AU606153B2

AU606153B2 - Process for gallium recovery

Info

Publication number: AU606153B2
Application number: AU15615/88A
Authority: AU
Inventors: Richard Fitoussi; Jean-Louis Sabot
Original assignee: Rhone Poulenc Chimie SA
Current assignee: Rhodia Pinjarra Pty Ltd
Priority date: 1987-05-06
Filing date: 1988-05-05
Publication date: 1991-01-31
Anticipated expiration: 2008-05-05
Also published as: ES2043864T3; IE872332L; EP0290318B1; KR880014123A; NO881951D0; IN170892B; NO881951L; KR930003637B1; JPS6465023A; DE3877813D1; JPH0463811B2; ATE85035T1; IE59640B1; BR8802170A; PT87418B; FR2614887A1; FR2614887B1; CN88102672A; CA1334891C; AU1561588A

Abstract

The process consists in extracting, in a liquid-liquid extractor 1, the gallium present in a basic solution of sodium aluminate (Bayer liquor) by means of an extractant known under the tradename of Kelex, dissolved in an organic solvent. The organic phase containing the gallium is subjected to a first liquid-liquid extraction 2 by means of an acidic solution to remove, to at least a large extent, aluminium and sodium and then to a second liquid-liquid extraction 3 by means of another acidic solution to recover gallium. This acidic gallium solution is purified by extraction of gallium with an extractant at 4. After the extraction of gallium the acidic solution is recycled to the extractor 2 to reduce the usage of acid in the process. <IMAGE>

Description

I I I I I I I I I I i

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LAA/V\\I 11ZQuOI UINYy IAl I lfl 'J-.JC V .U V L 111111.4 111111.6 :L -4 4 COMMONWEALTH OF AUSTRALIA FORM PATENTS ACT 1952 C. n M P T, T E S P E C I FFRA~Al TOZO4 1 C 0 M P L E T E FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: a Br'i.ority: S-e;lated Art: 4 10l 04f This document contains the amendments made under Section 49 and is correct for rinting_ 000444 4 0 Name of Applicant: o 46 0

A

0 tlUress of Applicant: 0 4a Actual Inventor: :,Actual Inventor: 4 1 t RHONE-POULENC CHIMIE 25, quai Paul Doumer, 92408, Courbevoie, France Jean-Louis Sabot and Richard Fitoussi Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney I I Complete Specification for the Invention entitled: "PROCESS FOR GALLIUM RECOVERY" The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1 LODGED AT SUB-OFFICE 5 MAYQRR Sydney

II

-la- PROCESS FOR GALLIUM RECOVERY I This invention concerns a process for recovering gallium by liquid-liquid extraction, using very basic aqueous solutions containing gallium, such for example, as the Sodium aluminate lyes of the BAYER process for the manufacture of alumina.

Following the french patent applications N6 2 277 897, 2 307 047, 2 307 882, 2 495 601, 2 532 295, 2 532 296, a process is known for recovering gallium present in alkaline aqueous solutions by liquid-liquid extraction using an organic phase containing an extractant and an organic solvent and a process for purifying the gallium solution which in particular allows the elimination of certain other cations, such, for example as the alaminium and sodium cations jointly extracted with the gallium from the aluminate lyes mentioned previously.

This process consists of causing the gallium in the strongly basic solution to pass into the organic extraction phase by a process of liquid-liquid extraction.. At a second stage, this organic phase is treatedwith a first acid solution so as to selectively extract at least a part of the alfminium and sodium cations jointly extracted with the gallium. This stage allows the organic phase to be impoverished of cations other than the gallium and therefore to reduce the content of impurities of the acid gallium solution obtained at the third stage. This third stage is an extraction or recovery of the gallium from the organic phase by treating it with a second acid solution.

The acid gallium solution obtained in this way also contains other metallic ions, for example, aluminium and sodium ions not extracted at the time the organic phase was treated with the first acid solution.

S0 In order to eliminate these metallic ions, numerous processes have been suggested, in particular, as examples; the processes described in french patents No. 2495 599, 2 495 600 and S2 495 601 of the applicants.

