CA1210735A - Method and apparatus for reclaiming storage battery components - Google Patents

Abstract

METHOD AND APPARATUS FOR RECLAIMING
STORAGE BATTERY COMPONENTS
Abstract of the Disclosure A method has been invented for separating metal component material from other component material of waste storage batteries. The method includes the steps of breaking the storage batteries into broken and liberated battery component materials, including fragmented nonmetallic polymeric component material and fragmented metallic component material. The fragmented metallic component material includes metal material and electrode active material. The broken battery material is separated in an elutriation column. In one form of the invention, the electrolyte fluid is neutralized.

Description

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Technical Field This invention relates to the reclaiming of storage battery materials and more particularly to the separation and recovery of the various components of batteries, such as lead-acid batteries.
Back~round Art While the invention is illustratively described in relation to the recovery of components of lead-acid batteries, as will be o~vious to those skilled in the art, the improved method and apparatus can be readily applied to the recovery of component materials of other types of storage batteries.
As is well known, the main constituent materials of conventional present day batteries include hard ~ubber, polypropylene, polyethylene, or other similar materials forming the battery container. These materials, in combinati~n with the materials forming ~`

lZ~)735 the vent plugs, spacers, separators, insulators, and wrapping, are commonly referred to as nonmetallic, or polymeric, compo-nents. The electrode grids and electrical connections between the grids and external circuit are conventionally formed of metal. These metal components, in combination with the electrode active material which, in most cases, contains metal compounds, are commonly referred to as metal-containing, or metallic, compo-nents.
A further major constituent material of conventional bat-teries is the electrolyte. Generally, in processing lead-acid batteries, the electrolyte is removed before the battery recov-ery processes are begun. In known prior art processes, after the battery acid is removed, the remaining components are fed into an impact or shredding mill to be shattered or shredded into small pieces. Typically, the resulting heterogeneous battery scrap mix-ture has been separated by numerous screening and other mechanical or physical separation processes into nonmetallic and metallic portions wherein the metallic portions include coarse metallic pieces, fine particle-size metallic components which consist essentially of lead oxides and lead sulfate, and pure lead powder from the electrode fill, as described in U.S. Patent No. ~,107,007, of Andreas F. Gaumann et al.
In another known process, such as disclosed in German Patent Disclosure 28 56 330, published July 12, 1979, Inventors, M.
Okuda and K. Tomisaki, Diamond Engineering Co., Ltd., waste con-taining le~d sulfate is contacted with an aqueous solution of an alkaline substance which converts lead sulfate into a water insoluble lead salt such as lead carbonate, and also forms a water soluble sulfate such 2S sodium sulfate, as a by-product.
Thereafter, the water insoluble lead salt is prepared for roast-ing reduction.

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Several problems have existed with these various known recovery processes. Illustratively, before ~echanical processing of the scrap batteries can take place, the electrolyte must be removed from the battery to prevent corrosion of the machinery thereby in the subsequent steps of the process.
Such removal of the electrolyte from the battery in the conventionally employed dry mechanical process involves a costly time-consuming and labor-intensive operation.
Another problem arising in the known recovery method has been the undesirable cross-contamination of the various constituents of the battery due to inefficient separation of the components. It is desirable to separate the battery components into as pure a form as possible for efficient recycling. The substantial cross-contamination of the constituents in the known recovery methods has effectively prevented the economical obtaining of a useful recycle product.
Additionally, environmental regulations concerning toxic metallic compound exposure to employees and processing effluents present substantial problems relative to the known recovery methods. The cost of compliance with such regulations has made such recovery economically impractical where such control is obtained by using conventional processes with add-on systems.
Because of the depletion of petroleum resources, the desirability of use of battery-powered electric vehicles and the like is manifest. It is very important that a battery reclamation apparatus and process which is environmentally pollution-free be developed. The present invention meets those stringent environmental demands and produces reprocessable 7~S

battery component products with efEectively minimized detrimental effect upon the environment.
Disclosure of Invention Accordingly, it is an object of the present invention to pro-vide a process for reclaiming whole storage batteries, includingthe electrolyte. A further object of the present invention is to provide a wet mechanical reclamation process for reclaiming whole storage batteries, which produces independent isolated streams of battery constituen~s. In particularly preferred embodiments, several streams of battery constituents such as electrode active material, metal material, electrolyte material, and polymeric or other nonmetallic material, ar~ produced.
A still further object is to provide a storage battery reclaiming process which operates within both environmental and work safety standards.
Another object is to provide a storage battery reclaiming process which is easily adaptable to the various designs and sizes of battery containers and the various metallic and nonmetal-lic constituents comprising the storage batteries.
Still another object is to provide a storage batteryreclaiming apparatus and process which are inexpensive and sim-ple to utilize.
In accordance with one embodiment of the present invention, there is provided an apparatus suitable for separating higher density and lower density feed material having a predetermined nominal particle size, or larger particle and smaller particle feed material having substantially the same material density, de-rived ~rom the breaking of lead-acid batteries, comprising an elutriation column having a circular horizontal cross-section, a liquid manifold circumferentially disposed exteriorly to and in liquid communication with the interior of the lower portion of D

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the column through a plurality of sized and spaced inlet ports located in the lower column; the inlet ports being sized and spaced to control the liquid introduced radially inwardly into the column to produce a uniform ascending stream current having a sustained and substantially constant velocity; and means for introducing liquid to the liquid manifold; an overflow weir located at the top of the column for discharging lower density or smaller particle material and liquid from the column, a cylindri-cal feed inlet chute concentrically disposed at the top of the column and projecting into the upper portion of the column, and discharge means at the bottom of the column for discharging the higher density or larger particle material from the column.
In accordance with another embodiment of the present inven-tion, there is provided an elutriation column apparatus for separating higher density and lower density feed material derived from the breaking of lead-acid batteries and having a predetermined nominal particle size, the column comprising an upper cylindrical section and a lower cylindrical section having a smaller diameter than the upper section and concentrically disposed thereto; the upper and lower sections joined by a truncated conical transition section; the upper cylindrical section terminating in a horizontal circumferential lip defining an overflow weir; a vertically adiustable cylindrical material f~ed inlet chute having support means and a circular horizontal cross-section, concentrically disposed with and extending downwardly into the upper cylindrical column section; a collection collar attached circumferentially about the exterior of the upper column section, having a sloped floor and exterior walls e~tending vertically above the floor to collect and 3Q discharge liquid and low density overflow material discharged from the overflow weir; discharge means disposed at r~

