US2061698A - Apparatus for treating ores - Google Patents

Description

av. 24, 1936. EWART APPARATUS FOR TREATING ORES Filed May 17, 1954 3 Sheets-Sheet 1 5% W "ME Nov. 24, 1936. A. EWART APPARATUS FOR TREATING ORES Filed May 17, 1934 3 Sheets-Sheet 2 NOV 24, 1936. EWART 2,061,698

APPARATUS FOR TREATING ORES Filed May 17, 1934 3 Sheets-Sheet 3 Patented Nov. 24, 1936 UNITED STATE PATENT QFFEQE APPARATUS FOR TREATING ORES Archibald Ewart, Chicago, Ill., assignor of onehalf to Ralph M. Welch, Chicago, Ill.

This invention relates to improvements in process of and apparatus for treating ores to recover the metal content thereof, and one of the objects of the invention is to reduce the ores. and remove therefrom substantially all of the arsenic, sulphur, phosphorus and other constituents which have a melting or volatizing point within the range of the temperature employed, as well as remove other constituents with the sulphur gas.

A further object of the invention is the treatment by sublimation or purification of the constituents in the ore and the preliminary treatment of the same, so that after the sublimable elements have been removed, the ore is in a practically red hot condition in very small particles, and is then in a suitable condition for further treatment to remove the precious metals, and the remainder is discharged and is separated into diiferent constituent ores, which latter may be further separately treated, if necessary, and in any suitable or preferred manner.

A further object is to provide an improved process and apparatus of handling and separating comparatively low grade ores, and also the utilization of the sulphur as a gaseous medium for carrying or conveying other gases or sublimed products, such as arsenic, phosphorus and other contents.

A further object of the invention is to provide an improved apparatus for carrying the process into operation, embodying improved means for carrying or conveying the ores being operated upon through a treating, purifying or sublimation chamber, in a dry condition, and in which apparatus, should for any reason any portion of the conveying or advancing mechanism for the ores becomes damaged or interrupted in operation, the same may be readily repaired without necessitating the dismantling of the entire conveying mechanism.

A further object is to provide an improved apparatus of this character which will be of a simple, durable and compact construction, and efiective and efiicient in operation.

To the attainment of these ends and the accomplishment of other new and useful objects as will appear, the invention consists in substantially the process hereinafter more fully described, and in substantially the construction, combination and arrangement of the parts of the apparatus for carrying this invention into operation, as hereinafter more fully described and claimed and shown in the accompanying drawings in which an apparatus for carrying the invention into operation, is shown.

In the drawings,

Figure 1 is a vertical, longitudinal, sectional view of an apparatus of this character with parts omitted and parts broken away.

Figure 2 is a detail side elevation, partly broken away, of a portion of the apparatus shown in Figure 1.

Figure 3 is a vertical, sectional view taken on line 3-3, Figure 1, on an enlarged scale.

Figure 4 is an enlarged, detail sectional view of a portion of the amalgamating chamber.

Figure 5 is a top plan view of the parts shown in Figure 1.

Figure 6 is an enlarged vertical sectional view of one of the rotary separating chambers.

Figure '7 is a sectional view taken on line ll, Figure 6.

Figure 8 is a detail sectional view taken on line 8-8, Figure 1, on an enlarged scale.

Figure 9 is an enlarged detail perspective view,

through a sublimation or purifying chamber where it is heat treated, the material being agitated or turned over a number of times during its passage through the chamber to insure the freeing or extraction of gases and various volatiles therefrom.

The gases and volatiles are preferably freed without the presence of oxygen or air and heated by radiation at about a temperature of 500 F., the gases being removed from the sublimation chamber preferably by suction.

As the material is discharged from the sublimation chamber it is subjected to a cold water spray that disintegrates the ores, and the cooled and shattered ore falls into a pit of water and mercury, and is caused to pass through the mercury, (which latter is preferably continuously agitated) by means of a weir or baflle submerged. in the mercury, from where it passes into a rotary centrifugal separator to insure recovering the mercury carried by the ores and the reclaiming of any precious metals carried into the rotary separator.

The ore is then discharged from the separator on to an agitated sliming or separating table, the heavier metals being deposited through the table on to a conveyor, while the gangue is discharged from the table over the end thereof.

