Show W practical work wa by students utah state school of M mines ines BY ROBERT H BRADFORD ph D PROF metallurgy in the educational institutions of today laboratory instruction has come to be an essential part of almost every course in modern science no course in chemistry in physics in botany in mineralogy is considered of much value except it embraces laboratory instruction requiring practical work on the part of the student A course in applied science such as surveying hydraulics 0 ore r e dressing or smelt ing without actual experience with the apparatus involved would today be scarcely considered an engineering school established for providing practical I 1 instruction st in applied science requires abundant laboratory bor atory equipment for the use of students the utah state ate school of mines which is the engineering ngi school of if the state uni yer verity sity is among le the best equipped concentrating then roasting awl smelting smelling sm elting or crushing and leaching with some solution that dissolves the metal and then precipitation and refining or fine crushing and agitation with a solvent where leaching is not effi efficient clent proximity to the mammoth smelters shelters sm elters and concentrating mills of this region is a pa az ett 14 4 W V I 1 Z metallurgical laboratory ore dressing machinery schools of its kind I 1 for instruction ruction in engineering subjects i the equipment of the metallurgical la lor oratory atory is ig very complete as is indicated y the illustrations ores which are easily provided by nearby mines are carried trough all the processes of treatment esary ary to obtain the metals for the market ta in the crude products of the mines pese hese processes may include crushing and most important advantage of our school of mines over others and students are given every opportunity of examining these commercial iner cial works through the courtesy or of the various com companies banies but visits to these plants fall fail to show the student many details of operation involved in the successful working of the plants as the mills and smelters shelters sm elters are usually running smoothly giving one the impression that the practical application of the principles of the class room is a very simple matter it would be folly to expert any mill or smelter superintendent to put any part of his plant out of adjustment in order to show the students the effects of lack of attention to the details that underlie the successful operation of his plant the superintendent is OP operating the plant to make money for the stockholders and not for instructing ting students it is only occasionally that a class happens to be at hand when some accident occurs that may show forcibly to the students that there are these numerous details that the successful mill or smelter man must be acquainted with laboratory instruction st on a large scale is provided for our stu dents in metallurgy A brief description or one of the laboratory experiments required of all seniors in the mini mining ng metallurgical and chemical courses will here be given the blast furnace smelting smelling sm elting 0 of lead ore is one of the largest experiments carried out in the metallurgical laboratory the blast furnace employed is a round water jacketed furnace twenty inches inside diameter at the buyers the shaft from the crucible to the charging floor is seven feet high and consists of a single water jacket above the jacket rises a stack reaching up through the roof of the building directly above the jacket is connected an inclined flue or down comer leading to a dust chamber that connects with the main steel stack outside the building the crucible consists of a 71 ir L 1 IM kw 7 Sni elting furnaces and equipment furnace floor rectangular box four feet square and two feet deep of heavy cast iron plates lined with fire brick laid in clay mortar the crucible as it came from the manufacturers had a one inch plate cover with a cir cular opening in the top the size of the furnace jacket three buyers are pro provided aided vided for the blast which enters the furnace through tapered auyer openings of two inches inside diameter thess these buyers enter the jacket eleven inches above the level of the slag spout as the furnace is put out by the maiers allis chalmers co the lead well is provided for by cutting away a semicircular piece fifteen inches in diameter from one of the side plates of the crucible and bolting around this opening a bowl shaped casting large enough to admit of a brick lining made by laying fire brick edgewise leaving a well seven inches in diameter connected with the bottom of the crucible the crucible is mounted on low wheels and can be b e readily removed from under the jacklet jacket the jacket is suspended by four heavy bolts from timbers of the charging floor th furnace floor is entirely cement concrete with a concrete block five inches high on which the crucible stands three conical slag pots two feet in diameter and two feet deep are used for the disposal of the slag the lead blast furnace run was made this year during the first week in february the fire was kindled for warming up the crucible preparatory to blowing it in on thursday the fourth and on friday noon the lead was melted in about pounds being required to fill the crucible the lead bath was cleaned