Aluminum citrate

A clear solution of aluminum citrate neutralized to pH 7 is used for in situ gelling of polymers in polymer flooding and well stimulation in enhanced oil recovery techniques (128—132). The citrate chelate maintains aluminum ion solubiUty and controls the rate of release of the aluminum cross-linker. 

Aluminum citrate Chromium sulfate Ferrochromo-lignosulfonate Manganese nitrate Potassium hichromate Sodium bichromate Ferric acetylacetonate Ammonium ferric oxalate... 

Aluminum Citrate. Aluminum citrate can be used as a crosslinker for many polymers the gels are made of low concentrations of polymer and aluminum citrate in water. This crosslinker provides a valuable tool, in particular, for in-depth blockage of high-permeability regions of rock in heterogeneous reservoirs. The formulations can be mixed as a homogeneous solution at the surface. 

Partially hydrolyzed polyacrylamides, carboxymethylcellulose, polysaccharides, and acrylamido methylpropane sulfonate have been screened to investigate the performance of aluminum citrate as a chelate-type crosslinker. An overview of the performance of 18 different polymers has been presented in the literature [1646]. The performance of the colloidal dispersion gels depends strongly on the type and the quality of the polymer used. The gels were mixed with the polymers at two polymer concentrations, at three polymer-to-aluminum ratios, and in different concentrations of potassium chloride. The gels were quantitatively tested 1,7, 14, and 28 days after preparation. 

Interactions of Metal Salts with the Formation. Interactions of metal salts with the formation and distribution of the retained aluminum in a porous medium may significantly affect the location and strength of gels. This interaction was demonstrated with polyacrylamide-aluminum citrate gels [1514]. Solutions were displaced in silica sand. The major findings of this study are that as the aluminum-to-citrate ratio increases, the aluminum retention increases. Furthermore, the amount of aluminum retained by silica sand increases as the displacing rate decreases. The process is reversible, but the aluminum release rate is considerably slower than the retention rate. The amount of aluminum released is influenced by the type and the pH level of the flowing solution. The citrate ions are retained by silica sand primarily as a part of the aluminum citrate complex. Iron, cations, and some divalent cations cannot be used in the brine environment. 

C. A. Rocha, D. W. Green, G. P. Willhite, and M. J. Michnick. An experimental study of the interactions of aluminum citrate solutions and silica sand. In Proceedings Volume, pages 403-413. SPE Oilfield Chem Int Symp (Houston, TX, 2/8-2/10), 1989. 

J. E. Smith. Performance of 18 polymers in aluminum citrate colloidal dispersion gels. In Proceedings Volume, pages 461-470. SPE Oilfield Chem Int Symp (San Antonio, TX, 2/14-2/17), 1995. 

Ghazali, H.A. Willhite, G.P. "Permeability Modification Using Aluminum Citrate/Polymer Treatments Mechanisms of Permeability Reduction in Sandpacks," SPE Paper 13583, International Symposium on Oilfield and Geothermal Chemistry, Phoenix, April 9-11. 

Ackley DC, Yokel RA. 1997. Aluminum citrate is transported from brain into blood via the monocarboxylic acid transporter located at the blood-brain barrier. Toxicology 120 89-97. 

Priest ND, Talbot RJ, Austin JG, et al. 1996. The bioavailability of 26Al-labelled aluminum citrate and aluminum hydroxide in volunteers. BioMetals 9 221-224. 

Quarterly B, Esselmont G, Taylor A, et al. 1993. Effect of oral aluminum citrate on short-term tissue distribution of aluminum. Food Chem Toxicol 31 543-548. 

Slanina P, Falkebom Y, Freeh W, et al. 1984. Aluminum concentrations in the brain and bone of rats fed citric acid, aluminum citrate or aluminum hydroxide. Food Chem Toxicol 22 391-397. 

Taylor GA, Ferrier IN, McLoughlin IJ, et al. 1992. Gastrointestinal absorption of aluminum in Alzheimer s disease Response to aluminum citrate. Age Ageing 21 81-90. 

D. Aluminum-Citrate Complexes Aluminum Toxicity and Iron Overload References... 

Given the poor uptake of Fe + by ferritin, it is not surprising that is not taken up in large amounts. Both we (F. H. A. Kadir and G. R. Moore, unpublished observations) and Dedman et al. (36) have found that apoferritin and holoferritin will only take up at most 40 Al atoms per ferritin molecule after prolonged incubation with aluminum citrate. However, in their more extensive study, Dedman et al. found that 120 Al atoms per ferritin molecule were bound to the iron core when the exposure to aluminum citrate occurred during its reconstitution. This is comparable to the 164 aluminum atoms bound to holoferritin reported by Sczekan and Joshi (122). 

Figure 4. The stracture of the aluminum citrate trimeric complex (Feng et al. 1990). There are no bridging hydroxyls and a single bound water molecule.

Feng TL, Gurian PL, Healy MD, Barron AR (1990) Aluminum citrate isolation and stractural characterization of a stable trinuclear complex. Inorg Chem 29 408-411 Fitzgerald JJ, Rosenberg AH (1999) Chemistry of aluminum chlorohydrate and activated aluminum chlorohydrate. In Antiperspirants and Deodorants, 2nd edition. Laden K (ed) Marcel Dekker, New York, p 83-136... 

Lothenbach B, Furrer G, Schulin R (1997) Immobilization of heavy metals by polynuclear aluminum and montmorillonite compounds. Environ Sci Technol 31 1452-1462 Marklund E, Ohman L-O (1990) Equilibrium and structural studies of silicon(IV) and aluminum(III) in aqueous solution. 24 A potentiometric and Al NMR study of polynuclear aluminum(III) hydroxo complexes with lactic acid. Acta Chem Scand 44 228-234 Matzapetakis M, Raptopoulou CP, Terzis A, Lakatos A, Kiss T, Salifoglou A (1999) Synthesis, structural characterization, and solution behavior of the first mononuclear, aqueous aluminum citrate complex. Inorg Chem 38 618-619... 

Toluenesulfonic Acid 26761-40-0 Diisodecyl Phthalate 31142-56-0 Aluminum Citrate... 

Figure 10.5. Chemical shifts in the NMR resonance lines associated with the structural moieties of the citrate molecule as a function of pH and the presence or absence of Al. Reference citrate resonance lines were obtained using 1 mol citrs solutions. Aluminum-citrate resonance lines were obtained using 1 mol L citTs+ 0.25 mol L AIts solutions. (Modified from Gregor and Powell, 1986.)...

---