Salt Lake Mining Review | 1922-09-30 | Page 11 | New Era of Extensive Operations on the Comstock Given Impetus by Starting of Big Milling Plant

new era of extensive operations on the comstock given impetus by starting of big milling plant from the nevada mining press of the without fuss or feathers and with no spec special ial exercises in observance ance of the event the great modern cyanide mill of the united comstock mines co started on ore wednesday morning september 20 marking markin the commencement of a new era in the operation of mines on the famous comstock lode bulkeley welts wells president of the corporation fred G parish farish general manager for the metals exploration co of which the united comstock is a subsidiary walter L re d engineer for the metals exploration Coni company pany who developed the process and designed the mill and his assistant A J mill superintendent lee C fitus construction engineer and roy A hardy general manager of united comstock were present among others present were alex wise of virginia city who initiated the plans for the development and milling of the large low grade ore bodies in the gold hill mines from which this great enterprise resulted H G humphrey of reno vice president united comstock company who financed wise to a point where success was assured governor emmet D boyle a native of the comstock henry rives secretary of the nevada mine operators association and other mining men today september 23 will be fete day when the nev completed cyanide mill showing office buildings and ami clousin Hou for employees employ ces in background portal of kaulave Kau lase tunnel Is hs in right background tipple in rig lit center r forc ore around cyanide T tank ink house ouse on extreme left sight and the entire force had to turn out with shovels and scrapers to dg out the successful conclusion of the huge task almost on schedule is due mainly to the ability experience and pertinacity of lee C fillius construction construct on engineer and his engineering staff the new mill is the most complete if not the largest plant of its kind inthe united ui difed states devoted to the recovery of gold and silver and embodies the latest developments in the treatment of ores by in construction it stands by itself excepting the cyanide tank house the buildings are or of reinforced concrete throughout the cyanide tank house is of reinforced concrete to the ground line the superstructure of structural steel this is the largest of the three buildings covering two and one fourth acres and housing 40 redwood tanks on two working floors built to endure method of ore treatment the only wood used in construction of the buildings was for sheeting on the roofs and the ma material teral used in the redwood tanks in all construction including retaining walls foundations for machinery and the buildings yards of concree was used all of which was poti poured alred from the tower shown P r IL Z va 1 S 00 pv 7 I 1 ada section of the american institute of mining ZI 11 and metallurgical engineers will hold its annual meeting t at gold mill hill the nevada section on this occasion will b be h host ost to a number of prominent engineers adom eastern cities and the mem members beris and their guests will be entertained by president wells and his staff the mines will be inspected in the rn morning orning and the mill in ln the afternoon A buffet luncheon will be served at midday mid day and aa a dinner in the evening tests were exhaustive the te united comstock manes mines company took over the gold hill mines in may 1920 and early in 1921 walter L reid metallurgical engineer for the metals exploration company parted barted metallurgical tests to determine the process to be used the e first laboratory work was done at the smuggler union mill n at telluride colorado later mr reid accompanied by uy AJ AV einig his ass assistant stant came to gold hill and libed y a laboratory to co conduct induct the work on a larger scale till mul construction started late in july 1921 avd and was conned through the winter without cessation although the vork was frequently interrupted and delayed by stormy eu ed snow storms several times buried building build ng material from in an accompanying picture this type of construction for buildings was chosen largely because of its elasticity and to avoid the inevitable delay in having the steel fabricated in the far off east there are tons of structural steel in the cyanide tank house and failure of this material to arrive on time delayed completion of the plant several weeks the method of ore treatment adopted is the cyanide process by continuous decantation supplemented supplement edi by concentration the mill is designed to treat tons minimum per month regardless of loss time or possible necessity for f afner ner grinding should values run above the average for which the plant was designed it has seen been rated at 2500 tons per day and it is probable that the tonnage treated will average well above tons per month the coarse crushing plant is capable of 2000 tons per day on a 16 hour shift in the cyanide plant approximately 60 per cent of the product will be leached beached and 40 per cent treated by agitation A longer period of avi agitation tation will vill be required on higher grade ore but this will not lower the minimum of tons per month two and one half per cent of the product of the mines is su sulphide lohide ore and carr es 40 per cent cent of the values the te metals contained in the sulphide sulpha de ore are recovered by concentration the products of the tables being treated by in a stron stronger stroner er solution than is used on the oxidized ores and at a higher temperature concentrates will run from 70 to per ton in in value and the tests show a recovery of 97 per cent in general mill practice a recovery of 91 per cent is indicated with cost under per ton on tons per month A novel feature introduced in the mill is the washing of the crushed ore before subjecting it to the cyanide solution early laboratory tests showed the presence of soluble iron salts in the ore that caused a prohibitive consumption of cyan de and lime an average sample of unwashed ore on which tests weer veer made showed a on of 46 lb ib cyanide and 22 7 ib of lime lest being made on ore crushed to 16 mesh biesh the sanie same sample when washed was m lied with a consumption of 68 ib cyanide and ib linie lime with an extract on of per cent in mill practice the ore will be crushed to ya 4 inch mesh anesh and washed with warm warin water from the mines as it passes over the aikens classifiers three main buildings house the ina machinery chinery and equipment of the mill the coarse crushing fine grinding and the cyanide tank house and refinery the concentrating tables are in the fine grinding plant several days must elapse before bull on is produced as it will require tons of ore to fill the plant and tons of cyanide solution the coarse crushing plant