Iron oxides dispersibility

Sodium polymethacrylates are also anionic and are useful as iron oxide dispersants and iron stabilizers. Typical MWs range from 6,000 to 20,000. Examples include Polacryl F70-40S, Tamol 850, Tamol 960, and Aquatreat AR-232. 

Some acrylic acid copolymers are promoted as having a very wide range of functions that permit them to act as calcium phosphate DCAs, barium sulfate antiprecipitants, particulate iron oxides dispersants, and colloidal iron stabilizers. One such popular copolymer is acrylic acid/sulfonic acid (or acrylic acid/ 2-acrylamido-methylpropane sulfonic acid, AA/SA, AA/AMPS). Examples of this chemistry include Acumer 2000 (4,500 MW) 2100 (11,000 MW) Belclene 400, Acrysol QR-1086, TRC -233, and Polycol 43. 

Acrylic acid terpolymers have appeared on the market in recent years. With their broad spectrum of functions, they offer the potential for excellent waterside conditions. In particular, the terpolymers have proved to be very effective particulate iron oxides dispersants and colloidal iron stabilizers. Examples include acrylic acid/sulfonic acid/sodium styrene sulfonate (AA/SA/SSS), such as Good-Rite K781, K797, K798. A further example is acrylic acid/ sulfonic acid/substituted acrylamide (AA/SA/NI), such as Acumer 3100. 

Evaluation of the Copolymers The polymer solutions were evaluated for their deposit control and dispersant activities. The tests included calcium phosphate inhibition, calcium carbonate inhibition, iron oxide dispersion, and clay dispersion. The procedures for these tests have been previously reported (12). A commercially available polyacrylic acid was also tested for comparison. The results are shown in Tables II to V. 

Sodium polymethacrylates are recognized as being useful as iron oxide dispersants and iron stabilizers. A typical MW is 6000 to 10,000. More typically, polymethacrylates now tend to be used in boiler water formulations rather than in CW formulations. 

Certain acrylic acid terpolymers have proved to be effective iron oxide dispersants and iron stabilizers (an example is acrylic acid/sulfonic acid/sodium styrene sulfonate, or AA/SA/SSS). 

Ca (P04)2 inhibitor/dispersant (without sol. Fe) and iron oxides dispersant. 

Iron oxide dispersant, CaiPOn and Zn stabilizer/dispersant (with sol. Fe) for high stress... 

Iron oxide dispersion-induced micropore filling of supercritical NO... 

Iron oxide dispersed-ACF (Fe-ACF) can adsorb great amount of NO (maximum 320 mg/g adsorbent) in the dimer form at 303 K[17,42,43,52-55]. Figure 17 shows the ad-... 

Figure 17. Adsorption isotherms of NO on iron oxide dispersed-ACF and ACF at 303 K.

Duma and Honicke were the first to report the successful use of N2O in propene epoxidation. A PO yield of 5% was obtained over silica-supported iron oxide catalysts promoted with Na ions [43bj. The pore shape and diameter of the support as well as iron oxide dispersion are crucial parameters in the reaction [43b,cj. Doping vdth alkali metal may also considerably affect the Fe dispersion, and favor epoxidation over allylic oxidation [43fj. Further modification by boron can also significantly enhance the catalytic performance of the K-doped FeO /SBA-lS catalyst [43gj. 

Addai-Mensah, J. and Ralston, J., Interfaciai chemistry and particle interactons and their impact upon the dewatering behaviour of iron oxide dispersions. Hydrometallurgy, 74, 221, 2004. 

The prevention of iron-oxide-induced corrosion can be accomplished by mechanical filtration of iron oxide, by the use of additives (iron oxide dispersants), and by adding inhibitors for corrosion. Standard procedures for reduction of corrosion in boilers include deaeration of the feedwater and the use of additives such as sodium sulfite. 

The sintering characteristics of quicklimes are influenced by impurities. It is reported [15.1] that the presence of high levels of sodium, either in the limestone, or added to the stone as a solution of sodium chloride or sodium carbonate, reduces sintering of some limes [15.1j. The effect on lime reactivity does not appear to have been reported. Finely divided silica, alumina and/or iron oxide dispersed in the limestone may increase sintering (see also section 15.5). 

Figure 4. Viscosity of trans iron oxide dispersions...

Uses Deposit control additve, dispersant, crystal modifier, antiscalanL sludge preventive in boilers and rxxrling towers caldum phosphate inhibitor iron oxide dispersant iron control aid on-line cleaner Features High pressure and thermally stable Regulatory SARA nonreportable... 

Uses Deposit control additive, sludge dispersant. Iron oxide dispersant for Industrial boiler water treatment... 

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