ROYALTIES
ROYALTIES. The average royalty charged by the process owners for the use of these flotation processes is one shilling per ton of ore treated. This is very high royalty as measured by others with which miners and metallurgists are familiar. It is conceded that the inventor deserves compensation for his ingenuity, but is. per ton is about four times as large a royalty as the mine manager would expect. Large royalties have the disadvantage that they place a premium on infringement, and for this reason alone are, from the standpoint of the process owner, not good business. The combined capital of all the companies owning flotation processes is close to 1,000,000. This means that 20,000,000 tons of ore will have to be treated and pay royalty of is. per ton before the capital is returned. These companies have been in existence now about seven years, and if we consider the investment ought to earn 10%, then the processes should have treated to date, besides the above tonnage, 14,000,000 tons more, making a total which should have been treated to date 38,000,000 tons. They are still about 30,000.000 tons behind the game. This does not mean anything particular, except that as a class these process companies were considerably over-capitalized, and have also wasted their money, both revenue and capital, on expensive litigation.
WORKING COST. Figures on cost and recovery, owing to entirely unnecessary secrecy on the part of some of the companies, are not to be secured in the ordinary manner. But there are few secrets* which do not yield to the cruel analysis of the mathematical equation, assisted by scraps of evidence which can be collected in the broad light of day. By these means and the published returns of those who are proud of their work, a fairly correct summary of the whole position can be made as to the treatment of Broken Hill zinkiferous tailing. The following is a general average of all the processes :
s. d.
Tramming to plant . . . . . 6
Re-crushing . . , . ... i 8
Flotation treatment . . 3 7
Handling concentrate . . . . 6
Handling residue . . . . . . 6
Re-treatment of concentrate . . 1 6
Royalty . . . . . .1 6
Total . . . . . .9 3
Of these figures the only one which needs discussion here is the general average of 35. yd. for the flotation treatment, and it will be interesting to compare the cost of different processes in this particular. These figures do not exactly correspond to those given in previous chapters, because certain items have been reduced to a comparative basis by using one price for the respective materials used.
LABOUR. Considering the simplicity of operations, this cost is excessive when measured by general practice, the general inefficiency of Broken Hill labour, coupled with its high cost, being responsible. The figures given are thought to be reasonably correct for each of the processes, but may contain some error. The Potter-Delprat takes the least number of men to operate ; the De Bavay covers a wide area and requires close attention ; and the Elmore requires more men than either the Potter-Delprat or Minerals Separation.
FUEL FOR HEATING. The Potter-Delprat process is conducted at a higher temperature than any of the others. The De Bavay operates at the normal temperature, as does the Elmore also generally. The Minerals Separation uses 60 to 70 C. ASSAYS. This is a comparative charge, and should not differ in any of the processes ; some of them may have no assay charge. WATER. Water at Broken Hill costs 55. per 1,000 gallons. The loss per ton by unreclaimed water in the residue will be almost identical in each case, as the methods of reclaiming water are similar, being by way of settlement first in tanks until sufficiently dry to travel on a belt or be handled in trucks. The losses by leakage and evaporation should be about the same in each case.
GENERAL EXPENSE. This charge, being accurately known in one case, is assessed for purposes of comparison to all of the processes at the same figure. There is really a big difference, but this difference is not inherent in the process ; some of the plants are managed efficiently for half the cost of the bad management in others.
CONCLUSIONS. There is not much to choose between the working costs of the four. The advantage which any one process may have over the others lies in the comparative recovery, grade of concentrate, cost of plant, and general applicability. The working cost of treating copper ores will be about 25% less than the figures given, because less concentrate is handled and less acid in general is used. In spite of the fact that the general average of treatment cost is in the neighbourhood of 45. per ton in the plants studied, I think that under the efficient management that is given to American mines, and with an efficiently designed plant and properly chosen process, a working cost of 2s. per ton is easily within reach. The royalty of is. per ton does not seem imminently reducible.
As a demonstration of the utility of the invention, we may say, then, that it has already added to the world's wealth nearly 1,000,000 tons of spelter, 100,000 tons of lead, 20,000,000 oz. of silver, and 5,000 tons of copper ; and at the present rate is adding 200,000 tons of spelter, 20,000 tons of lead, 5,000,000 oz. of silver, and 1,000 tons of copper yearly.
