Show the bl big g four exploration on mill RECORD PARK CITY UTAH through the kindness of superintendent davis and mill foreman mike cloonan the record is pleased to be able to give the following technical description of the new milling plant of the big four exploration company located near atchison about seven miles from park city on the union pacific railroad this mill which is designed for the treatment of a large accumulation of tailings below park city will have a capacity of tons or more when in operation and will be one of the most up to date plants in the west containing the latest in concentrating machinery it will also have in connection a flotation plant of tons capacity for the treatment of the slimes designed and planned by a well known expert of the west who has been very successful in the treatment of zinc ores by flotation processes the tailings are hauled nearly one and one half miles by two 14 ton steam locomotives which haul ten cars or fifty tons to the train and are dumped into a bin of fifty tons capacity this material is fed by jeffrey apron conveyors into elevators of continuous type which discharge into two revolving screens covered with punched plate three sixteenths of an inch thick with one inch slotted holes the oversize from these screens consists of rocks wood and rubbish and as it carries no values it is discarded as waste the undersize runs to a 30 inch conveyor which distributes to bins of 2000 tons capacity from these bins the ore is continuously fed to the main elevator halcli consists of a 30 inch 12 ply belt with staggering buckets and capable of elevating 2000 tons in twenty four hours it is then discharged to four double revolving screens each four by twelve feet which classify the material into the following sizes mesh ore falls directly into two esperanza classifiers ore between 8 mesh and 3 mesh is sent to four single three compartment hartz jigs and ore greater than 3 mesh is rejected as waste the undersize of the esperanza is sent directly to a dorr thickener the oversize goes to four IG 16 mesh duplex callow screens this under size is distributed evenly on sixteen double deck wilfley tables where a lead iron zinc middling is made the oversize is treated on tables and the product sent to a five by four foot allis chalmers ball mill for re grinding the jigs gs are of a three compartment plunger type have a screen area of nineteen by thirty two inches for each compartment and make inake a hutch product of lead iron and zinc nc which goes to a four by three 11 marcy farcy mill for grinding for table treatment the jig tailings being rejected as waste the tailings of the double deck Wilf leys are treated on ten second rougher tables of the wilfley type which produce a lead iron product and zinc kirk leavell classifiers all the zinc of the mill are sized by kirk leavell hydraulic classifiers and retreated on six wilfley finishers and eleven bixter slime tables where a high grade zinc product is made and delivered by two shaking launders to a drag which reduces the in the concentrates to less than 7 per cent this discharges int the concentrate bins or directly into railroad cars as desired A lead iron and silver product is made on all the finishing tables throughout the mill and delivered to shaking launders then to the concentrate bins A twenty six by ten foot dorr thickener handles all slimes from the esperanza and kirk leavell classifiers when desired all pulp under 40 mesh from any or all ot 0 the concentrating machines can be run into the dorr for thickening the thickened pulp is treated on single deck deister slime tables the clarified overflow is pumped back into the mill and used for service water the water supply for the mill which requires approximately 1200 gallons a minute is provided by a reservoir the outlet of which flows to a sump and is then forced to the mill supply tanks by a 6 inch centrifuge and a goulds triplex pump seven by eight inches the force employed at present is men after operations are resumed it will require about sixty men to operate twenty four hours continuously the tailings that are to be worked vary from 5 to 12 per cent zinc the electric power the power for the mill is supplied by the utah power light company from its main volt line by a branch line one fourth mile long it is transformed down to volts by means of three 50 K V A to volt general electric transformers and two 50 K V A and two 40 K V A and three K V to and volt A to G E transformers from tile the substation sub station the volts are carried thirty five t feet by two circuits of three main switch board then it is wires to a carried by separate circuits to tile following motors one horsepower two SO 50 horsepower horsepower house two 75 and one 25 horsepower general electric two 15 horsepower one 40 horsepower one 30 10 and one 1 horsepower allis chalmers motors and one 30 horsepower wagner motor the following small mo tors are now being installed tive five 5 horsepower five TVs horsepower general electric vertical motors and one 5 horsepower and one TVs horsepower general electric motors the lighting system is fed out from a switch board at a pressure of volts mazda and mazda type G C lamps are used exclusively to the number of or about 18 K W the substation sub station is arranged to change from the bank of small transformers to three K V A transformers on short notice all motors and lights are protected by the latest safety devices in the line of lightning arresters and circuit breakers all lamp cords are of reinforced rubber covered cord which is thoroughly insulated against weather and water in fact the installation of the electrical equipment is in keeping with all the equipment of the rest of the mill no money has been spared to buy the best of everything |