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US 4,387,142 AGranted
Granular material consisting of microporous hollow granules of lead powder
OwnerAlfons S. M. Lindholm, Rolf C. G. Magnussoninventors
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OwnerAlfons S. M. Lindholm, Rolf C. G. Magnussoninventors
Estimating the term…
The present invention relates to a granular material consisting of microporous, substantially hollow granules of lead powder, which is a powdered mixture of lead and lead oxide; a method for the production of this granular material; and the use thereof as an active substance in an electrode plate in a lead accumulator. The present invention provides a granular material lead powder that fulfills the requirements of resistance, size and quality, and which, when being used as an active substance in the lead accumulator, does not deteriorate in its capacity or lifetime. The qualities are achieved by means of the microporous, substantially hollow granules containing 0.5-2.0% by weight of a binder, with a particle diameter of 40-500 m and with the bulk density of 2.4-3.4 g/cm.sup.3.
Method for production of a granular material consisting of microporous, substantial hollow granules of lead powder wherein the lead powder is suspended in water and a binder is added whereupon said suspension is transferred into granules, characterized in that the binder is added in an amount of 0.5-2.0% by weight calculated on the dry substance, the suspension is heated to 100.degree.-150.degree. C. and thereafter spray-dried to granules present in substantially two fractions with a particle diameter of 40-60 .mu.m and 110-150 .mu.m, respectively, by forcing through a nozzle under pressure into a drying chamber of an elevated temperature.
Granular material for use as an active substance in an electrode plate of a lead accumulator, comprising:
Dependencies are inferred from the claim text.