Outotec Pty Ltd v Xstrata Technology Pty Ltd and Yunnan Metallurgical Group - [2014] APO 48

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Outotec Pty Ltd v Xstrata Technology Pty Ltd and Yunnan Metallurgical Group
[2014] APO 48
Patent Application: 2006299743

Title:Method and Apparatus for Lead Smelting

Patent Applicant:                   Xstrata Technology Pty Ltd and Yunnan Metallurgical Group
Opponent:  Outotec Pty Ltd
Delegate:  Matt Kraefft
Decision Date:  4 July 2014
Hearing Date:  14 April 2014
Catchwords:  PATENTS – section 59 – opposition to grant of a patent – novelty – lead smelting furnaces and their operation per se known – particular claimed combination and the claimed operational parameters not known – inventive step - ascertainment of non-patent literature and Chinese patent specifications considered – some claimed operational parameters and the overall combination found to be inventive - manner of manufacture - fair basis – clarity of claims – opposition unsuccessful on all grounds raised.

Representation: Patent applicant: Mr Jonathan Lewis and Mr Gary Nock, patent attorneys of Cullens, Brisbane.
Opponent:Mr Ian Horak, counsel, instructed by Mr Adrian Crooks, patent attorney of Phillips Ormonde Fitzpatrick, Melbourne.

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Patent Application: 2006299743

Title:Method and Apparatus for Lead Smelting

Patent Applicant: Xstrata Technology Pty Ltd and Yunnan Metallurgical Group
Date of Decision: 4 July 2014
DECISION
The opposition is unsuccessful on all grounds raised in this opposition.
Subject to appeal, I direct the application proceed to grant.
Costs awarded against the opponent.
REASONS FOR DECISION
BACKGROUND

Xstrata Technology Pty Ltd and Yunnan Metallurgical Group (“the applicants”) filed patent application 2006299743 on 5 October 2006. The application claims priority from an Australian provisional application, 2005905513, filed on 6 October 2005. Application 2006299743 was advertised accepted on 12 April 2012.
Outotec Pty Ltd (“the opponent”) filed a notice of opposition on 12 July 2012. A statement of grounds and particulars in support of the opposition followed on 11 October 2012. The opponent completed its evidence in support on 11 June 2013.
The applicants filed a request on 10 September 2013 under Section 104 of the Patents Act to amend the complete specification. The applicants proposed to replace the claims pages. The proposed amendment principally deleted several dependent claims. The applicants’ request was allowed on 24 March 2014 and advertised allowed on 3 April 2014.
The applicants completed their evidence in answer on 11 September 2013. The opponent completed its evidence in reply on 11 December 2013.
On 18 February 2014 the applicants applied to file further evidence. The applicants’ reasons for making that application were to address issues raised for the first time in the opponent’s evidence in reply. One statutory declaration which constituted the further evidence was filed concurrently.
After inviting representations from the parties, a delegate of the Patent Office allowed the filing of the further evidence on 7 March 2014. The opponent chose not to file responding evidence.
THE SPECIFICATION
The specification relates to lead smelting. The specification states that conventional lead smelting included a sinter plant. Lead sulphide containing concentrate would pass through the sinter plant. The sinter plant would oxidise the concentrate and remove the bulk of the sulphur from the concentrate. The sinter leaving the sinter plant was subsequently used as a feed to a lead smelting blast furnace.
The specification mentions that other processes for recovering lead from sulphide ores and concentrates have also been developed. These include the Kivcet process, the QSL process and the ISASMELT^TM process.
The ISASMELT^TM process used gas injection into melts via a top entry submerged lance (“TSL”). Injection of gases in a TSL furnace produced a very turbulent bath in which high intensity smelting or reduction reactions could take place.
A stated object of the alleged invention is to provide an alternative lead smelting method and apparatus for producing lead from lead sulphide containing materials.
The specification, as amended, ends with nine claims defining the claimed invention. Aside from omnibus claim 9, the only other independent claim is claim 1. This claim reads as follows.
1. A method for producing lead from a material containing lead sulphide comprising the steps of:
a)   feeding the material containing lead sulphide to a top entry submerged lance lead smelting furnace to produce lead bullion and a lead containing slag that contains lead silicate, wherein the material that is fed to the lead smelting furnace contains from 50 to 75% by weight Pb;
b)   removing the lead bullion from the lead smelting furnace;
c)   removing the lead containing slag from the lead smelting furnace, cooling the lead slag at a cooling rate of less than 50^oC per minute, and forming the lead containing slag into lumps having a size distribution suitable for use as feed material to a blast furnace, said lead containing slag having a lead oxide content in the range of 45 to 55% by weight and a CaO/SiO₂ ratio of greater than 0.6, and a mineralogical structure consisting of an interlocking network of needle or lath-like melilite crystals enclosing a lead silicate glass phase; and
d)   feeding the lumps of lead containing slag to a blast furnace, the lead slag from the lead smelting furnace comprising the main part or all of the lead containing feed material fed to the blast furnace, wherein the lead containing slag is converted into lead bullion and a discard slag.
STATEMENT OF GROUNDS AND PARTICULARS
As a consequence of the Intellectual Property Legislation Amendment (Raising the Bar) Act 2012, there are substantial changes to the Patents Act 1990. In the case of the present application the grounds of opposition are governed by the Patents Act in force before 15 April 2013.
The opponent’s grounds of opposition were that the alleged invention was not a manner of manufacture, was not novel and did not involve an inventive step, was insufficiently described, was not useful, and that the claims did not define an invention, and were not clear or fairly based. The opponent provided particulars against each of these grounds.
Following the allowed amendment under Section 104, the opponent did not pursue the ground of lack of usefulness.
