Abstract: Disclosed is a deagglomeration apparatus, to improve the quality of a mixture used for the production of concrete blocks. An illustrative embodiment of the deagglomerator comprises a vertical shaft high-shear mixer, wherein a rotational force (hydraulic or electric) is mounted to a vertical shaft onto which are mounted chains and/or knives, housed within a flexible rubber “boot” or tube. The deagglomerator is configured to be controllably powered, to rotate the shaft and the attached tools. Partially mixed formula is introduced to a top region of the deagglomerator, and falls downwardly past the rotating tools wherein the formula is pulverized and mixed, before exiting the lower area of the mixing region.
Abstract: A cement admixture and a cement composition having a carbonation suppressing effect and a heat-of-hydration suppressing effect are provided. A cement admixture containing one or more non-hydraulic compounds selected from the group consisting of ?-2CaO.SiO2, ?-CaO.SiO2 and calcium magnesium silicate, a cement composition containing said admixture, and a carbonation suppressing method by use of said cement admixture or cement composition. According to the present invention, a remarkable carbonation suppressing effect can be obtained particularly when used in portland blast-furnace slag cement. This leads to an effective use of steelmaking slag and the like, and the load of clinker can be reduced, so that a cement composition of a low environmental load type can be attained. Further, this is suitable for cements in conformity with the EN standards, which are used in civil engineering and building industries.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of phosphoric acid, and from about 0.1 to about 4% by weight of a source of fluoride ions. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of a hexafluorosilicate salt, and free of or having only small amounts of an inorganic acid, an inorganic acid salt or a mixture thereof. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of a boron tetrafluoride salt, free of or having only small amounts of an inorganic acid, an inorganic acid salt or a mixture thereof. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of an inorganic acid, and from about 0.1 to about 4% by weight of a tetrafluoroborate of ammonia, an alkali metal or an alkaline earth metal. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of an inorganic acid, and from about 0.1 to about 4% by weight of a hexafluorosilicate of ammonia, an alkali metal or an alkaline earth metal. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition also is disclosed.
Abstract: A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30% by weight of an acid component, optionally a source of fluoride ions, and a corrosion inhibiting amount of thiourea, a lower alkylthiourea, a C.sub.8 -C.sub.15 alkylpyridinium halide or mixtures thereof. A method of transforming an asbestos-containing building material, while part of a building structure, into a non-asbestos material by using the present composition also is disclosed.
Abstract: The invention refers to a process of treatment and environment-friendly utilization of asbestos-cement products including a thermal process to transform the asbestos component. Inventively, this is achieved by a coarse reduction of the asbestos-cement products under black side conditions with maintained vacuum. Then, the material is ground to asbestos-cement meal and fed to the flame zone of the rotary kiln of a cement clinker production line. Depending on the fuel type used, the portion of fed asbestos-cement meal varies between 2 and 5%, related to the amount of cement raw meal, substituting 2 to 5% of the cement raw meal mix at a time. The thermal transformation of the asbestos component takes place with temperatures of approximately 1800.degree. C. in the burner zone. The modified residual substance becomes a constituent of the cement clinker due to assimilation in the kiln charge.
Type:
Grant
Filed:
June 20, 1995
Date of Patent:
October 14, 1997
Assignee:
Institut fur Baustoff- und Umweltshcutz-Technologie IBU-tec
Inventors:
Gert Gleichmar, Joachim Kieser, Stefan Ambrosius, Helmut Gormar, Arno Krahner, Wolf-Joachim Buhrandt
Abstract: Asbestos cement may be converted to a harmless product by melting at a melt temperature of 1400.degree. to 1700.degree. C. a blend of 50 to 85% by weight asbestos cement with 15 to 50% by weight of additives that include naturally occurring silicate material such that the total blend has a CaO content of not more than 50%. The melt is discharged from the furnace, cooled and solidified and may be used as aggregate or, generally after solidification as regular units, may be used as part or all of the charge for producing MMV fibre material. It is of particular value for the production of man made vitreous fibre material that has low alumina content and is soluble in lung fluids.
Type:
Grant
Filed:
September 8, 1995
Date of Patent:
March 25, 1997
Assignee:
Rockwool International A/S
Inventors:
Anders U. Clausen, Vermund R. Christensen, Soren L. Jensen
Abstract: Disclosed is a fiber-reinforced cement composition particularly useful to make pipes or sheets. This composition comprises up to 70% by weight of a fibrous-like synthetic forsterite obtained by calcination of chrysotile asbestos fibers at a temperature of from 650.degree. C. to 1450.degree. C., said synthetic forsterite having an MgO:SiO2 ratio lower than 1.1, a raw loose density of from 3 to 40 pcf, a thermal conductivity "k" factor of from 0.25 to 0.40 BTU. in/hr. .degree.F. ft.sup.2 and a fusion point of from 1600.degree. to 1700.degree. C. The composition also comprises a hydraulic binder, which is preferably Portland cement, and reinforcing fibers such as cellulose, synthetic fibers, glass wool, rock wool or their mixtures, in such an amount as to give sufficient strength to the composition to make it operative.
Abstract: Disclosed is a heat-resistant composition particularly useful to produce heat-resistant boards, tubes, linings or similar articles, capable of resisting to a high temperature for a substantial period of time. The composition comprises from 30 to 70% by weight of a fibrous-like, synthetic forsterite obtained by calcination of chrysotile asbestos fibers at a temperature of from 650.degree. C. to 1450.degree. C., the synthetic forsterite having an MgO: SiO.sub.2 ratio lower than 1.1, a raw loose density of from 3 to 40 pcf, a thermal conductivity "k" factor of from 0.25 to 0.40 BTU. in/hr. .degree.F. ft.sup.2 and a fusion point of from 1600.degree. C. to 1700.degree. C. The composition also comprises colloidal silica as a binder. If desired, the composition may further comprise reinforcing fibers in such an amount as to give sufficient strength to the composition to make it operative depending on the intended use of the article produced therefrom.
Abstract: A ceramic fiber containing refractory moldable composition suitable for use with molten aluminum alloys, the composition comprised of 10-18 wt. % ceramic fiber, 33-45 wt. % colloidal silica, 30-42 wt. % total content of liquid carrier, 0.2-2.5 wt. % organic polymer and 1-15 wt. % barium sulfate. The composition has a high level of resistance to attack or penetration by molten aluminum.
Type:
Grant
Filed:
April 28, 1989
Date of Patent:
February 12, 1991
Assignee:
Aluminum Company of America
Inventors:
Jed L. Dulberg, John K. Steelman, Timothy K. Myers