A blast of iiuid, such as water or steam may be employed to assist in forcing the ores through the mercury, and if steam is employed it will heat the mercury, rendering it more active to the separation or extraction of the gold and silver content of the ore, the mercury forming an amalgam therewith.

A suitable apparatus for carrying this process into operation will now be described.

The ore to be treated is supplied to a suitable hopper l5 and treated in a dry state and if not in a sufficiently dry state, a drier IE will serve the purpose of further drying the same and from the hopper the material will pass through a crusher ET. From the crusher ll the material will be fed through a chute it to a pulverizer l9, and if desired a blast fan 22 may be provided that discharges into the drier H5.

The pulverizer iii discharges at 2% into a suitable separator 22 and the separator in turn is provided with a discharge outlet 23 and from which latter outlet the material is discharged into a purifying or sublimation chamber.

All of the apparatus above described is of the ordinary and well known construction and the various units of the apparatus may be operated in a well known manner.

The sublimation or purifying chamber constitutes a furnace and may be constructed of any desired size and consists essentially of an upper or gas receiving chamber 2 3, an intermediate chamber in which the ore is purified or sublimated and a lower chamber 26 constituting the heating chamber.

Each of these chambers is of a considerable length and is arranged in an inclined plane, inclining downwardly from the receiving end to the discharge end.

From the discharge outlet 23 of the separator 22, the ore is discharged into a hopper 26 to be delivered to the heating or treating chamber 2a.

The chamber 25 is provided with a bottom 2?, the upper face of which is shaped to form a se- "ies or flight of steps 28, which incline downwardly from the hopper 26 to the discharge outlet end EQ and the top 36 of the chamber is provided with a series of openings 3! to permit the gases formed in the chamber to pass into the upper or gas chamber 2 1. From this chamber 25 the gases may be withdrawn in any suitable manner, preferably by means of pipes 32, and through medium of a pipe 33 which may be connected with any suitable suction or exhaust device so as to be conveyed away for the purpose of future separation.

Windows or sight openings may be provided in the side walls of the chamber 25 for the purpose of inspecting the contents of the chamber.

As the material is discharged from the hopper into the chamber 25, it will be conveyed through the chamber by means of gravity assisted by conveyors which operate in directions transverse to the length of the chamber. These conveyors consist preferably of scraper members one being preferably provided for each of the steps 28. These members are preferably in the form of a plate, the lower edge of which rests upon the respective steps .3 and is of a length preferably substantially equal or slightly greater than the width of the tread of ne step and. of a height to extend a considerable distance above the tread of the next adjacent step. The plate is provided with an opening 36 therethrough and a rod 31 eX- tends through the opening, the external diameter of the rod being considerably less than the diameter of the opening so that the plate or element 35 will have a rocking movement with respect to the rod. Nuts or collars are secured to the rod on each side of the plate and the collars are spaced from each other for a distance considerably greater than the thickness of the plate so that as the rod 3? is reciprocated the plate or element 35 will be moved over the tread of the respective step to scrape the material therefrom and deliver the same on to the next adjacent step. The plate has a loose connection with the rod so that it will rock with respect to the rod during its reciprocating movement thereby insuring a proper positioning of the plate so as to scrape the material from the step.

As before indicated, one of these plates or scraper elements is provided for each of the steps and the alternate rods Ell are connected on one side of the chamber 25 by means of a rod or bar (see particularly Figure 5) while the other alternate rods 3? may be connected on the other side of the chamber by a bar or red 20 so that the alternate rods will be simultaneously moved in the opposite directions.

To accomplish this there may be provided a shaft ii journaled in suitable bearings Crank arms d3 are secured to the shaft and links i con-- nect the respective crank arms with the bar or rod 5%.

Similarly a shaft 55 journaled in suitable bearings 56 is provided on the other side of the machine, and this shaft 55 has crank arms i'l secured thereto and the crank arms 4? are connected by means of links '18 to the bar or rod li'l.

