History and heritage: Metallurgical progress in the Australian Commonwealth
The following Presidential Address is an edited excerpt from the Proceedings of the AusIMM, No 103. It was delivered in Melbourne on 20 August 1936.
In choosing the subject for my address to you this evening I was actuated by the knowledge that in the past Australian metallurgical problems have been solved by the introduction of extremely interesting processes. Frequently such processes originated in this country, or at least were first adopted here on a large scale.
Chronologically there comes to mind the application of chlorination to the Mount Morgan ores from 1888 onwards. Then the application of pyritic smelting to the Mount Lyell orebody in 1896, followed closely by the successful flotation of zinc blend at Broken Hill, about 1900, and the treatment of the refractory Kalgoorlie gold ores by roasting and cyaniding.
With the development of the differential flotation process at Broken Hill came the production of a slime lead concentrate carrying zinc, which necessitated the use of a high zinc slag in the lead smelting process. Although previously considered impossible, the necessary technique was successfully evolved at Port Pirie resulting in the accumulation of large tonnages of zinc-bearing slag as potential sources of that metal. The past twenty years have witnessed:
- the establishment of a flourishing iron and steel industry, with its attendant coking and by-product plant at two centres in New South Wales, namely, Newcastle and Port Kembla
- the establishment of an electrolytic zinc process at Risdon in Tasmania
- the application of flotation processes to the metallurgical treatment of gold ores at several centres in Western Australia, notably, Kalgoorlie and Wiluna, and in Queensland at Mt Morgan
- the application of flotation processes to the concentration of copper ores at Mount Lyell in Tasmania and Mount Morgan in Queensland
- the establishment of an electrolytic copper refinery at Mount Lyell
- the conversion of the lead refining operations at Port Pirie from batch treatment to a continuous process
- and finally, the establishment and rapid growth of secondary metallurgical industries, ferrous and non-ferrous, in Newcastle, Sydney, Port Kembla and Melbourne, and to a smaller extent also in the remaining state capital cities.
The picture so presented is one of continual change, a continual adaptation of processes either to the changes in character of orebodies as at Mount Lyell; or in order to take advantages of knowledge gained in some other field, as in the application of flotation in gold metallurgy; or the development of an entirely new process based on original research, as in the continuous lead refining.
It appeared to me, therefore, that it might be of service to the Institute if an attempt was made in the course of this address to bring before you in an ordered sequence the kaleidoscopic changes which this most progressive field of human activity has undergone during recent years.
In order to do this authoritatively, the help of the managements of various plants has been enlisted to supply the details of recent changes; and I take this opportunity of thanking them for the spirit of co-operation they have displayed in providing the material on which this address is based. It augurs well for the continued development of the industry that such a broad-minded attitude prevails amongst its leaders, that detailed information on recent progress has been so readily provided. In assembling material of this nature it is possible to adopt several methods of classification, but, whichever main scheme is decided upon, a certain amount of overlapping is unavoidable.
Only the major metals – gold, lead, zinc, copper, iron and steel – will be considered, and only data from typical plants in each case to illustrate the particular points.
Before passing on to details, however, there are some general observations I should like to put before you, for it appears to me that an occasion of this kind should be utilised for making a general survey of matters pertaining to the progress of the metallurgical art in the Commonwealth.
Perhaps the most important of these is the application of scientific method to the art, and, therefore, I will first deal with the position of research work in the various branches of metallurgy. The latter, however, depends primarily on the existence of orebodies. It is of interest, therefore, to record that scientific method has been applied to the search for orebodies in Australia on a large scale during the past few years.
In 1928-29 an Imperial Geophysical survey party carried out experiments with various methods of geophysical prospecting, but it was not until 1934-35, under the stimulus of the increased monetary value of gold during the economic depression, that attempts were made to utilise these methods on a grand scale. During the past few years aerial surveys have been made in Western Australia by private companies. The Federal Government, in cooperation with the Western Australian and Queensland Governments, is at present carrying out a combined aerial geological and geophysical survey which constitutes by far the most systematic attempt at large scale prospecting which has been attempted in the Commonwealth. Coupled with the organised activities of the Council for Scientific and Industrial Research, to be mentioned later, it forms a complete investigational scheme for studying the mineral resources, which is only limited by the resources placed at the disposal of the survey parties.
The position of this combined survey to the end of 1935, that is, after some seven or eight months' field operations, was as follows:
- A coordinated scheme of examination of selected areas in the three territories had been evolved, and some 3000 square miles of country covered by the aerial survey. This year a further 9000 square miles is to be covered.
