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Of the world's total production of gold the largest proportion comes from the more regularly consistent ore bodies, but in the aggregate an important part comes from those which are often irregular, uncertain and small. These smaller ore bodies are often high in grade and, as the capital required to work them is not large, they appeal to people seeking a quick and profitable return for a small outlay.These small mining concerns cannot afford detailed geological and petrological investigations and mapping, so they are very often dependent on local knowledge and experience which admittedly may be of really great value.Nevertheless the absence of skilled guidance may not only cause good opportunities for intelligent exploration to be lost, but discourage the seach for other ore bodies.lVIining engineers in the course of their travels in the examination of mines often come across such cases and also others where problems of finding lost ore bodies have been solved by the man on the spot. As records of cases are valuable and useful additions to the knowledge of ore occurrences, the writer now proposes to describe one such case coming under his observation in recent years.It is that of a small mine, known as the Idaho, at the southern end of the famous "Golden Mile" at Kalgoorlie (see Fig. 1). This mine has been a small and very erratic producer ever since it was abandoned by an English company which owned it forty years ago. Except for one period of four years it has always been owned and worked by parties of co-operative miners and during its time has gone through a tortuous career. Although it has often...

Jan 1, 1938

The Illawarra District, from 50 to 100 miles south of Sydney, is one of the State's important coalfields. It extends from Clifton on the north, to the Shoalhaven river on the south, and from the coast westward beyond the coastal scarp.For descriptive purposes, this area falls naturally into two zones:(a) the coastal belt backed-by the eastern edge of the plateau;(b) the plateau, westerly from the coastal scarp.(a) The Coastal Belt.A triangular shaped area extending from Clifton to the Shoalhaven river, composed for the most part of soft coal measures strata of Permian age, which, on weathering, undermines the massive overlying Mesozoic sandstones and causes the gradual recession of thecliffs.South of Wollongong, upper marine sediments and contemporaneous igneous rocks make their appearance beneath the coal measure beds and occupy the greater portion of the coastal belt.(b) Plateau Area.Extending westerly from the coastal escarpment is a plateau known as the Robertson Tableland, composed of Triassic sandstone and shales dipping gently in a northerly direction, and capped in places by Wianamatta. shales and r.rertiary basalts. This tableland is approximately 2400 feet above sea level in the vicinity of Robertson, and gradually falls to about 750 feet at Waterfall.The plateau area for the most part is highly dissected, rough, steep gorges alternate with sharp ridges.A large part of the northern watershed of the Robertson tableland is a reserve for Sydney water supply, and large dams have been constructed at Cataract, Avon, Burke, and Cordeaux.

Jan 1, 1938

The works of Metal Manufactures Ltd are situated at Port Kemblam NSW, within a few hundred yards of a deep-water harbour. At present they occupy about 26 acres, and ample provision has been made for future extensions. Rail connection exists between various parts of the Works and the main South Coast Railway, the harbour jetties and the adjacent copper refinery of The Electrolytic Refining and Smelting Co Ltd. A plan of the works is shown in Fig 1.The company was incorporated in March 1916, and commenced production of copper wire in June 1918. Early in 1920, tube manufacture was undertaken, followed by telephone cable mnufacture in 1923. Today the Works consist of five principal sections: Founrdy, Tube Factory, Wire Factory, Cable Factory and Case and Drum Factory. Whilst the last four are engaged in producing the finished materials for despatch from the Works, the first-mentioned is engaged in producing copper, brass, and other non-ferrous billets for use in the Tube and Wire factories. In addition, there are Engineering and Metallurgical Departments supporting the manufacturing sections, and in these, as well as in all other sections of the Works, extensions have been carried out from time to time to provide for increased output and new types of products.

Jan 1, 1938

By Miller F. S

The famous Golden Mile of Kalgoorlie in Western Australia was, between 1888 and 19ft, one of the richest and most important gold camps in the world. Annual production, which reached a peak of nearly 1,300,000 oz. in 1903, however dropped to below 400,000 oz. after 1920.Depression seized the camp, and many mines closed down. The output from this old field is now steadily mounting under the stimulus. of a higher price for gold. In 1935 300,000 oz. of precious metal were recovered and the future is bright. Total production from the field is 21,400,000 oz., whereas something like £23,600,000 have been paid in dividends.The Golden Mile has been studied by many geologists. Their somewhat diverse findings were published for the most part in the Australian technical press which, unfortunately, is not sufficiently represented in foreign libraries.The following article is based on an eighteen months' study in the district for Gold Mines of Kalgoorlie Ltd., preceded by four years' experience with almost identical rock types in the, Porcupine district of Ontario. The excellent record of observed fact left by previous invesigators, augmented by talks with observant mining men...