holds 1600 tons of ore the fine grinding plant of the fine crushing plant which feeds the giant ball mills the fine crushing plant houses the ball mills classifiers tube mills and concentrating tables the product discharging by gravity into the cyanide tanks the railroad in the haulage tunnel is single track of 60 lb steel rails with switches for the passing of trains running in opposite directions from the portal it follow folloN vs a straight line for 1600 feet to the knickerbocker aa a r shaft swinging thence in a long curve into the country of the lode which it i t follows to the north end line of the group of mines the extreme depth of the lode reached by the tunnel is feet in the he in imperial 1 aerial mine there are two main haulage levels and two suly sub levels above the haulage tunnel each of which is about feet long the upper tipper of the ma main in mines levels is the yellow jacket surface tunnel the second is feet deeper and the third will be established just above the haulage tunnel underground trans por tation is by electric storage battery locomotives ore passes have been driven at intervals through to automatic loading bins on the tunnel level the sub levels will be used principally to clean the ore of old tm timbers bers etc much of the product of the nine irine being drawn from old fills the ore will be taken out in three blocks from the surface down dowin by mine methods known as top slicing glory holing and caving the ore bodies are of large dimensions attaining a maximum maximum width in one WP IMI I 1 t V 4 fir i t fa i 5 tons an idea of the size of the buildings and the amount of material used in construction is given iby by the fact that yards of concrete was used panes of glass and eight tons of metal sash putty went into windows and 47 miles of iron rods were used as hoops for the redwood tanks in spite of the size and capacity capaci y of the plant it is so constructed for economical one operation ration that 57 men comprise the entire force on three shifts electric transportation and ore crushing mines and mills are connected by a haulage tunnel feet in length the ore is transported in trains of 10 ton automatic dumping steel cars twelve cars to a train hauled by two 8 ton general electric locomotives driven in tan tandem deni there are four of these locomotives operating two trains by electric trolley system there are two sets of trucks under each car with four wheels to each truck the trains are drawn to a revolving tipple and split into four car divisions that being the capacity of the tipple the cars are fastened in the tipple without uncoupling coupling un and quickly emptied of their loads the ore is dumped into a long concrete bm which feeds into gyratory crushers from this coarse crushing plant the product s elevated lo 10 the bins ht at the head site of united comstock mill as it aphea appeared ed august 30 20 1921 grading on lett left vor for fine grinding plant mess mesa house ouse and dormitory in background place of feet john degart re gart formbly of michigan who has had a wide and varied experience in mining large ore deposits is mine superintendent nevada men in company the united comstock mines co is a nevada corporation it was organized in may 1920 with capital stock of represented by shares of stock later the cap vitalization was increased to par value the saine sameS lw per share bulkeley wells of colorado is pre president ss 14 G humphreys of reno and ro roy y H elliott vice pre presidents th oher ober directors are roy A hardy general manager united un comstock mines company A D snodgrass of new W york secretary treasurer humphrey wise andl and hardy received reed 40 of the of and wells W per cent stock the original capitalization supplied working and equipment capital th the ca boj and horation po ration assumed property p payments aggregating cr had taid oaid humphrey and associates the amount of money that 1 the been expended in acquiring the mines and developing wells interest i is owned by bv the metals explorations co with offices at broadway new york harr harry y payne whit ani ney is president bulkeley wells vice president and mana director fred G parish farish general manager the metals betais exploration company is the holding company for all the bulkeley wells mining ining operations in the iv west est the investment of the united comstock mines company to date is between and according to a recent statement by general manager hardy to the state board of equalization in a hearing against the company for improvements by the assessor of storey county roy A hardy is manager 6 john reigart mine superintendent and A J weini mine correspondent of the nevada mining press and published june 10 1920 shortly after the property had passed from herbert C humprey and alex wise to the united comstock mines company mill plans enlarged the story which is deleted here on account of aits length za also quotes mr wise concerning b the amount and value of the ore then exposed which has been largely increased 14 got 4 G E electric Ir trolley rolle s locomotives Loco moti es working in Tand hamlein ellik transport ore to in 12 1 car trains through rh rough haulage tunnel on right is tower from which concrete was poured for and foundations superintend erit eilt the mines are at gold hill and the mill at comstock on american flat about one mile west of gold hill the mines mines owned by the united comstock mines company from north to south are the alpha imperial challenge confidence yellow jacket kentuck crown point belcher seg belcher and overman many of thern them famous producers of the old bonanza days covering feet on the comstock lode with a recorded production of and the and globe on the southwest branch of the lode it seems impossible that with such a production there could be any ore left in the mines that the entire lode was not gutted is due to the enormous costs of mining and rf milling lilling in the bonanza days and the poor extraction made by y the old part pan amalgamation process then in vogue conditions are e explained in graphic style in a story written by a staff by subsequent development it is significant that early tentative plans for reduction works were on a basis of 1000 tons As development progressed it became evident that a mill of twice that capacity could be kept running for many years and a 2000 ton plant was designed and built in march 1919 bulkeley wells was given a 60 day option on an interest in the enterprise wells sent in a staff of six engineers and geologists 6 with 20 men including his own surveyors samplers and assayers these men took more than samplings checking back and in places cutting entire sides of drifts it was found through the sampling that bulk samples invariably variably iti gave higher I 1 returns that did the hand band sampling b at the end of the 60 day period mr wells exercised his option and the engineers proceeded with plans for mill construction and broad scale development