Show electricity in gold Extract extraction fon BY ELMER ELLSWORTH CAREY 04 A the miner has robbed natures stored up treasures since 49 of precious metals valued at many millions of dollars he took those golden treasures most rea readily dilys secured e cured but nature seemingly anticipating this raid on her treasure vaults cunningly hid additional millions as a reserve for emergencies gen cies but these hidden treasures ha have aca been located and frantic efforts have been made to turn them into golden dollars it appears that the values are so fine so attenuated so elusive being microscopic or submicroscopic that all ordinary efforts toward recovering them have been futile the following article describes a plan to coin millions from desert ocean beach and river liver silt and to open a new era in the metallurgy of gold it is the story of a raid on natures gold god reserve N A in the early days of mining on the pacific coast the miner was content to save the larger pieces of gold nuggets coarse gold and melon seed gold were some of the terms used unless every pan of dirt about twenty pounds yielded at least twenty five cents the ground was considered poor As the richer claims were worked out the miner was satisfied to handle dirt yielding ten cents per pan then five cent dirt was not spurned in time all the coarse gold de posits were practically exhausted and improved appliances for gold saving were devised now it is possible to work profitably low grade deposits yielding ten fifteen and twenty cents per ton of dirt the introduce intro duc tion of the hydraulic system of mining made it possible to tear down mountains and expose the pay streak over thousands of acres in the days of hydraulic mining torrents of water under enormous enoF enormous pressure were thrown against massive cliffs through six eight or ten inch nozzles called monitors and thousands of tons of dirt washed daily into the sluice boxes with this system dirt averaging as low as fifteen cents per ton in effree gold could be profitably mined then came the dredges the gold ships which tear up 2000 or yards per day and extract on an average about fifteen cents per yard placer gold is caught by gravity in a sluice box behind transverse cleats or rif fibbs laid in the bottom of the sluice box rocks sand loam and the lighter material are carried down the flume by the water and deposited on the tailing dump the debris of the mines alter after the gold has been extracted is known as tails tailings or baling tail ng tailings from hydraulic mines are also known as 11 raw natural material entering the sluices or gold saving device is known as heads or headings millions of yards of from the mountain placers have been carried by the rivers into the lower valleys till the river beds contain many feet of silt debris sand etc the filling up of the river beds causes disastrous floods as the river channels cannot hold the waters of the wet season recently investigators have found that the countless million tons of debris and tailings that the miners have discarded still contain gold often the tailings by assay show more gold than the miner extracted originally the gold in these tailings cannot be caught in riffles fiffles or in any device working on the gravity principle some of the values consist of gold particles so small that the golden color disappears a bottle of this flour gold looks like soot the gold in the tailings s is so light that it easily passes off with the water some of it will remain in suspension in water flowing only two miles per hour in this way gold has been carried a hundred miles down the sacramento river this elusive gold is known as fine flour flaky microscopic or sub micro gold flake gold is so thin it will float on the surface of water some of the gold in the tailings is encased in minute pieces of quartz some exists as minute rusty scales which adhere to the particles of black sand or magnetic iron magnetite ne tite sometimes the grains of magnetic iron carry gold values amounting to several hundred dollars per ton black sand is found in all placer ground and usually comprises from one to five per cent of the auriferous material in its natural state the black sand is heavy and when it is plentiful it soon fills the riffles fiffles rif fles then the lighter particles ox gold slide over the packed black sand and are lost while millions of dollars dollar s have been extracted from the placers of the west yet there remain in the tailings nearly as much gold as has been taken out in addition to the tailings debris etc there are immense deposits of sand in the west covering thousands of square miles in which the same elusive values are found the southern part of california large areas of nevada arizona new mexico and mexico contain immense tracts of gold bearing sands many desert deposits contain values averaging over per ton these deposits are of unknown depth they consist of conglomerate sand dry lake bottoms and becom posed ledges one square mile of such deposit Ps it one yard deep contains gold to the value of over and there Is not one square mile containing these values but thousands of them prospectors tell me that death valley contains values amounting to over per square mile so impalpable that they can only be recognized through the medium af the assayers assayed crucible but bua such elusive values exist all over the pacific coast from the isthmus to the arctic circle these deposits form a vast treasure house containing a million times as much gold as the combined coinages coi nages of the nations when the gold bearing ledges and present placer mines are exhausted the world will turn to the so called low grade deposits for its supply of gold there are also mountains of low grade base ore assaying from 1 to and 10 per ton which cannot now be profitably mined as no economical method of extraction is known here then in these vast stretches of sand and in these mountains of low grade ore we have natures gold reserve safely locked and guarded by rebellious conditions which defy the miners arts the miner works with pick and shovel he saves those values heavy enough to be caught in riffles fiffles or on a copper plate coated with mercury but the hidden values of the west cannot be saved by these methods alone there is one other system of gold recovery which is sometimes used on refractory ores it is a chei chemical method the finely ground ore is agitated in a solution capable oaf oit dissolving the gold and then the values are recovered by some method of precipitation this is called the cyanide method it isi is slow expensive and unsatisfactory except under favorable conditions but the introduction of the formulas of chemistry into metallurgical methods was a long step in advance by the aid of chemical solutions much gold has been recovered which would otherwise be lost yet there remains ren lains much to be accomplished before the problem is solved but today there are indications that the correct solution is at hand the way has been pointed out it but remains for oti aers to