US1164636A - Process of extracting values from ores. - Google Patents

Description

H. FOERSTERLING & A. L. HALVORSEN. PROCESS- OF EXTRACTING VALUES FROM ORES.

APPLICATION FILED JUNE 3.1914.

1,164,636., Patehted Dec. 21, 1915.

WITNESSES JWW " Hans sennsri v RING K, A conrona'ricn' or.

nzaocnss or miss.

Specificativ pplication filed Jun E- "T ail whom it may concern. I

1 city of Perth Amboy, v

and State-of New Jersey, haveflni. certain new and useful Improvemer or gold, etc., the object of mg to. provide a process it known that we, Hans FOERS'IERLIIH- a suhj'ect of the Emperor of Germany, a ARTHUR Lonwron HALvoRssN, a siihject o. the-King of Norway, both residents or 1 county of Middl Processes of Extracting- Values fi om (ares, of which the following is a specification.

I This in'vention relates to improvenients'in processes for the treatmentof ores and more particularly to a process for extracting values from ores containing copper, silver our invention befor producing tithe entire metals by treating ore i metal content of is ob er:

With these and other objects in View the invention consists'in certain novel steps the process of treating the ores with suitable cyanid solutions in the presence or absence 'espeeiallyv from cya'nid v it'j'ifs necessary,

' from" the aforesaid convenient rate of reaction metals 11} the r respective comb1nat1ons,such.

0t mercury and to precipitate the metal solutions by means of alkali metals. 5

."ltiskfiown that metallic Na may be suitably" diluted with Hg so that it'willjata re lace various metals as released in lmmediate contact With.- g, 'enteringinto vthe Hg forming the respective amalgams. As a practical demon- "stration may be taken the following ,ac-

knowledged equation stances difiicult .Na trengt hof the alloy or amalgam constant or varying Within the 'desiredlimits;

in case of Hg being used as diluting agent tion of- @EFFKCE nannoasnn, or PnnTH-AMBoY, NEW HASSLAOHER CHEMICAL 00.; on NEW 'QZALUELS FROM GEES.

m. Patented DeeZLiifi iE.

Serial No. 842,56fi.

diiiicult to get areasonably large con uo'nsly active surface capacity per certain weight of Hg in use. As it is e well known fact that all the by: drometallurgical processes for the extrac-' tion of copper ores labor under certaindis advantages and as especially in the extraccopper all the advantages of our process (TE easily seen we will particularly refer .inthe description by way of example to' the extraction of copper though gold,-

silver, etc., show an analogous behavior.

In descrlbmg the invention reference is had to the accompanying drawing of which- Figure l is a longitudinal and F ig. 2 is a cross sectional view of one form of thenpparatus we prefer to use in the the process I The apparatus shown in Figs. 1 and 2 consists of a cylindrical casing 1 made preferably of soft steel, an axis 2 being cen--,

trally located in suitable journals 3and 4 and protruding on either side from the plates 5 and 6 of the casing. The axis 2 bears a closed drum 7 on which, at a small distance from each other, 'nular plates 8 of soft steel with perforations 8 for the passage of the solution. The upper part'of the casing is furthermore provided with two pipes 9 and 10 through which, respectivel liquors may enter and leave, Whereas pipe 11 at the'top of the cats pipe 13 permitting Iadmisinto said pocket 12. f 1

understanding of our. in-

sion of materials For the'better ampies of the precipitation of metals from the c anid solution bv means of metallic;

sodium.

. Example 1: Our process is of great importanceabr the reduction of copper from p inasmuch as cyanid solution is its ores, known to be a good solvent of copper him free metallic state as well as of both natural and'artificial copper oxid. For the extram tion of copper from ore, same is treated with operati'ohsqf are provided an.- i

'85 mg serves as an exit for gases. At the bottom of the casing'we have provided a kind of pocket 12, a

vention We will now describe in connection, withthe apparatus disclosed above some excyanid solutions so that the dissolutionfof i i metallic copper or suitably reducedcopper oxids respectively goes on according to the tollowing equations:

v In the meantime we charge the apparatus,- with 1300 lbs. of mercury and a small quantity of sodium metal-,ithe latter roducin'g the-wellknown amalgam. After eeding in the metallic sodium the soft steel plates 8 on drum 7 are rotated by any suitable power arrangement acting on axis 2. The apparatusthus being started the cyanid solution saturated with copper from the ore and .hereinafter referred to as the pregnant solution is admitted through pipe 9 into the casing of the precipitating apparatus; From Fig.1-2it is easily seen that the plates,

