Battery pastes

Your facility also processes metallic lead as an article component. This activity occurs at several points in the process, including during the addition of lead to the battery paste and the welding of metallic lead terminals and leads in the three-process operation. 

Processing Technology for Lead Acid Battery Paste, Maschinenfabrik Gustav Eirich, Post-fach 1160, D-74732 Hardheim, Germany H.J. Vogel, Power Sources, 1994, 48, 71. 

Newer secondary recovery plants use lead paste desulfurization to reduce sulfur dioxide emissions and waste sludge generation during smelting. Battery paste containing lead sulfate and lead oxide is desulfurized with soda ash to produce market-grade sodium sulfate solution. The desulfurized paste is processed in a reverberatory furnace. The lead carbonate product may then be treated in a short rotary furnace. The battery grids and posts are processed separately in a rotary smelter. 

Chemclood is a commercially available technology for the treatment of waste battery sites. Whole or broken batteries are typically sent off-site to separate the lead, plastic, and battery paste. The Chemclood process can provide potential profits from recovered lead and plastic, which can be recycled and sold. 

Nishi Y (2001) Lithium ion secondary batteries past 10 years and the future. J Power Sources 100 101-106... 

Fibres made from carbon-filled polyolefin or polyester have been added to battery paste to increase life [42]. In another approach [43], a battery plate was made by filling a non-conductive polyvinylchloride grid with paste and covering the plate with a sheet of partly carbonized, organic, non-conductive fibres. The carbonized layer on the fibres provided the electrical conductivity. 

Particles of lead dioxide in lead monoxide, such as those formed in a ball-mill, can be formed by treating the oxide with ozone before paste mixing [49]. The use of persulfate [50-53] and peroxides [54] to effect the partial conversion of lead oxide in the paste to lead dioxide has also been proposed. A proprietary process for treating the surfaces of unformed plates with ozone gas produced a thin coating of lead dioxide, which enhanced formation [55,56]. Much lower quantities of lead dioxide are needed with this approach than when red lead is added to the plate, and the normal battery paste mix can be used. Dipping or spraying the plate with a persulfate solution has also been adopted to oxidize the surface PbO to conductive Pb02 [57]. 

Once received at a secondary smelter, a lead-acid battery undergoes several processing stages to recover and treat the various component parts. In most modern plants, automatic battery breakers are used to process and recover these parts. There are many variations to battery-breaking operations throughout the world, although the outputs obtained from each operation are similar, namely, battery pastes, metallic fractions, acid, plastic components. 

The recovered lead paste is a mixture of the positive (lead dioxide) and negative (lead sulfate) active materials, small metallic fractions from the grid and other materials that have been added to the battery paste such as carbon black, expanders, and reinforcing fibres. A typical range of components in recovered battery paste is given in Table 15.1. 

Table 15.1. Typical composition of components in battery paste.

Lead-bearing residues. These materials consist of pre-treated battery paste and scrap, dusts, wastes, etc., and make up the major portion of the charge. 

The lead-bearing residues are generally lead oxides, although carbonates may be present in the pre-treated battery paste, depending on the de-sulfurization process used. Any lead carbonate present in the paste will quickly decompose once the temperature increases above 315°C. The material converts to lead oxide (reaction... 

In all of the above processes, pre-treatment of the battery paste is required so that compounds, such as lead sulfate and lead dioxide, can be accessed by electrolytic methods. Short summaries of the three processes are given below. 

Engitech process. This technology uses a leaching solution of fluoroboric add and lead fluoroborate. The desulfurized battery paste (Section 15.2.) is added to a reactor with the leaching solution. The solution is heated and stirred, and metal is recovered via an electrolytic cell. 

Modern secondary plants take in whole ULAB batteries and break them in a mechanical hammer-mill. The broken battery pieces are usually gravity separated in a series of water-filled tanks with slow-moving classifier belts to promote the capture of the battery paste. In this way, battery electrolyte is contained within the recycling process, and the acidic component can then be treated in one of the five ways [10] ... 

Washed and dried polypropylene pieces are sent to a plastic recycler, where the chips are melted [12] and extruded to produce plastic pellets for use in the manufacture of battery cases and other plastic components. Great care must be taken to ensure that the mechanical breaker cleans the polypropylene chips free of any residual oxide, because subsequent handling of the chips by operating personnel, especially at the plastic recycling plant, can result in significant levels of lead exposure. Should the wash sprays on the breaker fail to remove all traces of battery paste, consideration should be given to further washing with a dilute sodium hydroxide solution. 

Another option for secondary smelters is to desulfurize the battery paste prior to smelting. Chemical desulfurization, however, is dependent on physical mixing conditions and temperature. Chemical desulfurization is achieved by adding a concentrated sodium carbonate solution to an agitated mix of battery paste sludge to convert the lead sulfates to lead carbonates. Complete conversion of lead sulfate to lead carbonate eliminates sulfur in the furnace feed material and sulfur dioxide in the exhaust gases. Complete desulfurization is, however, rarely achieved under normal industrial conditions. 

The grid metallics should be stored and recovered separately from the battery paste so that metals from the alloys in the battery grids do not contaminate the relatively pure lead paste, which is ideal for producing soft lead. Alloys used to manufacture VRLA batteries do not contain either antimony or arsenic, and this means that the potential hazard of stibine (antimony hydride, SbHs) and arsine (arsenic hydride, AsHs) formation during the storage of the metallics is removed. Many automotive batteries with antimonial and arsenical alloys are still in use. 

DSC and TG were used for quality control of the materials and the technological processes during battery manufacture, Matrakova and Pavlov presented the results of an investigation on lead-acid battery pastes and active materials, aimed to estimate the efficiency of the two thermal methods for the analysis and the control of the processes taking place during battery production and operation [190]. 

This lead compound forms prismatic crystals with a length of 1—4 pm and 0.2—08 pm in cross section. Its density is 6.5 g cm. It is poorly soluble in water, 0.0262 g L. 3BS is obtained when leady oxide is mixed with sulfuric acid solution (up to 8 wt % H2S04/Pb0) and constitutes the basic component of the battery paste when the latter is prepared at temperatures below 70 °C. Tribasic lead sulfate exerts an influence on the structure of the lead dioxide active mass and thus on some of the performance characteristics of the battery. 

Paste density is the weight per unit volume of battery paste. Paste density is measured by dividing the weight of paste contained in a cylinder by the cylinder volume. Most often, the paste used for positive plates has a density between 3.90 and 4.40 g cm and that for negative plates, between 4.10 and 4.50 g cm. Pastes based on red lead have densities higher by 0.20—0.30 g cm. ... 

Type Of Secortdaries 6% Battery Paste 94% Reaidties Zinc Plant Residues, Drosses. Smelter Residues Pb Sulphates, R>-bearing Residues, Battery Paste, Residues... 

Type of Secondaries i Mainly Zinc dominated Battery Paste, EAF-Dust, Waelz Oxide, ... 

These commercial developments have occurred after many years of development work at Ausmelt. In excess of sixty pilot plant tests processing high, medium, and low grade sulphide concentrates, battery pastes, dusts and high grade slags have been carried out at the Ausmelt pilot facility in Dandenong, Australia. 

Concentrates Battery Paste Secondary Materials Fluxes Reductant Coal... 

Pilot plant data on lead battery paste, computer boards and scnq> portable battery material smelting, taken on a number of occasions by NATA or USEPA/ISO registered analysts, has indicated dioxin and furan levels very much lower than the statutory limit of 0.1 ng/Nm. ... 

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