free from ashes and a wood fire kindled in the furnace the breast or front opening at the bottom of the jacket was vas bricked in and charcoal added to form a fuel layer two feet with the fluxes twenty per cent fuel was gradually changed to sixteen per cent as the furnace became thoroughly heated the labor of weighing out the charges J MILL blast furnace charging floor 3 thick before any charge was added the first charges consisted entirely of slag sia from a previous run crushed to pass a two inch ring charges of pounds alternating with 20 pounds of charcoal and gas coke as fuel were added until the shaft shaf was filled almost to the top A gentle blast of two or three ounces had been turned on when the first slag charge was introduced the blast was increased and in twenty minutes slag was wa to be seen passing the buyers on its way to the slag tap when the molten sla slag had risen almost to t the he level of the buyers the students who had been aE assigned signed their duties on the furnace floor tapped off the slag plugging the tap hole when the blast began to blow through the charge was now changed to half slag and half lead ore mixture an and 1 l the two students operating the scales and shovels of the charging floor were kept very busy maintaining the burden in the furnace at a constant level after the all slag charges had melted out the furnace ceased to drive so fast and the charging floor men obtained some relief after one hour and a half to two hours lead began to rise in the lead well and the student delegated to take care of the bullion began pouring lead into small moulds provided for the purpose Ee the charge was again changed to three fifths lead ore mixture and two fifths slag with the requisite limestone and iron ore fluxes and finally for regular running to two thirds ore mixture and one third slag and fuel and shoveling the same into the furnace kept two men busy and a third was LIMp employed loyed wheeling in the materials as the respective piles became low while the work of tapping and disposing of slag and pouring the bullion kept two and at times three men actively engaged thus five or six students are required on each shift and the three shifts require at least fifteen students unless some desire to work longer than eight hours durin during the four years that the furnace has been operated there have been sufficient men in the class to provide plenty of labor du during ring the entire run of from thirty to forty hours to blow out the furnace the men on top ceased charging and the ma material teral was allowed to settle from the top as it was melted away and tapped out below As the depth of the burden decreased to three or four feet the heat crept to the top and finally near the end of the run the flames from the burning fuel filled the whole furnace and great excess of jacket water was needed to keep steam from forming in the jackets by this procedure the material was all melted out of the furnace except a small amounts of coke and larger barger pieces of ore and flux that were readily scraped out at the breast upon removing the brick the lead in the crucible was out from the lead well until the major part had been removed when the remainder was tapped from the bottom by driving a bar in through a hole in the bottom of one of the side plates of the crucible the percentage percenta ge extraction during the entire run was low as would be expected since there was so much of the run devoted to blowing in and blowing out the furnace while the furnace was working normally the extraction was much higher than while blowing out and judging from the rate at which lead appeared in the well and from the absence of lead fumes from the slag and matte and from the top of the charge the lead loss in slag and matte and in fumes was but little the flags however with the limited means employed for proper settling and separating of slag and matte run around two per cent lead three classes of ore were smelted smelter this year 1 concentrates from the ore dressing mill 2 galena ore from the fortuna mine bingham utah and 3 ore from the uncle sam mine at eureka utah the concentrates and the galena ore were previously roasted in pot furnaces made by dra drilling illing a hole in the bottom ot of each of our slag pots and providing a grate and a hood the limestone flux was prepared by crushing to the proper sized size limestone boulders from the hills near by the tron iron ore was kindly given the institution by the operators of the dragon dra on iron mine at eureka E ureka all these materials were assayed by the students and the calculation of the blast furnace anace charge from thesa these materials and their air compositions made a valuable problem for r each man in testing his knowledge of mast blast furnace calculations owing to its small size the furnace is very ry delicate and easily put into bad condi tio on because of the short time the furnace is running normally and the comparatively long time in blowing in and blowing out the percentage extraction of lead is not equal to that obtained in practice nevertheless th eless because of the abundant opportunity it affords the student to apply the principles of lead smelting smelling sm elting the blast furnace f ur run will always be classed among the most valuable laboratory work done by the students of metallurgy |