EVIDENCE-IN-SUPPORT
The opponent served evidence-in-support from Mr Jim Happ. Mr Happ has extensive experience in metallurgy, and particularly lead smelting, dating back to 1970. In his evidence Mr Happ principally discussed the background art before the priority date and several pieces of documented prior art.
EVIDENCE-IN-ANSWER
The applicant served evidence-in-answer from Dr William John Errington. He is an executive metallurgist for one of the applicants. Dr Errington’s experience in this field dates back to 1980. In his evidence, Dr Errington principally challenged much of the state of the background art and the relevance of the documented prior art that was provided in the opponent’s evidence in support.
EVIDENCE-IN-REPLY
The opponent served evidence-in-reply from Mr Happ. In this evidence Mr Happ substantiated much of his evidence in support with further detail in response to the applicants’ evidence in answer.
FURTHER EVIDENCE
The applicants’ further evidence constituted a declaration by Mr Alistair Burrows. He is a principal metallurgist for one of the applicants. Mr Burrows has provided evidence that two papers raised in the opponent’s evidence in reply were published after the priority date of the present application.
PERSON SKILLED IN THE ART
Both parties indicated that the person skilled in this field would be a metallurgist, particularly one skilled in lead smelting.
PATENTABLE INVENTION
Section 18 of the Patents Act relates to patentable inventions. Relevant parts of subsection (1) appear below.
(1)Subject to subsection (2), an invention is a patentable invention for the purposes of a standard patent if the invention, so far as claimed in any claim:
(a)   is a manner of manufacture within the meaning of section 6 of the Statute of Monopolies; and
(b)   when compared with the prior art base as it existed before the priority date of that claim:
(i)is novel; and
(ii)involves an inventive step; and
(c)   is useful; and …….
NOVELTY
In referring to several earlier decisions in respect to novelty, the Bristol-Myers Squibb Company v FH Faulding & Co Ltd decision, (2000) 46 IPR 553 at 576, states that what the authorities contemplate is that a prior publication, if it is to destroy novelty, must give a direction or make a recommendation or suggestion which will result, if the skilled reader follows it, in the claimed invention.
There may be circumstances where a document can deprive a claimed invention of novelty even though it does not expressly make that complete disclosure of all the integers of the claimed invention. The Full Court in Novozymes A/S v Danisco A/S, [2013] FCAFC 6, dealt extensively with the subject of anticipation by inevitable outcome. A passage from the General Tire & Rubber Co. v Firestone Tyre & Rubber Co. Limited decision, [1972] RPC 457, quoted in Novozymes (supra) at [145] appears to be pertinent in the present case.
“… if carrying out the directions contained in the prior inventor’s publication will inevitably result in something being made or done which, if the patentee’s patent were valid, would constitute an infringement of the patentee’s claim, this circumstance demonstrates that the patentee’s claim has in fact been anticipated.
If, on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee’s claim, but would be at least as likely to be carried out in a way which would not do so, the patentee’s claim will not have been anticipated, although it may fail on the ground of obviousness.”
Then in Novozymes at [187],
“… the General Tire approach, if taken at all, may be taken only with respect to the whole of any claim asserted to have been anticipated. The “precise destination” at which the flag must have been planted is one which includes every integer of the claim. The approach cannot, in my view, be taken for some integers only, leaving others to be dealt with by reference to the understanding of the skilled addressee. In the present context, what this means is that, to the extent that the appellants’ case is based on General Tire, it is not sufficient that they be able to point to passages in the Novo patent from which it would appear to the skilled addressee that inactivation was contemplated or intended by the earlier inventors. It is necessary that they show that, if Example 20 were worked as directed, it would inevitably, as a matter of hard fact, have involved inactivation of the enzyme ….”
D1 – ISASMELT^TM – 25 YEARS OF CONTINUOUS EVOLUTION (“Arthur paper”)
This document lists the authors as P.S. Arthur and S.P. Hunt from Xstrata Technology (“Xstrata”), published in July 2005, and was presented at the John Floyd International Symposium on Sustainable Developments in Metals Processing, 3-6 July 2005, Melbourne.
The Arthur paper traces the development of the ISASMELT^TM process from the late 1970s. The process was a joint initiative by Mount Isa Mines Limited (subsequently owned by Xstrata) and the CSIRO. In respect to the claimed invention, the most pertinent disclosure of the Arthur paper is on pages 17 and 18. Xstrata had designed an ISASMELT^TM furnace for Yunnan Metallurgical Group’s (“YMG”) new lead smelter in China. The ISASMELT^TM furnace would smelt 160,000 tonnes per annum of lead concentrate to produce lead bullion and a high lead slag. The high lead slag would be solidified and fed to a YMG-designed blast furnace for reduction. This process would combine the benefits of the ISASMELT^TM furnace for smelting with the benefits of the blast furnace for reduction. The ISASMELT^TM furnace would effectively replace the sinter plant of a traditional lead smelter.
The above process is essentially the same as the process claimed in claim 1 of the present application. However D1 does not disclose the details of the lead feed percentages, the cooling rate of the lead slag, the lead oxide content, the CaO/SiO₂ ratio and the claimed mineralogical structure as claimed in claim 1.
The opponent submitted, with reference to Mr Happ’s first declaration at [94] and [100], that a metallurgist reading the Arthur paper would understand that, to implement the process described in that paper, they would have to form the slag into a physical form suitable for use as a feed material to a blast furnace. This was stated to inevitably involve replicating the mineralogical characteristics of sinter. The opponent further submitted that all the above conditions and properties absent from D1 were consistent with the standard preparation of high lead sinter for blast furnace reduction for the conventional two stage process.