Motion may be imparted to the shafts =i-s5 in any suitable manner such as by means of a motor 38, the shaft of which is connected by means of a belt 55 with a pulley l that is secured to a shaft 52 (see Figure 8). Pulleys 53-54 are secured to the shaft 52 and belts 5Ei56 pass respectively over the pulleys 53--54i and also over pulleys 5'i--58 respectively secured to the shafts l54i. Thus, it will be manifest that when the shafts li-i5 are rotated a reciprocating movement will be imparted to the scraper plates and the alternate plates will be reciprocated in opposite directions.

The chamber 26 forms the heating chamber and at the lower end thereof there is provided one or more openings 59 (see particularly Figure 1) so that the flame from burners or nozzles ii will be directed into the chamber and the products of combustion, owing to the fact that the chamber 2 5 is inclined upwardly, will flow beneath and in contact with the bottom of the chamber 525 to be discharged into a chimney 65 (see Figure 5).

If desired and in order to retard the flow of th products of combustion out of the chamber and into the chimney, baflie plates or walls may be provide so as to retard the flow thereof, and at the same time maintain the chamber at the entrance end thereof at a high temperature.

As the material flows through the or let it? from the chamber it will be discharged into a chamber in which mercury ii i provided and the precious metals will be separated from the gangue in the chamber 63. The chamber may be of any desired depth according to the amount of mercury desired to be used, and a bafile or weir B5 is provided with one end thereof submerged into the mercury so as to force the products from the chamber 25 through the mercury before it will enter the chamber 66.

Arranged to operate in the chamber 63 and in advance of the weir or baffle 65 is an agitator 6'! which is connected with a rod 68 and is adapted to be reciprocated so as to move up and down within the mercury to agitate the same and to assistin forcing the material from the chamber 25 through the memory. This agitator may be operated in any desired or suitable-manner, and the upper face thereof is preferably inclined as at 69 so as to assist in shedding any of the material which may pass on to the upper side thereof.

As a means for assisting in cooling the hot product as it comes from the chamber 25 and for breaking down the product by disintegrating the same, it is subjected to the action of a cold spray of water from a pipe iii, and if desired a baffle ll may be provided against which the water strikes.

a This spray may be in the form of any other fluid if desired and if steam is used it will assist in heating the mercury to keep the same in a condition which will result in a ready action thereof upon the ores or products passing therethrough.

If desired and in order to cool the product as it enters the chamber 63, suitable blast fans 12 may be provided for directing a current of cold air into the chamber.

The chamber fili may be of any desired length and the bottom thereof is corrugated or undulated as at F3 for the purpose of confining any of the heavier particles which will be separated from the liquid as it flows through the chamber 86. The bottom of the chamber 66 is inclined from the inlet to the outlet end and the material may be discharged from the chamber 66 through one or the other of discharge outlet openings lll'5.

The numeral. l5 designates generally a rotary separator mounted to rotate upon a horizontal axis and are provided for the purpose of separating the precious metals if any should escape from the amalgam bath.

In the present form of the invention two of these separators are disclosed, one being connected with each of the outlet openings i lib of the chambers 16 and as the construction and operation of each of these separators is the same, the description of one will apply equally as well to both of them.

The separator is provided with a circular body portion having an inlet opening l'i'. The opposite end of the body is preferably tapered or conical as at E3, and connected with the apex of the conical portion is a tubular extension it. The separator is supported preferably by means of a yoke 8d, the arms 8l--82 of which form bearings respectively for the tubular ends 79 and ill and these separators may be rotated in any suitable manner, such as by means of a belt 83 passing over the body portion of the separator and also over a pulley ti l secured to a shaft 85. The shaft 35 is provided with a pulley 86 over which a belt 8? passes, and this belt in turn passes over another pulley 88 secured to the shaft ll so that motion will be imparted to the shaft from the shaft ii. A clutch device s9 is provided in the shaft 85 and an actuating lever 9i) controls the clutch.

Thus it will be manifest that either one or both of the separators 715 may be rotated by rendering active or inactive the respective clutch devices 8Q.

The chamber $6 is provided with a gate 9i (see particularly Figure 5) adapted to be positioned so as to out 01f the outlet opening l4 and direct the material through the outlet it? as shown in Figure 5 in full lines. The gate 9i, however, may be positioned as shown in dotted lines in Figure 5, so as to direct the products through the outlet openings i l and prevent their flowing out of the outlet '45.

In this form of the invention the gate 9| is a sliding gate adapted to be positioned into co-operating guides er.