'mechanically and chemically cleansed, are

partly submerged in the mercury 16 andvby rotating they soon become covered on, their surfaces with a film of adhering amalgam. The steel platesfafter emerging fromthe sodium-mercury amalgam, carry a film of such sodium-mercury amalgam into the pregnant solution thus continuously exposing a minute quantity of metallic sodium to the pregnant solution thereby causing interaction between the contents of the solution and the sodium according to the equa-.

tion:

Cu (ON) (NaCN) +Na --NaCN +Cu the copper bcing absorbed by ,the mercury,

forming copper amalgam.

The precipitation of the copper is favorably influenced by the, vigorous agitation of the cyanid solution by means of the rotation of the enfilmed soft steel plates. The bar ren solution, which has been deprived of part of its copper content, is continuously discharged through pipe 10 and is enriched -with.coppe'r by extracting same from the ore, and the solution, now state again, is then returned to-the preci itating apparatus and -.so on. alternate y.-

Gase may, eventually escape through pipe 11. The solution passes theapparatusgat the vrate of 100 tons per 24 hours; to show t e rapidityofii'ie precipitating process we tr state that itj woi'ild a certain partile of the solution within, about one minute through the apparatus. Metallic. sodium, suitably in the form of its amalgam, is simultaneously fed through pipe 13. at the rate of approximately 350 Lbs;

, charged through pipe 15 in dilute'form at a rate which m iy per 251 hours. The copper amalgam is disbe varied. The copper. amalgam is separated for instance, by filtering, into a- .liquid as well as into a solid part; the liquid part of the copper amalgam eing in pregnant e sufficient to pass then returned to the apparatus throu h'p'ipetiidist'illation furnishing the co sodium metal is added, the amalgam being admitted into the apparatus. I

- In connection with the aforesaid -wewish 'tosta-te that furthermore the success of the prdcess greatly depends on the ratio of Cu ,to ,NaCl in the so ution and weha've found it best to have the cyanid solution satur ated withcopper, i. e. to have the ratio of Cu to NaCN as high as possible, the NaCN including here' both free cyanid and that contained in the copper alkali cyanid.

' A desirable solution of good saturation and consequentl satisfactory results is obtained by cyani ing ores containing the co per values as 011,0; a co copper in the form of n 0 is treate 13, whereasthe solid ainfi l'gani is su jected.

per in solidformandto the mercury thus a so recovered pregnant solution containing 1.15% Cu is obtained, 2'. e. the ratio of total Cuto total sodium cyanid is 1 to 2.17. The success of the precipitation is all the eater the higher aCN the ratio of Cu to N It is therefore best to withdraw the coppercyanid solution y from the precipitation apparatus when so much copper has been precipitated 'outof the solution that the ratio ofCu to NaCN is getting low, forinstance about 1 to 3; in this case the barren solution is reused for extraction until againsaturated'and thus continuously. passed through the cycle.

The circumstances accompanying the treatment-of ore containing the copper in'.the form of Cu O suggest to reduce cupric to Cu,O. In case a sulfid oreis to be worked an oxidizing and then to a reducing roast in order to bring the ore intosuch favorable state for treatment by our process.

followed by the precipitation of the dissolved copperr'and liberationv of the cyanidup same may be therefore first submitted my Ill? through reaction with alkali metal suitably alloyedwith mercury, the total theoretical,

codsuriiption ofalkali metal being36 lbs. of

N per lbs. of Cu extracted from the ore,

ecipitated from the solutionan'ct recovered as metallic copper. With a redumdcarbpnate oxid copper ore or an ore containnig native copper in simultaneous contact w th cyanid solution and mercuryjor cyanidsol'ution and alkali amalgam, after meter-mes come chemically cleansed by the" dissolvingthe extractionby'cyanid alarge-part' of the are or copper value is recovered without #of the reduced; metallic.'particles'havejbe zinc nose above chemical consumption, the chemical consumption per total amount of recovered. copper being thereby decreased accordingly.