The above law requires a prior publication, if it is to destroy novelty, to give a direction or make a recommendation or suggestion which will result, or would inevitably result for the present case, if the skilled reader follows it, in the claimed invention. It may be that the claimed conditions and properties were standard or typical for the standard preparation of sinter. On the other hand, whilst acknowledging the similarities of lead sinter and lead slag, they are not the same. It may also be desirable that, in producing suitable feeds to a blast furnace, one would have wanted to replicate the properties of sinter in the slag from the ISASMELT^TM furnace. However D1 has no teaching or example as to how this would have been done, much less an example that, if worked as directed, would inevitably as a matter of hard fact have resulted in the claimed invention. In the absence of the above-mentioned features from D1, I conclude that claim 1 is novel. I similarly conclude the remaining claims are novel over D1.
D2 – CN 1131699 – Translation by Asia Technical Translation Pty Ltd
This document is similar to D1 in disclosing lead sulphide ore concentrates, flux, fume and solid fuel being fed into an ISASMELT^TM furnace to generate and then process lead-rich molten slag into solid slag which is then fed into a blast furnace for reduction to produce lead bullion. D2 similarly does not disclose the details of the lead feed percentages, the cooling rate of the lead slag, the lead oxide content, the CaO/SiO₂ ratio and the claimed mineralogical structure of the present application. I conclude the present claims are novel over D2.
D3 – CN 1334349 – Translation by Asia Technical Translation Pty Ltd
This document principally provides a disclosure of blast furnace feed preparation and a blast furnace reduction process only. There is no particular description of a source of the lead-rich slags fed to the blast furnace. D3 discusses known lead smelting technologies such as the Kivcet process, the QSL process, the Kaldo process and the top-blown sinking smelting technique. However no particular process is chosen or discussed for producing feeds to the blast furnace. There was some conjecture in the evidence and at the hearing as to whether the latter technique was the same as the TSL lead smelting technique. I will address this later where necessary.
D3 does not disclose the details of the lead feed percentages, the cooling rate of the lead slag, the lead oxide content, the CaO/SiO₂ ratio and the claimed mineralogical structure of the present application. I conclude the present claims are novel over D3.
D4 – CN 1584075 - Translation by Asia Technical Translation Pty Ltd
D4 discloses the oxidation of lead concentrate by top-blown immersion smelting in a sealed furnace to generate a compact slag. Mixtures of the slag, flux and coke are fed into a blast furnace in which pulverized fuel is injected into the tuyere area of the blast furnace.
D4 does not disclose the details of the lead feed percentages, the cooling rate of the lead slag, the lead oxide content, the CaO/SiO₂ ratio and the claimed mineralogical structure of the present application. I conclude the present claims are novel over D4.
INVENTIVE STEP
In respect to inventive step, the Wellcome Foundation Ltd v VR Laboratories (Aust.) Pty Ltd decision, (1981) 148 CLR 262 at 280, states the question is whether the invention would have been obvious to a hypothetical skilled addressee armed with the common general knowledge at the priority date. Also from that decision at page 286, an appropriate test is whether a person skilled in the relevant field, and faced with the same problem, would have taken as a matter of routine whatever steps might have led from the prior art to the invention.
The High Court in Aktiebolaget Hassle v Alphapharm Pty Limited, (2002) 56 IPR 129 at [50] – [53], appeared to approve of the Wellcome (supra) test. In discussing what was meant by a matter of routine the High Court noted and accepted an affinity with the approach in Olin Mathieson Chemical Corporation v Biorex Laboratories Ltd, (1970) 87 RPC 157, of whether the person skilled in the art would directly be led as a matter of course to try what was claimed in the expectation that it might well produce a useful alternative. In Lockwood Security Products Pty Ltd v Doric Products Pty Ltd[No. 2], [2007] HCA 21, (2007) 235 ALR 202, general principles regarded to be of continuing relevance, at [50] – [52], were that “obvious” means “very plain”, a scintilla of invention remains sufficient to support the validity of a patent, there must be some difficulty overcome, some barrier to be crossed, and an invention must be beyond the skill of the calling.
The courts have commonly continued to determine the starting point for consideration of inventive step in terms of an existing problem for which the inventor found a solution. In Lockwood (supra) at [105]:
“While not every invention constitutes a solution to a problem, it is commonplace so to describe an invention when it is appropriate to do so”.
Federal Court decisions have followed this approach. In Ranbaxy Laboratories Ltd v AstraZeneca AB, [2013] FCA 368 at [203] – [218], Middleton J cited Jagot J’s comments in Apotex Pty Ltd v AstraZeneca AB (No. 4), [2012] FCA 162 with approval:
“In assessing obviousness, it is necessary first to determine the nature of the claimed invention and the inventive step described in the Patent. This may involve ascertaining the “starting point” of the inventive step, sometimes described in terms of an existing problem for which the inventor found a solution. The obviousness of the invention as claimed is then assessed by reference to common general knowledge in Australia at the priority date.”
Common General Knowledge
The opponent submitted, with reference to Mr Happ’s evidence, that the following matters were common general knowledge in Australia before the priority date.
The smelting of lead sulphide concentrate to produce lead metal consisted typically of two key steps. The first was the oxidation of the lead sulphide to form lead oxide. This was then followed by reduction of the lead oxide to lead metal.
The conventional process for smelting lead involved performing the oxidation and reduction steps by the use of a sinter plant and a blast furnace, respectively. Alternatively the use of TSL furnaces, such as the ISASMELT^TM furnace, was also well known.
The above points appeared not to be in dispute between the parties and I accept those as common general knowledge at the relevant time.
