Show the M mines ines 0 and M mills III S of ely nevada no 3 written for the mining review by leroy A palmer in producing metal from a low grade ore three operations are usually necessary first the mining of the ore second the preparation for he furnaces and third the actual con conversion vergion into the metal sought the first two processes as practiced in the ely district have been considered in preceding artieres artic artie fes and the third the conversion of the concentrates into copper ready for the refinery will be described in this the steptoe smelter is located about halt half a mile from the concentrator with which it is connected by standard gauge tracks which have a convenient down grade to it it consists of the three different departments part ments of a complete copper smelter a roasting matte and converter plant near the building is the 4 q b ix at V 1 k xvi IMP 41 imp t V 4 V 42 al ml NIN 0 converter building and stack roaster stack in background steptoe smelter power house one of the finest west of the mississippi which was built at an expense of and which supplies power for the smelter mill and mine and as this is an important part of the plant and an interesting te feature from the point of effic lency and economy it will be considered first I 1 I 1 I 1 the power house boiler and engine rooms adjoin the boiler room feet of heavy corrugated iron over a steel frame and the engine room feet of brick over steel frame with concrete floors the boiler room con bains four batteries of two horsepower babcock and wilcox water tube boilers two batteries having babcock and wilcox and the other two foster internal super heaters there is also a separate foster for the steam which is supplied by the waste heat boilers back of the furnaces all of these boilers generate steam at pounds pressure the waste heat boilers are eight in number arranged in four batteries one to each furnace one battery is babcock and wilcox and the others are stirling during one month these boilers supplied steam the equivalent of 2400 tons of coal so their use effects an economy of eighty tons per day an amount equal to 64 per cent of the total the boilers at the power house are fired by hand and the ashes removed in the same manner the coal is brought in in 1200 pound buckets by an overhead over head crawl from by forty feet draught for these stacks is furnished by two sturtevant tans fans each connected to a thirty horsepower sturtevant slide valve engine making to r p m the condensed steam from the engines is discharged to a sump from which a suspended pump raises it to a filter in which the oil is removed thence it goes to the hot well where the temperature about degrees is recorded from the hot well it is pumped to two goubert feed water heaters where the exhaust from the feed and air pumps raises the temperature to degrees from the heaters it R goes to the economizers back of the boilers two green and two sturtevant in which the temperature is brought to degrees containing the condensers air pumps oil niters filters etc electrical equipment the following equipment is used for generating electricity two allis chalmers cross cros s compound corliss engines of 1100 horsepower inches with kw bullock alternating current generators mounted on the shaft two nordberg cross compound corliss engines of 2000 horsepower inches with 1500 kw bullock alternating cur rent generators mounted on the shafts next in line are the blowers and compressor in the following order one nordberg cross compound corliss engine horsepower inches tandem connected to inch air aylin 4 4 4 L 7 imn awo A 0 A SALT N converters and casting belt steptoe smelter the stock pile ou outside side the ashes from the furnaces are quenched by a stream of water from a hose and are hauled to coal bunkers back of the boilers this ash contains about 50 per cent moisture and sixty per cent of the dry weight is good coal that it is well worth saving can be seen from the fact that 30 per cent of the coal used in powerhouse operation is derived from this source the use of the wet ash makes it advisable to use forced draft which is supplied by two five foot sturtevant fans direct connected to 50 horsepower motors making r p m this draft is automatically recorded on a bristol gauge and gauges are also kept on the bridge wall of each boiler each double battery is provided with a steel stack nine by the hot gases which have passed through the boilers this temperature being near the boiling point at this altitude the pipes in the economizers are kept clean of soot by scrapers driven by the fan engines which move up and down the water is injected into the boilers by an epping and carpenter twin tandem piston pump L exl 6 inches having a capacity of gallons per hour and two show duplex outside center packed inches with a capacity of gallons per hour each the engine room adjoins the boiler room it consists of a main floor containing generating blowing engines etc three exciters excite rs switchboard etc and a basement ders with a capacity of cubic feet of free air per minute compressing to 18 pounds for the converters one laidlaw dun cross com pound engine horsepower inch tandem connected to inch air aylin compressor with a capacity of cubic feet per minute compressing to pounds for tamping machines pneumatic