Jan 1, 1937

The following paper describes the refining practice for the production of lead, silver and gold at the works of The Broken Hill Associated Smelters Pty. Ltd., Port Pirie, South Australia.The refinery is situated on the wharf frontage and is built parallel with it. The refinery occupies an area of approximately 3380 square yards. (Fig. 8)There are two buildings, one containing the softening and de-silverising sections, measuring 225 ft. x 57t ft., while the other building, which measures 225 ft. x 90 ft. covers the de-zincing, lead moulding, retorting, cupellation, and dore parting sections. (Fig. 1)The retorting, cupellation, and dore parting sections are completely isolated from the rest of the plant by strong small-mesh wire gratings welded to steel uprights. The dore parting plant and generator room are further isolated by a brick wall, built up to the roof. The two main buildings are steel structures, with outer walls and roof of "Robertson" corrugated sheeting; the side and end walls are open for some distance above the ground, and this, coupled with the high roof which is 50 ft. from ground level, ensures the free access of air and light. Conditions are such that operators work in a clear atmosphere.

Jan 1, 1937

By Met B. E

During the operation of the Parkes process of desilverising, and in the earlier days of the continuous process, gold and silver were removed separately from softened lead bullion. Gold was removed in the Parkes process by a selective zincing, and -in the continuous process by treatment with zinc in a special de-golding kettle, in each case a crust being obtained carrying the gold and a small portion of the silver. Actually the process could have been more correctly termed a de-copperising process, on accountof the relatively large amount of this metal present, and its affinity for zinc, which caused it to enter the crusts produced.The crust was treated in reverberatory furnaces, where the bulk of the copper and zinc was removed in by-products, and the resulting "gold bullion" cupelled to give adore bullion containing approximately 2,000 ounces gold per ton.For the purpose of parting this dore, a small Balbach-Thum plant of 11 cells was used, and once each six months a short campaign was conducted on the accumulated metal.With the development of the process of de-copperising smelter bullion by means of sulphur, when a bullion averaging about .004% copper was constantly available for refining, the need for a separate de-golding process disappeared.The de-golding kettle of the Continuous Process...

Jan 1, 1937

The usual metallurgical, engineering and administrative activities associated with the handling and smelting of ores, and the subsequent handling and treatment of the products of smelting, present also problems of hygiene that engage the earnest attention of executives in all well-managed concerns.Again, associated with the employment of any considerable number of men, there is always present the problem of accident prevention.INDUSTRIAL HYGIENE.In the earliest records of lead min.ing and smelting there are references to the injurious effects of lead oh the health of the employees, and, with the advancement of medical science, lead poisoning has been the subject of many works by various authorities in many countries.Moreover, in practically every civilised country, there are laws governing the conduct of the lead industry, and in most cases these laws stipulate that employees shall receive compensation for disability caused by lead poisoning.This provision gives the problem an economic aspect. Apart from the legal and the economic aspects, however, there is the humanitarian aspect, which implies that the...

Jan 1, 1937

Notwithstanding full concurrence with the dictum of a famous scientist that "definitions are the most accursed of all things on the face of the earth," in view of the considerable confusion which exists in jigging nomenclature, it is considered advisable to commence this paper with the following explanations of the terms which will be used throughout the text.Jig Bed. The whole layer of material lying on top of the jig screen.Ragging. The layer of denser material lying immediately above the jig screen, which is too coarse to pass through this screen and is confined horizontally by the cells of the top grid.Ore Column. The layer of ore pulp between the ragging and the top-water.Top Water. The water, carrying fine material in suspension, which flOiWS over the surface of the jig bed.Hutch Water. The water added to the jig below the screen. (Except for the water discharged with the hutch concentrate, the "hutch-water" eventually becomes "top-water.")Feed Water. The water in the ore pulp fed to the jig.(This water becomes part of the "top-water.")Pulsion. The period of the jigging cycle during which the water is moving upwards relative to the particles in the jig bed.

