniform paper qualities, the circulating oooooc SC 15 water has to be substantially free from paper fibers and auxiliaries. Paper fibers and auxiliaries, for example 0 0 fillers, sizes, dyes, foam inhibitors and/or dispersants, a 4 V o which enter the circulating water during the papermaking process, are removed from the circulating water by filtration, 20 flotation or sedimentation processes. Fibers and filler particles are often separated off by flotation, i.e. by forcing or sucking air through the circulating water of the JtU papermaking machine. Small air bubbles combine with the fibers and filler particles and form a froth at the water surface which is removed with collectors.

However, known flotation processes do not completely remove the fillers from the circulating waters in paper manufacture. This is a disadvantage particularly when, in addition to mechanical wood pulps, half stuffs and/or chemical wood pulps, waste paper is also used as the fibrous material for papermaking, because the incomplete removal of the fillers entering the water from the waste paper leads to difficulties in the production of papers having standardized quality features, Accordingly, the object of the present invention is to L_ I 1. 11 =Ed u~L I 0000 0 0 0 00 0 0 00 00 0 0000 0000 0 0 0000 00 00 00 0 0 0 000000 0 0 0 00 ooooo 00 a o 00 0 o00 00 0 0 a0C 00 a 0 o 0¢ 0 0

C;S

C I Cr o- 1 develop a process by which it is possible to increase the removal of fillers from circulating waters in paper manufacture.

The invention is based on the surprising discovery that the removal of ash, i.e. the separation of fillers, from circulating waters in paper manufacture can be considerably increased if the circulating waters are floated by addition of water-soluble salts of trivalent metal ions.

Accordingly, the present invention relates to a process 10 for the flotation of fillers from circulating waters in paper manufacture which is characterized in that i. water-soluble salts of trivalent metal ions are added to the circulating waters so that pH values of from 4.5 to 9 are established and 15 2. the circulating waters are floated in known manner 3 after addition of 5 to 100 g anionic surfactants per m circulating water as collectors.

The present invention also relates to the use of watersoluble salts of trivalent metal ions for the removal of ash 20 from circulating waters in paper manufacture.

Fillers commonly used in paper manufacture are, for example, aluminium silicates, such as kaolins or siliceous alumina, calcium carbonates, such as chalk or lime, talcum, calcium sulfate and/or barium sulfate.

The pH value at which the process according to the invention is carried out is preferably in the range from 6 to 8.

This pH value in the circulating waters is established by addition of water-soluble salts of trivalent metal ions, preferably in quantities of 0.05 to 1 g and more preferably in guantities of 0.2 to 0.5 g per liter circulating water. Watersoluble sulfates, chlorides, acetates, hydroxides, phosphates i and/or polyphosphates of trivalent metal ions, particularly chromium(III) sulfate, aluminium sulfate and/or iron sulfate, are suitable as water-soluble salts of trivalent metal ions for the process according to the invention. Aluminium sul-

STR.,

A

3 1 fate is particularly preferred.

The subsequent flotation is carried out with 5 to 100 g 3 and preferably with 20 to 40 g anionic surfactants per m circulating water as collectors.

Suitable anionic surfactants are, in particular, C 8

-C

24 alkyl sulfates prepared by reaction of C 8

-C

24 alcohols, for example lauryl alcohol or tallow fatty alcohol, with oleum, amidosulfonic acid, chlorosulfonic acid or sulfur 'rioxide, SC8-C24 alkyl ether sulfates prepared by reaction of C8-C24 0°0o° 10 alcohols with 1 to 100 mol ethylene oxide (EO) and subseo a quent sulfatization with oleum, amidosulfonic acid, chloro- 000 oooo sulfonic acid or sulfur trioxide, for example lauryl alcohol +30 EO salfate, C 3 -C24 alkyl phenol ether sulfates prepared by reaction of mono-, di- or trialkyl phenol with 1 to 100 15 mol ethylene oxide and subsequent sulfatization with oleum, amidosulfonic acid, chlorosulfonic acid or sulfur trioxide, for example nonyl phenol 4 EO sulfate, C -C 24 alkyl and/or

C

3

-C

24 alkyl phenol ether sulfates prepared by reaction of

SC

8

-C

24 alcohols and/or mono-, di- or trialkyl phenols with 1 to 100 mol ethylene oxide and subsequent reaction with F polyphosphoric acids or phosphoric anhydride, for example lauryl alcohol 10 EO phosphate, sulfosuccinic acid semi- Sesters of C 8

