Patent · US Expired

Process for preparing hydrated alumina consisting essentially of spherical particles by homogeneous precipitation

US4902494A · kind A · utility

2Cited by
1References
17Claims
0Family size

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Inventors

Key dates

Filing dateMay 26, 1989
Grant dateFeb 20, 1990
Priority date
Expiry dateMay 26, 2009

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01P2004/64
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A process for preparing hydrated alumina consisting essentially of spherical particles having a narrow granulometric distribution (polydispersion index dw/dn.ltoreq.2) starting from aqueous solution of aluminum sulphate, the molar ratio SO.sub.4.sup.= /Al.sup.3+ being greater than 1, by homogeneous precipitation in the presence of cationic polyelectrolytes, which are soluble under the reaction conditions and have a mean molecular weight higher than one million and an ionicity, deriving from the cationic groups present in the polyelectrolyte, of at least 3 milliequivalents/gram.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.