Jan 1, 1937

As this is the first occasion I have had, and probably will be the only opportunity I shall have, of addressing such a large gathering of members and of student members of the Institute, I desire to- express my very deep appreciation of the honour 'you have paid me in electing me to the office of President for the current year. I realise also that such selection is a tribute to the Company which controls operations here, the centre selected for the annual meeting, but nevertheless there is afforded to the recipient a great deal of pride and of pleasure to hold the highest office in what is, in my opinion, undoubtedly the most important engineering society in Australasia.The past year has witnessed an unprecedented and unparalleled event in the history of the British Empire, and I think that we must all feel a wonderful sense of proud patriotism; the whole world was forced to admire the public calm and the dignity which accompanied the change in our Sovereign Ruler, and great tribute is due to the statesmanship of the Prime Minister, Mr. Baldwin. At this time, we should, I think, place on record our prayer, in common with all his people, that His Majesty, King George the Sixth, may enjoy a long and prosperous reign.The meeting at Port Pirie recalls one who did so much for the advancement of mining and metallurgy, especially in Australia. I refer to the late Mr. Delprat, who, as General Manager of The Broken Hill Proprietary Company Limited, had under his control for many years the smeltery in this centre. As you are aware, he had been elected an honorary member of this Institute, as well as of our sister Institutes in England and in America...

Jan 1, 1937

This Department handles all ores prior to blast-furnacing, the object of the operations being to mix the lead-bearing material with fiuxes, eliminate sulphur from the mixture, and produce a homogeneous sintered product which is chemically and physically suitable for treatment in the blast furnaces.During the financial year ended the 30th June, 1937, the tonnage of charge treated was 458,960 tons, containing some 183,470 tons of lead and 8,504,000 oz. of silver.The quantities of the principal components of the charge treated were as follow:-

Jan 1, 1937

A BRIEF DESCRIPTION OF TELPHER HANDLING AND BLAST FURNACE EQUIPMENT.The various sections will be described in the following order:(a) Telpher Handling and Storage Bins.(b) Blast Furnaces.(c) Slag Disposal.(d) Bullion Handling to Drossing Kettles.(e) Copper Drossing.(f) Copper Matte Furnace.(g) Bullion Delivery to Refinery.(h) Fume Handling.(a) TELPHER HANDLING.The telpher installation is an all-steel structure designed to carry out the work of assembly and delivery of charge materials to the blast furnaces.To simplify description, the primary telpher installation will be divided into three (3) sections:-No. 1 Section. 395 ft. long, running north and south, parallel to the water front, and so located that coke, which...

Jan 1, 1937

The whole of the iron ore required by the Broken Hill Proprietary Company Limited at the Newcastle Steel Works, and Australian Iron and Steel Limited, at Hoskins' Kembla Works, is drawn from the Iron Knob, Iron Monarch, Iron Prince and Iron Baron deposits situated in the northern part of Eyre's Peninsula, South Australia.The Iron Knob and Iron Monarch deposits are near the township of Iron Knob, approximately 42 miles W.S.W. of Port Augusta, whilst the Iron Prince and Iron Baron deposits are some 18 miles due south from Iron Knob, in another group of leases, the adjacent township being known as Iron Baron.The ore mined at Iron Knob, Iron Monarch, Iron Prince and Iron Baron is conveyed on the Company's 3ft. 6-in. gauge tramway to Whyalla, on the western side of Spencer's Gulf, approximately 45 miles south by west of Port Augusta whence it is shipped to Newcastle and Port Kembla.SHORT HISTORY.The establishment in South Australia of the lead smelting industry at Port Pirie, Dry Creek and Port Adelaide in the...