tools etc one allis chalmers cross compound corliss engine horsepower inch tandem connected to inch air cylinders with a capacity of 6 cubic feet of free ar per minute compressing to IS 18 pounds for the converters one nordberg tandem compound horsepower inch direct connected to a no 10 Conners connersville ville blower making r p m with a capacity of cubic feet of air per revolution one nordberg cross compound corliss engine horsepower inch tan dem connected to inch air cylinders with a capacity of cubic feet per minue compressing to tc eighteen pounds A bif N IM fill mh Z gr A 4 S fir 4 V A yla I 1 r I 1 X boiler house power house transformer house and building smelter photo by will C hissim higgins for the converters the blower engines are equipped with relief valves to prevent shock to the engine in case the discharge oi of air at the converters is suddenly stopped each engine is connected to a wheeler surface condenser and wheeler and edwards vacuum pump giving a vacuum of 21 inches water from the main line is used in the condensers and after use is sent to the concentrator the progress of the condensed steam hack back to the boilers has been noted during the month mentioned the consumption of coal at the boiler room for powerhouse power house operation was 1082 tons with an equivalent in ash of tons a total of 1348 tons the average horsepower for the month was a consumption of 28 tons per horsepower month three exciters excite rs are used in connection with v ith the generator units these are bullock make two of them direct connected to horsepower allis chalmers induction motors and one to a 75 horsepower vertical piston valve engine electricity is generated at GOO volts and carried to a concrete transformer house wh which ch has the following equipment four kw bullock water cooled transformers stepping up to volts for transmission to the mines F four our kw westin westinghouse water cooled transformers stepping up to 0 o 13 volts for transmission to the mill three volt choke coils one volt lightning arrester ar three volt lightning arresters the smelter plant Roaster Roa stera 4 the smelter is located near the power house it consists of a roaster building two matte bu bullings bul dings one for furnaces and one for blast furnace and a converter building all of these buildings are of corrugated iron over steel frames the concentrates are hauled to the roaster building build ng or to the storage bins nearby the roaster building consists of four floors with sixteen 18 foot macdougall ro asters each of which has s six x hearths heart hs the roasters asters ro are fed by dumping direct to thern them from the feed floor which is on a level lev el 7 4 J i A roaster building and part of flue steptoe smelter photo paoo by bj fill C higgins with the trestle over which the cars are brought in eibach roaster is provided with two hoppers F fourteen of the roasters asters ro have air cooled arms and the other two have water cooled each roaster disc discharges hartges through two thirty two inch elbows to a brick hue flue running between the two rows the dust settles from this chamber into steel hoppers from which it is piped to the ground floor where it is loaded into cars this dust chamber discharges to the ma n flue which is likewise of brick and is built double so that one part can be cut out cut for cleaning this flue is 1070 feet long and 35 feet wide the length including the dust chamber which is feet the flue ends in a brick stack feet high with an inside ins de diameter at the top of IS 18 feet for feet the flue is built at a height which will allow a dinkey engine to run under it to collect the dust from the steel hoppers beneath the roast is made according to the amount of copper in the concentrate and leaves anywhere from four to sixteen per cent sulphur in the calcine the average being about 10 per cent and the elimination of sulphur from 65 to 70 per cent the roasie ro asters rs are driven by a 30 and a 10 horse horsepower power motor the calcine di discharges 1 to hoppers hoppe rs beneath n the roasie ro asters rs and is hauled to the I 1 U y ies or to the storage bins of which there are nine with a total capacity of 1350 tons the ies the building contains four ton furnaces feet stayed kayed on oil the ends with 10 inch Is and on the sides with 12 inch Is in each side are eight iron doors through which the furnace men can insert their paddles to feel the charge these doors are counterweighted and work in guides at the firebox end of the furnace is a bin with five gates for coal and two bins for charging between the two charge hoppers is a 15 inch pipe through which the hot converter slag is charged into the furnace in the top of vie the ecal hopper is a latticed grizzly with 5 inch openings ope whigs on which the coal of which a good grade lump is used is dumped As noted the ashes are extinguished and ra turne to the power house for use in the boilers the stack is feet high sufficient to provide natural draft as there are no baffle walls of bags in the dust chamber in the flue back of each furnace is a battery of two water tube boilers to which reference has been made the dust chamber between the furnaces and the stack is feet terminating in the stack which has an inside diameter at the top of fifteen feet in the back of each furnace