GB530778A - Improvements in permeable materials and/or articles and in methods of manufacture thereof - Google Patents

Improvements in permeable materials and/or articles and in methods of manufacture thereof

Info

Publication number
GB530778A
GB530778A GB823039A GB823039A GB530778A GB 530778 A GB530778 A GB 530778A GB 823039 A GB823039 A GB 823039A GB 823039 A GB823039 A GB 823039A GB 530778 A GB530778 A GB 530778A
Authority
GB
United Kingdom
Prior art keywords
calcium sulphate
rehydration
moulds
effected
atmosphere
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB823039A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB823039A priority Critical patent/GB530778A/en
Publication of GB530778A publication Critical patent/GB530778A/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/14—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements
    • C04B28/141—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements containing dihydrated gypsum before the final hardening step, e.g. forming a dihydrated gypsum product followed by a de- and rehydration step

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Drying Of Gases (AREA)

Abstract

530,778. Calcium sulphate cements; moulds. BEAN, M. March 14, 1939, No. 8230. Drawings to Specification. [Classes 22 and 87 (ii)] Moulds for casting metals &c. filter plates tiles &c. formed from calcium sulphate cements are treated to increase the permeability by forming within the body nucleated crystal groups by dehydrating the body to form calcium sulphate hemilydrate and then rehydrating to form the dihydrate. The dehydration may be effected by heating in a dry or moist atmosphere or in an autoclave by steam under pressure at above 110‹ C. The rehydration is effected by exposing the body to the atmosphere while still wet. The body may be dehydrated while immersed in dry sand or sawdust which retains sufficient moisture for the rehydration. Moisture may be removed from the surface during the rehydration to obtain a fine-grained coating. The body is dried and may be heated to 300‹C. to remove all the water of crystallization without affecting the granular structure. Where the mould consists of interfitting parts, the recrystallization may cause the parts to unite. The calcium sulphate may be mixed with talc, asbestos, silica, granular material, clay or a deliquescent salt such as calcium chloride ; both an accelerator and a retarder for the setting may be added. For casting magnesium alloys a small proportion of sulphur, boric acid, or a fluoride may be included in the mix Or be coated on to the surface.
GB823039A 1939-03-14 1939-03-14 Improvements in permeable materials and/or articles and in methods of manufacture thereof Expired GB530778A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB823039A GB530778A (en) 1939-03-14 1939-03-14 Improvements in permeable materials and/or articles and in methods of manufacture thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB823039A GB530778A (en) 1939-03-14 1939-03-14 Improvements in permeable materials and/or articles and in methods of manufacture thereof

Publications (1)

Publication Number Publication Date
GB530778A true GB530778A (en) 1940-12-20

Family

ID=9848453

Family Applications (1)

Application Number Title Priority Date Filing Date
GB823039A Expired GB530778A (en) 1939-03-14 1939-03-14 Improvements in permeable materials and/or articles and in methods of manufacture thereof

Country Status (1)

Country Link
GB (1) GB530778A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0210027A2 (en) * 1985-07-12 1987-01-28 Hitachi, Ltd. Method for forming cast article by slip casting

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0210027A2 (en) * 1985-07-12 1987-01-28 Hitachi, Ltd. Method for forming cast article by slip casting
EP0210027A3 (en) * 1985-07-12 1988-01-27 Hitachi, Ltd. Method for forming cast article by slip casting
US4883621A (en) * 1985-07-12 1989-11-28 Hitachi, Ltd. Method for forming cast article by slip casting

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