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5a the bottom of the column for discharging the higher density material from the column, the discharge means comprising conveyor means discharging the higher density material above the liquid level in the column; a liquid manifold circumferentially disposed exteriorally to and in liquid communication with the interior of the lower portion of the column through a plurality of sized and spaced inlet ports located in the lower column; the inlet ports being si~ed and spaced to control the liquid introduced radi.ally inwardl~ into the column to produce a uniform ascending stream current having a sustained and substantially constant velocity;
and means for introducing liquid to the liquid manifold.
~ n accordance with a further embodiment of the present inven-tion, there is provided an apparatus suitable for separating solid feed material derived from broken lead-acid storage batter-ies, into a less dense material fraction and a higher densitymaterial fraction comprising a liquid elutriation column having a ratio of column length to effective diameter of not greater than 6 to 1, and a uniformly distributed ascendiny liquid stream intro-duced into the column through a liquid manifold in liquid communi-cation with the lower portion of the column, the stream having alinear flow velocity through the column of about 50 feet per minute and a liquid flow rate between approximately 450 and 500 gallons per minute through the column.
A still further embodiment of the present invention pro-vides an elutriation column for separating feed material derivedfrom broken lead-acid storage batteries into a less dense mate.rial fraction and a higher density material fraction wherein the column CGmpriSeS an upper cylindrical portion and a lower cylindrical portion concentrically joined thereto; means for feeding material to ana discharging material from the column; the column having a ratio of column length to effective diameter of not greater than 6 to 1, and a uniformly distributed ascending liquid stream introduced into the column through a liquid manifold in liquid communication with the lower portion of the column, the stream having a linear flow D

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5b velocity through the column of about 50 feet per minute and a liquid flow rate between approximately 450 and 500 gallons per minute through the column.
~et another embodiment of the present invention provides a method for separating less dense material from heavier density material, or smaller particle material from larger particle material, derived from the breaking of lead-acid batteries, com-prising the steps of:
(a) providing a feed material for a liquid elutriation column wherein the material comprises a less dense material and a heavier density material, or a smaller particle material and a larger particle material, the feed material having a predetermined maximum solid fragment size;
(b) providing a liquid elutriation column having a circular horizontal cross-section, a liquid manifold circumferentially disposed exteriorly to and in liquid communication with the interior of the lower portion of the column through a plurality of sized and spaced inlet ports located in the lower column; the inlet ports being sized and spaced to control the liquid introduced radially inwardly into the column to produce a uniform ascending stream current having a sustained and substantially constant velocity; and means for introducing liquid to the liquid manifold; an overflow weir located at the top of the column for discharging lower density material and liquid or smaller particle material and liquid, from the column, a cylindrical feed inlet chute concentrically disposed at the top of the column and projecting into the upper portion of the column, and discharge means at the bottom of the column for discharging the higher density or larger particle material from the column;
(c~ introducing a liquid uniformly through the inlet ports into the lower portion of the column circumferentially about th~
column;
(d) forming a uniform ascending liquid stream in the column;
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5c (e) feeding the feed material into the feed receiving means at the top of the column;
(f) contacting the feed material with the ascending liquid stream;
lg) separating less dense material from heavier density material, or smaller particle material from larger particle material in the column;
(h) discharging the less dense or smaller particle material at the top of the column;
(i) collecting the heavier density or larger particle material at the bottom of the column; and (j) discharging the heavier density or larger particle material from the bottom of the column.
Yet another embodiment of the present invention provides a method for separating a higher density material from a lower density material, or a larger particle material from a smaller particle material, derived from the breaking of lead-acid bat-teries, the method comprising the steps of:
(a) introducing a liquid circumferentially through a plurality of sized and spaced inlet ports into the lower portion of an elutriation column having a circular horizontal cross-section; the inlet ports being sized and spaced to control the liquid introduced radially inwardly into the column to produce a uniform ascending stream current having a sustained and substantially constant velocity;
(b) establishing a uniform ascending liquid stream in the column, the stream having sufficient flow velocity to lift the lower density or smaller particle material to the top of the column for discharge therefrom;
(c) introducing higher density and lower density feed material having a predetermined nominal particle size, or larger particle and smaller particle feed material, into the top portion of the elutriation column (d) separating the higher density material from the lower density material, or the larger particle material D

5d from the smaller particle material, by action of the ascending liquid stream thereupon;
(e) discharging the liquid and lifted lower density material, or liquid and lifted smaller particle material, from the top of the column;
(f) collecting the higher density or larger particle material at the bottom of the column; and ~ g) discharging the accumulated higher density or larger partic]e material from the bottom of the column.
In accordance with yet another embodiment of the present invention, there is provided the method of separating a higher density material from a lower density material, or a larger parti-cle material from a smaller particle material, derived from the breaking of lead-acid batteries, in a liquid elutriation column, comprising the steps:
(a) introducing a liquid uniformly and circumferentially radially inwardly into the lower portion of the column to distribute the liquid and establish a uniform ascending liquid stream having a sustained and substantially constant velocity, the flow velocity being sufficient to lift all but the higher density or larger particle material to the top of the column;
(b) feeding material having a predetermined nominal particle size, or material having larger and smaller particle sizes, into the top of the column to establish a descending feed stream therein;
(c) contacting the descending feed stream with the ascending liquid stream to disperse the material in the feed stream, lift the lower density or smaller particle material to the top of the column and allow the higher density or larger particle material to fall to the bottom of the column (d) discharging the liquid and the lower density or smaller particle material from the top of the column; and ~ e) discharging the higher density or larger particle material from the ~ottom of the column.

