Lightweight aggregate(sometimes is called as low density aggregate) is a generic name of a group of aggregates for structural concrete, mortar, or plaster that weighs less than usual rock aggregates including natural sand, gravel, and crushed stones.It is used to produce lightweight concrete products such as concrete blocks, structural concrete, and pavement. It can be classified into 3 types--Structural lightweight aggregate, Masonry-lightweight aggregate and Insulating aggregate.
Most lightweight aggregates are made from materials such as clay, shale, or slate. Additionally, blast furnace slag, natural pumice, vermiculite, and perlite also can be used as substitutes.
Mining & Quarrying:The production process begins from mining or quarrying the raw materials.
Crushing & Screening:Then the stone processing machine including jaw crushers, cone crushers or hammermills, or pugmills will crush the materials. And then the screening machine will screen the materials for size. Oversized materials are returned to the crushers while the materials that pass through the screen will be transferred to hoppers via the returning belt.
Heating:The hoppers feed the materials to a rotary kiln (Although the majority (approximately 90 percent) of plants use rotary kilns, traveling grates are also used to heat the raw materials) that is fired with coal, coke, natural gas, or fuel oil, to temperatures of about 1200°C (2200°F). As the material is heated, it liquefies and carbonaceous compounds in the material form gas bubbles, which expand the material.
Cooling:From the rotary kiln, the expanded product (clinker) is transferred by conveyor into the clinker cooler where it is cooled by air, forming a porous material.
Screening or Crushing & Stockpiling & Shipping:When the cooling process finished, the lightweight aggregates are screened for size, crushed if necessary, stockpiled, and shipped.
Camelway Machinery can offer various stone processing equipment including jaw crushers, cone crushers, screening and conveying machine, etc. to meet your requirements for producing lightweight aggregates.