Example 2: For the reduction of silver 5" and relatively small quantities of gold from its pro we treat the latter in suitable tanks with sodium cyanid solution until We obtain 100 tons of a solution containing silver and gold cyanid in the form of their double salt with sodium cyanid, the solution showing per ton for instance, a content of 8.5 oz.

silver, 0.095 oz. gold, 3.7 lbs; free NaGn and 0.5 lb. of CMOHMF Vi e admitthe cyanid solution referrecljto above through pipe 9 into the precipitation apparatus which was used in Example 1 for precipitating copper.

Also here a film of sodium amalgam is lifted .While' adhering to the soft steel plates when emerging from the sodium amalgam. thus causing "interaction between the metallic sodium of the amalgam and the silver cyanid contained in the solution whereby metallic silver is precipitated according to the equation:

and is absorbed by the-mercury forming silver amalgam.

Like the copper amalgam in Example 1 the silver amalgam is Withdrawn from the precipitating vessel through pipe 15 and sub sequently separated into liquid and solid amalgam the solid amalgam is subjected to distillation to obtain the silver as Well as the mercury in its free state. To the mercury thus recovered as well as to the liquid silver amalgam is added a new charge of sodium and theses. um amalgam thus obtained is returned to the precipitatation vessel the situation may require. ,The sodium 'is' thus fed, preferably in the "form of its amalgam at the rate of lbs. per day; the cyanid solution. to be treated passing the vessel at the rate tons per day, While the rate for witlul-rawing silver amalgam may be re ulatedaccording to the arrangement used for sodium feed and varied from about 35-350 lbs. per hour. The barren solution discharged from the precipitating apparatus contains per ton value Oil? $0.07in Ag-Hiu, -l-.1 lbs. of free sodium cyanid and 1.? lbs. equivalent-Ca(OH) .The el'liciency of our process'is evident from consideration of the values contained in the pregnantsolution and those left in the barren solution discharged from thepreeipitating apparatus approximately 142 minutes after entrance into the same. On the basis of $.60 and $20 respectively for silver and gold prices the value of the pregnant solution per ton amounts to ltlOOwhereasihe barren solution carries "only a value-of $.07 per ton, thus showing a precipitation ,efiiciency of 99%.

The advantages of our invention are great economic success of our ful influences of 21: the sodium amalgam.

and important inasmuch as the process outlined above is very simple in its operation and free'from complications; it is especially importantfor its great efliciency in completely and economically recovering the entire m tal content of suitable ores by applying a relatively small quantity of mercury in continuous use. In our case one may recover for instance all the values of gold, silver and coppersimultaneously Whereas in the former art much cyanid Was spent on an ore containing the three metals, in dis-' solving same all together, whereas, however, copper could'not be recovered unless under great difliculties resulting in great loss of materials, labor and time.

In our process no cyanid is lost as it,is always recovered as seen from the equation:

The cyanid originally applied is therefore liberated again and replenished to circulate in a cycle between the cyanidation and pre cipitation apparatus.

Though the soft steel plates offer an enormous surface to the solution notwithstanding the only source of loss of metallic sodium which may be sustainedin our process by interaction with water, is reduced to a minimum owing to the extremely small per centage of metallic sodium in the film of sodium amalgam adhering to the carrying means, such as plates, etc, steel or other suitable materia It is of considerable importance for the process that We are able to prevent further losses by oxidizing reactions attacking the sodium in the amal gain as well as the cyanid in the solution.

An oxidizing action may be due to oxygen statunascendz' and as the formation of suchoxygen is invited. if C is dissolved in sodium cyanid, we therefore prefer all the more to reduce the oopper compounds for treatment by our process; by furthermore incasing the sodium amalgamentirely in a closed vessel we also exclude the harmmospheric oxygen from A further and rather important advantage of our process consists in the purity the metals obtained by the precipitaion process, for though of course according o the various metallic contents of an ore a re of metals is ohtained, said mixture is particularly free from sulfur, phosphorus, silicon and other like impurities the removal of which by chemical methods is known to cause great expense in time and money.