Mr Happ at [64] of his first declaration further suggested that the use of a blast furnace to treat high lead slags produced by a TSL furnace, as in the Arthur paper, was a routine application of well-known and reliable technology. He supported this position by noting at [57] that, for many years before the priority date, the oxidation and reduction steps had been performed by a sinter plant and blast furnace respectively. Mr Happ stated that by 2005 a number of alternative means for performing these two steps were available, including the two stage TSL furnace processes known as ISASMELT^TM. At [58], Mr Happ stated that while the use of a TSL furnace for the oxidation step had proven very effective with advantages over sintering, particularly in relation to recovery of sulphur dioxide, the second reduction step had proven less successful. Mr Happ at [59] then referred to the long known use of blast furnaces to obtain lead metal from lead containing slags. From this Mr Happ appeared to draw the conclusion that the use of a blast furnace (instead of the second-stage TSL furnace) to treat high lead slags produced by a TSL furnace (first stage) was a routine application.

The applicant challenged this stating it was incorrect to regard that as common general knowledge to address known difficulties encountered in using a second stage TSL furnace for the reduction step. I am inclined to agree.
It may seem simple to suggest that if the second-stage TSL furnace was problematic then one would revert back to the use of the proven blast furnace for reduction. As noted above, I am prepared to accept that TSL furnaces and blast furnaces were individually well known at the relevant time. On the other hand, the direct combination of the two is a different matter.
The Arthur paper traces various approaches in the development of the ISASMELT^TM technology over the stated 25 year period. Aside from whether the Arthur paper and its contents could be regarded to have been common general knowledge at the relevant time, the opponent has other difficulties with its approach. Page 4 of the Arthur paper describes the commissioning in 1983 of a single furnace used exclusively for oxidation smelting of the concentrate. This furnace produced a high lead slag that was granulated and subsequently added to the sinter plant feed. That is, referring to Mr Happ’s first declaration at [41], this first stage TSL furnace augmented the sintering process. He stated the lead containing slag from the TSL furnace was tapped, granulated and fed to the blast furnace via the sinter plant. In 1991 the above-mentioned two-stage lead ISASMELT^TM furnace processes had been developed and began operation. Subsequently it was the second stage TSL furnace that proved problematic. Commonly the discard slag from the second stage TSL furnace contained high levels of lead compared to slags obtained from blast furnaces (Mr Happ’s declaration at [45]). The Arthur paper also mentions, at pages 7 and 8, short lance lives in the reduction stage and blockage and wear of the coal injection system leading to erratic lead content in the final slag. These problems were stated to have been overcome by redesign of the coal injection equipment and modifying the lance tip design.
Subsequently the Arthur paper discusses the Xstrata-designed ISASMELT^TM furnace in combination with the YMG-designed blast furnace in China as discussed under novelty above. Notably the ISASMELT^TM furnace would effectively replace the sinter plant of a traditional lead smelter. It is also noteworthy that the Arthur paper discusses this combination in the future tense. At the time of writing, it appeared the combination was merely in the design and planning stages. The paper was also published only about three months before the priority date of the present application. While the paper was presented at an international symposium there is insufficient evidence as to how widely read or regarded that paper would have been at the time. Furthermore Mr Happ at [56] of his first declaration has indicated that he considered it unlikely that he was aware of a proposal to combine a TSL furnace for oxidation of lead concentrate with a blast furnace for reduction of lead rich slag produced by the TSL furnace before the priority date.
I conclude that, on the available evidence, the use of a blast furnace to directly treat high lead slags produced by a TSL furnace was not common general knowledge at the relevant time.
Starting Point
A similar outcome appears to arise when one addresses the starting point, as suggested by the opponent.
The opponent noted the specification makes it clear on pages 1 and 2 that the alleged invention resides in an alternative to existing processes. The opponent described the well-known uses of sinter plants in combination with blast furnaces, the use of TSL furnaces to produce lead containing slag, and the use of blast furnaces to reduce slag to lead bullion. From this background the opponent noted the combination of the first stage TSL, for example ISASMELT^TM, process with a blast furnace as described in the Arthur paper. The opponent stated that such a combination takes advantage of the well-known properties of the first stage TSL furnace while avoiding the well-known disadvantages of the second stage TSL furnace by employing the well-known and reliable blast furnace for the reduction stage. Thus, as the opponent put it, if the person skilled in the art wished to improve on the known use of a single stage ISASMELT^TM furnace then the addition of a downstream blast furnace would have been routine. Similarly if the person skilled in the art started with the two-stage ISASMELT^TM processes they would naturally appreciate that the output of the first stage would need to be compatible with the input of the second stage blast furnace.
I have already determined above that a TSL furnace and blast furnace combination with the blast furnace directly treating high lead slags produced by the TSL furnace was not common general knowledge at the relevant time. The opponent also appears above to have enunciated a position that the person skilled in the art would be an improver of the existing ISAMELT^TM process (single stage), and that a swap of a second-stage ISAMELT^TM furnace with a traditional blast furnace would be entirely natural if the two-stage ISASMELT^TM process was the starting point. The above authorities allow matters of routine or matters of course to support findings of lack of inventive step. However the opponent’s statements appear to be based more on hindsight, or ex post facto analysis, which the authorities have often warned against. See for example Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd, [1980] HCA 9, (1980) 144 CLR 253.
The specification does not specifically describe problems relating to the ISASMELT^TM process. Nonetheless the specification acknowledged the existence of the single stage and two-stage ISASMELT^TM processes, along with the previous sinter plant and blast furnace combination. I am prepared to accept this as a starting point in this case.
Whether There is an Inventive Step
Common General Knowledge Alone
The use of a blast furnace to directly treat high lead slags produced by a TSL furnace was not common general knowledge (see above), and it has not been established that this would have been a matter of routine.
