RU2135612C1 - Method of cropping of lead-acid cells - Google Patents

Abstract

FIELD: cropping of lead-acid cells with expired service life into components and their preparation for further processing. SUBSTANCE: method includes separation from organic wastes in aqueous medium of light fraction which consists of polypropylene and wood; reduction into particles sizing 8 mm; washing them from lead slimes; drying in ascending air flow at velocity of 4-4.5 m/s at specific loading of not more than 4 t/h per sq.m of air flow section to separate propylene. EFFECT: reduced amount of dump waste products and polluting environment, and produced additional commercial product.

Description

 The invention relates to non-ferrous metallurgy, in particular, to preparing lead batteries that are outdated for metallurgical processing, which consists in cutting the batteries into components — antimony metal lead (gratings, contacts, jumpers), sulfate-oxide lead (electrode active mass) and organic matter (battery housings and insulator gaskets for separators).

 A known method of cutting battery scrap in heavy suspensions prepared from the slime portion of the sulfate-oxide fraction of battery scrap or in magnetite suspension (German patent N 1533129, class 40a, 7/00, 1973).

The disadvantages of this method:
equipment for the preparation, pumping and regulation of the density and flow rate of the suspension is necessary;
for high-quality separation of the light fraction from the heavy fraction, it is necessary to maintain the density of the suspension at the minimum acceptable value, since with an increase in its density, viscosity increases and the quality of separation deteriorates;
a heavy suspension in the absence of mixing quickly exfoliates, so even brief interruptions in operation are unacceptable.

 The closest in technical essence and the problem to be solved by the claimed solution is a method for preparing scrap of lead batteries (Gushchin K.A. Mechanized preparation of scrap of lead batteries for metallurgical processing. - Non-ferrous metals, 1990, N 12, pp. 41 - 43).

 The method includes scrap crushing, wet sieving of the crushed product into 3 fractions, withdrawal of the first fraction from the process (lead sulfate-oxide compounds) and parallel separation of the other two fractions into metallic lead and organics in an upward flow of circulating water. Lead-containing products are sent to smelting, and organic waste is dumped.

 Current environmental requirements dictate the need for low-waste technologies or the disposal of waste products.

 In world practice, it is known to utilize battery organic matter by burning to produce secondary heat. Neutralization of the resulting gases containing sulfur and chlorine compounds after dust removal devices is carried out with lime with the formation of waste sludge, the storage of which is also associated with problems, since they contain water-soluble compounds.

 Battery organic matter contains ebonite, polypropylene, polyvinyl chloride, bitumen mastic, wood, fabrics, etc. A valuable component is polypropylene, which can be reused.

 The battery industry is increasingly using this plastic instead of hard rubber for the manufacture of battery beams and its amount in scrap is constantly growing.

 The objective of the invention is to extract polypropylene from organic wastes and deeply clean the wood from inclusion, which makes it possible to use it for injection molding on standard equipment of various industrial products.

The problem is achieved in that in the known method of preparing battery scrap for metallurgical processing, including crushing raw materials, wet sieving of crushed product into fractions by size, separation of large fractions into metallic lead and organics containing polypropylene according to the invention from organics in an aqueous medium according to specific light fraction is selected by weight, consisting of polypropylene and wood, it is crushed to a particle size of 8 mm, washed from the remains of lead strains, dried and in ascending at a speed of 4 - Polypropylene is extracted from it at a flow rate of 4.5 m / s at a specific load of not more than 4 t / h per 1 m ^{2 of the} cross section of the air flow.

The separation of organic waste into light and heavy fractions is based on the fact that polypropylene and wood have a specific gravity below 1, and the remaining plastics (ebonite, polyvinyl chloride, etc.) are above 1. When the original organics is immersed in water, whose density is 1, polypropylene and wood floats to the surface of a water mirror, and the rest sinks. The floated light fraction is discharged and subjected to grinding to a particle size of less than 8 mm. With this size, due to the difference in the physical properties of polypropylene and wood, they are selectively crushed - the first is crushed in the form of crumbs, and the wood in the form of fibers. With larger grinding, part of the wood is also crushed in the form of chips and it is not possible to isolate it in subsequent operations. The dried product, after preliminary washing it with clean water from the residues of lead sludge, is subjected to separation in an upward flow of air at a speed of 4 - 4.5 m / s at a material loading speed of no higher than 4 t / h per 1 m ^{2 of the} flow cross section. Under these conditions, wood fibers are carried upward by the air flow, and polypropylene crumb, overcoming the air resistance, downward. With an increase in air velocity above 4.5 m / s, part of the polypropylene is taken out with the wood and its extraction from the concentrate is reduced. When the air velocity decreases below 4 m / s, part of the wood remains in polypropylene, polluting it. Polypropylene is contaminated with wood and at a loading speed of more than 4 t / h per 1 m ^{2 of the} cross section of the air flow.

 The method is as follows.

Scrap lead batteries are crushed, wet sifted material by size into fractions and separation of fractions into lead-containing products and organic waste containing polypropylene. A light fraction is separated from organic waste in water, crushed to a particle size of less than 8 mm, washed with water from the residues of lead sludge, dried and polypropylene is isolated in an upward flow of air at a speed of the last 4 - 4.5 m / s and a specific feed of no more than 4 t / h per 1 m ^{2 of} cross-section of air flow.

 Example. When cutting 4 tons of scrap scrap, 2.7 tons of lead-containing products and 840 kg of organic waste were obtained. Organics in water were divided into light and heavy fractions. The light yield was 15% with a polypropylene content of 79%, the rest was wood. The resulting light fraction was ground in a plastic knife chopper to a particle size of minus 8 mm, washed in water, dried and subjected to pneumatic separation in an upward air flow at the above parameters. As a result, 105 kg of polypropylene chips with a content of the main component of 99% were obtained. Various industrial products, which confirmed the possibility of using this secondary product, were cast under pressure from the obtained product using the well-known technology of plastic processing.

Claims (1)

A method for cutting scrap lead batteries, including grinding, wet sieving of material by size into fractions, separation of fractions into lead-containing products and organic waste containing polypropylene, characterized in that a light fraction is separated from organic waste in water by specific gravity, it is crushed to a particle size of less than 8 mm, washed with water from the residues of lead slurry, dried and recovered polypropylene in an upward air stream with a speed of 4-4.5 m / s and at a specific feed raw material is not more than 4 ton / hr per 1 m ² Poper cross section for air flow.