These processes consist either in treating the gallium solution by passing it over a resin which is an exchanger of ions of the strongly basic type, or in extracting the gallium by o~ 7 4. The basic Applications) referred to in paragraph 2 of this Declaration wasf/~em the first Application(b) made in a Convention country in respect of the invention, tho subject of the Application.

DECLAED atCOjRBE.VOIE D EC LA R E D at this dOcavlp 19 88 2 liquid-liquid extraction, the extracting agents could, for example be quaternary ammonium salts or alcohols.

The solution of gallium obtained can then undergo further stages of purification.

The final solution of gallium is then treated by various processes to produce a gallium metal of very high purity or gallium alloys with other compounds.

The process which is described above allows a gallium solution to be obtained having a very high purity with very good extraction and recovery yields. However, the second stage of the process, i.e. the treatment of the organic phase with an acid solution requires the use of a large quantity of acid solution which is discarded as an effluent after use, as well as the acid solution recovered after the selective extraction of the gallium. This quantity of liquid effluent is an inconvenience as it requires processing before it is discarded and thereby increases the cost of the process.

This invention has an objective to avoid these disadvantages by offering a process which, on the one hand will reduce the amount of acid used and on the other hand will notably reduce the quantity of effluent which is discarded. In this way the invention will considerably improve the economic value of the process.

According to the invention, there is provided a process for recovering gallium from a very basic aqueous solution by liquid-liquid extraction using an organic phase comprising an organic extractant and an organic solvent, said process comprising the steps of: extracting the gallium from the very basic solution with the organic phase, (ii) washing the gallium containing organic phase with a first acid solution, (iii) extracting the gallium from the gallium containing organic phase by washing with a second acid solution, (iv) adjusting the halide ion concentration, if any, of the gallium containing acid solution obtained from step (iii), 1(4 C 4.

4I

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L u i i L~ T FF -C-TA PATIEN, 0- 1 VI:GE Am M 0 a~ 3 selectively extracting the gallium from the gallium containing acid solution, and (vi) recovering the gallium extracted by this method, characterised in that the first acid solution used in step (ii) comprises at least a part of the acid solution recovered at step after the selective extraction of the gallium.

The various stages to (vi) have already been described in numerous patents and particularly in the French patent applications No. 2 277 897, 2 307 047, 2 307 882, 2 495 601, 2 532 295, 2 532 296, the texts of which are an integral part of this application.

The organic phase used in step includes an extracting agent. Preferably the organic extractant is a substituted hydroxyquinoline compound having the following formula: a j 0 00 o o o 0 9 0 0 0 0 o aoo 00 0 0 0 S0k00 0 0 o 0a o 0 0 D 0 00 0 0 0 D 0 a 0 wherein for example, R 1

R

2

R

3

R

4

R

5 and R 6 are the same or different, and each represents hydrogen, halogen, an alkyl, alkenyl, alicyclic or aryl radical, with the proviso that R 1

R

2

R

3

R

4

R

5 and

R

6 cannot simultaneously be hydrogen, for example 7 -(5,5,7,7-tetramethyl-l-octene-3-yl)-8-hydroxyquinoline.

Among such substituted hydroxyquinolines, especially preferred for the purposes of the invention are the a-alkenylhydroxy-8-quinolines, the P-alkenylhydroxy-8quinolines and the alkylhydroxy-8-quinolines. The hydroxyquinolines marketed under the name of Kelex 100 by the Schering Company or LIX26 by the Henkel Company are examples of suitable extractants.

The amount of the substituted hydroxyquinoline in the organic phase is not critical and may vary over wide limits. However, desirably the amount ranges from 1 to *1 ~'ccl

I

ii ft i 14 irr 4 by volume with respect to the organic phase and is preferrably about The organic solvent employed in the invention may be any diluent conventionally used in liquid/liquid extraction or a mixture thereof. However, the aliphatic hydrocarbons for example, heptane and the petroleum cuts of kerosene type; the aromatic hydrocarbons, such as, for example, benzene, toluene, xylene and cuts of the SOLVESSO type (registered trademark of EXXON Corp.) and, halogenated derivatives of compounds, such as, for example, chloroform, carbon tetrachloride, dichloroethane and trichloropropane are preferred.

