Kaffir Compound, New Primrose Gold Mine, Johannesburg
As regards the internal circumstances on which the progress of the mining industry depends, these are the employment of the most improved methods and means of production. They comprise the most perfected machinery and appliances, and the latest processes of metallurgical and chemical science. Speaking generally, it may be said that on the Rand at the present time are employed the most up-to-date skill and technical knowledge, and the latest devised mechanical appliances. This, by the way, is only true of individual mines however. The equipment of the mass varies greatly, and necessarily so, since the conditions of one mine differ vastly from those of its neighbour; and distant and even contiguous localities require unlike treatment, according to the nature of the ore or reef worked and other local conditions. The improvement effected hitherto is evidence, however, of the initiation and energy which have been displayed by the heads of the mining industry in the past, and an earnest for the future, while the progress achieved abides as an invaluable guide for all future mining operations in like geological formations.
The knowledge of how best to treat the peculiarities of the banket reef has, however, only been slowly gained, and at the cost of much money and many unavoidable blunders. For instance, the only metallurgical operation for the extraction of gold employed up to 1889 was the stamping mill, and fine gold and amalgam were necessarily abundant in the tailings which were cast away on the spoil heap. The cyanide process, and that of the treatment of slimes, were only applied in 1891 and 1898 respectively. Their use has added millions to the yearly output of gold. The amalgamation process, the chlorination treatment of concentrates, and the use of frue vanners are other innovations gradually introduced as results of experiment and experience, and which have likewise increased the efficacy of the extractive operations. Similar progress has been shown in the improvement effected in the mechanical equipment. At first the mining operations were confined to the primitive digging of a huge trench over the site of the outcrop, with the simplest delver’s tools furnished by the locality. This method has advanced to the stage of sinking shafts to the enormous depth of a mile into the bowels of the earth, equipped with the most elaborate hoisting plant, with underground equipment lit and worked by electricity, and the complementary surface establishments, at a cost running into hundreds of thousands of pounds. There yet lies before the industry the general adoption, not only of these but of other improvements which experience has shown to be desirable, such as the practice of sorting of ore, the use of heavier batteries on the score of greater economy, &c., and their utilisation is merely a question of time. As, therefore, all these improvements and betterments have been successively made, and the mining industry is only now gradually—it is not yet, so far as a large number of them are concerned—entering into the full use of them, it is obvious that future mining operations must not only enjoy the same favouring circumstances as those which enabled the huge mining output of the past, but a very much better environment, through the more general use of all those methods which experience and science have shown to be advisable. As a consequence, and in the measure of the value of these improvements, will the effective output be ameliorated from now onwards.
The value of the improved circumstances of the mining industry alluded to is convertible into figures in the terms of working costs and divisible dividends. The former may be said to be the barometer of the latter. In the past, in the early days of the mining industry, when the problems of mine equipment and gold extraction and winning were only imperfectly understood, the wasteful expenditure of money on inefficient methods and appliances swallowed up in many cases every vestige of profit.
Cyanide Works. Witwatersrand Gold-Mining Co.
(Photo by Horace W. Nicholls, Johannesburg)
It was incidental to the first operations on the then unknown geological formation of the Rand, when the very science of the goldfields had to be created. Costs of working on the Rand are now, through the excellent system devised by the Chamber of Mines, tabulated so that the outlay of individual mines, or of the mining industry in the aggregate, may be seen at any moment at a glance. For instance, taking the record for the eight years from 1890 to 1898 inclusive, for example, the working costs ranged from 80.8 per cent. of the total value of the gold produced by eighty-five companies in 1890 down to 68.1 per cent. in 1898, the last full year before the war, the decrease showing the extent of the progress made in reducing the working costs. Simultaneously the dividends increased from 19.2 to 31.9 per cent., testifying to the close kinship with the costs factor. These figures are a general average taken over the aggregate of the mines working, and do not represent the ratios of working costs of individual mines, which differ of course according to the greater richness of the ore, the fewer difficulties to be dealt with in winning it, and the methods employed to secure the end in view. This is exemplified by the fact that in a few of the best equipped mines costs have been brought down to as low as 17s. 6d. per ton, while on others they rise to 79s. 6d. and above. The Robinson mine is a case where, despite adverse circumstances, the enlightened employment of the latest appliances of science and mechanics has resulted in reducing costs to an extremely low level. In 1888 the working costs of the mine were 72s. 1d. per ton; in 1892 they were reduced to 46s. 5d., and in 1896 to 30s. 11d. They have subsequently been reduced to a still lower figure, and this despite the fact that the ore changed from an oxidised character to a pyritic, involving greater difficulty and cost to treat. This mine was the first to introduce frue vanners, the cyanide process and the treatment of slimes, expending as much as £80,000 in the last innovation. By means of these it raised its gold extraction from 65 to 90 per cent., and gave encouragement and impetus to all mining on these fields. The latest costs published for the month of September this year of thirty-six mines in working give an average of 26s. 3d. per ton, which shows that operating charges are now at about the same ratio as they were before the war. Although so reduced, however, they are still relatively higher than they may be expected to be when the mines settle back into their normal grooves. The reason for this is that only a few mines are now working up to their full battery power, and, while costs are on the full scale, results are less, surface dumps are being drawn upon for mill service instead of the mine itself, owing to lack of full supply of labour, &c. When, however, the effects of the important fiscal reductions just made have had time to exercise their effect in reducing the cost of imported mining stores, foodstuffs, and the smaller machinery and metal goods charged by the mines to the working account, further reductions in the working costs will be possible. Of the actual money value of this per ton of ore milled, various opinions have been ventured. It has been estimated by experts that it is possible under favouring circumstances to reduce the expense of working by some 10s. per ton, at which rate ore yielding over 5.6 dwt. per ton bullion could be made to yield a profit. The importance of this not only in improving the present position of all mining undertakings, but in stimulating the low-grade mines to come into the working stage, can hardly be overestimated. With the various difficulties besetting the mining industry removed, the future working cost level should be lower than at any preceding period, taking into account the benefit of the recent fiscal reductions and other governmental assistance in prospect.
