CHAPTER lY. 



TREATMENT OF THE COMSTOCK ORES 



Section I. — GtEneral outline of the process — Classification of ores — Crush- 

 ing — Grinding AND AMALaAMATioN — Pans— Settlers — Eetorting furnace — 

 Melting furnace. 



Section II. — ^Details of crushing and amalgamating machinery — Stamps for 



WET CRUSHING — QUANTITY OF WATER USED— PANS : WHEELER'S, GREELEY'S, 



Varney's, Hepburn and Peterson's, Wheeler and Eandall's, McCone's, 

 Fountain's, Horn's — Settlers or separators— Agitators — General ar- 

 rangement OF mills. 

 Section III. — Costs and results of milling operations— Costs of labor 



AND MATERIALS — EELATION OF MINES TO BIILLS — SAMPLING OF ORES — MILL- 

 ING RESULTS — EeLATION OF YIELD TO ASSAY VALUE. 



Section LV. — Treatment of the residues — Amalgamation of slimes m pans — 

 The O'Hara roasting furnace — Concentration op tailings — Tailing 



RESERVOIRS — AjMALGAMATION OF RAW TAILINGS. 



Section V. — Treatment of first-class ore — Drying — Crushing — Eoasting — 

 Barrel asialgamation — Stetefeldt's roasting furnace. 



SECTION I. 



GENEEAL OUTLmE OF THE PEOCESS. 



Classification of gees. — -The ores of the Comstock lode consist chiefly 

 of various sulphureted forms of silver, native silver, and gold, finely, almost 

 imperceptibly, disseminated through a gangue of quartz. With these are as- 

 sociated a few other accessory minerals in inconsiderable proportions. Their 

 mineral composition and chemical nature will be more fully discussed in an- 

 other chapter. 



For metallurgical treatment they formerly were, and to some extent still 



are, divided into three classes. The basis of this assortment is, of course, ar- 

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