Show PROBLEM IN metallurgy SOLVED the department of metallurgical research of the university of utah which is conducted in operation cooperation co with the united states bureau of mines has apparently worked out a method of removing iron pyrite from zinc sulphide concentrates one of the most pressing problems in me treatment of mixed sulphide ores A lately issued official statement says the method consists of treatment of the mixed sulphides sulp hides in a ducting deducting re atmosphere at about degrees C the pyrite loses one atom of sulphur under these conditions and is reduced to a form which will react with dilute sulphuric acid while the zinc sulphide is resistant to the acid in this way the iron can be removed making a marketable zinc product in many western ores the presence of large amounts of iron in the zinc concentrate has been a curse to the milling industry because when iron was above 10 per cent the concentrate might contain as much as 30 worth of zinc to every ton and yet be the success of the method depends upon the use of cheap sulphuric acid but at the same time the large smelt ing interests are at a loss to know what to do with their sulphur fume from the smelting smelling sm elting furnaces the conversion of this sulphur into sulphuric acid is quite cheaply done but heretofore the trouble has been that there was an insufficient market for the acid this process of removing iron from the zinc concentrate should prove to ibe be an important consumer of acid and is only one illustration of how one branch of the bureaus work may fit in with another as one section of the bureau has been studying smelter fume problems while up to tho present time the salt lake station has been devoted entirely to the metallurgy of zinc and lead one of the other operative cooperative co fellowships fellowship 3 in the department of metallurgical research of the university of utah and under the direction of the bureau of mines is now studying the question of the use ot 0 sulphur dioxide from smelter roaster and other fumes in the removal of zinc and copper from complex mixtures containing zinc lead copper and iron after the removal of the zinc a residue containing copper lead and iron can be treated in a lead copper smelter while the lead copper smelter never pays for the zinc and usually penalizes the presences of more than 7 per cent of the zinc the idea of forming a soluble bisulphate of the zinc by the application of solutions of sulphur dioxide to an ore is not new but the trouble has been that a number of engineering difficulties have arisen in applying the process the present work is taking up a study of each difficulty and the methods of turning it into an advantage it is believed that the bureau has carried this pro cess nearer to successful completion than any other institution which has taken it up and it would now look as though most of the difficulties encountered can be disposed of |