Inventive Step in Light of Prior Art Documents
At the relevant time, subsection 7(3) restricted prior art information used to support lack of inventive step to that which the person skilled in the art could be reasonably expected to have ascertained, understood and regarded as relevant.
In Rohm and Haas Company v Nippon Kayaku Kabushiki Kaisha and Sankyo Company, Limited, [1997] APO 40, it was stated:-
“A document would be ascertained if it was published in such a manner or form that it could reasonably have been expected to be found by a person skilled in the art. A patent document dealing with the same technical issues would prima facie have been ascertained by a person skilled in the art. The requirements of understood and regarded as relevant are not likely to be an issue where a document relates to the same art as the problem.”
The Arthur paper was presented at an international symposium about three months before the priority date. While there may be insufficient evidence to establish the paper was widely read or regarded as mentioned above, the issue of whether a person skilled in the art could be reasonably expected to have ascertained the document is a lower threshold issue. I expect the symposium would have been attended by a diverse group of interested parties from across the industry from within and outside Australia. Mr Happ attended the symposium and while he did not recall reading the paper, he stated it is very likely he did so at or shortly after the symposium (Mr Happ’s declaration at [54]). Moreover the paper traced significant developments of the ISASMELT^TM technology at established lead smelting plants in Australia and overseas. In this sense I find the paper could have been of importance to persons skilled in the art.
I am satisfied a person skilled in the art could be reasonably expected to have ascertained the Arthur paper.
In respect to D2 – D4, these are Chinese patent specifications. Mr Happ indicated he did not routinely read patent literature but did so when investigating a particular issue, like a major development such as TSL smelting. Dr Errington indicated that persons skilled in the art did not search for nor consult patent literature when seeking a solution to a problem. The evidence is finely balanced on this point. There has been a reasonable degree of patenting activity in this field, including by the parties or their related companies. I favour the view that a person skilled in the art could be reasonably expected to have generally reviewed patent literature when investigating a particular issue.
The applicant further submitted that, as the patent documents are in Chinese, they would not have been understood by a skilled addressee.
In Shino Kaneko v Nemoto & Co. Ltd, [2004] APO 17 at [34], the delegate indicated it is more important how the documents were located rather than the language they were in. This suggests the language of a document is not inherently a barrier to a document’s ascertainment or understanding. In the present case, the opponent has provided English language abstracts for D2 – D4 from the European Patent Office’s esp@cenet database in evidence. While all three abstracts are relatively brief, they each contain headings and opening statements about lead smelting or blast furnace smelting. I think there is enough in each of these abstracts such that a person skilled in the art could have regarded the Chinese patent specifications of importance. It follows that, if such persons were not conversant with the Chinese language, then I would think translation services would have been pursued. I conclude a person skilled in the present art could be reasonably expected to have ascertained the Chinese patent specifications.
D1 – Arthur paper
From the novelty discussion above, the key differences of the claimed invention over D1 are the details of the lead feed percentages, the cooling rate of the lead slag, the lead oxide content, the CaO/SiO₂ ratio and the claimed mineralogical structure.
The opponent submitted the alleged invention was routine insofar as the slag from the TSL furnace needing to be a suitable feed for the blast furnace. Mr Happ, in his first declaration at [66], indicated the composition of lead containing slag produced by a TSL furnace would be similar to the composition of sinter produced by a sinter plant. At [67], in relation to the physical shape of the slag, this would mean forming the slag into suitable sized lumps, probably in the range of 20 to 70 mm in size. At [68], in relation to mineralogy, Mr Happ stated the factors relevant to the formation of sinter, that is the composition and cooling rate, are also relevant to lead containing slag. By adjusting the concentration of CaO, CaO/SiO₂ ratio and the cooling rate of the lead containing slag, it would be possible to achieve the formation of a melilite/spinel network within the slag. At [31], Mr Happ described a sinter cooling rate of 20 to 50^oC per minute as typical. He stated it was well understood that the rate of cooling of a liquid phase would affect crystal formation. At [29], Mr Happ discussed the importance of flux in achieving sinter with desirable microstructure and physical properties and in particular the importance of an interlocking network of melilite laths. He described typical fluxing procedures at Mount Isa Mines resulting in a CaO/SiO₂ ratio of over 1. On these points Mr Happ relied on a 1980 paper, “Development of Optimum Fluxing Procedures for ISAMINE Lead Concentrates”, McLoughlin et al (Exhibit JH-8). Mr Happ stated that while this fluxing procedure resulted in high quality sinter, there were costs associated with the level of lime added. In evidence in reply at [13], Mr Happ cited a 1998 paper entitled “Mineral Chemistry and Structure of Lead Sinter Products from Mount Isa Mines Limited Lead Smelter”, Riley (Exhibit JH-13), regarding optimum melilite morphology being obtained in plant sinter at a CaO/SiO₂ melt ratio of between 0.65 and 1 and at low undercooling. Finally the opponent relied on Mr Happ’s statement at [47] that, dependent on a number of operating conditions, a lead oxide content between about 40% and 50% allowed operation of a first stage TSL furnace at a relatively low temperature. The opponent thus submitted the working parameters, reflecting the key differences of the claimed invention over the Arthur paper, were all well-known and understood conditions for achieving the sinter-like mineralogy.
The applicants submitted the opponent’s suggestion that liquid lead slag and semi-molten lead sinter were somehow analogous materials is incorrect. The applicants described sinter as a collection of solid granules with liquid boundaries and gaseous interstices. The applicants further noted the Arthur paper does not disclose the slag cooling rate. The applicant also challenged the opponent’s assertion about the importance of the cooling rate of sinter determining the quality of the sinter. With reference to Dr Errington’s evidence at [23]-[25], the applicants submitted the peak bed temperature, which Dr Errington described as the peak temperature at a given point of a sinter bed as the reaction front moves through the bed, and the addition of flux were the key factors on sinter quality.