It is obvious that our process is not restricted to the reduction of gold, silver and copper to their metallic metal which itself as Well as its oXid dissolves in cyanid solution is equally amenable our process and We therefore claim such made of soft state as any other ever We speak of an felkalij metnlfi we mean to include as well an alkalienrth m.etal',;.m1

' .-ores consisting in treatin ,the ore with n solution of a cyamdcaps leof forming u vention and coming with p p to to state that when; 1 I

.sur

e'large thou hi-irregu'liir surface 'us;is'fofined upon any ot er suitable carrying-means do sirable for the purposes-f of our inven-- tion. As such a'film on'othe orn flolfering like advantage may be pnoiluced byfluiiens means and as this may viating from, the spiritl or vantage of our inventio' also any such deviation use be ied without a wf fi ing the min o ghe efore jclaimport of our in v -5the scope same. Finally we wish tures of alkali metals or of "alkali q dgnkgii eerthmetels.

-Wjeclaim: v r, p '1. The process of extracting values from,

soluble cyanid salt with the vnlfue, find' react inglupon the value-char d-solu'tiou with Q e moVing' adherent 0- an amalgama 2. The process of extracting velnesifrorn ores consisting ,in treutin'glthe. bre -with} q solution of a, cyanid-capa le'.. o ,iformi3g e soluble cyanid salt. with the volumaml-reuctg ing upon the value-charged solution. within," I of hmalgam and constantly renewi vertical, adherent, rotating fihn. of'ams am.-

3. The process'of extracting values rom ores consisting in treatin the ore with a. solution of a; cyanid c'apa 1c of forming a soluble cyanid salt with the value and reach ing upon the value-charged solution with :a moving, adherent film of an amalgam ee'puble of displacing the value in the'solutwn and of regenerating the original cyunid.

4. The process of extracting values from ores consisting in treatingdhe ore with a solution of a cyanid capable of forming a soluble cyanidsaltoviththe value and reacting upon the vulue charged solution with a moving, continuously-renewed, adherent film of an amalgam capable of displncin'g the value in the solution and ofregenernting the original cyanid.

5, The process of extracting values from ores consisting in treating the ore with a solution of a cyanid capable of forming n soluble oyanid salgi glth the value and react ing upon the val efiarged solution with a continuous, moving, adherent film of an amalgam capable of displacing the value in the solution andof regenerating the original cyanid.

6. The process of extracting values from ores consisting in treating the ore with a solution of n cyanid capable of forming a soluble cyanid salt with the value and passing the value-charged solution through and ngainst a series of moving, adherent films of amalgam.

"solution of e cyanid c soluble cysrucl.

an A lgem";

ores fiionsistingin trestingtiie ore with a res consisting in treating the .,in e n ngainst'e pli1rality of moving, adherent '{ronsistiug solution of :1. cys'niti soluble cysn'id sult with 2*" solnt ,i Bu,

solution of 9 eye. soluble cyeniu ing the values 9. The prooessoi cons sting in treat he t ainee/hex eclsolni' n surface of amalgam and blue i .ot perforutcgl, moving, adheres Oiffihe of essctsecting; vein solution oi'n 'oyunid cope-hie of forming a soluble cyihiid salt withfthe vellue, passing 'theivnlue-nhnrged solution horizontellx over, s surface of amalgam through a series of "iicrfomted, vertie'ei, adherent, rotating filing sai r to ation,

film's l passing the same ID. tlibl tin-6n e body of'nmalgiinn f #211. 3 lhe process of extrgcting filmsof amalgam.

15!; The process of'extrecting I ores joonsisting in treetin the. ore with u solution of a, yenicljca-pa leof forming at soluble cyeni'd. salt with the vein solution is substantially sate acting upon said substantie 1.3, value-chsrged solution with e 1 moving, adherent films of ninnlgcns 13; The p 'pcess ox extractingel: v ores consisting" treating t solution of n cyanid capuhle o I firming s soluble cyunid salt with the vull l and. re-

acting upon the value-charged solution, un-

der exclusion of air, with a'moving, adherent film of amalgam.