There may also be used as an organic phase those described in the following French patents No. 2 277 897, 2 307 047, 2 307 882, 2 532 295, 2 532 296; the Japanese patent applications No. 60 042 234, 59 186 683, 59 500 24; and the European patent application No. 199905. In a general manner, the invention can be put into operation with any organic phase which allows the extraction of gallium in accordance with a process which includes the stages to (vi) as mentioned above.

In short, the organic phase includes the extracting agent, a solvent such as kerosene, one or several compounds with alcohol functions such as heavy alcohols or heavy phenols as well as various other solvating compounds such as certain phophoric esters. It is also useful to add compounds which will increase the speed of extraction of the gallium such as compounds containing at 3east one caboxylic acid function, organophosphuretted compounds or sulphates or substituted sulphonates.

There may also be used as an organic phase a polymer charged with a hydroxyquinoline substitute such as that described in the Japanese application No. 6042234, the stages (ii) and (iii) of the process then become elution operations of a charged polymer.

Japanese application No. 59186683 describes the use of a substituted hydroxyquinoline mixture, i.e. a mixture 1 j fk: 4a of 7-alkyl-8-hydroxyquinoline and tetramethyll-octene-3-yl) 8-hydroxyquinoline.

According to the invention, the first acid solution used in step (ii) is a dilute aqueous solution of an acid such as for example, sulfuric acid, nitric acid, perchloric acid or phosphoric acid having an acid concentration preferably in the range of from about 0.2 M to about 0.7 M.

The second acid solution used in step (iii) to recover gallium is a strongly concentrated aqueous solution of an acid such as for example nitric acid, perchloric acid or sulfuric acid having an acid concentration preferably higher then 1.2 M and preferably in the ranges of from about 1.2 to about 2.2 M when a solution of hydrochloric or hydrobromic acid is employed.

The washing of the organic solution containing the gallium (stage ii) is carried out by a counter-current process of liquid-liquid extraction with a first acid solution having a H ion concentration and a supply flow such that the concentration of H+ ions in the acid solution in contact with the organic solution which enters extraction stage (ii) counter-current, is approximately less than 1, preferably between 0.1 and 1 and can advantageously be between 0.2 and 0.7 approximately.

However, when halide ions such as for example chloride ions are present, the concentration of H+ ions can be selected higher than 1 N on the condition that the concentration of chloride ions is at least 4 M.

The concentration of chloride ions can be between 4 and 12 M, usefully between 4 and 6 M, the concentration of SH ions can usefully be between 4 and 6 N.

In stage (iii), the extraction of the gallium from the organic phase, using a second acid solution, the extraction is also done by liquid-liquid extraction, counter current. As in stage (ii) above, the flow and the J concentration of H+ ions of the second acid solution is determined so as to have an established concentration of *i 4 4b H ions in the acid solution in contact with the organic solution entering stage (iii).

This concentration of H ions must be greater than N, preferably approximately between 1.5 and 6 N and can usefully be between 3.5 and 4.5 N approximately.

However, if the acid solution contains halide ions such as for example chloride ions, the concentration of chloride ions must be less that about 2.5 M.

In stage v, the selective extraction of the gallium from the acid solution can be carried out in a number of numerous ways already described in patents and publications.

For example, the liquid-liquid extraction processes using an extracting agent one or several solvating agents, such for example as ethers, ketones, alcohols, esters or organophosphuretted compounds or anionic extraction agents such, for example as amines or quaternary ammonium salts.

I It is also possible to selectively extract the gallium by passing the acid gallium solution over a resin which is an ion exchanger. The resins which are suitable are those of the basic type able to retain the gallium, 4certainly in the form of an anionic complex GaX 4

X

representing a halogen, preferably chloride or bromide and chloride being preferred.

As an example we quote the resins described in the French patent No. 2 495 601 which have the following type of formulae: LN 2 t

CH

3 R-N-HCH j 0- X )CIC~ TWIL g- L 5 in which R represents, for example, a divinylbenzenestyrene or divinylbenzene-acrylic copolymer. For example the products marketed under the name: Dowex 1, Dowex 2, Dowex 3, Duolite A 101 D, Duolite A 42, Lewatit M 500, Amberlite IRA 400, Amberlite IRA 900, Amberlite IRA 910, Duolite A 14, Amberlite IR 45 are suitable for use.