Each of the separators i5 is of sectional construction (see particularly Figure 7) comprising a body portion 83 and a removable section 94 held together in any sui able manner. A lining comprising sections 95 is provided for the body portion of the separator, and these sections 95 are preferably in the form of plates constructed of copper or any other suitable material which has an aflinity for mercury or amalgam, so that in the event any of the mercury is carried by the product into the separator it, it will be picked up or will adhere to the plates or sections 95.

These plates 95 are secured together in any suitable manner, preferably by means of sockets 96 along one edge of the plates, and a shouldered or rounded portion er along the other edge of the plates, and which portions 97% are adapted to be sprung into the sockets 96 so as to d-etachably secure the sections together.

Anchor bolts 98 may also be provided, which pass through the respective plates and through the body portion of the separator to hold the plates in position.

When it is desired to remove the plates 95, the section. of the body of the separator is removed after the bolts 98 have been loosened. One of the plate sections 95 may then be removed by springing the ends thereofout of locking engagement with the next adjacent plates and then the remaining section of the plate may be removed.

Agitators or wings 99 are secured within the body portion and are suitably supported, the ends of the agitators extending into the conical end of the body portion. These wings or agitators are spaced from the walls of the body so as not to interfere with the insertion or removal of the plates 95.

Thus it will be seen that when the material is discharged from the chamber 66 into one or ,the other of the separators it, when the latter is rotated, centrifugal force will throw the heavy particles outwardly against the plates 95 and any amalgamated metal in the separator it will adhere to the plates 95 and may be recovered after the plates have been removed.

From the separators it the material is discharged upon a separator or slirning table 586, which is preferably inclined and is adapted to be given an endwise vibration by mean of a crank shaft ltl having cranks use, and the cranks are connected by means of links it? with the table so that when the shaft ldl is rotated an endwise vibration will be imparted to the table, with the result that all of the metals which remain after the precious metals have been separated will be separated upon the table liiil. The shaft iii! may be rotated in any suitable manner such as by means of a belt passing over a pulley H15 on the shaft and also over a pulley lilii on the shaft 52.

he top of the table is provided with downwardly projecting V-shapcd grooves iii? in the bottom of which grooves are arranged a series of openings ifilil that extend entirely through the top of the table, and beneath the top is arranged an endless conveyor 6E9 which may be given motion in any suitable manner such as by means of a pulley i id, over which a belt from any suitable source, may pass, and which pulley is connected with the shaft 5 i i and on which shaft is mounted a roller H2, over which the endless conveyor passes.

The discharge end" ject for any suitable cistance, but are not long enough to prevent the separator chambers 16 from being tilted in the direction of their longitudinal These separator chambers are preferably mounted so that they may be tilted when it is desired to drain out any of the liquid which might be confined within the chambers, owing to the conical ends 'EB.

In order to accomplish this tilting the yokes 89 are mount upon a standard H3 and are connected thereto by means of pivots l The pipes i lli which rm connections between the respective inlet end l? of the respective separators it with the respective discharge outlets 'MTi of the chain are of flexible material and are surhci t length so that the tilting of the separators i l will not be interfered with u. r is of a sufficient length so as to permit a flow of the material therethrough which will be sufficient to permit the ieavier elements to be precipitated and retained within the between the riiiies or corrugations on the bottom of the chamber (56.

During the treatment of the material in the purifying or sublimation chamber the process is carried on without the admission of air.

It will be manifest that in the operation of the device the actuation of the scrapers or conveyors will cause the material to be gradually fed downwardly along the steps or the bottom of the sublimation chamber to the discharge end thereof, and the operation of these blades in thus scraping or moving the material from one step to the next lower step will cause the material to be thoroughly agitated and turned over a great many times so as to insure and assist in the extraction or removal of the gases therefrom, the ore concentrate being turned over and moved from side to side of the chamber a great many times during its travel from the intake to the discharge outlet thereof. This effects the presentation of almost a continuous new surface of the ore concentrate to the applied radiated heat at all times.

The continual agitation of the ore and its passage or movement down and across the bottom of chamber in. addition to the presentation of new surfaces will result in the surface continuously giving cii vapors and also prevents melting of the metal contained in the ore, which formation would prevent further vaporization.

