Show THE ROMANCE OF A FAMOUS GOLD MINE BY DON MAGUIRE and L 0 HOWARD the story of the mercur mine has been brought to the point where the promoters met the men from nebraska prosperous farmers with money to invest the promoter err succeeded in their fondest desires and unloaded the property upon these men ana arrangements were made to treat the ore b by amalgamation pan amalgamation the mercur gold mining milling comp company ny be ing organized for this purpose A milt mif was built at manning some three miles away where water was more plentiful than at mercur this company was formed in 1890 A tenton ten ton plant was erected at a cost of about and the ore started through it the ore kept on going through mostly unchanged except that it was reduced in size for the extraction was less than twenty per cent at a cost of 4 per ton the operation like its predecessors of the early days failed of success an attempt was then made to treat the ore by roasting preliminary to amalgamating and upon the assurance of one cyanide smith that he had worth ot of amalgam ready john dern and E H airis came caine on from fremont nebraska to be present at the retorting with some ceremony the amalgam was retorted the net result was a retort the size of a hens egg dern and airis threw up their hands they were through with the attempt to treat this rebellious ore all was gloom in the offices of the mercur gold mining milling company the owners of the worthless mine were in despair only two of the men connected with the enterprise refused to give up hope these two gil S peyton formerly a tremont druggist and hal brown manager and stockholder respectively having received a circular describing the macarthur forrest process of gold treatment by the use of potassium cyanide saw some of the possibilities for the mercur ore and against the arguments and opposition of officers and directors samples were sent to the metallic extraction plant at denver on which recoveries of about 90 per cent of the gold value were made by dint of much effort these men succeeded in getting out a car of ore no money was forthcoming to pay the freight so peyton borrowed the money from the bank on his own responsibility so sure was he of the success of the cyanide treatment eighty five per cent or thereabouts of the gold was extracted tr in the test on this lot made at denver peyton returned to manning where a tank was set up the ore crushed and an 3 ab SR 1 lae an M zt ar OW 1 wa 1 J aa Z its IV J at the golden gate mill in january 1898 attempt made to leach it it would not leach the solution would not percolate happening to notice some of the coarse rejects from sampling he tried the effect of the solution on them and found that they would leach this showing convinced the owners to the extent that they rustled about and succeeded in mortgaging the mine to raise the money to remodel the plant the original cyanide plant at anning Mj was but a testing plant as plants are rated nowadays it had a dodge crusher wall corrugated rolls and five seven ton leaching tanks eight men yere were employed in the mill and six in the mine an interesting bommen tary on the labor thought necessary to carry out the process although the tribulations tribulation atio ns were not yet over the treatment had been started on the right track the mercur ores at this time only the oxidized ores of the camp were mined these were of 0 a reddish to brownish color the values being in a limestone which was very porous and friable some of the ore was exceedingly talcy dalcy the first thought was that the ore should be ground to a fine sand in order that the cyanide solution might reach the gold this idea was fostered perhaps by the fact that the gold did not amalgamate and even the microscope revealed no gold however the first attempts at extraction resulted in the production of an excessive amount of taley slimes which prevented percolation of the solutions it was then that peyton discovered that the coarse would leach further study resulted in the application of the other pronounced property ot the ore its multiplicity of cleavages the ore was full of small cleavages on the planes of which the gold had deposited it was found that in material as coarse as one inch the solution aou would permeate these little fissures and pick up the gold the idea so long spread broadcast by writers that porosity of the ore enabled the solutions to act on the gold is a wrong one for the solutions did not penetrate tho rock itself but passed through the crevices along the cleavage planes there were two distinct advantages in this method the absence of slimes allowing rapid percolation and the coarse size of the particles making the crushing a simple problem the process then being in its in infancy rancy but little was known as to what could be expected from it on mercur ores the first precipitates sent to the at omaha were a source of mystery and were held in some contempt and were carelessly handled for that reason the did not know how to treat this mercur mud but assays essays soon convinced them that a way must be found and it was found in the beginning the ore was given a wash lasting from four to six weeks strips of zinc were hung in the effluent solution in order to determine when solution was complete the gold would discolor the zinc titration was