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In the above method and apparatus, preferably the relation-ship of the diameter of the cylindrical portion of the column, measured in inches, to the rate of liquid flow through the cylin-drical portion of the column, measured in gallons per minute, i9 above approximately 1 to 25.
Preferably, the column has a truncated conical transition section having the larger diameter end of the transition section joined to an upper cylindrical column section equal in diameter thereto and the smaller diameter end of the transition section joined to a lower cylindrical column section equal in diameter thereto; and a vertically adjustable, cylindrical material feed inlet chute in axial alignment with and extending downwardly into the upper cylindrical column section.
In another preferred embodiment, the horizontal cross-sectional area of the lower cylindrical column section is substan-tially equal to the effective annular cross sectional area defined by the extexior wall of the chute and the interior wall of the upper cylindrical column section.
Still further, the diameter of the upper cylindrical column section is preferably sufficiently large to permit unrestricted passage of the less dense material between the wall of the upper cylindrical column section and the chute wall.
The vertically adjustable material feed chute is desirably selectively vertically positioned to control the linear flow rate of the liquid within the upper cylindrical column section.
In still further preferred embodiments, the elutriation column comprises an upper cylindrical column portion, a central cylindrical column portion and a lower column portion, the cylin-drical feed inlet chute defining an effective horizontal cross~
sectional area between the outer surface of the feed inlet chute and the inner surface of the upper column portion, and the hori-zontal cross-sectional area of the central column portion is sub-stantially equal to the effective horizontal cross-sectional area.
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12107~i Preferably, the liquid introduced into the elutriation column has a density of at least 1 and is preferably recycled in a closed system.
_rief Description of the Drawings Other objects, advantages and novel features of the present invention will become apparent from the following detailed des-cription of the invention when considered in conjunction with the accompanying drawings wherein:
FIGURE 1 is a flow, or process, diagram showing the steps of a battery reclamation method embodying the invention;
FIGURE 2 is a side view of a dewatering screen apparatus used in carrying out the process of the invention, FIGURE 3 is a side view of a water elutriation column appara-tus used in carrying out the process of the invention;
FIGURE 3a is a sectional view of the elutriation column showing constructional features and relationship of components of the column; and FIGURE 4 is a flow, or process, diagram showing another reclamation method embodying the invention.
Best Mode for Carrying out the Invention Figure 1 is a flow diagram showing the steps of the pre-ferred embodiment of the process for breaking or crushing whole composite batteries B for separating the broken parts into the component material.
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As shown, the first step of the process illustra-tively comprises a step of breaking or crushing the whole batteries into fragments of which a majority are in fractions of less than l l/2 inch size. The fragmentation causes substantially complete liberation of the metal from the nonmetal materials and releases the electrolyte. The metallic material comprises the electrode active material, terminal posts and electrical i~terconnectors. The nonmetallic material comprises polymeric and possibly other electrically nonconductive materials, and includes the case material, which is usually of polypropylene, poly-ethylene or hard rubber; spacers, if used; separator material placed between the plates of the battery; and other nonconductive materials.
It has been found thatj after the feeding of the batteries through a conventional hammermill H, 97% of the broken battery material is in a minus 1 l/2 inch size fraction. Illustratively, such a hammermill made by Williams Patent Crusher and Pulverizer Co., of St.
Louis, has hammers on concentrically located shafts around a central drive shaft. The hammers strike the battery case with an impact force against a steel breaker plate to break the battery into fragments. The batteries may be fed continuously by suitable conveyor means into the hammermill. The hammermill with the feed conveyor and inlet hopper are substantially enclosed and ventilated to a conventional acid-mist removing device. The acid-mist removing device, used in processin~ lead-acid batteries, removes particles of electrolyte and lead compounds from the air by impingement or by spraying a scrubbing mist of water therethrou~h, thereby maintaining the air substantially acid-free and lead-free. Such devices are well known lZ~)73S

and will not be described in detail here, as they are commercially available.
Many of such batteries fed into the hammermill may contain electrolyte within the battery case. Thus, the parts of the hammermill which are exposed to such electrolyte are preferably made of materials which are corrosion-resistant with respect to the type of electroly.e which may be present in the batteries being processed, i.e., acid or alkaline. Resultingly, the process is simplified by not having to drain the electrolyte from the battery before the fragmentation step.
The broken battery material, including any such electrolyte, is then transferred, as by means of gravity, into a mixing reactor M. In a mixing reactor for lead-acid battery processing, the sulfuric acid electrolyte is neutralized by adding sodium carbonate in the form of soda ash. The electrolyte neutraliza-tion step may be carried out as a batch process in the mixing reactor. However, the present invention also contemplates the step as being carried out as a continuous process. In such processing of lead-acid batteries, the amount of neutralizing reagent added to the sulfuric acid electrolyte need only be adjusted to compensate for the di$ferences in the volume and concentration of electrolyte present due to the quantity of batteries being processed. In the batch processing method, the pH value is measured approxi-mately every ho~r and neutralization reagent is added accordingly.
In the continuous processing method, a pH probe is preferably used to provide a continuous monitoring of the pH, and adjustments are made as require~ in order to maintain the desired pH level. For neutralizing the acid, a pH level of 7 is desired. However, in order to provide for the conversion of lead sulfate to lead carbonate and sodium carbonate to sodium sulfate, it is S desirable to maintain a pH level of about 9.0 to 9.3.
The sulfuric acid reacts with sodium carbonate to form sodium sulfate which is soluble and remains in solution if the concentration of sodium sulfate is kept below its saturation level to prevent crystallization and precipitation of the compound.
It is desirable and advantageous to use a reagen~
which also reacts with the sulfur-containing lea~
compound from the electrode active material to form a sulfur-free lead compound for subsequent recovery and processing. The sodium carbonate also converts a sub-stantial quantity of lead sulfate in the electrode active material to lead carbonate. The amount of soda ash required for the dual function of neutralizing the acid and converting the lead sulfate preferably equals the stoichiometric equivalent required for these reactions plus at least a 10~ excess over the amount required for the latter reaction. Additionally, it is desirable to add sufficient water to maintain the con-centration of the neutralization product, sodium sulfate~ at about 90~ of its maximum solubility at ambient temperature.
It was found from a test sample of 50 lead-acid batteries that neutralizing of the sulfuric acid required approximately 1.8q lbs. of 1~a2CO3 per battery. I`o neutralize and remove the sulfur from the electrode active material in a test sample of 200 lead-acid batteries was fou~d to re~uire about 7.3 lbs. of r~a2co3 per battery. The ~ifference in ~he amount of Na2CO3 re~uired per battery comprises the ~21~)735 necessary additiona] amount of Na2CO3 to convert the lead sulfate to lead carbonate. These exemplary ap~roximations are not intended as limitations.
The present invention contemplates the use of other neutralizing reagents for neutralizing the sulfuric acid electrolyte, comprising, but not limited to, reagents such as ammonium carbonate, sodium hydroxide, ammonia, etc. For example, when ammonium carbonate reagent is used, lead carbonate and ammonium sulfate are the products; when sodium hydroxide reagent is used, lead hydroxide and sodium sulfate are the products and when ammonia is used, lead hydroxide and ammonium sulfate are the products. Other reagents will, of course, become readily apparent to those skilled in the art and are contemplated for use herein.
All of the lead and lead compound products, as well as the nonlead products, are valuable and are preferably separated and recovered for their values, as well as to control the purity of the desired end product. Important advantages of this neutralization step are the reduction of battery-electrolyte corrosion of the equipment, and in lead-acid battery processing, the desulfation of the sulfur-containing electrode active material, or lead sulfate compound, by conversion of this compound to a sulfur-free metallic compound, such as lead carbonate, thereby greatly simplifying its subsequent processing.
It is important to note that the electrolyte neutralizing reagent may differ from the reagent used to remove sulfur from lead sulfate in the electrode active material. Additionally, electrolyte neutrali-zation and active material desulfa~ion, or conversion, may take place at di~erent times during processing.