is a inch iron door through which the slag is skimmed the only slag forming material lacking in the ore is lime rock so the charge of calcine is mixed with 9 to 10 per cent of lime carrying 51 per cent of calcium oxide the charge is dumped from the hoppers to a deep bed of molten ore so that it goes into a state of partial fusion almost immediately the matte is tapped through holes closed with a clay plug and runs through the floor in a steel launder to tons of ore and flux per twenty four hours there are four steel water jackets over each side and one over over each end on each side are twenty four 4 inch buyers ten inches apart which receive a blast of forty ounces from a 30 inch bustle pipe the fumes discharge through a inch down take to a brick flue feet which terminates in the main roaster flue the converters the converter building is about feet from the building the matte cars are brought in over a trestle to a point filiere the metal which is carried hot can be poured directly into the converters the plant is equipped with four stands for leghorn converters which are manufactured by the power and mining machinery company each converter has fourteen one inch tu yeres which receive the blast of eighteen pounds from the blowing engines 7 41 irk wi KV M furnace steptoe smelter to the matte cars which are so constructed that they can be tapped hot to the converters or tipped and poured the cars have a capacity of ten tons of matte which averages 45 per cent copper twice a shift the slag is skimmed through the slag door and falls to a cast iron box which flows to a lined launder here a jet of tailings water from the concentrator cen granulates it and carries it to the dump the slag which collects and solidifies around the discharge opening is barred off and crammed out in cars the slag carries 40 to 45 per cent silica 6 to 12 per cent lime 40 to 33 per cent iron oxide and 4 per cent aluminum oxide the blast furnace the blast furnace is located in a build ing near the building and between it and the converter building it is inches at the tuy tu yeres erds and inches at the shaft the capacity is from the plant is equipped with two five mo tor shaw electric cranes each with a capacity of sixty tons one for handling the ladles and the other the converters electrically tri cally operated gearing driven by 40 horse power motors tips the converters which are poured to 10 ton ladles A crane picks up the ladle and carries it to the pouring stand where it is attached to a hydraulic lift which draws it into place and tips it the blister r copper is poured to moulds mould on a conveyor belt which cast it into ingots ingols of about pounds each which is marked SV in the casting these ingots ingols are dropped onto a steel conveyor running on an incline the lower end of which is submerged in water so that the ingots ingols are cooled at this point this conveyor dumps to the shipping floor and the blister copper is loaded to box cars and shipped for refining to the works of the american smelting smelling Sm elting and refining co the converters are lined with sil lelous ore from copper plat flat it is hauled to a mill beneath the steel trestle at the concentrator and passed through a blake crusher and elevated to a set of inch allis chalmers rolls passing the rolls it goes to a tron imel with one inch punched holes the oversize of which goes back to the elevator and the undersize to the shipping bins this mill is also used to crush the lime rock and the ore is hauled to the converter building and dumped to bins from which it is fed to i three 6 foot allis ailis chalmers chalme rs pu pug 1 mills here it is ground and mixed with clay in the i proportion of six parts of ore to one of clay this lining is tamped camped into the converters with ingersoll rand P piston ston drills drill shod with a 12 inch shoe the drill working under eighty pounds air pressure the converter fumes discharge through a brick stack feet high with an inside diameter at the top of ten feet aside from the plant as described there are the accessories which are necessary for a work of this magnitude situated at a distance e from the manufacturing centers and the lar large lare e machinery depots there is a foundry where all of the ordinary castings can be duplicated a machine shop carpenter shop storehouse locomotive house etc according to the last annual report the nevada consolidated which had not at that tame absorbed the cumberland ely produced pounds of copper at a cost including all charges for management rental of steptoe plant which is is owned by a separate corporation etc of cents ter ier pound this production is being far exceeded during the current year as during the year mentioned the plant was in full ope operation ration only a small part of the time the present rate of production is about pounds per month and this is doubtless being accomplished at a figure very close to seven cents this is undoubtedly the lowest cost obtained by any company unless it be some of the lake superior properties which are treating a good grade of native copper ore this low cost is obtained by having a deposit that can be cheaply mined and an equipment second to none in efficiency th the e plant is favorably situated the only flux necessary being found within a mile from the smelter |