| Show metallurgical research at the university of utah BY ARTHUR H E WELLS the work of the department of metallurgical lurg ical research of the state school of mines university of utah which is under the direction of the metallurgists of the united states bureau of mines has been continued during the year 1917 and the years work has proven most satisfactory the department of metallurgical research was created four years ago by an act of the state legislature the purpose of this department as defined by the law has been to conduct experiments and researches either alone or in operation cooperation co with the U S bureau of mines and other agencies with a view of finding ways and methods of profitably treating low grade ores of obtaining other information that shall have for its object the benefit of the mining industry and the utilization and conservation of the mineral resources of the state and to publish and distribute bulletins and articles relating to the department and its work during the past year the work of the department part ment has been in charge of arthur E wells metallurgist of the U S bureau of mines oliver C ralston also a metallurgist in the U S bureau of mines acted as mr wells assistant for the greater part of the year mr ralston has recently been succeeded by frederick G moses the more important results obtained in connection with the various investigations conducted by the department of metallurgical lurg ical research during the year has been as follows recovery of lead and zinc from mixed sulphide ores As a rule in the treatment of ores containing both lead and zinc sulphides sulp hides either the lead or the zinc is lost as a salable product this is due largely to the great difficulty experienced in separating lead and zinc sulphides sulp hides by gravity concentration processes at the present time the lead zinc sulphide concentrates are difficult to handle at either the lead or zinc smelters shelters sm elters and the only people who will buy them are the pigment manufacturers who pay only a low price for either the lead or zinc content of metallurgist in charge of mining alining experiment station the material consequently any process that will make possible the separation of lead and zinc or their sulphides sulp hides will be very valuable much time and work has been given to this problem by the metallurgists at the university and as a result of their work a process has been devised whereby the metals contained in these mixed sulphide ores or in a concentrate can be separated more or less completely the ores are given a preliminary roast with a small amount of salt which converts practically all of the lead into a form soluble in saturated brine solutions the lead can then be precipitated in the form of spongy lead by an electric current or as a high grade lead oxide by means of calcium hydroxide the major portion of the zinc is unaffected by the roast and can be recovered by concentration or by flotation recovery of zinc from solutions the department of metallurgical research has also done a large amount of work on the precipitation of zinc from leaching solutions the greatest difficulty encountered in the leaching of zinc ores is the recovery of the zinc from the solutions the amount of electrical apparatus and energy necessary to affect the precipitation of the zinc is so large that it would not be a commercial possibility for the average small plants to use this method to recover the metal from solutions the amount of chemical energy required is also very large and there are only a few common and cheap reagents that could be used to precipitate the zinc from solution the possibility of using lime has been thoroughly investigated this year the results obtained with this reagent are far from good and the indications are that some other material will have to be used the work with other reagents is progressive gres sive at the present writing the new work lias has been in progress for such a short time thile that it is impossible to give an indication of just what the results will be recovery of zinc and lead from oxidized ores other work with zinc has consisted in attempts to treat complex oxidized lead zinc ores this has consisted in giving the ore a roast with salt at a temperature that is high enough to volatilize the lead or a part of it and then leach the remaining zinc and lead from the calcines this work has been quite successful thus far it has been possible to volatilize about 75 per cent of the lead and not more than 20 per cent of the zinc the zinc remaining has been fairly easily leached beached with acid solutions it is believed that more work along this line will be profitable some flotation work there are several products produced by the forest forest products laboratories that were thought to have possibilities as flotation reagents samples of all these materials were obtained and tested the results that were obtained from most of these materials were very satisfactory and indicate that several products that would otherwise be of little value can be used with excellent results in the e flotation process volatilization of lead and zinc ores it was discovered in the of lead and zinc ores for brine leaching that there was always a certain amount of the metals lost during the roast by volatilization the discovery was then followed up to see if it would be possible to use this fact as the basis of a process for recovering lead and zinc from ores that could not be handled by any of the present methods investigations were made in which the aim was to volatilize the lead or zinc from the ores by roasting in the presence of salt and collect the fumes of lead and zinc by means of a cottrell electrical precipitator the ore was ground to 20 mesh or finer slightly dampened with water and then formed into pellets the pellets are then mixed with small amounts of salt and roasted on a downdraft down draft roaster with a small amount of coal dust the roast has been carried on oil in both the knight chris christensen tens en and Holt Dern type roasters asters ro the fumes were precipitated by an electrical precipitator the precipitate was collected and flagged with a small amount of calcium carbonate the two products resulting were lead bullion and calcium chloride slag that could be used in the |