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~o Since the electrode active material in lead-acid batteries comprises lead oxides and lead sulfate, which in the preferred process is converted to a substan-tially sulfur-free lead compound, and all of these lead compounds are desirably processed and recovered together as environmentally desirable substantially sulfur-free lead compounds for subsequent processing, the specific process and timing of the conversion of lead sulfate to sulfur-free lead may be varied consid-erably. Alternatively, the lead sulfate may beprocessed through and reclaimed as lead sulfate for later conversion to a sulfur-free compound in subse-quent processing. For these reasons, no limitation is intended to be placed upon the process sequence or the specific process used in recovering and/or converting electrode active material, as the recovery of such material is the major factor, whether in the converted sulfur-free or unconverted nonsulfur-free form. Such electrode active material may, therefore, be referred to herein as "electrode active material" or as "solid lead compounds" without regard to whether or not such conversion has taken place and the use of either of these terms herein should be broadly interpreted as being equivalent and interchangeable with the other for the purposes of describing and claiming the process and variations thereof set forth herein, as the actual process sequence for such lead sulfate conversion to a sulfur-free form is not considered to be critical.
In the next step, the battery material and neutralized electrolyte, containing suspended solid lead compounds, are fed to a dewatering screen where the neutralized electrolyte and a majority of the solid lead compounds are removed as hereinafter described. A

vibratin~ feeder may be used to transfer the broken battery material to the header box on the dewatering screen. A side view of the suitable dewatering screen is shown in Figure 2. The operation of the dewatering screen 20 involves introducing particles through a feeder 22 and onto screen 26 having the desired aperture size. The particles pass through screen 26 if they are smaller than the apertures. They collect on the screen 26 if they are larger. The smaller parti~
cles and liquid fall into chute 2g and the larger particles fall off screen 26 at point 30.
It has been found that in the disclosed process, over 90~ of the solid lead compounds, along with the neutralized acid, passes through the screen. The most common lead compound found in the electrode active material, in addition to lead dioxide, is lead sulfate which, as mentioned above, is converted to a substan-tially sulfur-free compound, i.e., lead carbonate, in the preceding neutralization step by controlling the ~0 amount of sodium carbonate neutralizing reagent used~
The solid lead carbonate and lead oxide compounds in suspension in the neutralized electrolyte liquid, which contains sodium sulfate in solution, are then pumped to a solid-liquid separator tank S for settliny and con-centration of the solids therein. Alternatively, theliquid, containing the suspended solids, may be processed through a cyclone separator C which may be added to supplement the solid-liquid separator to concentrate and remove the solid material from the liquid.
The solid-liquid separator allows the solid lead compounds, in the form of lead carbonate and lead oxides, to separate out of the sodium sulfate solution lZ~0~73~

which is then separated ~rom the insoluble solids as by decant-ing. Sodium sulfate solution adhering to the solid lead-containing materials may be removed with a water wash. The sulfur-free lead compounds thereafter may be smelted free of environmental contamination as by sulfur pollution. The resul-tant so~ium sulfate-rich li~uors can be concentrated and reco-vered by evaporation to produce an anhydrous sodium sulfate pro-duct.
The present inven-tion further contemplates the use of other solid-liquid separation techniques and equipment. Any means for separating the converted or unconverted electrode active material from the electrolyte may be used within the scope of the invention. In most cases, the active materials, whether converted or unconverted, proceed throughout the pro-cess together to be recovered simultaneously. ~he selected separating means is dependent on the type of battery being reclaimed. Thus, as nickel-cadmium, silver-zinc, nickel-zinc, and lead-acid batteries have different electrode active mater-ials and electrolytes, the recovery processes may be selected accordingly.
Following the separation steps, the remaining cxushed, or broken, solid oversize material 31 which does not pass through the dewatering screen is conveyed to the top of a fluid elutria-tion column or rising-current separator column. This oversize material normally comprises both metal material and nonmetallic components. The invention contemplates the use of various liquids or liquid-solid suspensions as fluids for use in the elutriation column. However, as indicated herefollowing, water is preferred.
As shown in Figure 3, the novel elutriation column of the present invention is comprised of an upper column portion 42a, a central column portion 42b and a lower column por-tion 42c. Each portion of the column is circular in cross-section and the upper column portion 42a is connected to the central column portion 42b by a truncated, conical transition section 62. A ver~ically adjustable inlet chute or feed funnel 46 is concentrically positioned at the top of the upper column portion 42a with an inlet chute skirt 63 projecting into upper column portion 42a as hereinafter further described.

