Acid-resistant bricks and tiles

Ceramic materials have a cross-linked structure and are therefore brittle. 

Borosilicate glass (known by several trade names, including Pyrex) is used for chemical plant as it is stronger than the soda glass used for general purposes it is more resistant to thermal shock and chemical attack. 

Where failure of the glass could cause injury, pipes and equipment should be protected by external shielding or wrapping with plastic tape. 

Chemical stoneware is similar to the domestic variety, but of higher quality stronger and with a better glaze. It is available in a variety of shapes for pipe runs and columns. As for glass, it is resistant to most chemicals, except alkalies and fluorine. The composition and properties of chemical stoneware are discussed by Holdridge (1961). Stoneware and porcelain shapes are used for packing absorption and distillation columns (see Chapter 11). 

High-quality bricks and tiles are used for lining vessels, ditches and to cover floors. The linings are usually backed with a corrosion-resistant membrane of rubber or plastic, placed 

High-quality bricks and tiles are used for lining vessels, ditches and to cover floors. The linings are usually backed with a corrosion-resistant membrane of rubber or plastic, placed behind the titles, and special acid-resistant cements are used for the joints. Brick and tile linings are covered in a book by Falcke and Lorentz (1985). 

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Lining vessels and equipment using this type of construction consists of a membrane, acid-resistant bricks or tiles, and chemical-resistant mortar for joining the bricks (tiles) together. 

The reducers for iron and acid reductions are sometimes equipped with side and bottom cast-iron lining plates, which may be reversed or replaced, in order to protect the vessel against the continuous erosive action of the iron borings. Alternatively, the reducers may be lined partially or entirely with acid-resisting brick or tile. Such a protective coating lasts almost indefinitely and performs satisfactorily in service. 

Concrete is not usually used as an acid-resistant material but as a building material it is often superior to steel in resisting acidic fumes. In many cases a decorative finish is more easily maintained on concrete than steel. Concrete tanks and floors are often lined with acid-resistant bricks or tiles or plastic materials. 

Acid-resisting Brick or Tile. A fired clay brick or tile of low porosity and high resistance to a variety of chemicals. B.S. 1902 Pt 3.12 specifies an acid resistance test for refractories, Pt 3.15 a test for bulk material. ASTM C-279 specifies three grades according to resistance to H2SO4. ASTM C-410 specifies industrial floor bricks. 

Furan resins are produced by the polymerization of furfural or furfuryl alcohol in the presence of acids (see Figure 15.8). The properties of these dark-colored resins are shown in Table 15.6. Furan resins have a relatively low heat deflection temperature (80 °C) and good mechanical properties. These materials, which are widely used as jointing materials for brick and tile, are characterized by excellent resistance to nonoxidizing acids, alkalis, and salts but are affected by the presence of oxidizing acids such as nitric acid. The furan plastics are also resistant at room temperature to nonpolar solvents, such as benzene, and to polar solvents, such as ethanol. 

Washing tanks for the final washing of nitro compounds with water (the water from the operation is slightly acid) are made either from stainless steel or from wrought iron lead lined or they may be constructed of bricks bonded by an acid resistant cement and lined with sheet lead and with acid resistant tiles (Fig. 83). 

The electrolysis is carried out in a set of steel tanks arranged in cascades (for a 9000 to 12 000 A load the tank measures 3 000.2 000. 1 400 mm). They are lined with acid resisting bricks. Suspended in each tank are 144 anodes and 28 steel sheets acting as cathodes arranged in parallel rows. The magnetite electrodes shaped as narrow, hollow tiles closed at the bottom (120.50. ... 

The classic thermosets, such as ebonite, phenolics, ureas, melamines and polyesters as well as the epoxies, when reinforced with fiberglass or graphite fibers could also be classified as high performance thermosets. While these plastics cannot be readily extruded or injection molded, they are resistant to the effects of moderately high hostile environments. Phenolic resin mortars have been used for over a half century for the construction of chemical resistant vessels and for joining brick and tile used as linings in hot acid environments. (1.)... 

In modem science, ceramic is used in various aspects. Besides this ceramics developed on the basis of clay have some special uses such as stmctural building materials, refractory materials, non-stmctural products, stmctural products, earthen ware, stone ware, porcelain, and technical ceramics. The products of ceramic materials are known to us as bricks, terra cotta, flue lining, cement-clinker, chemical ware, refractory ware, table ware, tiles, sanitary ware, insulators, split bricks, quarry tiles, acid-resistant bricks etc. 

Polyester and Vinyl Ester Mortars These two mortars, of which there are many types, are suitable for a pH range of about 0-11 and a continuous service temperature of 225°-230°F. The two related resins, which complement the epoxy resins, resist dilute and concentrated acids and weak alkalies. Their resistance to acid bleaches such as chlorine dioxide and to oxidizing acids such as nitric and chromic is superior to that of other resinous mortars, and they are excellent in acetic acid and related esters. However, polyester and vinyl ester mortars are the poorest resin mortars in other organic chemical exposures including solvents in general. Such mortars are widely used in paper mills and are suitable with acid brick or ceramic tile in the lower temperature zones of mildly acidic utility FGD systems. 

The difference between expansion joint design and location in floors protected with bonded tile or brick, and monolithic toppings and surfacings, and in floors protected by "acid brick" laid with chemically-resistant mortars over an impervious membrane. 

In aqueous media where hydrochloric and hypochlorous acid and halogens are present in either vapor or liquid phase, the utility of the above materials of construction is severely lin ited and can best be determined by rates of corrosion study during pilot laboratory operation. Tantalum, zirconium, and titanium are usually resistant but expensive. The plastics are of variable resistance and are severely limited by temperature and solvent attack. Stoneware, Karbate, glass, glazed tile, carbon brick, and enameled steel all have utility within rigid limits. The other metals and alloys are usually questionable but may be desirable for replaceable piarts i... 

Another use of cement is that of jointing and bedding material for tiles and bricks of all types, and cement in this context includes many synthetic materials which are produced to meet particular conditions. For example sodium silicate and potassium silicate cements are acid resisting, whereas rubber latex, furan resin, and epoxy resin cements are both acid and alkali resisting. In most cases the suitability of a particular cement for a given condition should be carefully checked with the manufacturer before it is used. 

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