not practiced solutions were standardized by rule of thumb peyton and brown left the company in about a year and sold their stock to the dern interests it is stated that peyton received 25 per cent down and that the dividends on oil his portion of the stock paid the deferred payments as they became due so the change from poverty to affluence was Tas rapid for this company the railroad enters the mill at manning was gradually enlarged as the operators gained more experience with the process it was first enlarged enlarge d to a capacity of fifty tons then in 1893 to tons in january the salt lake mercur railroad tortuous but bui efficient was completed from mercur through manning to fairfield a station on the oregon short line which at that time had a road down the east side of the oquirrh mountains this road owned now naw b by the salt lake route still handles limestone from the topliff quarries to the valley ley smelt eries there being little passenger traffic on this section of the road the coming of the railroad simplified the transportation por tation of ore and supplies ore hauling by teams was suspended in 1896 the mill was treating tons of ore daily the flow sheet was as follows the ore was dumped from railroad cars to a bin 49 feet by 20 feet by za W feet and was crushed in dodge crushers and wall rolls to about one inch size it was 1365 13 65 milling 86 cents transportation 35 cents a total of 2575 leaving a net of 3 the latest manning practice in the latter part of 1898 near the end of operations at manning on mercur ore the mill had one no D gates crusher and two 12 inch by 14 inch wall rolls in the crushing department after the first crushing the ore was elevated by a bucket elevator 60 feet long 18 inches wide with buckets at 24 inch centers to a 5 foot by 3 foot inch ginch G 6 having apertures aper tures of one inch the oversize went to the wall rolls and was returned by the same elevator to the thus completing a closed circuit the undersize from the screen was carried by a 16 inch belt conveyor running at an ail angle of 16 degrees to a pulp bin in the tank room the tank room was feet by 60 feet and contained 10 tanks 30 feet in diameter and 5 feet deep solution was run on through a 4 inch pipe for 68 hours the strength being kept at 1 pounds pound s e 4 14 A bailin tailings s dumps at murcur choto pl oto by L 0 howard to 15 ton vats 12 feet f and 8 inches in diameter these vats were ot oi iron with redwood bottoms and burlap filters the treatment took about 40 hours the ore being washed continuously with solutions containing 01 to 0 03 3 per cent the solution went to a collecting tank from which single acting blake pumps delivered it to zinc boxes where the gold was precipitated on zinc shavings these boxes were 26 to 36 inches wide 10 to 12 inches deep and 20 feet long the cyanide consumption on ore containing 10 to 12 in gold was 06 pound per ton treated the extraction was given as from 80 to 87 per cent at a treatment cost of 85 cents in july of that year the mill was again enlarged to a crushing capacity of tons and leaching capacity of tons the number of tanks being increased from 31 to 52 in 1897 as a result of increased capacity the company was able to treat a lower grade ore the values for that year running about a ton mining cost was the solution easily standard standardized zed but the increased strength of solution at this thi point aided the precipitation and increased increase d the recovery or 9 when cleaning up the slimes from the zinc boxes were settled in a tank 10 lo feet 6 inches by 3 feet 6 inches the filter box used was 6 by 3 by 2 feet screen analyses of the material treated show that about 72 per cent of it was coarser than 14 inch and about 50 per cent of the value was in these sizes like wise about 45 per cent of the value left i in the tailings was in these coarse sizes at this time the extraction on the various sizes was between 69 and 78 per cent and the lowest tails were the coarsest running about 80 cents per ton while the very small amount of the finest sizes ran up to 3 60 showing a very poor extraction on I 1 the slimed material the general average was probably about on 5 ore quicksilver recovered from precipitates the consumption of was 05 to 06 pounds per ton of ore treated and of zinc f V side view of mill 1913 photo by A 0 selba to the ton A 4 hour water wash followed the pregnant solution was drawn off to a gold tank of redwood 12 feet 8 inches in diameter by 3 feet 6 inches deep for charging these tanks two tracks were provided over each and tailings were discharged by shoveling through four 1114 inoh gates to cars standing on similar tracks below A horse was used to pull the cars to the dump where they ran out on a self dumping section of the track from the gold tanks solution flowed to a set of twelve zinc boxes having compartments part ments 12 inches deep 30 inches wide and 32 12 inches long thence to a sump tank of the same size as the gold tank the barren solution was then pumped to a storage tank 12 feet 6 inches in diameter and 6 feet 10 inches deep the solutions were standardized by what appears at first sight a crude method at half hour inter vals the millman added a predetermined amount of KON ax T to the head of each zinc box when a single solution process was used this gave excellent