Show GET fiET ORE TREATMENT DOWN DOVIN TO LOW LOI COST COS Homestake Specialists Accomplish Accomplish Ac Ac- Wonders with Slime Plant PROFIT CENT IN CENT 90 ORE Total Milling Cost Is Brought to About 50 Cents a Ton What a 3 well organized properly equipped mining mining- organization can accomplish accomplish ac nc- ac- ac In tho way of or treating low- low grade graile gold ohl rc with the help of or good technical talent Is shown h by r a special report made I 1 by C. C W. W Merrill in charge chargo of or the sUmo slime plant of or the Homestake Mining com company pan at Lead S. S D. D The oro ore treated In that new plant was wa valued at nt 00 90 cents a ton the cost of of treatment averaging 33 2 cents a ton The addition of the plant has I brought the recovery from Homestake oro ore to 93 per cent at It a total milling cost for crushing ama amalgamating and of approximately 50 cents a ton These figures figurel are based on actual operation of or the plant for tor the month of November during which period 21 presses were completed and running Today the entire 24 4 filter presses arc are arcIn In operation and a still furth further r change Is being made In the cost and recovery recovery recovery ery figures During the month of November ember the plant treated tons of or slime for fora a recovery recover of or SS 88 per cent h by charge and residue assays and 91 01 per cent b by bullion while the total co COts costs ts were approximately 3 32 cents a l ton The rhe average value of or tho the slime treated was wac 90 cents cent The cY cyanide decomposition was 3 37 of or a poun pound for the fir first t 10 days 33 for tor the tho second 10 and 32 for tor the last 10 days daS The rime zinc consumption consumption con con- was 2 pound zinc dust per ton of slime while the lime consumption consumption consumption tion was 4 1 pounds per ton During the last 10 lays days o of the month which m may be he taken as a fair sample ample of the work being accomplished accomplish accomplish- ed eti at present In the big plant an nn average av av- as' as crage of oC 1435 tons of slime was as treated treated treated treat treat- ed per lay day for a recovery recover of oc 89 per cent The full capacity of the plant plantIs Is placed at 1600 tons tong every 24 I hours on tho the slime from the ore mixture mixture- now being milled io Low lo One of ot the interesting features of the work worl is the low consumption of or power This was lc less s than one one of ot a kilowatt per ton of or slime per day and according to Mr Mc lr Merrill this be he reduced to a n. merely merel nominal 11 figure ure were vere It not for tor the tho of or compressing a large volume vol vol- vol ume time of air In order to oxidize the re reducing reducing re- re chemicals in the o oi i ore This n Necessity c c s l calls i format for r at t leas Vea's est 70 p per i cent of the power used In the treatment of or the the slime The exp explanation a- a nation of the small amount of power used Is I the fact that there is no agitation agitation agitation agi agi- tation of or pulp and to the further possibility possibility pos pos- of using a very small bulk of solution namely 1 to 1 or less being all nil that Is leached through h the slime cakes A thorough test has been made with different ores During the period aCter after aft aCt er or the fire faro last summer Bummer when the mills v were ere able to resume crushing after a months month's Idleness the Home- Home Homestake stake o was obliged to secure its Us ore from Crom the open cut surface ore being used While this ore oro was of or lower grade and slower of treatment than that taken from the lower levels as ns today It yielded a slightly higher re recovery recovery re- re cove covery up to 93 per cent as l was tobe to tobo bo he expected from ore containing practically no sulphides |