Show STUDENTS RUN BLAST FURNACE WRITTEN FOR THE MINING REVIEW university of utah sept 22 the twenty inch round water jacketed blast furnace which constitutes part of the equipment of the metallurgy laboratories of the utah state school of mines comes into service each year by the senior class in III preparation for this run the materials to be treated are collected and carefully analyzed care is taken that the physical condition of the constituents of the charge is right in order that the small furnace may have no excuse for uncontrollable irregularities the students do all this work on the materials to be smelter likewise the work of preparing the crucible the lead well and the numerous other im devices about the furnace which must be carefully looked after before blowing in with last years class the furnace was gotten ready on thursday afternoon and during that night two shifts of two men each kept a charcoal fire in the crucible so that on friday at 7 a m the operation of blowing in was commenced all the members of the class being present the crucible was carefully cleaned a fresh fire of clean wood kindled and lead bullion melted in to fill the crucible and lead well the surface of the lead was skimmed and all the ashes and other foreign matter removed the crucible and its contents were hot enough to ignite the fresh layer layar of kindling wood now added this preparatory work took considerable time but bat was well done and the breast of the furnace was bricked up the buyers closed with balls of clay and a layer of wood added from the charging door upon the threefoot three foot layer of kindling wood lump gas coke was added to the amount of eighty pounds after this charges of slag from a previous run alternating with coke to the amount of 16 per i ent cent of the accompanying slag were added to fill the furnace to within a foot of the charging door the clay was then removed f from rom the buyers and slow combustion without forced blast continued until the wood was k g 7 I 1 e 1 A R 1 ts x ae JV anin 1 7 blast furnace at utah state school of mines thoroughly kindled the auyer pipes were then put in place and a gentle blast of a fraction of an ounce pressure introduced new charges of half slag and halt half ore mixture with the 16 per cent coke were now added by the students tending the charging floor and the furnace kept filled to within twelve to fifteen inches of the charging door the blast was gradually increased to six to eight ounces the air being furnished by a green rotary blower of two and one half feet displacement per revolution after fifteen to thirty minutes sla slag had accumulated so as to be seen through the peep holes of the buyers and the students on the furnace floor proceeded to tap the slag the molten slag was superheated super heated far above its melting point and thus had brought needed heat to the lead below As the ore began to smelt the lead rose in the lead well and the student assigned to this work ladled the lead out into small moulds it was nearly one p m when the furnace had reached the regular smelt ing stage and from that time on until it A was ready to be blown out the work proceeded very smoothly occasionally a auyer would need barring and now and then the opening of the slag tap required the use of a small sledge at seven p in the regular charges were discontinued and the contents of the furnace allowed to sink as the slag and lead were formed and removed from below the charge sank to within a 3 foot of the buyers without any barring and then the buyers were removed and the blast turned off the breast was taken out the solid materials mostly coke dragged out into an iron wheelbarrow and taken away by eleven p m the furnace was cleaned out the lead tapped from the ci crucible and the whole furnace run completed there was little work left for the graveyard shift but to clean up the room thus within twenty four hours the furnace was heated up blown in run regularly for six hours and blown out one smelter superintendent remarked who watched the run while everything was going smoothly well I 1 have thought it possible for such a toy of a furnace to behave so well we have found the furnace to be very delicate in that small mistakes of the charging crew are sometimes disastrous but the last years run was eminently successful cess ful and at no time was there danger of a freez eup R H B |