41. The latter minerals are rapidly soluble, and about 2 % of these in cement is needed to control tricalcium aluminate hydration. 42. In the second stage sodium hydroxide solution is added, which dissolves the sodium aluminate , leaving the impurities as a solid residue. 43. Upon reaching its saturation limit, the aluminate compound decomposes ( 2 ) into sodium hydroxide and a crystalline precipitate of aluminum hydroxide. 44. Colors with longer wavelengths can be obtained from the strontium aluminate as well, though for the price of some loss of brightness. 45. In nuclear technology, lithium aluminate is of interest as a solid tritium breeder material, for preparing tritium fuel for nuclear fusion. 46. Georges Friedel also synthesised Calcium aluminate ( 1903 ) in the framework of his work on the Macles theory ( twin crystals ). 47. An improved process using a combination of aluminium chloride and sodium aluminate with sodium acetate prepared " in situ " has been patented: 48. In Portland cement, a little calcium sulfate ( typically 3-10 % ) is added in order to retard the hydration of tricalcium aluminate . 49. It is one of a number of aluminium acetates and can be prepared in a reaction of sodium aluminate ( NaAlO 2 ) with acetic acid. 50. Three major transparent candidates currently exist : aluminum oxynitride ( AlON ), magnesium aluminate spinel ( spinel ), and single crystal aluminum oxide ( sapphire ).