The invention allows the reduction, even the elimination of the acid at stage The major part at least, of the washing solution of the organic phase being composed of the acid solution recovered during stage This reduction of the total consumption of acid allows an improvement in the viability of the process and considerably reduces the amount of liquid effluent which is discarded.

The recycling of the acid solution a stage (ii) does

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^W/

L 6 not affect the extraction yield, notably of aluminium and sodium cations during this stage.

In accordance w'ith another characteristic of the invention, regulation of the concentration of halide ions in stage (iv) is carried out by adding a metallic halide in the form of a solid, either in a concentrated solution, or hydrochloric acid in a gaseous form or as a concentrated solution.

An advantage, in particular when the concentration of chloride is adjusted by adding a metallic halide, is that the acid solution recovered after the selective extraction of the gallium (stage v) is recycled in its entirety at stage the washing Sof the organic phase.

In this variation, the discard of liquid effluent is limited to a minimum and only takes place at stage (ii).

i At stage the concentration of halide ions is adju'sted to a value between 3.5 and 8 M approximately.

This adjustment is done in the usual w, either by adding a halogenated acid in a gaseous form or a a concentrated Ssolution, or by adding metallic halides. The halides of alkaline 2U tt metals or alkaline-earth metals are an advantage.

Among the preferred halide ions of the invention are the chloride and bromide ions, the chloride ion being the most preferred.

For preference, as metallic halides sodium chloride is chosen, in particular when the strongly basic solution containing the gallium is a solution of sodium aluminate from the BAYER process for preparing aluminium, In accordance with another characteristic of the invention, the concentration of H+ ions and Cl and the flow of recycled acid solution recovered at stage are controlled and adjusted if necessary to maintain the level of H+ ions and Clin stage (ii) previously described.

The advantages, objectives and characteristics of the invention will become more evident from the drawings and the examples which follow and which are given only as indications of the invention.

The single drawinq represen-sa synoptic plan of the process in accordance with the invention.

i I s 7 Example 1 Through the supply pipe 6, of a counter-current liquidliquid extraction battery 1 is fed 1.000 1 of an organic phase with the following ponderal composition Kelex 100 8 n-decanol 10 Versatic acid 5 Kerosene 77 1.000 1 of a decomposed solution of sodium aluminate 1Q resulting from a Bayer process of manufacture of aluminium is also Sfed into the battery. This solution contains the following 3 82 g/l 166 g/1 Ga 240 mg/l c The decomposed solution, after mixing with the organic ''place and separation from it is removed through pipe I1, for example to be recycled in the BAYER process. After being treated o o this solution has the following composition °o A1 2 0 3 80 g/l Na 2 0 156 g/l SGa 80 mg/l °oo The concentrations of gallium, alumina and sodium oxide in the organic phase are the following SA1 2 0 3 2 g/l Na 2 0 10 g/l Ga 160 mg/l This organic phase is then fed into a counter-current liquid-liquid extractor 2 through supply pipe 6a.

The organic phase is washed in an acid solution supplied through pipe 16 and comes from stage operating in extractor 4.

Into this extractor 2, 1 000 1 of the organic phase mentioned previously is placed in contact with 60 1 of the acid solution from extractor 4 and also 40 1 of water.

This acid solution has a concentration of H 2

SO

4 of 2 moles/litre and of 4 moles/litre of HC1 After agitating and separating the phases, the organic phase recovered through pipe 6 contains 8 Ga 160 mg/i A1 2 0 3 0.05 g/l Na 2 0 0.1 g/l The acid solution evacuated through pipe 12 contains Ga 10 mg/l A1 2 03 13.9 g/l Na 2 0 70.7 g/l rH "0.46

N

fC~i~ 2.9 M I0 The organic phase collected at the exit of extractor 2 o is fed through pipe bb into an extractor 3 where it is mixed with 000 0 100 lof an acid solution supplied through pipe 7 and having a 0 0concentration in H 2

SO

4 of 4 moles/i.