By reason of the fact that there will be little or no air present in the sublimation chamber, there will be little if any oxidizing action, either as to the ore or as to the sulphur or arsenic and the like constituents.

Obviously, the suction pump may be operated during desired intervals, or continuously.

If any steam resulting from the spray from the pipes it should enter the sublimation chamber in the form of super-heated steam, it will be forced upwardly in the chamber towards the intake end and the sulphurous gases and vapors as well as the other vapors will immediately follow this movement, the vacuum or suction creating device operating to draw on" the vapors.

The ore which reaches the end of the bottom of it of the separator is prothe chamber 25 or the outlet 29 of the chamber will be in a practically red hot condition and still in particle form. If there is any bonding between the particles due to some peculiarity in the paricular ore or some localized heat condition, the ore will be broken up by dropping into the pit or chamber 63 where it is contacted with the discharge jets of cold water, and which discharge is continuous. The water will flow from the chamber 53 into the chamber 56, leaving only the metallic content of the ore or the relatively pure metals and these collect in the chamber 63 and work their way down beneath the submerged end of the weir or baffle 65 to enter the chamber 66.

In the process the material in a relatively fine, pulverized and dry form is fed in a relatively thin, fiat sheet along the steps or bottom of the sublimation chamber and is advanced and agitated and turned so all of the dry pulp particles are turned over and over. This permits the various volatiles in the pulp to be freed therefrom and this freeing occurs by reason of the employment of heat of a radiating or radiant character, preferably without the presence of oxygen or air. The temperature employed is governed by the nature or the material being treated, but is sufficient to substantially free the ore from all of its sulphuric, rsenic, antimony and phosphorus constituents and these are suitably removed from the sublimation chamber by applying suction.

The process which has been heretofore set forth and more or less specifically described in the description of the operation of the apparatus is what might be termed a dry separation process; that is, it is not a smelting process but is a sublimation process.

It its in the production of practically pure metal in their separate forms and this is possible,

befor stated, by breaking down of the complex ores, usually sulphur and arsenic combinations, by sublimation of the sulphur and arsenic and the prevention of oxidation and the prevention of smelting.

An inherent character of this process is that it is essentially a dry process and it can handle on a profitable basis ore that is now relatively unprofitable because it recovers as end products the various recovered constituents in substantial 1y final form and with a minimum of heat and power consumption.

The treatment of the ore after it passes from the end of the sublimation chamber, separates the amalgamated metals and minerals from the gangue and reduces them in raw state, whereby all of the metals may be reclaimed after smelting. The fineness of the ore, the exact temperature, and the rate of ore travel important factors in the dry production of the ore. The crusher first reduces he ore to a fineness for drying and for the pulve o fur operate upon.

While the 1 red process has been herein described and the referred form of apparatus for carrying the process into operation has been also shown and specifically described, is to be understood that various changes may be made in the steps of the process and in the construction, combination and arrangem nt of the several parts of the apparatus, within is scope of the claims, without departing from the spirit of this invention.

is claimec. as new is:-

l. An apparatus ror treating dry and finely divided ore, comprising an. inclined chamber through which the ore has a general direction of flow by gravity, means for heating the chamber, means for agitating the ore as it advances through the chamber, the last said means operating transversely to the general line of travel of the ore through the chamber, and means for confining and drawing ofi the vapors from the ore.

2. An apparatus for treating dry and finely divided ore, comprising a chamber through which the ore is conveyed, a table in the chamber over which the ore passes in a general direction from one end to the other end thereof, means for heating the chamber, means for agitating the ore as it advances across the table, the last said means operating transversely to the general line or travel of the ore across the table, and means for confining and drawing off the vapors from the ore, the ore engaging surface of said table being shaped to form a flight of steps, the tread of each step being of substantial width and length.

3. An apparatus for treating dry and finely divided ore, comprising an elongated chamber through which th ore passes, a table in the chamber across which the ore advances in a gencral direction from one end to the other end thereof, means for heating the chamber, the ore engaging surface of the said table being shaped to form a flight of steps the treads of which steps are of substantial width and length, scrapers contacting with and movable over said treads in directions transverse to the general direction of travel of the ore across the table, and means for confining and conveying the vapor from said chamber.