Jan 1, 1937

The sulphide ores of the Kalgoorlie goldfield have long been looked upon as' refractory, involving special metallurgical treatment. For many years two kinds of treatment have been practised-(l) wet treatment, including fine grinding, amalgamation or concentration of the free gold, concentration of the sulphide minerals with subsequent roasting and cyanidation, and cyanidation or bromo-cyanidation of the residue from the concentrating operation; (2) dry-crushing of the ore and roasting the whole of thecrushed ore, amalgamation of the gold in the calcine during fine grading, followed by cyanidation. The wet treatment was advanced a stage further when, in 1929, the Lake View and Star Ltd. adopted large scale flotation. As a consequence, however, further metallurgical problems were introduced. This paper covers the investigation, ,of one of the most prominent of these problems.Flotation preceded by strakes was satisfactory to a point.The flotation concentrate consisted largely of auriferous pyrite and tellurides, and the gangue minerals in the concentrate were practically barren.Several sources of loss of gold values were, however, found to be associated with this circuit, viz.-(a) There was the loss of gold in the flotation tailing.(b) Loss by dusting during roasting of the flotation concentrate.(c) Loss of gold in the cyanided residue.

Jan 1, 1937

The art of flotation may be divided into two distinct branches, namely:-1. Collective flotation.2. Selective flotation.(1) Collective flotation is applied when all the valuable minerals in an ore are required in one concentrate, leaving ,only gangue minerals in the tailing. The method is applicable, for instance, to such ores as auriferous copper sulphides associated with gangue minerals only, or to silver lead ores low enough in zinc and other valuable minerals.(2) Selective flotation is applied when there are present in an ore two or more valuable sulphides, which cannot be subsequently efficiently treated unless they are separated from one another as well as from the gangue. For example, a silver-Iead-zinc ore, or a copper-gold-iron ore; where the iron is not required with the copper gold concentrate.In order to make these operations practicable chemical reagents have been developed, having power to exert definite actions on the various minerals when brought into contact with them in a water pulp.COLLECTIVE FLOTATION.In order to bring about collective flotation it is generally necessary to add to the pulp a frothing agent and an activator or activators for all the minerals which it is desired to float.SELECTIVE FLOTATION.The object of selective flotation is to activate the mineral which is to be floated, and at the same time to prevent all other minerals from floating.

Jan 1, 1936

In a previous paper the author showed that silver considerably delayed the recrystallisation of lead after cold work. The effect of antimony on the rate of recrystallisation of distorted lead was studied next, and the experiments performed, and the results obtained, are described in this paper. Electrolytic lead was used as a standard of comparison.It was also used to make the lead antimony alloys.This electrolytic lead contained 0.0005% total impurities.It was prepared from commercial lead by fire refining, followed by electrolysis and finally by vacuum casting. The process was described in the previous paper and the description need not be repeated here. PREPARATION OF LEAD - ANTIMONY ALLOYS.The steps taken to procure pure antimony are outlined in the appendix. To make the lead antimony alloys a mother alloy was prepared thus:-A quantity of the antimony (it was received in the powdered form) was placed in a pyrex glass tube, which was closed at one end. The antimony was washed with hot hydrochloric acid (1: 1), then with more dilute acid, then with distilled water, and finally with absolute alcohol; it was dried by warming and evacu,ating the tube. This should leave the antimony more nearly free from surface oxides.The amount of antimony was determined by weighing quickly; the appropriate amount of vacuum-cast electrolytic *Research Fellow, Dept. of Metallurgy, University of Melbourne.

Jan 1, 1936

By Met M, Worner H. K

In pursuance of the investigation into the influence of various elements on the properties of lead during the past year, the effect of several elements on the creep rate of commercially pure lead has been investigated; a standard initial stress of 500 lb. per sq. in. having been adopted for comparison purposes. Other work which has been carried out indicates that the relative results of creep tests may be altered by varying the applied stress, but this aspect of the problem will need to await further investigations for itscomplete elucidation. The results obtained with dilute tellurium alloys are considered sufficiently interesting, and in some respects are so extraordinary, as to warrant publicatiorr at this stage.n must be realised however that, since the results obtained appear to be at variance with those said to have been obtained in practice and those previously published, the present investigation can only be considered as a contribution to our knowledge of the general problem.Consequently it is not considered advisable or necessary to offer detailed explanation of the results given. In fact, some features of the tests about to be described will need further investigation before an adequate explanation is possible.