After agitation and separation of the phases, the 00 oorganic phase is evacuated through pipe 6c towards an liquidliquid extraction battery 5 where it will be washed several times in water after being recycled in extractor 1 through pipe 6 after a possible addition of fresh organic solvent through pipe 6d.

o°°04°o The acid solution recovered contains Ga 1.6 g/l o p 0 A1 2 03 0.5 g/l o o° Na 2 0 1 g/l 0 0 4a 00 4f 4 N This solution also contains numerous other metallic 0 is cations, the concentration of which is from 10 to 200 mg/l.

Before extracting the gallium from this solution in extractor 4, the concentration of chloride ions of this solution is adjusted by adding hydrochloric acid through pipe 8 to a value of 4 M.

This solution is fed through pipe 15 at a flow of li/h into columns containing 0.6 1 of Duolite resin A 101 of the quaternary ammonium type.

The acid solution recovered through pipe 16 contains Ga 10 mg/l

H

2

SO

4 2 moles/l HCI 2 moles/i A1 2 0 3 0.5 g/l 9 Na 2 0 0.1 g/l of this acid solution is recycled through pipe 16 into the extractor 2, thus making up the washing solution for the organic phase.

In this way the major part of the acid supplied in the process of the invention is firstly used to extract the gallium from the organic phase (extractor 3) then to wash the organic phase by extraction in particular of the aluminium and sodium in extractor 2 before being evacuated as an effluent through pipe 12.

This dual utilisation of the acid solution represents a considerable economy in the cost of the process, both in so far as the consumption of of the acid reagents is concerned as in the treatment of the effluent.

The gallium retained on the resin of extractor 4 is recovered by elution of the resin with water (1 1/h) supplied through pipe 13 and recovered through pipe 14.

The solution obtained contains Ga 52 g/l A1 2 0 3 5 mg/l Na 2 0O 20 mg/l Fe 100 mg/l other metallic cations representing a few mg/l.

This concentrated gallium solution can then be purified several times using the usual known methods, such for example as liquid-liquid extraction or treating it over resin.

These purifying processes are inexpensive as the volume of solution to be treated is low due to the high concentration of gallium.

Example 2 This example is identical to example 1 with the exception that the acid solution arriving through pipe 7 from extractor 3 430contains 5 moles/l of sulphuric acid.

The solution recovered at the exit of extractor 3 contains Ga 1.5 g/l A1 2 0 3 0.8 g/l Na 2 0 1.5 g/l I c I; Ii

H

2

SO

4 2.5 moles/1 The chloride content of this solution is adjusted to a value of 4 M of Cl- by adding a solution of sodium chloride.

The new solution contains Ga 1.33 g/l A1 2 0 3 0.67 g/1 1.2 g/l

H

2

SO

4 2.1 moles/l NaC1 4 M This solution is supplied to the ion exchanging resin columns in exactly the same way as in example 1.

The acid solution recovered at the exit from the columns contains Ga 10 mg/1 H2SO4 2.1 moles/1 NaCl 4 M A12 0 3 0.8 g/1 0.15 g/1 This solution is entirely recycled at stage (ii) in 2Qo,*, extractor 2 to wash the organic phase and extract from it, at least partially,the aluminium and the sodium.

The acid solution recovered through pipe 12 contains: Ga 10 mg/l A1 2 0 3 16 g/l 83 g/l

[H+

1 0.3 N [C13 3.8 M The solution of gallium recovered after elution of the resin contains Ga 50 g/l A1 2 0 3 5 mg/l 15 mg/l Fe 150 mg/l other metallic cations representing a few mg/l.

Example 3 This example differs from example 1 and 2 in that the acid solution supplied in extractor 3 has a concentration of 1.8 N of hydrochloric acid.

A 11 The aqueous phase recovered at the outlet of extractor 3 contains Ga 0.64 g/l A1 2 0 3 0.2 g/l Na 2 0 3 0.4 g/1 HC1 1.8 N Fe 0.1 g/1 The gallium is extracted from this solution by liquidliquid extraction using as extracting agent a quaternary ammonium salt marketed by the HENKEL Company under the name of Aliquat 336, in solution in a a solvent marketed under the name of Solvesso 150, with a concentration of 0.1 M.

This extraction is carried out in a liquid-liquid extraction battery connected in series.

The acid solution of gallium is fed into an intermediate extractor simultaneously with a solution of hydrochloric acid at 12 N. The extracting solvent is washed at the exit of the battery with a hydrochoric acid solution at 6N.

