Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F13/00—Recovery of starting material, waste material or solvents during the manufacture of artificial filaments or the like
  • D01F13/02—Recovery of starting material, waste material or solvents during the manufacture of artificial filaments or the like of cellulose, cellulose derivatives or proteins
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
  • Y02P70/62—Manufacturing or production processes characterised by the final manufactured product related technologies for production or treatment of textile or flexible materials or products thereof, including footwear

Definitions

• sulphuric acid precipitating baths which, in addition to sodium sulphate, also contain magnesium sulphate.
• Durin use the amount of sulphuric acid contained in the teract dilution by the water, or in evaporatspinning bath becomes reduced, owing to its being neutralized by the alkali of the viscose, and the quantity of the'spinning bath decreases, because a portion of the liquid is carried away by the products, e. g., the threads, and passes into the washing Water.
• Thepresent invention hasfor its object the provision and elaboration of a regeneration process which can be used for spinning baths which are required to contain magnesium sulphate in addition to sulphuric acid or sul phuric acid and sodium sulphate. That with such baths the simple evaporating process does not achieve the desired object has been shown by experiments, both with the main bath and also with the so-called upper baths, washing baths and. the like. It has been found, as a matter of fact, that in the simple evaporation of bath solutions containing both salts simultaneously, the sodium sulphate content increases, disproportionately to the magnesium sulphate content, since fresh sodium sulphate is continuously being formed in the spinning bath.
• Glauber salts separates out in the form of Glauber salts and to the extent of more than 80 gr. of sodium sulphate per litre, so that, after the separation of the crystals, a final liquor remains which,
• the bath is of the same composition as in the Example 1. This time the bath solution is first diluted'by about 12% so thata bath with about 115 gr. H 80 per litre, 165 gr. MgSO per litre, 115 gr. Na SO per litre is obtained. This solution is now cooled down to about 5 deg. C. At this temperature sodium sulphate free from magnesium sulphate separates out in the form of Glauber salts and in such quantity that only about 47% of sodium sulphate per litre still remains dissolved. The remaining liquor is worked up and used as in Example 1. About the same degree of efliciency is obtained.
• T bird example The bath solution to be operated on is com osed of 130 gr. H SO per litre, 240 gr. MggO. per litre, 130 gr. Na SO per litre.
• magnesium sulphate content does not amount to more than about 170 gr. per litre, separation of the Glauber salts may be effected at once by simple cooling.
• magnesium sulphate content amounts to more than about 220 gr. per litre a portion of the magnesium separated out by a first cooling own to about 8 to 10 deg. C. and then, after suitable dilution, the main portion of the sodium sulphate can be caused to crystallize out by a further coolingldown to 5 deg. C., for example.
• magnesium sulphate content lies in the intermediate region between 17 0 and 220 gr. per'litre, the magnesium sulphate content must first be increased by addition. Then the procedure may be as above described. Instead the ma esium sulphate content may be diminishe to less than 170 gr. per litre, by suitable dilution, and then according to the first directions, the separation of the Glauber salts may be begun at once.
• the new process can be used partly for concentrating the main spmning bath and to free it from anexcess of sodium sulphate. It can also be used for the working up of so-called drop baths which drop from spells or rollers or of centrifuge baths which are slung ofi irom spinning centrifuges, or of upper baths wherein spun spools are subsequently fixed or leached out. Ina'ny case the baths to be treated or parts thereof are advantageously worked up according to the process and the concentrated final liquor,
• sulphate may be,
• magnesium sulphate per litre part of the magnesium sulphate practically pure form by cooling, separating out the crystalline masses, diluting the resulting liquor and separating out sodium sulphate in ractically pure orm by further lowering. t e temperature, concentrating the resulting mother liquor and adding it with a proportion of magnesium sulphate to the precipitating bath to be revivified.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7743552

Family Applications (2)

Family Applications Before (1)

Country Status (3)

Cited By (4)

• 0
  • NL NL32407D patent/NL32407C/xx active
  • US US18802D patent/USRE18802E/en not_active Expired
• 1928
  • 1928-11-27 US US322295A patent/US1793649A/en not_active Expired - Lifetime
  • 1928-12-13 FR FR665645D patent/FR665645A/fr not_active Expired

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