Rsr Technologies, Inc.

Rsr Limited

R David Prengaman

Timothy W Ellis

Matthew T Raiford

Clifford E Morgan

Andreas Siegmund

Gerald M Griffin, Jr

Homer P Hine

A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.

Lead-based alloy and related processes and products

In the manufacture of lead acid battery electrodes, the oxidation of lead, particularly recycled lead containing silver, is enhanced by addition of magnesium to the lead. During the production of the lead acid battery, at least about 0.001 weight percent of magnesium is formed into an alloy with lead. The resulting alloy is then subjected to oxidizing conditions. The alloy may further contain silver.

Method for enhancing lead oxidation during production of lead acid batteries

A lead acid battery grid made from a lead based alloy containing calcium, tin, and silver having the following composition: calcium above 0.06 and below 0.082%, tin above 1.0% and below 1.2%, silver between 0.005 and 0.020%, and optionally containing up to 0.025% aluminum. To enhance corrosion resistance and reduce grid growth, the grid optimally may contain 0.005 to 0.05% copper as an alloying element complementary to and as a replacement for part of the silver, provided the silver content does not fall below 0.005% and no more than a trace of aluminum is present.

Alloy for thin positive grid for lead acid batteries and method for manufacture of grid

An anode for use in zinc electrowinning is described. The anode is made of a lead-silver alloy which has been cast as a billet rolled and subjected to heat treatment either during or after rolling. The temperature of treatment is high enough to cause recrystallization of the alloy and to prevent precipitation of any alloying elements. The anode has a surface grain structure which facilitates rapid oxidation of the anode to condition the anode. The anode preferably contains at least 0.03 to 0.45% silver and Lip to 0.08% calcium.

Electrowinning anodes which rapidly produce a protective oxide coating

A process for recovery of substantially all the sulfur in a spent lead-acid battery as Na,SO,is disclosed. The process comprises (a) breaking the batteries to remove the acid, (b) separating the plastic from the lead bearing materials, (c) smelting the lead bearing materials in a reverberatory furnace in an oxidizing atmosphere to volatilize most of the sulfur in the feed as SO,, (d) scrubbing the SO,from the off gas stream using a soluble alkaline material such as NaOH, Na,CO,, or KOH to produce a soluble sulfite solution, (e) oxidizing the sulfite solution to sulfate, preferably by turbulent mixing of the solution with air, (f) adjusting the pH by adding the sulfuric acid separated from the batteries, (g) removing the contained heavy metals, (h) crystallizing the sulfate as Na,SO,or K,SO,, (i) separating a bleed stream from the crystallizer and removing the contained chlorides as a mixed sulfate-chloride product by evaporation of the bleed stream in another crystallizer. The process produces a high grade Na,SO,or K,SO,product, condensed H,O for recycle to the scrubber, and a mixed sulfate-chloride product while reducing sulfur dioxide, chloride and heavy metal emissions to extremely low levels.

Process for recycling lead-acid batteries

In an electrowinning anode in which a lead anode sheet is tightly fitted to a copper busbar, the anode sheet is additionally joined to the busbar by pinning to prevent damage to the joint. A lead coating is electrodeposited onto the busbar, pin and the soldered joint to provide a complete metallurgical seal and good resistance to acid corrosion.

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Dallas, TX, United States of America

R David Prengaman