A collection collar 60 is attached circumferentially around the exterior of the upper column portion 42_ to receive overflow liquid and lighter polymeric material 58 as they flow over the overflow weir 59, formed by the upper circular lip of the upper column portion 42a, and out the collection chute 61 to a de-watering screen 64. As seen in Figures 3 and 3a, the collec-tion collar 6~ has a sloped floor to direct the flow of liquid and solids from the overflow weir to a collection chute ~1. A
heavy material exit chute 50 is connected to the lower column 1~ portion 42c to serve as a gravity feed path for movement of heavier metal material 48 from the lower column portion 42c through the heavy material exit chute 50 to an enclosed screw conveyor 52. Rotation of the conveyor screw 53 causes the heav-ier metal material 48 to be transported to the top of the screw conveyor 52 and out the top for collection and subsequent pro-cessing. An inlet pipe 40 is connected to a circumferential liquid manifold 44 disposed about the lower portion of column 42 and which in turn is in liquid communication with the cen-tral column portion 42b through a series of manifold inlet ports or wall openings 45 selectively sized and positioned cir-cumferentially through the bo~tom wall of the central column portion 42b. As will be appreciated from Figures 3 and 3a, through these inlet ports, liquid, which is continuously recir-culated or recycled from the pump tank to the elutriation column to form a closed system, is controllably introduced cir-cumferentially into said central column portion 42b of the elutriation column 42 to distribute the in~roduced liquid and to establish a uniform upward flow pattern or ascendi~g stream current having a sustained relatively constant velocity.
It will be appreciated by those skilled in the art that the elutriation column must have minimum dimensions taking into account the size of the particles so that clogging of the column is avoided. As will be seen from Figures 3 and 3a, the inside diameter in the central column portion 42b may be several times the size of particles 48 and 58. The column dia-meter D of central column portion 42b therefore has a minimum diameter which prevents particle clogging of the area A' (Figure 3a) and provides unrestricted particle movement up ~Z~(~7~S
13a the upper column portion 42a, over weir 59 and into collec-tion chute 61. The selection of diameter D of central column portion 42b determines the cross-sectional area A of the cen-tral column portion and also determines approximately the effec-tive cross-sectional area A', defined as the cross-sectional area between the cylindxical segment of upper portion 42a and the outside of feed inlet chute skirt segment 63. As will also be evident from Figures 3 and 3a, it likewise controls the selection of the effective inside diameter D' of upper column portion 42a and the maximum effective outside diameter D'' of feed inlet chute skirt 63, as the effective cross-sectional area A' between upper column portion 42a and feed inlet chute skirt 63 desirably should be approximately equal to the cross-sectional area A of the central column portion 42b if preven-tion of particle clogging is to be achieved.
~ ith further reference to Figures 3 and 3a, it will beappreciated that the liquid manifold inlet openings or ports, in conjunction with the quantity and pressure of liquid enter-ing manifold 44 through inlet pipe 40, determine the liquid dis-tribution and flow rate entering the column 42 to establish anupward flow pattern. ~y regulating the number, size and posi-tion of the manifold openings 45, along with the regulation of the liquid flow rate, a uniform upward flow pattern is esta-blished. The manifold openings 45 preferably are sized and positioned circumferentially 50 that liquid is controllably introduced circumferential'y into said column to distribute the inlet liquid and establish an ascending liquid stream having a uniform upward flow pattern. Smaller manifold openings 45 are positioned in line with the direct impingement of liquid flow-ing into manifold 44 from inlet pipe 40 in order to control-lably provide or introduce circumferentially a uniform liquid flow into the column and establish the desired uni~orm ascend-ing liquid stream.
The feed inlet chute or feed funnel 46 is axially or con-centrically aligned with the top of the elutriation column 42,is vertically adjustable and is designed to receive the over-size material 31 from dewatering screen 20. Feed inlet chute 46 has a cylindrical skirt portion 63 which projects into the ,~

13b liquid and into the cylindrical segment oE upper column por-tion 42a to a point just above the bottom of said cylindrical seg-ment .
Upper column portion 42a is comprised of t~o sections, a cylindrical upper section and a lower -truncated conical transi-tion section 62. The circular lip of the cylindrical upper sec-tion serves as an overflow weir 59 and determines the liquid level 56. The truncated conical -transition section 62 is larger at the top and smaller at the bottom as shown in Figures 3 and 3a to cause the liquid velocity to decrease as the ascending liquid enters the widening transition section and per-mit the slower ascending liquid eurrent to act upon the solid materials to lift them over weir 59 or permit them to sink through the rising current and accumulate at the ~ottom of the column. The truncated cone segment 62 at the upper portion of the column is disposed between up~er and lower cylindrical column segments and the material feed chute 46, extending down-wardly into the upper cylindrical column segment 42a, is ver-tically adjustable to control the linear flow rate of the li~uid within the upper cylindrical column segment. under nor~
mal operating conditions, the solid materials will readily separate and either rise and exit at the overflow weir or will fall and accumulate at the bottom. If a significant amount of material becomes suspended in the transltion section, adjust-ment must be made in the liquid veloeity to eause the materialto either overflow at the weir or to fall and colleet at the bottom, depending on the eomposition of the material and the operator's desire.
The lower column portion 42_ serves to collect the heav-ier material 48 in the heavy material exit chute 50 which gra-vity feeds the material to enelosed serew conveyor 52 as the screw conveyor is operated. The lower column portion 42c is configured as desired to accommodate the selected discharge means, such as the depieted inclined enclosed screw conveyor whieh permits the discharge of the heavier material above the li~uid level 56.
Table I sets forth the preferred embodiments of applicant's novel elutriation column and preferred operatiny lZ:1~73~
13c parameters for a typical operation in separating lead-acid battery materials which are fed to the column as above described.
TABLE I

Dimensions and Relationships of Elutriation Column and Components Elutriation Column Dimensions:
Feet Inches D" (O.D. of feed chute cylindrical portion) l.. 01 12.16 D' (I.D. of upper column cylindrical portion) 1.62 19.40 D (I.D. of central column cylindrical portion) 1.25 15.00 L (Column length:distance from liquid manifold to weir top) 5.58 66.9 Length of upper column portion ~42a) cylindrical segment 1.00 12.00 transition cone (taper=7) 1.49 17.90 Length of central column portion (42~) 3.08 37.00 Length of lower column portion (42c) 1.80 21.60 L' (Distance from bottom of feed chute to weir top) 1.00 12.00 Rat~o of Co _mn Length to Effective Diameter of Column:
Maximum Ratio 6:1 Preferred Ratio 4.5~1 Cxoss-Sectional Areas:
A tCentral column portion) 177 in2 A' (Effective area between I.D. of upper cylindrical portion and O.D. of feed chute) 179 in2 1~