The gallium is re-extracted from the extracting solvent by washing in water.

The aqueous solution leaving the extraction battery has a concentration of hydrochloric acid of 6 N.

of this solution is recycled at stage (ii) through pipe 16 to wash the organic phase.

The acid solution recovered through pipe 12 contains Ga 10 mg/l A1 2 0 3 8 g/1 40 g/l 5.1 N [Cl- 5.9 M Thus, as in examples 1 and 2, the acid solution used I to extract the gallium from the organic phase (stage (iii) is also used to wash this organic phase to extract from it the aluminium and the sodium.

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Claims

1. A process for recovering gallium from a very basic aqueous solution by liquid-liquid extraction using an organic phase comprising an organic extractant and an organic solvent said process comprising the steps of: extracting the gallium from the very basic solution with the organic phase, (ii) washing the gallium containing organic phase with a first acid solution, (iii) extracting the gallium from the gallium containing organic phase by washing with a second acid solution, (iv) adjusting the halide ion concentration if any, of the gallium containing acid solution obtained from step (iii), selectively extracting the gallium from the gallium containing acid solution, and (vi) recovering the gallium extracted by this method, characterised in that the first acid solution used in step (ii) comprises at least a part of the acid solution recovered at step after the selective extraction of the gallium.

2. A process in accordance with claim i, characterised in that the first acid solution consists of the acid solution recovered at stage

3. A process in accordance with claim 1 or 2, characterised in that the concentration of halide ions in step (iv) is adjusted to a value between 3.5 and 8 M.

4. A process in accordance with any one of the preceding claims, characterised in that the adjustment of the concentration of halide ions of step (iv) is carried out I by adding gaseous hydrochloric acid or hydrochloric acid in solution, or a metallic halide either in a pure form or in a solution. A process in accordance with claim 4, characterised in that the metallic halide is selected from the group comprising alkaline chlorides and alkaline-earth chlorides. a

6. A process in accordance with claim 5 characterised in ,ioI A; l-"lir.r -rrr*iii~~.- .x~ 13 that the alkaline chloride is sodium chloride.

7. A process in accordance with any one of the preceding claims characterised in that the gallium containing acid solution from step (iii) has a H ion concentration of greater than 1.5 N, a halide ion concentration less than or equal to 2.5 N and in that the first acid solution in step (ii) has a H ion concentration of less than 1 N.

8. A process in accordance with claim 7 characterized in that the gallium containing acid solution of step (iii) has a H ion concentration of between 1.5 and 6 N.

9. A process in accordance with any one of the claims 1 to 6 characterised in that the gallium containing acid solution from step (iii) has a H ion concentration of greater than 1.5 N and a halide ion concentration of less then or equal to 2.5 N and in that the first acid solution of step (ii) has a H ion concentration greater than 1 N and a halide ion concentration of at least 4 M. A process in accordance with claim 9 characterised in that the gallium containing acid solution from step (iii) has a H ion concentration of between 1.5 and 6 N.

11. A process in accordance with claim 9 or characterised in that the first acid solution of step (ii) has a halide ion concentration of between 4 and 6 M.

12. A process in accordance with any one of the claims 7 to 11 characterised in that the H+ ion concentration in the gallium containing acid solution of step (iii) is between 3.5 N and 4.5 N.

13. A process in accordance with any one of the claims 1 to 12 characterised in that the H ion and halide ion concentration in the acid solution after step is controlled before it is recycled at step (ii).

14. A process in accordance with any one of the claims 1 4 4 to 13 characterised in that the extracting agent is a substituted hydroxyquinoline, a derivative thereof or a mixture thereof. A process in accordance with any one of the claims 1 Ii 14 to 14 characterised in that the selective extraction of gallium at step is carried out by passing the gallium containing acid solution over an anion exchange resin.

16. A process in accordance with any one of the claims 1 to 14, characterised in that the selective extraction of gallium in stage is done by liquid-liquid extraction, the extracting agent being selected from anionic or solvating agents. DATED this llth day of OCTOBER, 1990 RHONE POULENC CHIMIE Attorney: WILLIAM S. LLOYD Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS o Q V Oi AN