4. An apparatus for treating dry and finely divided ore, comprising an elongated chamber through which the ore passes, a table in the chamber across which the ore advances in a general direction from one end to the other end thereof, means for heating the chamber, the ore engaging surface of the said table being shaped to form a flight of steps the treads of which steps are of substantial width and length, scrapers contacting with and movable over said treads in directions transverse to the general direction of travel of the ore across the table, and means for confining and conveying the vapor from said chamber, alternate scrapers operating in opposite directions.

5. An apparatus for treating dry and finely divided ore, comprising an elongated chamber through which the ore passes, a table in the chamber across which the ore passes in a general direction from one end to the other end thereof, means for heating the chamber, the ore engaging surface of the said table being shaped to form a flight of steps the treads of which steps are of substantial width and length, scrapers contacting with and movable over said treads in directions transverse to the general direction of travel of the ore across the table, means for confining and conveying the vapor from said chamber, each of said scrapers comprising a plate like element disposed on one edge, an actuator therefor, and means connecting the scraper to the actuator for bodily movement therewith and for free lateral movements with respect thereto in directions lengthwise of the actuator.

6. In an apparatus for treating ore, a table over which the ore passes in a general direction from one end to the other end, and means for moving the ore backwards and forwards and in directions transverse to the general direction of flow across the table and for turning the ore as it advances, the said means embodying an operating member, a scraper member through which the operating member loosely passes, stops secured to the operating member on opposite sides of and spaced from the scraper member whereby the scraper member will move independently of the actuating member as the latter is reciprocated, and means for reciprocating the operating member.

'7. In an apparatus for treating ore, a table over which the ore passes in a general direction from one end to the other end, means for moving the ore backwards and forwards and directions transverse to the general direction of flow across the table and for turning the ore as it advances, the said means embodying an operating member, a scraper member through which the operating member loosely passes, stops secured to the operating member on opposite sides of and spaced from the scraper member whereby the scraper member will move independently of the actuating member as the latter is reciprocate d, and means for reciprocating the operating member, said table comprising steps upon which the ore is moved by the scraper, said scraper being individual to the steps.

8. A treating table for ore, said table being inclined to cause the ore to flow thereover, and

scrapers for agitating and turning the ore as it passes over the table, said scrapers operating in directions'transverse to the direction of fiow of the ore over the table, said scrapers embodying a scraper element arranged on edge, and an actuating member connected to the scraper, said connection embodying means permitting the scrapers to rock laterally and with respect to the actuating member as the latter is reciprocated.

9. A treating table for ore, said table being inclined to cause the ore to flow thereover, and scrapers for agitating and turning the ore as it passes over the table, said scrapers operating in directions transverse to the direction of flow of the ore over the table, said scrapers embodying a scraper element arranged on edge and an actuating member connected to the scraper, said connection embodying means permitting the scrapers to rock laterally and with respect to the actuating member as the latter is reciprocated, said table being stepped and said scrapers being individual to the steps.

10. An apparatus for treating dry and finely divided ore, comprising a chamber through which the ore is conveyed, an inclined table in the chamber over which the ore has a general direction of flow by gravity, means for circulating a heating medium through the chamber beneath said table, means for agitating the ore as it advances through the chamber, the last said means operating transversely to the general direction of flow of the ore over said table, a chamber disposed above and extending substantially from one end to the other end of the table and having openings for receiving vapors from the ore, and means for conveying away the vapors from the last said chamber.

11. An apparatus for treating dry and finely divided ore, comprising an inclined chamber through which the ore has a general direction of flow by gravity, means for heating the chamber, means for agitating the ore as it advances through the chamber, the last said means operating transversely to the general line of travel of the ore through the chamber, means for confining and drawing off the vapors from the ore, an amalgamator receiving the ore from said chamber, and a separator receiving the ore from the amalgamator.

12. An apparatus for treating dry and finely divided ore, comprising a chamber through which it advances over the table, the last said means the ore is conveyed, a table in said chamber, said Operating transversely t0 the general line table being inclined in a general direction from travel of the ore over the table, and means for one end to the other end of the chamber, and confining and drawing off the vapors from the over which table the ore passes, means for heatore. 5 ing the chamber, means for agitating the ore as ARCI-IIBALD EWART.

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