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13d Characteristics of Liquid and Liquid Flow:
Liquid linear f]ow velocity (typical rate) 50 ft/min Liquid 1ow rate (typical rate) 450 to 500 gal/min ~i~uid (preferred) water In operating the elutriation column as shown in Figures 3 and 3a, liquid, recycled from the pump tank T is introduced circumferentially uniformly through an inlet pipe 40 near the bottom of the column 4~ at a controlled pressure. Manifold 44 uniformly distributes the inlet liquid to establish a controlled upward liquid velocity and a uniform ascending liquid flow pattern. As broken oversize battery material 31 is introduced at the top 46 of the column~ the heavier metal material 48 sinks to and collects at bottom 50 of the column. An enclosed screw conveyor 52 continuously removes the collected metallic material 48. ~s shown in broken section ~FIG. 3), screw conveyor 52 is of sufficient length to extend above the liquid level 56 in the column so that the metal material may be readily collected in a container without need to remove liquid. The small amount of electrcde active material, or suspended solids, remaining in the process stream and the nonmetallic material, such as the polymeric material, illustratively polypropylene piece 58, is maintained in fluid suspension in the elutriation column. The polymeric, or nonmetallic, material and suspended solids are carried by the upward water flow over overflow weir 59 to a collection collar 60 from which the flow exits through collection chute or collar 61, permitting the nonmetallic material to be further processed in a subsequent processing step.
It has been found that a critical factor aEfecting separation efficiency in the Eluid elutriation column is the use of an optimum fluid flow rate. With an appropriate flow rate using water as the fluid, for example, the elutriation separation of the polymeric material, including hard rubber material and solid lead compounds in suspension, from the lead metal material has been caused to be over 97%
efficient. Illustratively, an elutriation column having a 15-inch diameter and a water flow rate of 450 to 500 gallons of water per minute providing an average linear flow rate of f~

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about 50 ft/min up the column has been found to provide such a high separation efficiency.
The fluid used in the elutriation column may be recirculated as by being pumped from a return pump tank T~ After the fluid has flowed through the column, it may be returned to the pump tank where the suspended solid lead compounds are removed via a bleed stream outflow. It has been found to be advantageous to remove the solids in the bleed stream from the return pump tank as by use of a hydraulic cyclone separator, as previously mentioned, as well as other solid-liquid separators as desired.
Remaining oversize solids which may comprise broken polymeric material, such as polypropylene, hard rubber and separator materials, are conveyed to a solid-solid separator S-S which is a liquid-filled tan~
where the different materials are separated. In the preferred embodiment, this is a sink-float step. The density of the material to be separated determines the appropriate liquid or liquid-solid suspension as the desired separator medium. In the preferred embodiment, water is used. The hard rubber and other polymeric materials which have a density greater than water, sink to the bottom of the separation tank where a screw ~5 conveyor S-S removes the material from the liquid bath for collection. The screw need be only of sufficient leng~h to extend above the liquid level of the bath so that the denser polymeric material will be freed of liquid as it is collected. The other polymeric materials, having a density less than that of the liquid used, float on top of the bath and are removed by a cleated continuous belt conveyor B-C which extends just below the liquid ~evel. One important advantage ~LZ~(~73S

of this step, from a product purity viewpoint, is removal of undesirable heavier polymeric materials, such as polyvinyl chloride and hard rubber which sink and are thusly separated from the lighter floating polymeric materials. This allows the material to be recycled more efficiently by providing a starting material having fewer contaminants, such as chloride compounds, from the remaining polymeric material and lead compounds to be processed.
While the operation described above is a solid-solid separation, the present invention contemplates, within the scope of the invention, the use of other means for separating the solid materials. Such means may be similarly based on the density of the solid materials or may use other chemical or physical proper-ties of the material being processed to accomplish the separation.
Another embodiment of the present invention is shown in the flow diagram of Figure 4. In the Figure 4 embodiment, the electrolyte, electrode active material and other undersized solid material are separated from the remaining crushed or broken battery material without neutralizing the electrolyte so that it may be collected and reused. ~s shown, the electrode active material is separated from the unneutralized electro-lyte by a solid-liquid separator means.
The electrolyte may be neutralized at a subsequent time during processing if desired. The electrolyte neutralizing reagent may differ from the reagent used to remove sulfur from the electrode active material.
Additionally, in processing lead-acid batteries, desulfation may be effected at subsequent times and in different steps during the processing.

lg735 The oversize solid material which is separated from the smaller broken battery material is normally wet with unneutralized electrolyte. It has been found that approximately 10~ of the electrolyte adheres to the oversize solid material and, thus, during subse-quent processing, it may be desirable to neutralize the electrolyte adhering to the oversize solid material before further processing. The remaining steps of the embodiment shown in Figure 4 are similar to the embodiment previously discussed.
As demonstrated by the disclosed embodiments, the present invention provides a process for reclaimin~, in relatively pure form, and as separate products, the different components of storage batteries. Such recovery includes a sulfur-free, environmentally desirable, active material product from lead-acid batteries. Since the electrolyte does not need to be drained from the storage battery before processing, the operation is simple and economical. Where the battery electrolyte is neutralized, as in the preferred disclosed process, the mechanical apparatus used in the subsequent steps of the process need not be made of expensive corrosion-resistant metal. The work enviroll-ment is made less hazardous to personnel and environmental problems concerning waste disposal and sulfur and lead content in the air are significantly reduced.
This invention provides a simplified process for the separation of the various constituents of storage batteries, including the active material, grid and other metal material, electrolyte, polymeric materials including spacerl container, insulator, and other nonmetallic materials. These m~terials are ~eparated 3~2~

and recovered in a form sufficiently free of contamina-tion to permit efficient and economical recycling thereof with minimum adverse impact on the environment.
The present invention is adaptable to be used to recover components of batteries other ~han lead~acid batteries.
The foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention.