14:. The process of extracting values from ore's consistingin treating the ore with a solution of a cyanid capable of forming u soluble cyanid salt with the value, renctupf upon the value ohargecl solution with a 'ing, adherent film of on amalgam capablijigof displacing the value in the solution ancliof regenerating the original cyanid, retrea'tin fresh ore with the. substantially valye-frefe ing a portion of the value'from the solution and regenerating the solution from which thevalue has been removed, retreating fresh "tire with the value-depleted and regenerated 15 s utio-n and repeating the process in a con nu ous cycle. p l

' 16. The process of extracting values from -hres consisting in treating the ore With a 4 solution capable of forming a soluble salt 2 fvvith the value and reacting upon the valuel" "of amalgam. 7 17. The process of extracting values fores consisting in treating the Wr lution capable of forming a soluble salt j with th'e'value and reacting upon the valuecharged solution with a moving, adherent ffilm of an amalgam c: pahle of di icing t Q. value in the solution and of 1" ,nerat- 3 0 gzphe original solution. I Y

"1'8'1 Ijhe process of extracting values from ores consisting in treating the ore with a sollltion capable of forming a soluble salt fwiththe value and reacting upon the valuefifi charged solution with a moving, adherent ffilms'of an alkali amalgam capable of dis placing the value in .tlie solution and of re generating the original solution, f 19. The process of extracting values from res consisting in treatingthe ore vitl a ",vith the value, and reactiig upon valuechaigel solution with a continuous, vertical, adherent, rotating film alkali amalgam ticonstantly emerging from a Well of nalgam, said amalgam being capable displacing the value in. the solution. of

regenerating the original somytion.

The process of extracting values from fi ll' oies consisting in treating the ore with a solution of a cyanid capable of forming a "soluble cyanid salt with the value and g'fupon the value-charged solution nth a "continuous, vertical, adherent rotating film amalgam. constantly emerging from a 'Well of said amalgam. A :21; The process of extracting values from oesgconsisting in treating the ore with a solution of a cyanid capable of forming a solublecyanid salt with the value, reacting i upon the value-chargedsolution With a moving, adherent film of alkali amalgam con st antly emerging from a Well of said amalgam and continuously malntainmg a subharg'ed solution with a moving, adherent contin ;s liitidn capable of form a soluble y constant content oit in the ,unalgain.

The process 5 extracting values from ores consisting treating the ore with solution of cyanid capable of forming a soluble cyanid sat With'the value,- passing the value-charged solution into a well containing an alkali amalgam, carr a continuous, adherent filinof alkali amalgam constantly eniergingfrom said Well through said solution and precipitating the and re 'eneratingthe solution by the reaction between 'yaluecharged solution and said amalgai :28. The process of extracting valaes ores'consisting in treating the ore solution of a cyanid capable of for-111m 5 soluble cyanid salt with the Value, passing the value-charged solution into a Well containing an alkali. amalgam, ca Wing con adherent :lilni of a f i between sa d am suostantially r at total in the alkali metal v 24. Theprocess o acking values from oresconsisting in the ore ith a solution of a I a oi soluble c1" rith the value, pa the vain ution into {sflfill taining an al Mi a portion of precipitate .zali m i so ing values from OIBSQODSIS JlHg in heating the ore with a solution of a anid capable of forming a soluhlewyanitl salt with the value, passing 11-5 the valuecharged solution into a well containing an alkali amalgam, carrying a continuous, adherent film of alkali amalgam constantly emerging from. said well through said solution, reacting on the solution with the alkali metal to precipitate a partofthe value therefrom, forming an amalgam of thevalue precipitated and the mercury ofthe alkali-freed amalgam, continuously Withdrawing the partly exhausted valuevcharged solution from the Well, treating ore witlrsaid partly exhausted value-charged solution, continuously returning .said resolution,

;; vdo? to the well, Withvaluercharged solution amalgam contamdiawing a portion of the gin the precipitated value, removing said. ya no fromfsaid amalgam, rechargm the "5' recoyeredfjmercury with alkali nets and 's aid a kali man; o the -well. v V p 26. The process of ertractingyaluesfrom sodium amalgam,: carrying a continui I ousfadherent film of sodium amalgam con-- saidwell through stantly emerg" from said solutioniiaacting' n the solution with theto recipitate a part of the value efrom/I amountofisodmm cyanid, forming an amalgain of the. 'valne' 'precipitated and the -mer' ofxthegsodium-depleted amalgam, continuouslyw'ithdrawing the partlyexhausted value-chilirged' and regenerated solution from theflwell, treating ore with said partly v eshausted value-charged "and regenerated continuously returning said re hai'ged solution to the a-portion' of the amalgam contain he precipitated value, removing -said N irom-said amalgam' recharging the m liel'edimercury with 'um and returnsaid sodium amalgam to the well.