- Teams of scientific workers, chiefly geologists and geophysicists, have been gathered together, and the difficult technique of making field observations and interpreting the results has been developed.
- Certain small mineralised zones have been explored, and a possible major occurrence of auriferous magnetite has been located at Tennant Creek, some 300-500 feet below the surface. This field is now being drilled to ascertain the exact nature of the orebody, and it is interesting to know that the geophysical data has so far been substantiated by the cutting of a haematite mass at a depth of 200 ft.
Spectacular results should not be expected immediately from a survey of this nature, covering such vast regions. The important point is that the necessary organisation and technique have been developed. From the point of view of the development of the Commonwealth, it is to be hoped that the present organisation will be maintained and possibly extended when the present three-year program has been completed. To get to know in detail the mineral resources, that is, the potential mineral wealth of Australia, will take many years of careful coordinated work.
Research pertaining to metallurgical industry
The dynamic progress which has been outlined in metallurgical development is an indication that keen intellects have constantly been at work in this fundamental industry.
The complexity of present-day engineering (advances in which are entirely reliant on metallurgical progress) necessitates that a continuance of such intellectual activity be increased rather than decreased. There is no cessation of the demands made by the engineering designer on the metallurgist. Whereas the problems associated with the production of metals are frequently specific; ie, relate to the conditions associated with the occurrence of the minerals in ore or concentrate, those associated with the utilisation of metals for service in daily life are frequently of a more general nature.
Yet, even in the former case there are some general aspects which are outside the investigational scope of individual companies, and it is pleasing to be able to record advance in this direction as well as in the actual plant operation. Within the last few years there has indeed been developed in this country a close cooperation of scientific research and industrial application which those interested in the general development of the Commonwealth must look upon with pleasure and gratitude.
This cooperation has been fostered by the decision of the Council for Scientific and Industrial Research to include the investigation of ore dressing problems amongst its activities, and by the decision of private companies, either individually or in groups, to subsidise work of a fundamental nature.
It was in 1927 that the Council for Scientific and Industrial Research, in conjunction with a group of mining companies, undertook responsibility for the mineragraphic work which Dr F Stillwell has been carrying out in the Geology School of the University of Melbourne. The value of the work that has been done can be judged from the fact that Dr Stillwell has examined most of the ores and many mill products from the chief mining properties within the Commonwealth, and has given valuable advice on mineral associations, which has aided in the solution of the metallurgical problems presented by the ores concerned. Most of the ore bodies opened up today consist of complex intergrowths of minerals and a detailed knowledge of the minerals present, and their distribution in the ore is an essential preliminary to the intelligent development of a flow sheet for the mechanical enrichment of the respective metals into concentrates for subsequent metallurgical treatment.
In 1934 the activities of the Council for Scientific and Industrial Research were further extended by the establishment of cooperative arrangements with the metallurgical laboratories of the Adelaide and Kalgoorlie Schools of Mines, and the University of Melbourne respectively for the investigation of metallurgical problems associated with the extraction of gold from ores.
During the eighteen months that this arrangement has been in operation, the three laboratories have issued approximately one hundred reports, more than half of which have emanated from the very active laboratory of the Kalgoorlie School of Mines under the direction of Dr Moore. Under this extended scheme, the services of Dr Stillwell and his co-worker, Dr Edwards, have been made available to the three metallurgical laboratories so that by close cooperation all means available are brought to bear on the problems submitted.
The wisdom of the dissemination of activities in three centres might be called into question, particularly in view of the success of the centralised activities of the Canadian Department of Mines at Ottawa. However, at the time, it was felt that under the conditions existing in the Commonwealth, and in view of the absence of funds for capital expenditure on laboratories, the only feasible plan was to utilise existing facilities and to extend these, rather than to set up a new organisation which would of necessity have been in competition with the older institutions.
Whilst it was originally intended to confine this extension of activities of the Council for Scientific and Industrial Research to gold ore problems, the Minister in Charge of Development has recently given his consent to the utilisation of the facilities in connection with base metal ores, provided that gold ores shall have preference in any case.
In general, the main mining companies have research organisations that have proved very capable of handling their own specific problems. The part played by some of these companies in maintaining a laboratory for the investigation of the physical chemistry of the flotation process is evidence that fundamental research is appreciated by the technical management of these concerns. This work is being done by Dr Wark and Mr Cox in the Chemistry School of the University of Melbourne, and is under the direction of Mr H Hey.