It may be that, having seen the Arthur paper, the aims of producing a slag from the TSL furnace with sinter-like physical and mineralogical properties would have been obvious. I accept the aim would have been to produce an interlocking network of needle or lath-like melilite crystals as claimed. On the other hand, the implementation in this case of the method to achieve these aims is important in assessing inventive step.
The opponent’s main case seemed to be that, knowing these aims, it would have been routine to achieve the desired product for input into the blast furnace with the operational parameters claimed. As the opponent put it, the effect of adjusting process parameters such as cooling rate, CaO/SiO₂ ratio and lead oxide content were well known and commonly done to ensure optimal efficiency. However the further issue in this case would seem to be whether a person skilled in the art would directly have been led as a matter of course to try the particular combination of parameters claimed with the expectation that would achieve the optimal efficiency.
Slag is normally regarded as the liquid or molten waste matter separated from metals during smelting. On the other hand, sintering is normally a process of fusing powders together at high temperatures but below the melting point. In this respect it is noteworthy that the Arthur paper described, in the initial stages of TSL furnace development, that the first stage TSL furnace augmented the sintering process. The lead containing slag from the TSL furnace was tapped, granulated and fed to the blast furnace via the sinter plant. Similar augmentation of slags with the sintering process is discussed in the above-mentioned 1980 paper.
Mr Happ, at [27] of his first declaration, described the raising of temperatures to about 1100 to 1150^oC from heat combustion of sulphides, and of coke if used, as the flame front moved through a sinter bed. At such a temperature, parts of the sinter mix were effectively cooled in a liquid phase similar to slag. While there may be similarities, it does not follow that performing the same process, such as cooling rate, on sinter and on slag would result in those two products having the same physical or mineralogical properties. I conclude the treatment of slag and sinter as analogous in this case, on the basis of the prior art in evidence, is incorrect.
It is only subsequently at pages 17 and 18 that the Arthur paper describes that the Xstrata-designed ISASMELT^TM furnace for YMG would produce a high lead slag that would be fed directly to the YMG-designed blast furnace. However there is nothing of substance described in the Arthur paper as to what processes or parameters enabled the previously used sintering process to be by-passed. That is, there is nothing as to how the ISASMELT^TM furnace would be operated to produce a slag having similar mineralogical properties to normal lead sinter.
In respect to lead feed percentages, the present specification at the foot of page 2 in the background discussion mentions the ISASMELT^TM process involving concentrates containing high levels of lead, such as between 55% to 80% but more preferably between 60% to 75% when the process was used to directly reduce some of the concentrate added to the smelting furnace to lead bullion. These ranges, respectively, overlap and are wholly within the claimed range. The Arthur paper at page 5 describes reduction trials where discard slags containing 2 to 5% lead were achieved from 50% lead concentrate. Both cases appeared to refer to the two-stage lead ISASMELT^TM furnace processes as distinct from the TSL furnace and blast combination furnace of the present claims. On the other hand, the lead feed relates principally to the smelting stage rather than any second-stage TSL furnace or blasting furnace. I conclude a person skilled in the art would directly have been led as a matter of course to try the claimed lead feed percentage in the claimed method in the expectation that it might well produce a useful alternative.
In respect to lead oxide content, Mr Happ at [47] stated the appropriate lead oxide content of high lead slag in a first stage TSL furnace is a balance of a number of factors. A high oxide content allows the first stage TSL furnace to operate at a lower temperature. However a lead oxide content that is too high can also lead to precipitation of spinel phases increasing the viscosity of the slag beyond acceptable levels. Where several factors need to be balanced, it would seem difficult, on the face of it, to regard a particular chosen direction, or some medium point, as a matter of routine or obvious to try. Mr Happ mentioned 40% to 50% lead oxide content allowing operation of the furnace at a relatively low temperature, depending on other operating conditions. That is, Mr Happ appeared to regard low temperature operation as important. I note Mr Happ’s point that this is nonetheless subject to other operating conditions. This would appear to leave work open to more than routine experimentation. I conclude there is little in the evidence that a person skilled in the art would directly have been led as a matter of course to try for the claimed range of 45 to 55% lead oxide content by weight of the slag.
In respect to the CaO/SiO₂ ratio, there is a question of whether the above-mentioned 1980 and 1998 papers could reasonably be expected to have been ascertained by the person skilled in the art. The former relates to the importance of flux in achieving sinter with desirable physical and mineralogical properties from lead concentrates at Mount Isa Mines. The latter relates to mineral chemistry and structure of lead sinter at Mount Isa Mines. Both documents clearly relate to the production of sinters with requisite, optimal properties from the lead smelter at Mount Isa Mines. In this respect, I would conclude the person skilled in the art of lead smelting could reasonably be expected to have ascertained the papers. Equally I would conclude the person could have understood and regarded them as relevant to the claimed invention. The next question would then be whether it would have been obvious to combine either document with the Arthur paper. In this respect, I note the Arthur paper also relates to activities involving lead smelting at Mount Isa Mines. Moreover, as mentioned earlier, the Arthur paper traces the development of the ISASMELT^TM technology at Mount Isa Mines over a 25 year period, including the initial TSL furnace augmented sintering process. I am satisfied it would have been obvious to combine either the 1980 or 1998 papers with the Arthur paper at the relevant time.