' 27;;The process of extracting copper from ,or'e consisting in treating the ore with a solution oi, an .alkali-metalcyan1d capable 50! forming, a solublecyanid salt with the copper "until said solution :is substantially y saturated, reacting uponthe solution with an alkali metal amalgam 1' to precipitate a portion of theco per from the solution and regenerate the al 1i metal cyamd, treating "re with the depleted copper-charged and re enerated solution until said solution is su stantially saturated and repeating the cycle. 1

28. The processof extracting copper from ore consist1n in treating the ore with a solution of sodium cyanid until said solution is substantially saturated, reacting upon the solution with sodium amalgam to preclpitat'e a portion of the 00 per from the solution and regenerate t e sodium cyanid, treating ore with the depleted coppercharged and regenerated sodium cyamd solution until said solution is substantially saturated and. repeating the cycle.

29. The process of extracting copper from ore consisting in treating the ore with a solution of an alkali metal cyanid capable of forming a soluble cyanid salt with the cop per until said solution is substantially saturated, reacting upon the solution under substantially non-oxidizing conditions with an: alkali metal amalgam to precipitate a. or

tion of the copper from the solution an recycle. p a

30.- Theprocess of extracting copp'crfrom the ore with a t solution of sodium cya'n'i regenerate a proportionate an. alkali metal ama well, with-.

ama

32. The process of extracting copper from ore consi in treating the ore with a generate the alkali metal cyanid, treatingre nerdted solution unt' said solution is su stanially saturated and repeating the ore consisting in treatin ,until said solution is substantially saturated reacting u on the solution under substantially, non-old iz-. ing conditions with sodium amalgam to preci itate a portion ofthe'copper from the so ution and regenerate'thesodium cyanid,

treatin ore with, the de let/ed opp rcharge and regenerated cyanl solution until said solution 'is' substantially saturated and repeating the cycle. 31. The process'of extracting copper fromv ore consisting in treating the ore. with a solution of an alkali metal cyanidca of. forming a solublec anid salt the copper until said solution is substantiall saturated, reacting upon the solution'wit gem to precipitate a portion ofthe co per mm the solution and regenerate the a ali metal cyanid, treating ore with the depleted cgpper-charlged a regeneratedsolution un said so cycle, continuously maintaining a su tiall constant content of alkali metal in" the solution of ium cyanid until said solution is substantially saturated, reacting upon the solution with sodium amal a portion of the copper mm the soution able bs n as d ih su tantia y satura an repeatingstmef m to preci itate andregenerate thesodium cyanid, treating ore with the depleted cop r-charged an regenerated sodium cyamd solution until said solution is substantially saturated and repeating the cycle, continuously maintaining a substantially constant content of sodium in the amalgam.

33. The process of eittractin'g copper from ore consistlng in bringing the ore into such condition that the co per therein is in the form of cuprous oxi reacting the cuprous oxid with-a solution of an a ali metal cyanid capable of forming a soluble salt with the copper until said solution is substantially saturated, reacting u on the substantially saturated solution wit an alkali metal amalgam to precipitate a (portion of the copper from the solution an to liberate a corresponding amount of alkali metal to form alkali metal cyanid, treating cuprous ,oxid with the depleted copper-charged'and alkali metal regenerated cyanid solution until said solution issubstantially saturated and re posting the cycle.

34. he process of extracting values from ores consisting in'recovering non-precious metals from ores with simultaneous recovery of precious metals by first treating the ore to bring the metals into oxydul and me tallic condition, dissolving the metals in that condition byalkali cyanid and precipitating the metals With-dilute alkali metal While liberating alkali cyanid.

35. The process of extracting values from ores consisting in recovering non-precious metals from ores with simultaneous recovery of precious metals by first treating the ore to bring a substantial part of the metals into metallic condition, recovering the met als in metallic form by direct amalgamation in the presence of cyanid-solution, dissolv

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