H I N TS — ON A M A LGA M AT I ON AND T H E GENE! AL CA! EOFGOLD MILLS A E . M . W . J . AD AMS, . M ' G radu a of h l f n of Col i a. n iv i te the Sc oo o Mi es uxfib U ers ty. New Yo rk . A Bmm mBOO K o r A U L GO LD - M L L P! CT CE AS c CT A I A I , D ETE! MIN ED BY AN E! PE! IENCE OF TWENTY YEABB W! ITTEN IN L ANGUAGE TH AT CAN BE UND E! STOO D BY AL L . A I LLUST! TED . CHICAGO M D O E! N MACH I N E! Y PUBL I SHING CO MP ANY. 1899 . f 1 8 En te red A cc ordi n g to Act o Co n gress i n the Ye ar 80 , W J . AD AMS BY . f h L i r ria n f o n ess W hi n I n the Offi ce o t e b a o C gr at as gton , D . C . TABLE O F C E O NT NTS. — ChapterZI General Process Arrangement of Mortars P lates Concentrators for Canvas P lant 2— Care of Quicksilver Amal gamation — - 3 Cleanin g up 4— ! etorting an d Melting 5— Concentration 6 Sampling 7 Conclusion INT! O D UCTION. Gold has been known from the earl iest ages , from its occurrence in a metall ic state in sedim enta ry deposits as well as in veins . On account of its great specific l i gravity , it can be col ected from placers and r ver beds , by separation with water alone , and in veins after the m atrix i s crushed , a great am ount i s saved by the same simple method . When only rich deposits were exploited , an ybody could manage as it apparently required only labor and opportu nity , w hile as lon g as money was s made , the lo ses tha t occurred did not trouble the own ers . Fro m this very s implici t y of working , the maj or ity of owners and i nvestors i magined that no special training wa s requisite to insure success , but that any tru stworthy man , skilled in m ercantile pursuits , was th e proper person for the place of general manager . - To day the sam e opinion is held by very many , in spite of the warnings from hosts of disastrous failures . One ca use for thi s belief has been the lack of literature for thi s speci al branch of metallurgy ; in fact , very near 1 890, there was practical ly no works written at all which spoke of gold except as a subsidiary prod uct rac of the m etall urgy of other metals . Volumes , both p i a t c l and scientific , have been published which deal with the special branches of the metall urgy of lead , copper , H I NT 8 S ON AMALGAMATI ON . an d silver, but the metallurgy of gold seemed so simple , it only requi red an occasional article in a paper or magazin e. In spite of this deart h of w ritten knowledge , practical m en in all parts of the world were rapidly improvin g the methods of treatment, both mechanically and with aid r a i the of chemist y , in their sever l localit es ; but , th rough lack of exchange of thought , ea ch section had f a di ferent process , on which faith was pinned to the exclusion of all other proces ses . As the rich deposi ts gave out , attention was turned to those of lower grade , which are now found to be very profita ble with improved machinery and increased - are knowl edge, but , even to day , we in the infancy of this sci ence . The treatises on gold , now before the n public , can still be counted on the fingers of one ha d , and are either devoted to the scientific discussions of processes now in vogu e , the history past and present c of gold m ill ing, or the m e hanics pure and simple of the various machinery used . Th ey are all good for the edu of direc cation the world , but are lacking i n definite ti ons of the best way to employ the methods they describe , and are generally understood by those only who h ave enj oyed a previous technical educat ion . This absence of intelli gent application of these known p rin ciples in the great m aj ority of the mills in this Sta te s (the hom e of gold m illing) , has been a con tant source n of wonder to m e, a d yet I have a fellow feeling from HINTS ON A MALGAMATION . u o - G my first experiences in g ld m ill practice . raduating i from a celebrated school of min ng engineering, I thought myself em inently fit to at once assume the absolute managem ent of the biggest m ining concern on earth , but , thank s to the kind influence of an elder brother, already well known in the m ining world, I was started at the bo ttom of the ladder in a gold mill , to l begin my rea education. I very soon found that t here was no bigger tenderfoot in California , as my technical education had only taught the chem istry and s in t r es cientific mechanics general , with no prac ical ul u s of how to apply this knowledge . These practical r le i in have been learn ed through bitter expe r ence, extend g are through many year s , and to try and help others who s j ust beginning , I have set down in the following page c the results of the observations I have made , all of whi h have be en practically demonstrated as correct by appli ou i lt cation several very d fi i cu ores , with marked suc to cess in every case . It has been a work of pleasure in su u contribute th is m ite of knowledge , and if I am mental in increasing the production of only one gold mill , I will feel amply repaid for my labor . he the I ask the indulgence of t reader , to overlook absence of rounded sentences and polished language , est an d take the will for the deed . I have done the b m to c. I a able , and can only leave the verdict the publi M. M . W . J . A DA S , E San Franci sco . C HAPTER I . GENE! AL P ! O C ESS . I t i s not t he purpose , in t his book to enter i nto a ny detailed description of gold milling , as the ground has already been amply covered by E . B . Preston , in h is re “ ” r on M “ po t G old illing , publi shed by the State Min ” of eralogist , C alifornia . Som e other points also may seem too well known and appreciated to be m entioned , but these require con stant repetition , and even then very little practical ap plication seem s to be m ade by th e average m ill man . In order clearly to understand the en tire me thod . we must start with the ore as it com es from the m ine . This ore m ust first be carefully exa m ined , as its character i and structure as well as its value , determ ne t he most . ma advantageous method to pursue First , the ore y be hard and tough , requiring force to disintegrat e it , though - o entirely free milling ;sec nd , the ore may be soft , giving a great deal of slimes ; third , the ore may be a m ixt ure of the above two divisions . o re First ! Here , the i s first dumped over a grizzly , 1 1 with the bars set 76 i nch apart , the coarse lumps goi ng - through a rock breaker of som e form , to m ix with the fines in the ore bin . Fro m this bin it m ust be carried to stamps , preferably of heavy weight , notwithstanding all as sertions to the contrary by patentees and makers “ of other pulverizing device s which are j ust a s good as ” stamps . Second ! When th e ore is soft , it also requires t o be passed t hrough a breaker, to enable the part i cles to be 12 HINTS ON A MALGA MATION . of uniform size ; but here , very frequently any kind of stamp , and always those of heavy weight , will slush through the bed of pulp , wearing out iron uselessly , and increase the proportion of slimes , always to be avoided as m uch as possible . Here we find a great advantage in f l the di ferent types of th e Chilian mil , such as the Hunt in ton g and Bryan , from both of which the pulp escapes as soon as i t is reduced to the requisite size , as de termin ed by the screen , and with t he mini mum of slimes to hinder future operations . ! Third In an ore containing both soft , clayey or talcose m ateri al , and hard bunches of quartz , sta mps are gener of s ally the be st , as the grit the hard quartz prevent i s u fi i ien t pound ng of iron on iron , and causes c splash to keep the screens fro m choking , while all operations can a be kept under close observation , which c nnot be done — with any pan or roller mill o n e of the greatest obj ec I n tions to the general use of these mills .