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The Pamphlet Collection of Sir Robert Stout: Volume 40

Antimony

Antimony.

There are three antimony lodes in the Province, one at Waipori one at Carrick Range, and one at Doolan's Creek. I will deal first with the Waipori lode. It occurs about 12 miles north-west of the Lawrence railway station. The outcrop of the lode was discovered about 15 years ago, when a few tons of ore were sent to England, in order to ascertain its value. The returns gave 47% and the ore realised £12 per ton. The discoverer, knowing nothing about ore, did not dress it, or it could have, with very little cleaning, been raised to 55 or 60 per cent. At that time, there were no roads fit for heavy traffic, and the railways had not then been even thought of. The lode being 60 miles from the port of Dunedin, the cartage, which was then very high, would have page 11 absorbed most of the proceeds. Besides, labour was also very high and not easily got, as the gold fever was then at its height. Consequently nothing further was heard of this antimony lode until January 1880, when Mr G. Watson and others, of Dunedin, applied for a lease of 80 acres. About that time one of the Government Geological staff reported on the lode. The report is published in the Geological Explorations for 1881, pages 155 and 156. The report speaks very highly of the lode and strongly recommends it being worked. The following are a few extracts :—

"The lode crops out in Stony creek (celebrated for its gold producing qualities), and strikes 70 degrees east, underlying north 20 degrees west, two feet in a fathom, structure massive, formation regular. Mineralogically the lode is composed of fibrous and compact stibnite; the former being almost pure. An adit level driven east on the course of the lode, by the original discoverer, shows a very promising lode. In another place a shallow shaft is sunk on the lode; at this place the lode is from 4 to 5 feet thick. A very large area of moss, which makes excellent peat, exists close to the mine, which will be quite sufficient to bring this easy reduced ore in to a concentrated state of rough metal. In conclusion, I consider the working of this mine a most legitimate undertaking, and one likely to be beneficial alike to shareholders, and to the Colony."

The expert in his report advised plans for opening the mine which were adopted, and work shortly afterwards commenced. A road had to be made to the railway station, the necessary cuttings for which were done by the County Council; and by July, the first shipment of 111 bags of ore was despatched to Melbourne. In a few months the lode had been found cropping out at various places, for a distance of quite half a mile, the ore occurring in large bunches and pockets. Several tunnels having been commenced on the line of lode, on what is known as the west or upper end of the lease, it was decided to put a shaft down near the outcrop of a large body of ore near the east end, where the ground will not permit of tunnelling to advantage, being too flat. At a depth of little more than 70 feet the shaft cut the lode, but here the party's troubles commenced, water coming in too freely to be profitably lifted by buckets. A pump was got, but proved too small. The manager in charge of the mine knew very little about lode mining, and disagreements arose amongst the shareholders, the result being that one party bought the other out. Soon after an experienced antimony mining manager from Victoria was employed, who advised the erection of water wheel, more powerful pump, winding gear, &c. This was done, the water overcome, and work resumed on the lode. No systematic stoping has as yet been done on the lode, but from the various drives and cuts 1500 bags of ore have been taken out, and sold to a Melbourne smelter who gives £10 10s per ton of ore. There was reason to believe that £10 10s was not a fair price, and to ascertain what the same ore would realize in London, a few tons were sent through Messrs. A. & T. Burt to their agent in London, who sold it at £18 per ton. But very little enquiries will serve to show that it is a mistake to dispose of the ore in its raw state, even at £18 per ton; that is to say when there is fuel procurable near the mine. To procure information on this point, Mr G. Watson and the writer visited the page 12 antimony mines of Victoria. The most productive in the world is one of the Costerfield lodes, having given half a million in dividends.

The metal, antimony, is generally worth about £60 per ton; two tons of 55 per cent, ore will give one ton of pure metal, allowing for loss, which makes the raw ore worth £30 per ton, less the cost of smelting and transit to market. Allowing £12 for smelting, and £4 for freight, &c., to London, that would make the ore worth £22 per ton to the miners. But that is not the only advantage gained by having a smelting works on the ground. In all mines there is a quantity of poor ore, which can be put into the furnace and turned into metal, which would otherwise be wasted, and the cost of hand dressing and bagging would also be saved. In exporting the unrefined ore, the rubbish contained in it, costs as much for transit as the metal; so that is another saving, by smelting locally. The Waipori mine is now in a fair way of development, with every prospect of a successful future.

