Silicate production granules

Many other patents on the production of detergents by agglomeration, granulation or two step processes have issued. Several advantages are often claimed for such processes such as control of particle size, better properties for the finished material, economy, etc. In most of these processes, the silicates play an important role due to their ability to act as a structure former-binder as well as for their effect on detergency. 

The rotacurrent dryer can handle particulate and non-sticky products such as aluminum silicate, copper powder, pyrite ore, charcoal, granulated rubber, chopped straw, detergents, and the like [75]. Performance data on the rotacurrent dryer are given in Table 21.21. 

As aforementioned, the efflorescence is not harmful for the durability of concrete. When the mechanism involved in efflorescence formation is known, the remedies of effective preventing its occurrence are also possible. For example cements with mineral additions can be used in the production of concrete elements. Silica fume has particularly beneficial effect, which prevents efflorescence already from 5 % addition. The groimd granulated blastfurnace slag or siliceous fly ash are good additives too. The latter one should be groimd when added to concrete or taken from the last section of electrical precipitator, where the finest fractions are collected. 

Several sintered glass and glass-ceramic matrix composites obtained from recycled silicate waste have been reported in the literature [100-106]. These are dense or porous products with potential application as building, decoration or architectural materials, such as wall partition blocks, pavements, wall and floor tiles, thermal insulation, fire protection elements, roofing granules and acoustic tiles. Other possible uses include abrasive media for blasting and polishing applications. 

FIGURE 22.6 Turbodryer process for the production of sodium silicate granules. 

The product is derived from a purified silicate liquor and has a much lower level of impurities than products made by the direct fusion route. By virtue of the granulating process, the spray-coated product has essentially an onion-type-layered structure and a superior particle size distribution and is relatively dust free and more readily soluble in water [1]. 

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