Barium aluminate cement

Barium aluminate cement may be produced by solid-state sintering of an approximately equimolar blend of BaCOj and AI2O3 at 1400-1500 °C (Borovkova et al, 1992 Raina el al., 1992). The sintering temperature may be reduced by adding a suitable mineralizei... 

At low water/cement ratios, below w/c=0.35, the main ciystalline phase formed in the hydration of barium aluminate cement is monobarium aluminate heptahydrate (BaO.Al2O3.TH2O), whereas at higher water contents tribarium aluminate hexahydrate (3BaO.Al2O3.6H2O), together with hydrous alumina, is also formed. 

Barium aluminate cement liydrates quite rapidly, and at sufficiently high water/cement ratios it may hydrate completely within three days. The hardened cement paste exhibits only a small strength loss if heated to high temperatures. 

Barium aluminate cement exhibits significantly improved refractory properties compared with calcium aluminate cement, and may be considered for applications at temperatures of up to about 2000 °C. It has also the capacity to absorb radioactive and X-ray radiation very effectively. 

In strontium aluminate and barium aluminate cements the main constituents are monostrontium or monobarium aluminate. Both these binders are discussed in section 10.9. 

Important inorganic aluminum compounds are aluminum sulfate (e.g., for water treatment), potassium alum (KA1(S04)2-12H20 e.g., for tanning skins, mordants, coagulating agents, styptic pencils, cosmetics, and hardening and setting acceleration in the production of marble cement and alabaster plaster), sodium and barium aluminates (e.g., for water purification, acceleration of concrete solidification, production of synthetic zeolites, in the paper industry, and in the enamel industry), and the Friedel-Crafts catalyst aluminum chloride [4]. 

Braniski, A., 1965. Infrared spectrophotometric study of hydrated monocalcium, monobarium aluminates, and of calcium, strontium, and barium silicate cements. Zement-Kalk-Gips. 54 449. 

Numerous other specialty cements composed of various magnesium, barium, and strontium compounds as siUcates, aluminates, and phosphates, as well as others, are also produced (85). 

Calcium aluminate chloride, phase in Portland cement clinker, 5 472t Calcium aluminate fluoride, phase in Portland cement clinker, 5 472t Calcium aluminoferrite, phase in Portland cement clinker, 5 472t Calcium aluminoferrite hydrate, 5 477t Calcium—aluminum alloys, 4 530 Calcium amalgam, 22 773 Calcium ammonium nitrate, 2 724 Calcium analysis, of water, 26 37 Calcium A zeolite, separation of hydrocarbons by, 16 823 Calcium—barium—silicon alloy, 22 519 Calcium-bearing manganese silicon,... 

---