The 1980 paper, in its introduction, discusses the fluxing of lead concentrates to give a fixed lime and silica level in slag. The lime in slag of 22.5% by weight CaO and silica level of 18.5% by weight SiO₂ maintained a high standard of productivity over a range of concentrate grades. The CaO/SiO₂ ratio was clearly >1. The paper though also relates the significant cost of high lime usage. The 1998 paper discloses an optimum melilite morphology being obtained in plant sinter at a CaO/SiO₂ melt ratio of between 0.65 and 1. Whilst acknowledging the difference between slag and sinter, I am satisfied on the basis of these disclosures that a person skilled in the art would directly have been led as a matter of course to try the claimed CaO/SiO₂ ratio >0.6 in the furnace processes described in the Arthur paper in the expectation that it might well produce a useful alternative.
As mentioned above, there was a dispute between the parties about the importance of cooling rate versus the peak bed temperature on sinter quality. Mr Happ in evidence in reply at [12] iterated the importance of cooling rate by commenting on differences in the formation of melilite and spinel phases between rapidly quenched blast furnace slags and slowly cooled blast furnace slags. I note that Mr Happ’s discussion had switched from discussing cooling rates for sinter in the evidence in support to cooling rates for blast furnace slags in the evidence in reply. Nonetheless I am prepared to accept that cooling rate is important while also noting that peak bed temperature may also be influential.
On the other hand, the evidence from both parties does not strongly point one way or the other for preferences between slow cooling and rapidly quenched slags. Mr Happ’s evidence in support at [30] and [31] acknowledged both options in the art. The two embodiments described on page 6 of the specification relate rapid and slow cooling rates respectively, dependent on other operational parameters. One of those is the CaO/SiO₂ ratio. In the first embodiment the ratio is <0.4, while in the second the ratio is >0.6. The specification also states that in the first embodiment, the slag characteristics do not change significantly with the cooling rate of the slag and thus this slag can be rapidly quenched.
The opponent made a number of submissions, with reference to Mr Happ’s evidence, for example Exhibit JH-12, for slow cooling to achieve the desired mineralogical characteristics. It may be that slow cooling was preferred to rapid quenching. Even if that is so, the quantum of slow cooling rate does not stand out in the evidence. Specifically, the evidence is light on the use of a cooling rate below 50^oC per minute of slag. Mr Happ stated at [31] that a cooling rate of sinter between 20 to 50^oC per minute was typical. On the other hand, Mr Happ also indicated this would depend on other factors such as the thickness of the sinter bed. Moreover there is insufficient evidence of cooling rates below 50^oC per minute for TSL furnace slags before the priority date. I would further note that the cooling rate, as claimed, is applied to the slag once removed from the TSL furnace. It is not an operation performed to produce a slag from the TSL furnace having similar properties to normal lead sinter. I am unconvinced from the evidence that a cooling rate as claimed for slags removed from the TSL furnace would have been obvious to try.
I have concluded above that some individual parameters would not have been obvious at the relevant time. The further issue against the opponent’s case is the combination of the claimed operational parameters. They are closely interrelated with one another. For example, as noted above, rapid quenching versus slow cooling choice is dependent on the CaO/SiO₂ ratio, amongst other things. The lead oxide content is also dependent on the CaO/SiO₂ ratio, amongst other things (Mr Happ’s first declaration at [35]). Costs were also mentioned in evidence, for example in respect to lime content, which may influence some of the above choices. Mr Happ, at [26], [68] and again at [100], has described the knowledge in the art of achieving desired mineralogical characteristics with suitable lead oxide concentration, suitable CaO/SiO₂ ratio and appropriate cooling rate, and adjustments thereof, without specifying any values. Where he has stipulated preferred or well-known parameter values in his evidence, Mr Happ has also conceded that such choices were dependent on other operational parameters, for example at [31] and [47]. The evidence is replete with how choices in varying any one operational parameter would affect others. In these circumstances it is difficult to see how the particular claimed combination of operational parameters to achieve the claimed physical and mineralogical structure was obvious at the relevant time.
I conclude the claimed invention has an inventive step over the Arthur paper.
D2 to D4
In respect to D3, there was some dispute between the parties on whether a top-blown sinking smelting technique as described therein was the same as the claimed TSL lead smelting technique. Mr Happ regarded them as the same technique. On the other hand, Dr Errington at [45] stated that the term “top blown” in the art describes a process where a lance or burner is located above a molten bath and which injects gases or feed material downwards to the molten bath. In contrast Dr Errington described the term “TSL” as the use of a lance submerged in the molten bath. Moreover Dr Errington indicated that D3 describes the need to conduct frequent repair and replacement of the refractory lining of the top-blown sinking smelting furnace which he stated is not the case with TSL furnaces.
The applicants also referred to D4 which describes a top-blown immersion smelting furnace. In this document the applicants further noted a reference to this being a sealed furnace whilst arguing in submissions that TSL furnaces are not sealed.
There is some difficulty differentiating the furnaces in D3 and D4 from TSL furnaces. I note D3 describes a top-blown sinking smelting technique (my emphasis). In very similar terms, D4 describes top-blown immersion smelting (my emphasis). These terms suggest a submerged lance from the top as with TSL furnaces. Furthermore the applicants’ submission that TSL furnaces are not sealed is seemingly without basis. Mr Happ at [43] of his first declaration described TSL furnaces as sealed, and moreover with the same result as mentioned in D4 and in the present specification, that being to enable recovery of sulphur dioxide from the flue gases or off gases for the production of sulphuric acid. I conclude the furnaces mentioned in D3 and D4 are TSL furnaces.
In any case, the disclosures in the Chinese specifications add no more in respect to the claimed invention than already disclosed in the Arthur paper. I conclude the claimed invention has an inventive step over the Chinese patent specifications.