Jan 1, 1936

This paper contains an account of some creep tests on electrolytic lead and some of its alloys. The stresses used in determining creep were 500, 350, and 200 lb. per sq.' in. The alloys contained silver, bismuth, tellurium, antimony and zinc respectively. All were castin vacuo, and tested "as rolled." Tests were done also on electrolytic lead which had been cast in air.The electrolytic lead contained 0.0005% total impurities.The preparation and vacuum casting of this lead have been described in a previous paper in this series. The preparation of the alloys, and the air casting of the electrolytic lead, are described in the next section.EXPERIMENTAL PROCEDURE.Every effort was made to keep the vacuum-cast specimens from contact with the atmosphere throughout their history.The ingots were stored eIther in a vacuum desiccator or immersed in heavy oil. The creep specimens were coated with vaseline except during rolling, etching and photography, which involved exposure to the atmosphere for about 45 minutes all told.It is not claimed that vaseline is a perfect shield against the intrusion of atmospheric gases. Possibly during the months that some tests were in progress the gases diffused through the vaseline and gained a limited access to the lead.Nevertheless, the use of vaseline gave protection that brought the tests nearer the ideal at which the author aimed, *Research Fellow, Dept. of Metallurgy, University of Melbourne.

Jan 1, 1936

By Morgan W. M

It is not the primary object of this paper to treat with the scheme of prospecting in detail, but it is considered that a brief description of the broad lines is necessary so that the significance of the points to be discussed later may be appreciated.The finding of payable gold reefs on the Bendigo field resolves itself into a two-fold problem, firstly the location of quartz bodies, and secondly the location of gold shoots in such bodies. The country rock of the field has been folded and faulted, and the occurrence of known reefs is associated with the fold axes and the faulting. The "lines" of the field are the anticlinal axes, and practically all known reefs are at or near centre country. Very little work has been done on the synclines, which may have some potential value.Quartz has been introduced along the fracture systems, and gives rise to the three main types of reef met with on the field, namely, the "back," which is similar to a bedded quartz reef and is formed along a bedding plane fault; the "saddle," which forms at the crest of the anticline and has the typical shape from which it takes its name; and "spurs," which are irregular masses of quartz, making off reefs of the first two types.As the fracturing throughout the field is widespread and fairly intense, the first problem, that of finqing quartz, is comparatively simple, and any regular system of blocking out the ground will be productive of quartz bodies.*Field Superintendent, Bendigo Mines Ltd. Assistant Field Superintendent, Bendigo Mines Ltd.

Jan 1, 1936

In setting out to describe the methods and machinery employed at Iron Knob the writer does not attempt to give any information as to the situation, topography or geological features of the locality. This, together with estimates of the quantities of ore still available, has been carried out in a most thorough manner by R. L. Jackr and F. R. Hockey. This essay is intended to deal with working methods as they exist to-day, beginning with drilling, blasting, quarry traction, etc., and touching on such details as the supplyof electricity, water and compressed air.At the present time almost the entire output of ore is won from the hill known as Iron Monarch. The form of the hill, a smooth, rounded dome, rising some 640 ft. above the plain and having a base diameter of n miles, lends itself ideally to the "bench" system of open-cut quarrying.Fig. 1 shows the relationship of the benches "A," "B" and "E" in their order of development. Bench "E" is at present the principal working, but, as the greater part of the ore above this level has now been removed, bench "A," some...

Jan 1, 1936

The Middleback Ranges are a series of parallel northsouth ridges on the eastern side of the Eyre Peninsula, South Australia, about 20 miles inland from the Spencer Gulf, as shown in Fig. 1. They extend for some 20 miles across the centre of the County of York. North of them, on the same line of strike, in, the County of Manchester, is a disconnected series of lesser which ends in the Iron Monarch-Iron Knob ridge, the principal iron ore locality. These ridges are referred to in the following pages as an integral part of the Middleback Ranges.The deposits of hematite which outcrop in these ranges (Fig. 1) form the most important group of iron ore bodies in Australia, and are exploited by the Broken Hill Proprietary Company. The largest of them is the Iron Monarch (Fig. 6) .H: The next largest are the Iron Duke, the Iron Prince and Iron Baron. The Iron Knob, Iron Duchess, the North and South Iron Knights, Iron Queen, and the small body south of it, the Kimba Lease, and the deposits in the Cook's and Ash Leases, are all smaller.Numerous small lens-like bodies of hematite occur throughout the ridges, but are not of sufficient size to be of commercial use. At present only the Iron Monarch and the Iron Prince bodies are being worked. The Iron Knob was quarried previously, but its remaining supply is held in reserve.*Published by permission of the Council for Scientific and Industrial Research.

Jan 1, 1936