Calcium phosphate, scaling

SS/MA may be structured in different ratios of sulfonated styrene to maleic anhydride. Typically, it is 3 1 (20,000 MW) or 1 1 (15,000 MW). The application rates of all calcium phosphate scale/sludge inhibitors or stabilizers vary, based on the amount of calcium present in the cooling system, with increased calcium hardness leading to higher levels of polymer required. 

Calcium phosphate is equally as troublesome as calcium carbonate by forming scales that reduce heat-transfer efficiencies and sludges that foul the system. In addition, calcium phosphate scale is intractable and once formed, deposits can be extremely difficult to remove from dirty cooling systems, so prevention is vital. 

Alternatively, antisealants can be used to control calcium carbonate scale at LSI values as high as 2.0-2.5, depending on the specific antisealants. Calcium also forms scales with fluoride, sulfate, and phosphate. The LSI will not help predict these scales analysis of water quality, using the ion product and solubility constants, is required to determine the potential for scaling with calcium fluoride or calcium phosphate. Antisealants currently available can address calcium fluoride and calcium sulfate scale they do not address calcium phosphate scale (although newer antisealants will be available in the near future to address this scale). 

Antisealants are usually fed alone for most applications. Acid feed is sometime used in conjunction with an antisealant to control LSI for calcium carbonate scale and to control calcium phosphate and calcium fluoride scales. Antisealants currently on the market are not generally effective at controlling calcium phosphate scale and have difficulty controlling calcium carbonate scale when the LSI is greater than about +2, depending... 

Optimizing calcium phosphate scale inhibitor dosage in a high-TDS cooling system 122... 

Calcium ions are fixed into the biofilm by the attraction of carboxy-late functional groups on the polysaccharides. In fact, divalent cations, such as calcium and magnesium, are integral in the formation of gels in some extracellular polysaccharides. A familiar biofilm-induced mineral deposit is the calcium phosphate scale that the dental hygienist removes from teeth. When biofilms grow on tooth surfaces, they are referred to as plaques. If these plaques are not continually removed, they will accumulate calcium salts, mainly calcium phosphate, and form tartar (scale). 

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