Recent Developments in Controlling Silica and Magnesium Silicate Foulants in Industrial Water Systems
Fouling presents an enormous challenge in industrial process waters . Often system operators are obligated to discard critical equipment components because of fouling and the inability to remove it. Even if mechanical or chemical cleaning are viable options, they require several hours, total system shutdowns, and high costs . Foulants could be organic or inorganic, as illustrated in Figure 10.1. Organic foulants are a result of poor system biocontrol, or deposition of organic matter brought into the system from external sources (e.g., a river or lake) . Inorganic foulants include crystalline sparingly soluble salts such as calcium carbonate(s), calcium sulfate(s), barium, and strontium sulfates, as well as amorphous and colloidal deposits, such as amorphous calcium phosphate, silica, magnesium silicate, and many others, depending on the particular water chemistry . This chapter deals with silica and metal silicate scales and deposits (with an emphasis on magnesium silicate).