perfect the trail blazed by the pioneers As might be surmised the key of the problem is found in electricity today when a hard problem confronts the inventor he often finds the answer in the electrical field electricity has solved many industrial and metallurgical problems it will solve many more for we are entering upon the greatest age ox progress the age of electricity the problem of extracting gold from the vast tonnage of low grade material has been approached from two angles electro chem ical amalgamation and electrochemical via tion experiments begun twenty five years ago and continued from time to time by various investigators have given us the secret of the combination lock which mother nature used to secure the golden treasure from the hands bands of the despoiler the science of 0 electrochemistry electro chemistry is rapidly solving many metallurgical problems and the prophecy has been made that in time all metals will be leached beached directly from ores and recovered in pure metallic form by electro deposition even as copper sheets and tubes are now made it is well known that certain electrical conditions strongly intensify chemical action chemical affinities are greatly augmented it is also known that metals meta ls and gases in their nascent state have greatly increased affinities for other elements also that certain alloys or amalgams of mercury have a greater affinity for gold than ordinary mercury an element is in its nascent state just at the moment of its liberation from a chemical combination nascent hydrogen will reduce oxides at ordinary temperature and advantage is taken of this fact in cleaning rusty dirty or greasy metals coins etc by an electrochemical bath with a knowledge of the above facts and others equally as important a plan to wrest vast treasures from natures unwilling grasp has been formulated many experiments indicate that the plan of battle is well designed we will first discuss the subject of electrolytic amalgamation the auriferous material to be treated after screening is carried by a stream of water over a copper sheet or plate suitable elec arodes anodes are arranged so that they come in contact with the water flowing through the device A tiny stream of solution of chloride bi bl of mercury drops constantly into the water passing into the apparatus pa ratus the anodes are connected with a low voltage current which is not strong enough to produce a shock the current enters the water electrolyte which with the sand etc is at all times electrified from the water the electrical current passes into the copper plate cathode which is connected with the negative wire in brief the above comprise the essential elements of tho the electrochemical amalgamator which device promises to inaugurate a new era in the art of gold saving when the screened gold bearing material is delivered to this machine which is from thirty to forty feet in length and which can be made of any desired capacity several interesting te resting electrochemical processes are automatically in constant operation and all of these processes directly aid in the recovery 0 of f values nascent mercury is deposited on the copper plate by electro deposition from the solution all oxides dirt grease lobs coatings etc are removed from the particles of gold passing through the device the amalgam plate is at all times clean bright and in the best possible con to receive gold old minute particles ot gold in suspension are cleaned and coated with mercury by electroplating electro plating action these mercury coated particles are made heavier and the action of the electric current aided by gravity forces them into contact with the mercurial surface all gold particles no matter how small touching the mercurial amalgamating surface adhere tenaciously as amalgam at the first contact the gold is recovered in the form of amalgam which is scraped from the plate from time to time the amalgam is formed by the union of nascent mercury with clean gold under electrochemical tro chemical action such amalgam is really an electroplating electro plating it is smooth firm homogeneous and tenacious yet elastic and viscid it is not floured or broken loose or carried away by the passing volumes of water and sand it adheres to the plate with a bulldog like tenacity that would bring great joy to the heart of the n ane nane owner who knows too well the shortcomings of the usual amalgamating practice during the process we are describing nascent hydrogen is liberated at all times and this gas has a powerful cleaning and reducing action keeping the mercurial coating free from all impurities it forms hydrogen amalgam which has a powerful affinity for gold silver and platinum by adding some saline solution sodium is also deposited and hydrogen sodium amalgam H na hg is formed mercury in this combination has such a powerful affinity for the metals that it will amalgamate a rusty nail such are the processes in brief of electrolytic tro amalgamation which will be used in the new metallurgy and which promises to make the pacific coast rival the tabled mines of king solomon if values are en cased in minute particles of rock it will be necessary to grind the sand or ore SUM sufficiently fine to release all the gold if gold bearing ores are ground fine enough to ie release all the values the electrochemical system of amalgamation may be used to recover values instead of the ordinary mill plate concentrating tables cyaniding cyan iding and smelting smelling sm elting it may sometimes be necessary in treating ores that axe are unusually base and rebellious to use electrochemical in connection with electrolytic amalgamation or the two processes may be combined in one operation the electro cyanide process when is desirable the mass of pulp or sand is agitated for one or two hours while a low voltage current is passed through the cyanide solution the action of the cyanide is quickened and intensified values are dissolved which are immune in the ordinary process and the time of treatment is reduced to two hours or less even in the most refractory cases the gold is recovered in the form of amalgam this method of electro cyanide practice reduces the cost of installation from thousands and tens of thousands of dollars to hundreds the cost of treatment is reduced to leg less than ten cents per ton and the time of treatment reduced from twenty four J thirty six and seventy two hours to two and three hours while the percentage of extraction rises to 98 and 99 per cent and it in many cases to 99 per cent in closing I 1 might add that in some tests which I 1 made it was found that platinum amalgamates as readily as gold when sodium amalgam is present and sodium amalgam can be formed whenever desired at no appreciable expense electrolytic sodium amalgam alsor also readily holds gold covered with sili clous rusty or greasy coatings even sulphurous or arsenical conditions do not interfere with its amalgamating powers and values esin in vack black sand and alaska beach deposits are readily extracted san sad jose california |