AU615013B2

AU615013B2 - Method for the stiffening and straightening of starting sheets

Info

Publication number: AU615013B2
Application number: AU26763/88A
Authority: AU
Inventors: Matti Olavi Leiponen
Original assignee: Outokumpu Oyj
Current assignee: Outokumpu Oyj
Priority date: 1987-12-17
Filing date: 1988-12-09
Publication date: 1991-09-19
Anticipated expiration: 2008-12-09
Also published as: AU2676388A; BE1001703A3; FI79723C; FI79723B; FI875582A; DE3842510A1; FI875582A0

Description

4,4 AUSTRALIA 615 3 PATENTS ACT 1952 Form COMILETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: OUTOKUMPU OY Address of Applicant: TOOLONKATU 4 00100 HELSINKI

FINLAND

Actual Inventor: Address for Service: GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Complete Specification for the invention entitled: METHOD FOR THE STIFFENING AND STRAIGHTENING OF STARTING SHEETS The following statement is a full description of this invention including the best method of performing it known to me:t II~ ~-n~e 2 METHOD FOR THE STIFFENING AND STRAIGHTENING OF STARTING SHEETS 4r 4 44 44 0a 00 4 4 4 4 4a 4 '0 4 Field of the Invention The present invention relates to a method for the stiffening and straightening of starting sheets, simultaneously in groups of several pieces, prior to the automatic batching of the starting sheets into electrolytic tanks.

Lascription of the Prior Art The electrolytic refining of copper, for instance, is carried out so that the impure raw copper is cast into anodes about 40 mm thick, which in the electrolytic tank are dissolved in the electrolyte, and the pure copper is deposited onto t',e starting sheets located in between the anodes. The starting sheets are thin plates with a thickness of 0.4-1.2 mm. The straighter the starting sheets are when placed into the electrolytic cell, the nearer to each other the electrodes can be arranged, and the nearer to each other the electrodes are arranged, the higher the capacity of the electrolytic cell grows.

In making electrolysis more effective, the most important points are the increasing of the productivity of work and the elemination of such factors that cause decreases in the electrolysing current efficiency and in the production. Experience has shown that the best results are achieved when the tankside work in the electrolysis hall is automated and the progress of the electrolytic process is ensured by means of electrodes which are homogenecus in quality and are arranged exactly equia.stantly in the tanks.

The patent publication US 4,413,495 discloses a method and apparatus for the stiffening and straightening of starting sheets while the starting sheets are suspended from their lugs, in which case the starting rheet can be C C t r i "7

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3straightened with respect to its lugs. By the aid of a press, the starting sheet is provided with embossed patterns with a height of 2.5 mm at the most with respect to the plane of the starting sheet. The use of this press helps to fulfil the requirements for planar flatness (+7-10 mm) in the automated electrolysis, bat as a device pressing single, separate starting sheets it is too slow to function as a step in the process of automated batching.

The patent publication US 3,544,431 depicts a method for treating starting sheets. According to this method, the starting sheets stripped from the mother plate 0 0a a are first straightened by rolling, whereafter they are 0 0 0 Q 0a 0 provided with lugs and placed in the electrolytic tank 1 0 15 suspended by their suspension rods. The starting sheets are allowed to accumulate to the thickness of 2.2-2.5 mm, whereafter they are removed from the tank. The hot electrolytic solution has "heat -treated" the starting sheets, which thereafter are -,old-worked in a multiple press. The process as a whole requires a lot of labour, because at the first stage the starting sheets are rolled 0and at the second stage pressed, so that separate equipment is used at each stage. In fact the first-stage roiling of the starting sheets does not straighten the sheets at all, because the sheets are in any case distorted at the subsequent working stages (the fastening of lugs and suspension rods). Practice has shown that the planar flatness of the sheets straightened by rolling is roughly ±30 mm.

The Finnish patent application 870,285 (which is equivalent to US patent 4,894,129) relates to a method and apparatus for aligning sheet-like objects, particularly for aligning electrodeg in an electrolysis tank. In this case the batching can be carried out automatically by providing the batching cranes wi 0 th the described automatic z -4gripping member. The contents of that application are incorporated herein by reference.

