Search results
Results from the WOW.Com Content Network
A 6 m × 60 m (20 ft × 197 ft) kiln requires around 800 kW to turn at 3 rpm. The speed of material flow through the kiln is proportional to rotation speed; a variable-speed drive is needed to control this. When driving through rollers, hydraulic drives may be used. These have the advantage of developing extremely high torque.
Lightweight expanded clay aggregate (LECA) or expanded clay (exclay) is a lightweight aggregate made by heating clay to around 1,200 °C (2,190 °F) in a rotary kiln. The heating process causes gases trapped in the clay to expand, forming thousands of small bubbles and giving the material a porous structure.
The Waelz process is a method of recovering zinc and other relatively low boiling point metals from metallurgical waste (typically electric arc furnace flue dust) and other recycled materials using a rotary kiln (waelz kiln). The zinc enriched product is referred to as waelz oxide, and the reduced zinc by product as waelz slag.
The second raw material (materials in the rawmix other than limestone) depend on the purity of the limestone. Some of the second raw materials used are: clay, shale, sand, iron ore, bauxite, fly ash and slag. Portland cement clinker is made by heating a homogeneous mixture of raw materials in a rotary kiln at high temperature. The products of ...
PAHs (according to EPA 610) in the exhaust gas of rotary kilns usually appear at a distribution dominated by naphthalene, which accounts for a share of more than 90% by mass. The rotary kiln systems of the cement industry destroy virtually completely the PAHs input via fuels. Emissions are generated from organic constituents in the raw material.
51% (C 3 S), 24% (C 2 S), 6% (C 3 A), 11% (C 4 AF), 2.9% MgO, 2.5% (SO 3), 0.8% ignition loss, and 1.0% free CaO. A limitation on the composition is that the (C 3 A) shall not exceed 8%, which reduces its vulnerability to sulphates. This type is for general construction exposed to moderate sulphate attack, and is meant for use when concrete is ...
The rotary kiln's maximum temperature ranges between 1,230 and 1,260 °C, which significantly exceeds the 1,000 to 1,050 °C threshold for iron oxide reduction. The main objective is to achieve a paste-like consistency of the ore gangue. [21] The reduced iron agglomerates into 3 to 8 mm metal nodules called Luppen.
Rotary lime kiln (rust-colored horizontal tube at right) with preheater, Wyoming, 2010 Traditional lime kiln in Sri Lanka. A lime kiln is a kiln used for the calcination of limestone (calcium carbonate) to produce the form of lime called quicklime (calcium oxide). The chemical equation for this reaction is CaCO 3 + heat → CaO + CO 2