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
  • C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
  • C04B20/02—Treatment
  • C04B20/04—Heat treatment
  • C04B20/06—Expanding clay, perlite, vermiculite or like granular materials
  • C04B20/068—Selection of ingredients added before or during the thermal treatment, e.g. expansion promoting agents or particle-coating materials

Definitions

• This invention relates to" a process for the manufacture of aburnt silicate product having a cellular structure.
• Such products are frequently used" for insulating purposes'in wallsandfloors and oneof" the principal objects of the invention is toprovide a product havinga very low density, but very high crushing strength.
• a still further object is the provision of a a certain temperature thereby producing a con- 1 siderable increase of the volume of the product due to leavening or the formation of gas filled cavities in the argillaceous material.
• the latter becomes softened at the burning temperature thereby permitting the gas filled cavities to become evenly distributed and resulting in a highly cellular final composition.
• the waste products referred to above are sultits and sulfate lyes and their residues. It was found, for example, that by admixing Danish clay with 1% of concentrated sulfite lye, calcu latedon a dry basis, a unit weight of 540 lbs. per cubic yard was obtained in the final product.
• the clay before admixture, was in a moist and plastic condition, i. e. with a water content of 40%, calculated on the clay dried at 100 C.
• the clay was fed at the rate of 2.5 tons per hour to a brick-making machine consisting of a pugmill, two pairs of rollers and a string press. Sulfite lye with a water content of 40% was added in the pugmill at the rate of 30 kg. per hour with an equal quantity of water to uniformly distribute the lye in the clay.
• the clay coming from the press was cut into slices about 2 cm. thick by a rotating knife and then carried by a conveyor into'a rotarykiln -w-ith aF-length of 23* m'.
• the burning was effected at a temperature of about 1100-4125 C.”
• the resulting grainy" product' was thensorted into' tlireegrades of. grain size; namely, 3mm. or'less'; 3-I2 mm. and 12-30 mm: respectively.
• the greatest portion was classified of the medium grain size and it had a" unit wcight' of-fi'O '1bs; per cubic yard.
• sulfate lye which;.im additionszofl /i. o-.-1.% /22 of 1%, 1%, 2%, 4% and 7%, gave unit weights of 790, 720, 590, 540, 680 and 760 lbs. per cubic yard, respectively.
• a slate with a suction ability of 20% was crushed into pieces of a grain size of 12 mm. and moistened until saturation with a solution of sulfite lye containing 10% dry substance, whereafter it was burned in a rotary kiln at a temperature of 1225".
• the resulting product consisted of rounded lumps having a unit weight of 620 lbs. per cubic yard. Without any addition of sulfite lye a unit weight of 980 lbs. per cubic yard was obtained.
• German patent specification No. 594,000 it has been suggested to manufacture highly porous refractory bricks by means of highly porous chamotte burned in a rotary kiln.
• a finely ground plastic clay is mixed with a similar amount of sawdust and burned whereafter the difierent materials are moulded to the shape wanted and burned.
• the said material after its moulding is burned to a temperature, at which the sawdust and sulfite lye is burned out leaving cavities in the clay.
• the material is, however, not burned until it begins to soften, and the cellular structure of the final product could therefore not be the result of a bloating and expansion which would make the previous moulding to certain dimensions quite illusorious.
• the burning temperature necessary for making porosity by means of burning out substances is ordinarily below 1000 C.
• a process for the manufacture of a product having a cellular structure consisting essentially of uniformly distributing in an argillaceous material A; of 1% to about 4%, by weight on a dry basis, of a member selected from the group consisting of sulfite and sulfate lyes, uniformly baking the resulting mixture at the softening temperature of the material, whereby the material softens and gas is produced in the material causing it to bloat under formation of a cellular structure and then cooling the resulting bloated material.
• a process for the manufacture of a product having a cellular structure consisting essentially of uniformly distributing in an argillaceous material 2; of 1% to about 4%, by weight on a dry basis, of an aqueous solution of a member selected from the group consisting of sulfite and sulfate lyes, uniformly baking the re- 4 sultlng mixture at the softening temperature of the material, whereby the material softens and gas is produced in the material causing it to bloat under formation of a cellular structure and then cooling the resulting bloated material.
• a process for the manufacture of a product having a cellular structure consisting essentially of uniformly distributing sulfite lye in the proportion of about A; of 1% to about 4%, by weight on a dry basis, in a material selected from the group consisting of clay and. slate, uniformly baking the resulting mixture at the softening temperature of the material whereby the material softens and gas is produced in the material causing it to bloat under formation of a cellular structure and then cooling the resulting bloated material.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8111211

Family Applications (1)

Country Status (4)

Cited By (2)

Citations (3)

• 1940
  • 1940-12-09 DK DK226840AA patent/DK63553C/da active
• 1941
  • 1941-12-08 FR FR877596D patent/FR877596A/fr not_active Expired
  • 1941-12-09 BE BE443673A patent/BE443673A/fr unknown
• 1950
  • 1950-07-28 US US176522A patent/US2670298A/en not_active Expired - Lifetime

Patent Citations (3)

Also Published As

Similar Documents