Show new process of milling 11 at park city property A recent issue of the con tamed the following interesting art cle pertaining to the new process of milling that is now being worked out by the mires operating company an I 1 in view of the fact that the people who are responsible for the park city pant may eventually enter the local field we feel that the news item is worth republishing bashing in part it is as follows the mines operating company na ha been tl ti e pioneer in a new field of metallurgy metal lurg cal operations by the use of or a new process which it has per fectea at great cost of money and time it is 13 now making a commercial commer clat ore out of material that has hitherto been waste the company has a lease ease on the ontario mine from the level lo 10 the surface and f milling the old fillings process which has converted thia this waste into pay ore and which has thereby creat ted a new industry with a pay roll of men marl s a dis advance adval ce in metallurgy and 13 destined to play an important part in broadening the scope of mining operations in utah and other western states thet are many mines con large tonnages of ore too I 1 low grade to ship to smelters that h have long been idle for want of a s to treat the ore on the ground this appi es pa to cious I 1 gold coppel ores it is not claimed that the process is a universal one b it it w will ila certainly reclaim nurney i ous idle or abandoned properties and it will doi atless supplant other pro besses in many places nhen hen questioned about the moth ode employed general manager G tj dern said the vital part of the treatment Is the roasting Chlo ing roasting was formerly in wide use and was well ell known to give li extractions but the process was very ver costly aal an 1 it involved heavy losses 0 0 0 latil izat en on and dust and for these ve reasons the process has fallen into jut practical disuse the new methods methode we re are now no using will bring chload iz ng bick into fan faor or because we arc arf now doing the roasting at an astonish angly low cost and the and dust losses have been totally eliminated so that extraction and I 1 recovery arc aro now two different things I 1 it is sang sanguinely expected that th the e new methods will be revolutionary in their I 1 effects this applies not riot merely tol to continued on last page a new process of milling at park city property continued from pae pa e one but to oxidize ng and sul i 11 I 1 at hii g roasting as well the process which mr we have per f acted at I 1 baik ai k city was originated at the school of mines of the university of altah L tah it was the joint invention of N C christensen jr and theo dore I 1 holt these two metallurgists collaborated for months at the uni hersity and worked out the funcia mental details in tests on a large variety of ores the first ore tested was mercur base ore and in the course of these tests I 1 got into touch with the work that was being done subsequently suase christensen and holt camp came to mercur at my invitation t t and conducted their experiments on a somewhat larger scale when mr air christensen left mercur I 1 bought his interest in the process he suase reentered the field and the tile I 1 resent knight christensen mill at clintic differs from the methods used by mr air holt and myself only in the mechanical application A peculiar incident that arose in prosecuting the christensen holt application was that we found that the same in hal hat been independently made et it a little earlier date by dr wilhelm buddrus of 0 wiesbaden germany and we therefore there fole foie bought the buddrus pat ent which we now own in addition to the christensen Chri stemen holt patent in our roasting operation the tile fuel is mixed with the ore aid ai d the change charge is roasted by internal corn com bustion of a blast of air the ontario ci c e Is highly sili clous and cantali r little sulphur and yet we me roast this ore with fron 2 to 3 per cent of coal dust which is remarkable As coal dust is practically a waste product at tha coal mines it is the cheap est fuel obtainable but it answers our 1 just as well as the most cost ly grade of coal we get our results with a much lower Pell percentage of this cheap fuel than other roasting fur s use of lump or other costly coals we are at present us ng a five eighth return screen in our crushing department and yet with 4 i this coar coax e crushing we are making I 1 I 1 cn all extraction of 80 per cent along which aich is also remarkable fn F n er crusha R will give higher extrac tion but has not proved profitable in our present roasters the roas roasters I 1 j we are no v using are hand operated and are crude in many respects we wc have hecei UY perfected a mechanical roaster which we call the holtzem HoIt Dern roaster and which we me expect to in stall in the near future we havi hav had a tenton ten ton capacity model of thia roaster in operation for three in achs and have thereby satisfied ou ourselves relves that when v me e get the new furn kes es installed we will male 1 e an extraction of better than 90 per cent and that the cost of roasting exclusive of salt will be in the neighborhood of lo 10 cents pei ton we will then be ab abl to make a profit on seven ounce fill ings or material worth morth less tha than n 4 I 1 per ton ahe work and expense of borki morki working n 9 out a new process are h hard ard on the nerves to say the least but there is a compensation in having achieved athi eved a access |