Show I 4 Tooele's New Slag Plant 9 r 5 I i.- i. r h 7 4 C V N r I A Ar The basic purposes of oC the slag treatment plant is to recover from lead blast furnace slag zinc that Is Isnow isnow isnow now being wasted on the dump Its offset commercially will be the recovery of oC the greater part of oC the zinc that is now being lost in hi the smelting of oC ordinary lead ores and thus add to current national zinc production of oC from to pounds monthly from Tooele alone Zinc has always been an element that increases cost costIn costIn costin In lead blast furnace smelting and will still continue to be therefore the value of oC this operation is entirely entirely en in the recovery of oC such zinc and In no way affects the cost of putting it through the blast fur nace pace By such zinc recovery It Is hoped finally as soon as the economics economics eco of oC the whole operation are worked out to be able to treat lead ores much higher in zinc than at the present time and hence Increase the commercial limit of zincky lead ores particularly those which due to more or less less' oxidation oxidation oxidation tion or other causes are not amenable amen amenn able to treatment by selective flota tion Incidentally it will be possible to recover zinc from slag dumps which are sufficiently high in zinc to warrant their re treatment re Such slag can either be handled by putting putting putting put put- ting It cold Into the slag treatment furnace or by melting first through the lead blast furnace The choice between the two methods will be dictated by conditions in each case The metallurgy of this process procesa was worked out at Tooele some 15 16 years ago under patents granted to U. U A A. Garred which were acquired ac ac- by International Smelting Refining Company and Us its associated as companies A furnace of this type tyve was installed by the Anaconda Copper Mining Company to treat the slag from the American American Amer Amer- ican scan Smelting Smelting- Refining Company's Company's Com Com- pany's East Helena Plant some 12 to 14 years ago The process consists of at blowing air and pulverized coal cOllI through h molten slag in a furnace of oC the blast type The zinc Is reduced and Immediately re oxidized re-oxidized In the upper part vart of oC the furnace forming an oxide fume Any residual lead leadIs Is also reduced and the lead again oxidized re-oxidized in the upper part vart of the furnace The gas from the furnace containing the fume is 11 cooled and lead to a bag house houle where a zinc fume containing some lead is produced Inasmuch at ac fume with as little lead as possible Is preferred by the retort plants for the manufacture of prime western west welt ern zinc the leady zinc fume willbe will willbe willbe be passed through a rotary kiln for the elimination of ot the lead which will in turn be caught as a lead fume in tn a separate bag house The fume will be shipped to eastern refineries and the lead returned to the lead blut blast furnace here u r Jill |