AU680043B2 - Intertank screen - Google Patents

Description

AUSTRALIA

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44(511 Applicant POLYSCREEN PTY LTD A.C.N. 008 521 702 Invention Title: INTERTANK SCREEN The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 INTERTANK SCREEN This invention relates to an intertank screen for mineral recovery such as in a gold recovery installation.

In the recovery of gold, gold is leached in a cyanide solution and carbon is added to the solution. The gold in the solution adheres to the carbon. In order to recover the gold the carbon is screened through an intertank screen to separate the carbon and gold out of the solution. The gold is then separated from the carbon to recover the gold.

Usually, a number of intertank screens are located a "suitable tank. The solution passes through an intertank screen which is generally in the form of a cylinder. The intertank screen has a stainless steel frame and the screen Ii element is typically formed from wedge wire construction.

Cr t After an intertank screen has been in operation for some time, blinding or pegging occurs in the lower portion of the screen. Blinding is formed by a build up of materials I C S.such as calcium carbonate and generally blocks the screen thereby necessitating removal and replacement of the intertank screen. Intertank screens are an expensive item *and the need to replace the entire screen when blirdig occurs adds considerable expense to the gold separation process.

The object of the present invention is to provide an intertank screen which overcomes this problem.

The invention provides an intertank screen for a mineral recovery installation including: a screen Yody forming an enclosure through which solution can pass and for trapping mineral; the screen body being formed from a plurality of sections which are separable from one another and which are staffidalkeeptspec/75856.94 26.3.97

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-3releasably coupled together so that when blinding or pegging occurs, only the screen section in which the blinding or pegging has occurred need be removed and replaced; and wherein the screen body is cylindrical in configuration and comprises at least three cylindrical sections, the three sections being joined together by rims which are each of I cross-section providing a pair of grooves into which ends of the screen sections locate to join the sections together.

Since the intertank screen is formed from a plurality of sections, it is only necessary to remove the section in which blinding or pegging occurs and replace that section.

Therefore the entire intertank screen need not be replaced thereby decreasing the cost of replacement in the event of blinding or pegging.

t€e Preferably the intertank screen has a top rim and a bottom rim, at least one tie rod extending from the bottom rim to the top rim of the intertank screen to secure the sections together.

t Preferably each screen section is formed from polyurethane.

Preferably the polyurethane sections comprise a panel having ends for location in the grooves of the rims, the panels having side edges which are brought adjacent one 25 another to form the panel into a cylindrical shape, the side edges of the panel being secured by a sealing strip.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a view, partly broken away, of an intertank screen according to the preferred embodiment of i ~the invention; staflida/keepspecd75856.94 26.3.97 aI I: u 4 4 Figure 2 is a view along the line II-II of Figure 1; and Figure 3 is a view along the line III-III of Figure 1.

With reference to the drawings an intertank screen 10 is shown which comprises a screen body 12 of cylindrical configuration. The screen body 12 is formed from three sections 12a, 12b and 12c which are separate from one another and releasably coupled together to form the screen body 12. Each screen section 12a to 12c is formed from a polyurethane panel having apertures of a desired gauge so that solution can pass through the screen whilst gold and carbon is trapped by the screen. The panels 12a to 12c have free ends 14 and side edges 16.

Vtt 15 The panels are formed into a cylindrical shape by bringing the side edges 16 of the panel together and are joined by a cOCS sealing strip 18 which is of I cross-section and has cc grooves la for receiving the edges 16.

A bottom rim 20 of ring shape is provided with a recess 22 20 for receiving one end 14 of the section 12c. Two intermediate rims 28 are provided for securing the sections 12a, 12b and 12c together. The rims 28 are of I crosssection and have grooves 26. The other end 14 of the panel 12c locates in a groove 26 of a reinforcing rim 28. One free end 14 of the section 12b is received in the other groove recess 26 of that rim 28 and the other end 14 of the section 12b is received in a groove 26 of the next rim 28.

One end 14 of the section 12a is received in the other groove 26 of that rim 28 to thereby locate the sections 12a, 12b and 12c together. The other end of the section 12a is received in a top rim 38 which is identical to the i bottom rim 20. The top rim 38 may include lugs or the like to enable the intertank screen 10 to be lifted.

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The bottom rim 20 is provided with apertures 30 for receiving the ends of tie rods 32. The recess 30 has a larger diameter section 34 and the tie rods 32 have screw threaded ends for receiving a nut 36 which locates in the larger diameter portion 34 of the aperture 30 to secure the tie rod to the rim 30. The other end of the tie rod (not shown) is secured in a similar fashion to the top rim 38 to thereby tie the sections 12a, 12b and 12c together.

The rims 20, 28 and 38 are preferably steel reinforced polyurethane rims. As shown in Figure 3 the rims 20 and 38 have a steel member 40 embedded in a polyurethane body 42 "to form the rim.

During operation of the gold recovery i'astallation, should blinding or pegging occur in one of the sections 12a, 12b and 12c, it is only necessary to undo the nuts 36 so that the tie rods 32 can be released to thereby enable separation of the sections 12a, 12b and 12c. The section which is subject to blinding or pegging can then be removed and replaced by a new section thereby avoiding the need to replace the entire intertank screen.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodinent described by way of example hereinabove.

Claims (3)

1. An intertank screen for a mineral recovery installation including: a screen body forming an enclosure through which solution can pass and for trapping mineral; the screen body being formed from a plurality of sections which are separable from one another and which are releasably coupled together so that when blinding or pegging occurs, only the screen section in which the blinding or pegging has occurred need be removed and replaced; and wherein the screen body is cylindrical in i configuration and comprises at least three cylindrical sections, the three sections being joined together by rims S. 15 which are each of I cross-section providing a pair of grooves into which ends of the screen sections locate to I join the sections together.

2. The screen of claim 1, wherein the intertank S.C l c screen has a top rim and a bottom rim, at least one tie rod *i 20 extending from the bottom rim to the top rim of the intertank screen to secure the sections together.

53. The screen of claim 1 or 2, wherein each screen section is formed from polyurethane. 4. The screen of any one of claim 3, wherein the polyurethane sections comprise a panel having ends for location in the grooves of the rims, the panels having side edges which are brought adjacent one another to form the panel into a cylindrical shape, the side edges of the panel being secured by a sealing strip. staftfida/keepspec/75856.94 26.3.97 -U -7- An intertank screen for a mineral recovery installation, substantially as hereinbefore described with reference to the accompanying drawings. Dated this 246th day of March 1997 POLYSCREEN PTY. LIMITED By Its Patent Attorneys: GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia. V C C C C C t I r C C C C C .0 '1 V.C stafflida/keep/spec/75856.94 26.3.97 1 -1 I~113ill rrllC I II ABSTRACT An intertank screen for a gold recovery installation is disclosed which has a screen body (12) formed from three sections (12a, 12b and 12c). The sections (12a to 12c) are separable from one another and are releasably coupled by rims (28) which have grooves (26) for receiving the sections. If blinding occurs in one of the sections, that section can be removed and replaced by a fresh section to avoid the need to replace the entire screen. *o cc 9 rt e f. ©c i Cc ©CC t', C s t- t I" t <e t