Aggregate, lightweight

Clay. To produce lightweight aggregate for concrete, clay is calcined in rotary Idlns. Temperatures employed vaiy from 1350 to 1600 K. The apparent density of the clay is reduced by 50 to 75 percent. 

An expanded mica (hydrated magnesium-aluminium-iron silicate). Used in lightweight aggregates, insulation, fertilizer and soil conditioners, as a filler in rubber and paints, and as a catalyst carrier. 

Colliery spoil Mining Mainly tipping on land, some in sea Some used As fill and in manufacture of bricks, cement and lightweight aggregate... 

Internal Insulation The practice of insulating within the vessel (as opposed to applying insulating materials on the equipment exterior) is accomplished by the use of fiber blankets and lightweight aggregates in ceramic cements. Such construction frequently incorporates a thin, high-alloy shroud (with shp joints to allow for thermal expansion) to protect the ceramic from erosion. In many cases this design is more economical than externally insulated equipment because it allows use of less expensive lower-alloy structural materials. 

On April 19, 1996, U.S. EPA published a proposed rule, called the MACT rule, under the joint authority of the RCRA and the CAA, to upgrade the emission standards for HWCs. Specifically, this rule will affect incinerators, cement kilns, and lightweight aggregate kilns. It proposes emission standards for dioxins, furans, mercury, cadmium, lead, PM, hydrochloric acid, chlorine,... 

The combustors affected by this rule detoxify or recover energy from hazardous waste and include incinerators, cement kilns, lightweight aggregate kilns, boilers and process heaters, and hydrochloric acid production furnaces. U.S. EPA estimates that 145 facilities operate 265 devices that burn hazardous waste. These technology-based standards reduce emissions of hazardous pollutants, including lead, mercury, arsenic, dioxin and furans, and HC1 and chlorine gas. In addition, emissions of PM are also reduced. 

Neutralysis A process for converting municipal waste into lightweight aggregate. Developed by Neutralysis, Austria, and offered by Davy Corporation. 

Not all of the interest in mineral matter in coals is stimulated by its detrimental effects during coal use. In several instances coal is a source of desired elements and materials. Uranium has been produced from lignite germanium and sulfur could be produced from coal and coal ash has been used for construction materials such as brick, lightweight aggregate, and road paving material. 

The two applicational areas above are normally associated with minor quantities (less than 8% by volume) of entrained air. However, using different chemical types of materials, much larger quantities (up to 30% by volume) can be entrained to lower the density, enhance the thermal insulation properties, or to produce lightweight concrete in conjunction with lightweight aggregates. When air... 

The tests were conducted with the knowledge of the importance of post-combustion, low-temperature reactions, and represented an advance on the 1987 GCP study. The results of the trials on cement kilns, lightweight aggregate kilns, hazardous waste incinerators, liquid injection incinerators, fluidized bed incinerators, fixed hearth incinerators and hazardous waste boilers were summarized as follows 6... 

All hazardous waste combustors (HWCs), including hazardous waste incinerators (HWIs), cement kilns (CKs), and lightweight aggregate kilns (FWAKs), are subject to the MACT standards regardless of size or major source status. HWCs are required to be in compliance with the standards by September 30, 2003, and are required to demonstrate compliance by March 30,2004, through a Comprehensive Performance Test (CPT). The rule allows for a 1-year extension of the compliance date for facilities that need to install pollution control equipment to meet standards. 

Neutralysis A process for converting municipal waste into lightweight aggregate by calcination with clay. Developed by Neutralysis Industries Pty Ltd. in Australia from 1987 but abandoned in 1992 when the company went into receivership. The process was considered for use in Indiana in 1992 but was never practiced on a large scale. 

Sulfur-soils and lightweight aggregate sulfur concrete 0.3-0.6 2800-4800 psi 20-33 MPa... 

In the aging tests at —18 °C (0°F), however, the sulfur-asphalt-bound concrete with lightweight aggregate oertainly retains stiffness better than... 

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