Calcined bauxite

The quantity of feed materials required are 1—1.05 kg of metallic reductant, 5.4 kg of dolime, and 0.35 kg of calcined bauxite or alumina to produce 1 kg of magnesium. The quantity of slag produced depends on the feed material composition and may vary from 5.2 to 5.9 kg/kg of magnesium. 

The chlorination of aluminous materials in the production of aluminum chloride has been thoroughly investigated (2). The Gulf Oil Company produced aluminum chloride from calcined bauxite [1318-16-7] and coke from 1920 to 1960 (3). 

Calcinated bauxite (modified) sorbent Cationic surfactant and ultrafiltration Cerium-iron oxide sorbent Coconut coir pith anion exchanger... 

Ayoob, S., Gupta, A.K. and Bhakat, P.B. (2007) Analysis of breakthrough developments and modeling of fixed bed adsorption system for As(V) removal from water by modified calcined bauxite (MCB). Separation and Purification Technology, 52(3), 430-38. 

However, La Lande has shown that properly calcined bauxite develops color removal, ash removal, and alkaline buffering powers comparable to those of bone char.11 Bauxite and hydroxyapatite therefore appear... 

The traffic level is expressed in terms of the expected commercial vehicles (cv) per lane, per day (cv/lane/day). HFS, specialised high friction surfacing, incorporating calcined bauxite aggregate. 

In some countries, such as the United Kingdom, for high-quality surface dressings with calcined bauxite chippings, the thermosetting polymer-modified bitumen is the only binder recommended to be used. 

HFS, specialised high-friction surfacing, incorporating calcined bauxite aggregate. 

Some of the earliest major applications of adhesives in civil engineering involved the use of resins for abrasion resistant and non-slip surfaces to heavy duty floors and roads. This was achieved by the use of synthetic anti-skid grits, such as calcined bauxite, set in a resin base. Both epoxy and polyester resins have been used, applied either by trowel or in slurry form by squeegee. Trowelled systems are usually heavily filled mortars with an aggregate resin ratio of the order of 6 1 and as such usually require a priming... 

James, J.G. Calcined bauxite and other artificial polish resistant road stones, TRRL Technical Paper No. LR 84, Crowthorne, 1967. 

Figure 14.1 Effect of medium-size particles on compressive strength of DSP material. Mixing ratio cement microsihca medium-size particles=7 1 2. FA, fly ash PSA, paper sludge ash BX=calcined bauxite GBFS= granulated blast furnace slag.

Air-setting mortars using clay and phosphates were obtained in 1952 [21]. Mortars can be made from calcined bauxite mixed with a little clay (80%) and aqueous phosphoric acid (20%). A good refractory mortar can be obtained from an aqueous mix of 92% kaolin with 8% A1(H2P04)3. Another air-setting plastic refractory mortar can be obtained from 75% alumina, 20% clay and 5% A1(H2P04)3 [22]. 

At a position of about 10 mm behind the hot face of the brick, slag penetration stopped. Near the cold face of the brick, the microstructure of the brick was normal for a 70% AI2O3 brick product made using a mixture of calcined bauxite and clay. The conclusion from this study was that the normally expected corrosion reactions were found to take place, and the accelerated wear was likely due to poor thermal shock resistance, resulting in enhanced spalling that ultimately shortened the campaign of the electric furnace roof. 

AI2O3 MuUite Phases on phase diagram Major phase—mullite. Products made with bauxite contain corundum, mullite, and glass Made either from bauxitic clay or calcined bauxite and clay Can be used in excess of 1750°C... 

AI2O3 and Bauxite Made from calcined bauxite... 

The TiOa content of bricks may indicate the fact that they contain calcined bauxite aggregate (if >2.5%). Bauxite can also be recognized on a broken or saw-cut surface as a gray-appearing aggregate to the naked eye. 

The chemical composition and physical properties of the two types of 70% alumina brick are given in Table 10. The brick based on calcined bauxite exhibits much higher reheat expansion (PLC) and higher spalling loss than the brick based on bauxitic clay. On the other hand, the brick based on calcined bauxite may have superior performance where erosion resistance is required. 

Bauxitic clay base Calcined bauxite/clay mix... 

Figure 8 70% AI2O3 brick based on calcined bauxite and clay.

Rotary kilns have been lined with 70% AI2O3 brick for many years, and a typical choice has been calcined bauxite/clay base types. These bricks provide sufficient permanent expansion to keep the lining tight against the shell of the rotary kiln. This, in turn, prevents movement of brick as the kiln rotates. 

Some of the more subjective features are pore distribution, bond stmcture, degree of reaction, or dissolution and microcracking. In order to evaluate these parameters, it may be necessary to etch a sample to enhance grain boundaries or increase the contrast between components such as mullite and glass in refractory grog grain or corundum in calcined bauxite. 

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