-C

24 alkyl or C 3

-C

24 alkyl phenol polyglycol ether alcohols prepared by reaction of C 8

-C

24 alkyl or C 3

-C

24 25 alkyl phenol polyglycol ether alcohols with maleic anhydride and subsequent sulfitation with sodium hydrogen sulfite, for example nonyl phenol 10 EO sulfosuccinate, sulfosuccinic acid semiesters of C 8

-C

24 alkanols or C 8

-C

24 alkylamines, for example lauryl sulfosuccinate or tallow amine sulfosuccinamate, sulfosuccinic acid esters of C 4 -C1 alcohols prepared by sulfitation of the corresponding maleic acid diesters by the process described in EP-PS 87 711, C 8

-C

24 alkyl benzenesulfonates prepared by sulfonation of C8-C24 alkyl benzenes with concentrated sulfuric acid, oleum or sulfur trioxide, for example n-dodecyl benzenesulfonate, sul- 4 1 focarboxylic acid alkyl esters and/or sulfocarboxylic acids containing 8 to 24 carbon atoms in the carboxylic acid part, of the type described in US-PS 4,529,762 or DE-OS 35 13 046,

C

3

-C

8 alkyl naphthalenesulfonates prepared by reaction of

C

3

-C

8 alcohols with naphthalene in the presence of concentrated sulfuric acid or oleum, secondary alkanesulfonates prepared by sulfonation or sulfoxidation of paraffin hydrocarbons and/or sulfatized and/or sulfonated triglycerides, COT for example sulfatized castor oil. The anionic surfactants C' r 10 are used in the form of their water-soluble alkali and/or ammonium salts, particularly in the form of their sodium and/or ammonium salts. "Alkyl" stands for linear and/or branched, saturated and/or unsaturated alkyl radicals of natural and/or synthetic origin.

According to the invention, the water-soluble salts of trivalent metal ions are added to the circulating waters in quantities of preferably 0.05 to 1 g and more preferably 0.2 to 0.5 g per liter circulating water at 20 to 60 0 C, so that a pH value of from 4.5 to 9 and preferably from 6 to 8 is established and the circulating waters are floated at to 95 0 C and preferably at 45 to 60 0 C after addition of 3 to 100 g and preferably 20 to 40 g anionic surfactants per m circulating water. It is possible by the process according to the invention to remove at least 70% by weight of the total filler content from the circulating waters in paper manufacture.

EXAMPLES

A circulating water from a deinking plant, which had a filler content of 1.2 g/l, was floated at 45°C in Denver laboratory flotation cells after addition of sodium C12-C18 alkyl benzenesulfonate as anionic collector and A12(SO 4 3 as activator.

The results are shown in the following Table.

U

Example Collector Al A.(S.0 4 Ash.

g/l suspension g/l suspension removal 1 0.03 -43 2 0.03 0.3

Claims

1. A process for the separation of fillers from circulating waters in paper manufacture, characterized in that 1. water-soluble salts of trivalent metal ions are added to the circulating waters so that pH values of from 4.5 to 9 are established and

2. the circulating waters are floated in known manner after addition of 5 to 100 g anionic surfactants per m 3 circulating water as collectors, wherein the surfactants are alkali and/or ammonium salts of C 8 C 24 alkyl sulfates, C0 8 C 24 alkyl ether sulfates, C 8 C 24 alkyl benzenesulfonates and/or sulfosuccinic acid semiesters ofC8-C2 al cohol s. 2. A process as claimed in claim 1, characterized in that pH values of 6 to 8 are established in the circulating waters after addition of the C water-soluble salts of trivalent metal Ions.

3. A process as claimed in any one of claims 1 or 2, characterized in that the water-soluble salts of trivalent metal ions are added to the circulating water in a quantity of 0.05 to 1 g and preferably in a quantity of 0.2 to 0.5 g per liter circulating water.

4. A process asa claimed in any one of claims 1 to 3, characterized in that aluminium and/or iron, sulfate, preferably aluminium sulfate, is/are oused as the water-soluble salts of trivalent metal ions. aoC in

5. A process as claimed in any one of claims 1 to 4, characterized ithat the anionic surfactants are used in a quantity of 20 to 40g per 0 0 3 cruaigwtr 0 00C mcrcltngwtr

6. A process for the separation of fillers from circulating water in paper manufacture substantially as hereinbefore described. 000 C o00 0 DATED this TWENTY-EIGHTH day of MAY 1990 Henkel Kommanditgesellschaft auf Aktien Patent Attorneys for the Applicant SPRUSON FERGUSON P, A 4 TMS/8731M