Claims (34)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. An apparatus suitable for separating higher density and lower density feed material having a predetermined nominal particle size, or larger particle and smaller particle feed material having substantially the same material density, de-rived from the breaking of lead-acid batteries, comprising an elutriation column having a circular horizontal cross-section, a liquid manifold circumferentially disposed exteriorly to and in liquid communication with the interior of the lower portion of said column through a plurality of sized and spaced inlet ports located in said lower column; said inlet ports being sized and spaced to control the liquid introduced radially inwardly into said column to produce a uniform ascending stream current having a sustained and substantially constant velocity;
and means for introducing liquid to said liquid manifold; an overflow weir located at the top of said column for discharging lower density or smaller particle material and liquid from said column, a cylindrical feed inlet chute concentrically disposed at the top of said column and projecting into the upper portion of said column, and discharge means at the bottom of said column for discharging said higher density or larger particle material from said column.

2. An elutriation column apparatus for separating higher density and lower density feed material derived from the break-ing of lead-acid batteries and having a predetermined nominal particle size, said column comprising an upper cylindrical sec-tion and a lower cylindrical section having a smaller diameter than said upper section and concentrically disposed thereto;

said upper and lower sections joined by a truncated conical transition section; said upper cylindrical section terminating in a horizontal circumferential lip defin-ing an overflow weir; a vertically adjustable cylindrical material feed inlet chute having support means and a circular horizontal cross-section, concentrically disposed with and extending downwardly into said upper cylindrical column sec-tion; a collection collar attached circumferentially about the exterior of said upper column section, having a sloped floor and exterior walls extending vertically above said floor to col-lect and discharge liquid and low density overflow material dis-charged from said overflow weir; discharge means disposed at the bottom of said column for discharging said higher density material from said column, said discharge means comprising con-veyor means discharging said higher density material above the liquid level in said column; a liquid manifold circumferen-tially disposed exteriorally to and in liquid communication with the interior of the lower portion of said column through a plurality of sized and spaced inlet ports located in said lower column; said inlet ports being sized and spaced to control the liquid introduced radially inwardly into said column to produce a uniform ascending stream current having a sustained and sub-stantially constant velocity; and means for introducing liquid to said liquid manifold.

3. The apparatus set forth in claim 1, wherein said dis-charge means comprises a screw conveyor which removes said higher density material.

4. The apparatus set forth in claim 2 or 3, wherein the removal of said higher density material is accomplished at the bottom of said column at a position below said manifold.

5. The apparatus set forth in claim 1, wherein said column comprises a cylindrical segment and at least one trun-cated conical transition section.

6. The apparatus set forth in claim 5, wherein the rela-tionship of the diameter of the cylindrical portion of said column, measured in inches, to the rate of liquid flow through said cylindrical portion of said column, measured in gallons per minute, is above approximately 1 to 25.

7. The apparatus set forth in claim 1 or 2, wherein said ascending liquid stream has a linear flow rate of approximately 50 feet per minute.

8. The apparatus set forth in claim 5, wherein said column has a diameter of approximately at least 15 inches, said liquid has a density of at least 1 and said stream has a liquid flow rate of approximately 450 to 500 gallons per minute through said column.

9. The apparatus set forth in claim 5, wherein said column has an annular horizontal cross-section the diameter of which is at least 15 inches and said stream has a linear flow rate of approximately 50 feet per minute through said column.

10. The apparatus set forth in claim 1, wherein said column has a truncated conical transition section at the upper portion of said column disposed between upper and lower cylin-drical column sections and a vertically adjustable material feed chute extending downwardly into said upper cylindrical column section.

11. The apparatus set forth in claim 1, wherein said column has a truncated conical transition section having the larger diameter end of said transition section joined to an upper cylindrical column section equal in diameter thereto and the smaller diameter end of said transition section joined to a lower cylindrical column section equal in diameter thereto; and a vertically adjustable, cylindrical material feed inlet chute in axial alignment with and extending downwardly into said upper cylindrical column section.

12. The apparatus set forth in claim 11, wherein the hori-zontal cross-sectional area of the lower cylindrical column sec-tion is substantially equal to the effective annular cross-sectional area defined by the exterior wall of said chute and the interior wall of said upper cylindrical column section.

13. The apparatus set forth in claim 2 or 11, wherein the diameter of said upper cylindrical column section is suffi-ciently large to permit unrestricted passage of the less dense material between the wall of said upper cylindrical column sec-tion and said chute wall.

14. The apparatus set forth in claim 2 or 11, wherein said vertically adjustable material feed chute is selectively vertically positioned to control the linear flow rate of the liquid within said upper cylindrical column section.

15. The apparatus set forth in claim 1 or 2, wherein said elutriation column has a ratio of column length to the effec-tive diameter of the column of not greater than 6 to 1.

16. The apparatus set forth in claim 1, wherein said elu-triation column comprises an upper cylindrical column portion, a central cylindrical column portion and a lower column por-tion; said cylindrical feed inlet chute defining an effective horizontal cross-sectional area between the outer surface of said feed inlet chute and the inner surface of said upper column portion; and the horizontal cross-sectional area of said central column portion being substantially equal to said effec-tive horizontal cross-sectional area.

17. The apparatus set forth in claim 11, wherein said elu-triation column has a ratio of column length to the effective diameter of the column of not greater than 6 to 1.

18. An apparatus suitable for separating solid feed material derived from broken lead-acid storage batteries, into a less dense material fraction and a higher density material fraction comprising a liquid elutriation column having a ratio of column length to effective diameter of not greater than 6 to 1, and a uniformly distributed ascending liquid stream intro-duced into said column through a liquid manifold in liquid com-munication with the lower portion of said column, said stream having a linear flow velocity through said column of about 50 feet per minute and a liquid flow rate between approximately 450 and 500 gallons per minute through said column.

19. An elutriation column for separating feed material derived from broken lead-acid storage batteries into a less dense material fraction and a higher density material fraction wherein said column comprises an upper cylindrical portion and a lower cylindrical portion concentrically joined thereto;
means for feeding material to and discharging material from said column; said column having a ratio of column length to effective diameter of not greater than 6 to 1, and a uniformly distributed ascending liquid stream introduced into said column through a liquid manifold in liquid communication with the lower portion of said column, said stream having a linear flow velocity through said column of about 50 feet per minute and a liquid flow rate between approximately 450 and 500 gallons per minute through said column.