results not only 03 pound P per er ton of ore the precipitate was dried boxed sampled in salt lake and shipped to argentine kansas its val ue was about 40 per pound one of the th most interesting features of the drying ol of precipitate was the recovery of quicksilver quick the mercur ore carried ahnin cinnabar a small part of which was dissolved in hi the solutions and precipitated with the gold on the zinc the precipitates were dried in closed iron retorts and the reco ery of quicksilver by volatilization and coll sensation densa tion amounted to nearly a ton win annu ally the peculiar features of the mere merceir ore are manifest at every step with 0 on the power house was equipped 60 horsepower and one 40 horsepower toilet bolle a horsepower engine a light dynan two zin zilk driven by a 11 horsepower engine cutting lathes and one pump L 31 Is for the year ending december to tons the average daily output was 68 cell c a cost of per ton for mining for milling 54 cents for miscella ne JB f 35 w items a total of eight tanks in diameter and 5 feet deep were added bringing the leaching capacity to tons the only alterations made in the crush tr tractions actions so that this reason proved untenable assays essays for carbon have shown that there was enough of this substance pres 4 it 4 ag tr 2 4 t A t leaching room golden gate mill showing method of charging tanks and type of construction ing plant were to add another coarse break er and to speed up the conveyors after 1900 this mill was run only intermittently by the company and lessees lessels in the of tailings for a new factor had bad entered the field originally occupied and developed by the dern helm rich airis company in the shape of captain delamar who in 1895 bought the golden gate group of mines adjoining the mercur mine and started development developments at the golden gate in the development of the golden gate group considerable sulphide ore was encountered which did not appear to be amenable to the cyanide process the ore was a dark often black decomposed porphyry containing considerable pyrite and orpiment compounds of iron mercury sulphur and arsenic truly a discouraging combination to encounter at that early stage in the development of the process some investigators have given as the reason for the great refractoriness of the base ores the presence of tellurium but it is pretty definitely established that no tellurium ex ests in the mercur ore Anoff another ier reason advanced was that the gold was wag encased in which event fine crushing would release it the con mercur company however has never produced any tailings containing less than 62 cents a ton and fine crushing tests have resulted in no higher ex ent to seriously interfere with the extraction inasmuch as carbon is a precipitant for gold this ore proved a stumbling block for base ores could be handled so in 1897 and 1898 the golden gate mill was built this mill altered improved and somewhat enlarged was operated until early in the present year in 1899 the LaMars delamare De mercur mines company and the gold mining milling company the dern company were combined and the consolidated Consolidate il mercur mines company came into existence all of the ore from the mercur and golden gate mines was afterwards treated in in the golden gate mill the manning mill being used only for desultory operations on tailings the golden gate mill the original capacity of the golden gate mill was tons this gave it a position among the largest reduction works in the country power and light were supplied over high tension lines from a power plant itt in provo canyon forty miles away at that time this was the longest single trans in mission line in the united states fuel for the dryers and ro asters was provided by a loomis gas producer plant in these features the plant was notable at its very inc inception eption the gas producer plant did not prove a success and was practically never used in describing this plant the past tense will be used although the description applies almost completely to the mill as it was operated early in the present year the mill was erected on a hillside above the town of mercur on a twenty five degree slope the difference in elevation between top and bottom levels being feet in a horizontal distance of feet the width was feet the whole plant was built of structural steel and corrugated iron with L g 1 74 om 0 COA nsf ij my 4 1 PAM A AMO v et 0 onic nai orrine 4 18 1 i 7 GOLDEN GATE MILL fun ES N 1 01 A t wt 98 0 tafe sat S a t M 9 6 FINE t p c ST S T 1 2 ASTino RO ag 1 01 j i n rost ro ROASTING ST 1 0 10 49 st ft S 1 roasting NG n lb 3 1 sf bi araci DEPT 0 19 1 f r 4 2 L 1 s k 0 OF PT I 1 t 1 ta as 70 0 o 1 some time but experiments conducted for a 1 period of some two years showed that by crushing the ore finer roasting and leaching the base with the crude chide oxidized the concrete foundations and retain retaining int these structures were not so common then as now and this mill attracted attention among mill builders an idea as to iny ane slender but strong character of the construction st can be gained from the illustration showing the leaching room the plant was erected on the golden gate cate mine from which ore was hoisted in a three compartment shipway to the top 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