The Carrick Range lode was not discovered till about 1871. Its discovery caused some sensation at the time, as the miners, who were unacquainted with antimony, thought it was silver, and as an outcrop of considerable size and purity was exposed, all the interested parties thought their fortunes were suddenly made. But the report of the analytical chemist dispelled the silver theory by showing that it was only antimony of good quality. As nobody appeared to have any knowledge of antimony, nothing was done with the lode till taken up by the writer and party. A track was cut from the road leading up the range to the outcrop of the antimony, and with very little trouble 103 bags of ore were taken out by two men, bagged, and despatched to London, where it was sold by a broker for £12 per ton. The report that came from London was to the effect that the ore was of extra good quality, but very badly cleaned. In fact, a large quantity of blue quartz, containing very little if any ore, had been, through the ignorance of the miners, put into the bags in mistake for ore. If ordinary care had been taken the consignment would have realised several pounds per ton more. However, £12 was the price got, and considering the distance of the mine from a port, the very bad roads, the expense of carting at that time, which was £8 per ton, the margin of profit was not sufficient to justify anything further being done until some cheaper means of transit was available. The question of smelting the ore did not occur to the then owners. If they had made enquiries and ascertained the cost of smelting and the value of the "Star" metal, no doubt they would have continued working, because, notwithstanding the heavy items of cartage, a handsome profit would have been got by sending away pure metal. Nothing, however, was done at that time beyond sending away the 103 bags. Since then a railway has been made, connecting Lake Wakatipu with both Dunedin and the Bluff, consequently the only obstacle against the lode being profitably worked has been removed, and instead of £8, the ore or the metal can now be put on board of ship at Port Chalmers for £3 per ton. In view of this cheap means of transit, the lode is again being opened out, the owners being principally Dunedin men. The lode occurs about three miles west of the Bannockburn, at an elevation at the highest point of the outcrop of about 600 feet, and at the lowest part of about 400 feet above the level of the nearest flat. The general run of page 13 the lode is east 15 south, dipping north at an angle of 55°. It is opened at a number of places, and can be traced for about one mile in length, and as it travels diagonally the face of a steep hill, the difference in height of the highest and lowest outcrops found is about 200 feet. The lode between the walls varies from a few inches to three feet. In some places the ore is clean, in others mixed with quartz. On account of the precipitous nature of the locality, the mine can be worked to a great depth without the usual expensive machinery. Three miles from the mine, and on the road towards the Lake, there is a coalpit which the Company have wisely secured, near which the furnace will be erected and the ore reduced to metal, and sent by way of Lake Wakatipu to either Dunedin or the Bluff for shipment.

The Doolan's Creek antimony lode occurs about two miles from the main road, and 15 miles from Frankton Jetty, Lake Wakatipu. The largest blocks of ore yet found in the Province came out of this lode, showing that the lode is massive. The ore is of the ordinary class, containing something over 50 per cent, of metal. Fuel is also abundant, as Coal Creek, where there is a good seam of coals, from which supplies for the surrounding district is taken, is within two (2) miles of the antimony. As it is only within the last few months that any work has been done on the Doolan's Creek lode not a great deal is known as to its value, but as it is only a short distance from the Carrick Range lode, and on the same line, it is supposed to be a continuation of it.

On account of the increased uses to which the metal antimony has been put of late years, the demand exceeds the supply, and a consequent rise in price has taken place. The metal, as an alloy, is used in type metal, Britannia metal, pewter, German silver, and such like, but by far the largest quantity used as an alloy is in the patent metal, known as white metal, now coming extensively into use for the bearings of machinery. It is also used in medicine and in the art of dyeing.

For many years England depended for supplies of antimony from Borneo, but the mines there having been constantly worked for generations are now nearly worked out, and as the continental nations have none to spare, with the exception of Italy, which still exports 700 tons per year, and there being no lodes of importance in America, England is now depending almost entirely on the Australian Colonies for supplies of this metal.

Antimony being very heavy, (412 lbs. to the cubic foot), a very thin seam pays to work. One of the lodes examined by the writer in Victoria, was in no place more than eight inches thick, and in many places not more than 2 inches, and for hundreds of feet in some of the levels showed no ore at all. An average of four inches, under favourable circumstances, is a good payable lode. Allowing the ore to be only 300 lbs. per cubic foot, a lode of 4 inches will yield over tons to the fathom.

Furnaces for reducing the ore to "Star" metal, cost under £300. It will be seen that unless there are roads to make, no great amount of capital is required to prosecute antimony mining, consequently a small output of ore will not only pay but leave handsome profits. To make the bare statement that an output of 6 tons of ore per week would give a page 14 profit of over £4000 a year would be looked upon as ridiculous, but the following calculations are made on the very best authority, and from information gained from experience:—
6 tons of ore per week, or 312 tons per year, yield 130 tons of "Star" metal, at present market price, £55 per ton, gives £7150
Cost of raising ore per ton, £3 £936
Cost of smelting 130 tons, £12 per ton 1560
Transit to market, say from Carrick Range, £4 per ton 520
Bags, insurance, and contingencies, £1 per ton 13
3146
Leaving a profit of £4004