20. The elutriation column as set forth in claim 19 where-in the relationship of the diameter of the lower cylindrical portion of said column, measured in inches, to the rate of liquid flow through said cylindrical portion of said column, measured in gallons per minute, is above approximately 1 to 25.

21. The elutriation column set forth in claim 2, wherein said lower column portion has a diameter of approximately at least 15 inches, said liquid has a density of at least 1 and said stream has a liquid flow rate of approximately 450 to 500 gallons per minute through said column.

22. The elutriation column set forth in claim 2, wherein said lower column portion has an annular horizontal cross-section, the diameter of which is at least 15 inches and said stream has a linear flow rate of approximately 50 feet per minute through said column.

23. The elutriation column set forth in claim 2, wherein said elutriation column comprises a cylindrical feed inlet chute defining an effective horizontal cross-sectional area between the outer surface of said feed inlet chute and the inner surface of said upper column portion; and the horizontal cross-sectional area of said lower cylindrical column portion is substantially equal to said effective horizontal cross-sectional area.

24. A method for separating less dense material from heavier density material, or smaller particle material from larger particle material, derived from the breaking of lead-acid batteries, comprising the steps of:
(a) providing a feed material for a liquid elutria-tion column wherein said material comprises a less dense mater-ial and a heavier density material, or a smaller particle material and a larger particle material, said feed material hav-ing a predetermined maximum solid fragment size;

(b) providing a liquid elutriation column having a circular horizontal cross-section, a liquid manifold circumfer-entially disposed exteriorly to and in liquid communication with the interior of the lower portion of said column through a plurality of sized and spaced inlet ports located in said lower column; said inlet ports being sized and spaced to control the liquid introduced radially inwardly into said column to produce a uniform ascending stream current having a sustained and sub-stantially constant velocity; and means for introducing liquid to said liquid manifold; an overflow weir located at the top of said column for discharging lower density material and liquid or smaller particle material and liquid, from said column, a cylindrical feed inlet chute concentrically disposed at the top of said column and projecting into the upper portion of said column, and discharge means at the bottom of said column for discharging said higher density or larger particle material from said column;
(c) introducing a liquid uniformly through said inlet ports into the lower portion of said column circumferen-tially about said column;
(d) forming a uniform ascending liquid stream in said column;
(e) feeding said feed material into said feed receiv-ing means at the top of said column;
(f) contacting said feed material with said ascend-ing liquid stream;
(g) separating less dense material from heavier den-sity material, or smaller particle material from larger parti-cle material in said column;
(h) discharging said less dense or smaller particle material at the top of said column;

(i) collecting said heavier density or larger parti-cle material at the bottom of said column; and (j) discharging said heavier density or larger parti-cle material from the bottom of said column.

25. The method set forth in claim 24, wherein said column has a ratio of column length to column effective diameter of approximately 6 to 1.

26. The method set forth in claim 24, wherein said ascend-ing stream has a linear flow velocity of at least 50 feet per minute.

27. The method set forth in claim 24, wherein said ascend-ing stream has a flow rate of at least 450 gallons per minute.

28. The method set forth in claim 24, wherein said ascend-ing stream has a linear flow velocity of at least 50 feet per minute and a flow rate of at least 450 gallons per minute.

29. The method set forth in claim 24, wherein said feed receiving means comprises a vertically adjustable feed inlet chute projecting vertically into the upper portion of said column.

30. The method set forth in claim 24, wherein said liquid is recycled in a closed system.

31. The method set forth in claim 29, wherein said column has an effective cross-sectional area between said feed receiv-ing means and the inside wall of the upper portion of said column substantially equal to the cross-sectional area of the lower portion of said column.

32. A method for separating a higher density material from a lower density material, or a larger particle material from a smaller particle material, derived from the breaking of lead-acid batteries, said method comprising the steps of:
(a) introducing a liquid circumferentially through a plurality of sized and spaced inlet ports into the lower por-tion of an elutriation column having a circular horizontal cross-section; said inlet ports being sized and spaced to con-trol the liquid introduced radially inwardly into said column to produce a uniform ascending stream current having a sus-tained and substantially constant velocity;
(b) establishing a uniform ascending liquid stream in said column, said stream having sufficient flow velocity to lift the lower density or smaller particle material to the top of said column for discharge therefrom;
(c) introducing higher density and lower density feed material having a predetermined nominal particle size, or larger particle and smaller particle feed material, into the top portion of said elutriation column;
(d) separating said higher density material from said lower density material, or said larger particle material from said smaller particle material, by action of said ascend-ing liquid stream thereupon;
(e) discharging the liquid and lifted lower density material, or liquid and lifted smaller particle material, from the top of said column;
(f) collecting the higher density or larger particle material at the bottom of said column; and (g) discharging said accumulated higher density or larger particle material from the bottom of said column.

33. The method of separating higher density component material from lower density component material as set forth in claim 32, wherein said step of removing said higher density material comprises removing said material from the bottom of said column by conveyor means connected to the bottom of said column.

34. The method of separating a higher density material from a lower density material, or a larger particle material from a smaller particle material, derived from the breaking of lead-acid batteries, in a liquid elutriation column, comprising the steps:
(a) introducing a liquid uniformly and circumferen-tially radially inwardly into the lower portion of said column to distribute said liquid and establish a uniform ascending liquid stream having a sustained and substantially constant velocity, said flow velocity being sufficient to lift all but the higher density or larger particle material to the top of said column;
(b) feeding material having a predetermined nominal particle size, or material having larger and smaller particle sizes, into the top of said column to establish a descending feed stream therein;
(c) contacting said descending feed stream with said ascending liquid stream to disperse said material in said feed stream, lift the lower density or smaller particle material to the top of said column and allow the higher density or larger particle material to fall to the bottom of said column;
(d) discharging said liquid and said lower density or smaller particle material from the top of said column; and (e) discharging said higher density or larger parti-cle material from the bottom of said column.