MANNER OF MANUFACTURE
The opponent submitted the alleged invention, as described in the specification, consists of merely the use of known integers, being a TSL furnace and a blast furnace, the known properties of which make them suitable for use and/or combination. Moreover the opponent asserted there was no working relationship between the use of the known integers as each was nothing more than an ordinary ISASMELT^TM furnace and blast furnace, respectively, operating no differently from their previously well-known operation. The opponent further stated that the fact that the claims purport to exemplify the conditions for a suitable feed to the blast furnace does not provide an invention.
The NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd case, [1995] HCA 15, 183 CLR 655, considered whether there was a general threshold requirement of newness or inventiveness in S18(1)(a) of the Patents Act. The decision states that the threshold requirement of an alleged invention means that, if it is apparent on the face of the specification that the quality of inventiveness necessary for there to be a proper subject of letters patent is absent, one need go no further. In the present case the opponent’s argument appears more related to inventive step in the light of the known art which has been discussed above. On the face of the specification itself, it is clear the alleged invention resides firstly in the use of the combination of a TSL furnace and a blast furnace. These individual integers may well be accepted as known. However a working interrelationship between these furnaces is readily apparent. The claims of the specification further put forth a number of collective, allegedly unique operating parameters, chemistries and mineralogical structure in association with the furnaces.
I conclude the application relates to a manner of manufacture.
FAIR BASIS AND CLARITY OF CLAIMS
The opponent noted the claims require that the slag removed from the lead smelting furnace be cooled at a cooling rate of less than 50^oC per minute. The opponent submitted the specification was silent on how to monitor and control the rate of cooling other than to say that the process is operated to produce slag having similar mineralogical properties, softening properties and which behaves in a similar way in a blast furnace to normal lead sinter. If the claims go to more than known processes for cooling slag, then the opponent submitted they are not fairly based on matter described in the specification.
The opponent’s position on this point is unclear. The opponent’s own Mr Happ, at [94] of his first declaration, discussed a second embodiment of the invention. This embodiment begins at the foot of page 6. Mr Happ stated that, to the extent that this embodiment involved operating a TSL furnace to produce a slag having similar properties to traditional lead sinter, he considered this consistent with the approach he would have taken in seeking to implement the proposal set out in the Arthur paper. Good quality lead sinter is achieved when the sinter has a mineralogy which includes a melilite/spinel network which provides a refractory framework for the sinter within the blast furnace. Mr Happ stated such a mineralogy is achieved when the sinter is, amongst other things, cooled at an appropriate rate. He also stated the effect of cooling rate in respect to slags is equally significant. I conclude the claims are fairly based in respect to the cooling rate of slag removed from the lead smelting furnace.
The opponent submitted the phrase “wherein the material that is fed to the lead smelting furnace contains from 50 to 75% by weight Pb” in claim 1 is unclear. The opponent argued the expression “material containing lead sulphide”, earlier in the claim, could be interpreted as meaning either the totality of all material fed to the furnace or a subset of that totality. The question was whether flux additions and/or all lead bearing components, from which lead is produced, were included as part of the percentage weight measure or only the lead sulphide bearing components that were fed to the furnace.
The law is replete on principles of construction. See for example Décor Corporation Pty Ltd v Dart Industries Inc, 13 IPR 385 at 400, a decision from which the principles of construction were cited with apparent approval in Pfizer Overseas Pharmaceuticals v Eli Lilly and Company, [2005] FCAFC 224. Citing some points from [249] of Pfizer, one must read the specification as a whole. The specification should be given a purposive construction rather than a purely literal one. In Nesbit Evans Group Australia Pty Ltd v Impro Ltd, [1997] FCA 1092, Lindgren J added the following to the propositions from Décor Corp. There is a danger in considering the integers of a claim individually and in isolation: the approach can easily yield a literal rather than a purposive construction. The court should avoid too technical or narrow a construction of claims. In Austal Ships Pty Ltd v Stena Rederi Aktiebolag, [2005] FCA 805, the court stated at [71] that the specification, including the claims, is not to be read in the abstract but construed with common sense in the light of the common general knowledge in the art at the priority date.
If there is any ambiguity or inconsistency, it is appropriate to define or clarify, as best one could, the meaning of words in a claim by resorting to the descriptive part or body of the specification. See the Interlego AG v Toltoys Pty Ltd decision, [1973] HCA 1 at [14] of the Full Court decision.
Claim 1 opens by defining a method for producing lead from a material containing lead sulphide. That material is then defined as being fed to a TSL furnace and moreover this material contains from 50% to 75% by weight Pb. On a purposive reading, the material would appear to be in reference to lead concentrates. Further support for this may be found in claim 3. This claim defines additional material by way of a fluxing agent being added to that furnace. Moreover the description at page 5 lines 14-21 describes lead concentrates having a range of compositions including 50-75% by weight Pb, and that the lead concentrates, together with air, carbonaceous material and fluxing agents are added to the lead smelting furnace. Clearly fluxing agents, etc, are regarded as additional material to the lead concentrates that are added to the furnace. I conclude claim 1 is clear in respect to the percentage weight measure.
OTHER GROUNDS OF OPPOSITION
The opponent’s statement of grounds and particulars also mentioned insufficiency and lack of usefulness as grounds of opposition. The opponent’s submissions in respect to insufficiency cover essentially the same point about the cooling rate already discussed above under fair basis. There were no substantive submissions against usefulness.
CONCLUSION
I conclude the opposition is unsuccessful on all grounds raised in this opposition.
Subject to appeal, I direct the application proceed to grant.
COSTS
Both parties sought costs, whilst also seeking consideration in their respective favours for the proposed amendment made during the course of the opposition to delete several dependent claims. In the event, that amendment has not affected the outcome. I see no reason to depart from the usual practice that costs follow the event. I award costs in accordance with Schedule 8 against the opponent, Outotec Pty Ltd.
M G Kraefft
Delegate of the Commissioner of Patents