Summary of the Invention The object of the present invention relates to starting sheets provided with lugs and suspension rods being straightened in groups of several sheets at least prior to their batching in the electrolytic tank, in which case the starting sheets fulfil the standards of flatness required by the automated batching, and the straightening 10 takes place at a speed determined by the automation, 0, Therefore, the invention provides a method for a straightening and stiffening starting sheets for use in operation of an electrolysis tank comprising the steps of: arranging several of said starting sheets, each of which is provided with lugs and supporting rods, in a group; introducing the said group of starting sheets into a press; straightening and stiffening the group by operation of the press such that each starting sheet in the group has planar flatness to within a tolc-rance in the range 7-10 mm; and transferring the straightening and stiffened group of starting sheets to the electrolysis tank by means of an automatic aligning device attached to batching cranes.

Most preferably straightening is achieved when the starting sheets provided with lugs and suspension rods are straightened in groups which fill the whole tank prior to their batching in the tank. The straightening may also be applied for half a tankful or for a third of a tankful at a time. Thus the whole automation of the tankside work can be realized at minimum cost.

.4 Description of the Preferred Embodiment The preferred embodiment of the invention comprises a press with a press pattern suited both for the initial straightening and for the straightening of accumulated plates, and the press can be moved from one place to another. Thus the same press can be used both in the production linc uf the starting sheets for stiifening and straightening the fresh starting sheets, to be placed in the tank, right by the production post, and for 0 straightening plates which have been accumulated for 24-48% h in the hall, next to the group of tanks under o0 treatment. Naturally in many cases straightening prior to o the placing of the sheet in the tank is sufficient, and 0O further treatment becomes unnecessary. If the accumulated I1 plates are wished to be straightened, a crane can be used for moving the pruss.

The method of straightening according to the present invention, combined with an automatic gripping S member to be provided in the batching cranes, allows for a 20 gradual modernization of old electrolytic processes. The improvements by the tankside and by the production post can be realized alm..-t independently of each other.

The starting sheets are thin, 0.4-1.2 mm, and because they are of copper they are soft and can easily bend. If these kind of starting sheets are straightened to be horizontally level and are to be provided with lugs after straightening, they will bend when raised to a vertical position for fitting of the lugs, and their planar flatness will not within +7-10 mm. If straightening occurs after the lugs have been fitted and the sheets are in a vertical position, they will not bend before immersion in the electrolytic tank and their planar flatness remains within a tolerance in the range +7-10 mm.

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Claims

6- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: i. A method for straightening and stiffening starting sheets for use in operation of an electrolysis tank comprising the steps of: arranging several of said starting sheets, each of which is provided with lugs and supporting rods, in a group; introducing the said group of starting sheets into a press; ~a at straigltening and stiffening the group by oo" operation of the press such that each starting sheet in o a 0o1 the group has planar flatness to within a tolerance in the o range 7-10 mm; and transferring the straightening and stiffened a, group of starting sheets to the electrolysis tank by means of an automatic aligning device attached to batching cranes. 2. The method of claim 1, wherein a group of starting sheets forming a whole tankful is straightened simultaneously prior tc placing in the electrolytic tank. 3. The method of claim i, wherein a group of starting sheets forming half a tankful is straightened simultaneously prior to placing in the electrolytic tank. 4. The method of claim i, wherein a group of starting sheets forming a third of a tankful is straightened simultaneously prior to placing in the electrolytic tank. The method claim i, wherein the press for pressing a group of zLarting sheets is physically movable. 6. The method of either one of claims 1 or wherein the straightening and stiffening is repeated with the same press after the starting sheets have spent 24-48 hours undergoing electrolysis in the electrolysis tank. i ;d i~~~enr;-rr~--rr~-glrr=EYFnrr~L 7
7. The method of claim 1, wherein by means of the press, there are embossed patterns in each starting sheet in a group, the height of these patterns from the surface plane of the starting sheet being at most 2.5 mm. DATED THIS 23RD DAY OF MAY, 1991 OUTOKUMPU OY By Its Patent Attorneys 00 00 oo e o 0 o 4 000 oo o a o a o o e0 0 I t GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia *P 0 0 00