US1253935A - Ore-concentrating apparatus. - Google Patents

Description

l. CALLOW.

ORE CONCENTRATING APPARATUS.

APPLICATION FILED MAR. 3. 1917.

Patented Jan. 15, 1918.

olocul UNITED STATES PATENT OFFICE.

JOHN I. OAIILOW, OF SALT LAKE'OITY, UTAH, ASSIGNOB 'I'O METALS RECOVERY CODANY, 0F AUGUSTA, MAINE, A CORPORATION OF MAINE.

OBE-GONOEIl'TBATING APPARATUS.

emu 0f um Rient- Patented J a 15, 1918.

Application illed Hatch 8, 1917. Serial No. 152,818.

To all 'whom it may concern:

Be it known that I, JOHN M. CALmw, a subject of the King of Great Britain, residing at Salt Lake Cit in the county of Salt Lake and State of tah, have invented certain new and useful Improvements in Ore- Concentrating Apparatus, of which the following is a specification.

My invention relates to a flotation apparatus designed for the concentration pf metallic ores by separating the metalliferous y particles from the barren or rocky or nonmetalliferous constituents of an ore pulp, composed of finely ground ore, water, and frothing agent; and 4my invention consists of the parts and the constructions, arrangements and combinations of parts which I will hereinafter describe and claim.

-This application is a continuation in part of and a substitute for my prior application, Serial Number 68,046, l'iled December 21, 1915, and renewed October 5, 1917, Serial Number 195,208.

In the accompanying drawing forming part of this specification, Figure 1 represents a vertical longitudinal sectional view of av flotation tank showing one embodiment of my present invention. Fig. 2 illustrates an enlarged sectional fragment o the septum or blanket. Fig. 3 is a plan view of The apparatus to which my invention relates is specifically identified with the art commonly known as flotation, wherein a certain percentage of oil, or of two dissimilar oils, or an oil and an acid, or an oil and an alkali, or some substance having the property of producing a suitable froth, is mixed with finely ground ore and water and the mixture then subjected to the action of a gaseous medium, preferably air under pressure, whereupon a froth or suds is produced in which the metalliferous particles are re covered by iiotation.

In a more restricted sense, the present improvement has specific reference to a {iotation apparatus provided with a porous bottom or covering for al gas compartment, the object of the improvement being, essentially, to provide an apparatus having such a bottom or covering wherein the pores thereof are maintained in substantially their normal condition and wherein the tendency of the pores to contractand finally to close andimpede the passage of the gaseous medium therethrough is reduced to a minimum and l practically entirely eliminated.

Vrectangular form as also of' circular form,

and although I have shown in the present instance, for purposes of illustration, a tank A having an inclined bottom, B it will be understood that the improvement which I am about to describe, is applicable to or in connection with any of the above mentioned forms of tanks, or in connection with chambers or passages in which the gaseous medium 1s introduced under pressure and discharged from the chamber into the flotation cell or tank.

In the operation of pneumatic flotation cells (by which name the tanks above referred to are commonly called,) or in fact, any pneumatic machine which is used for floating mineral particles, or the like, and thereby separating the same from other and rejected material, and particularly in.those cells or tanks, hollow arms, and like equivalent agencies, which employ blankets or fibrous coverings as the bottom or porous member, or as a wrapping or covering for perforated hollow arms, and through which blanket or covering a gaseous medium is designed to be discharged under pressure, great difficulty has been experienced from the clogging or closing of the pores of the fibrous material of which the blankets 0r coverings are usually composed. Ordinarily, these blankets or coverings, are made up of one or more thicknesses e of loosely woven canvas, quilted into a mat or blanket, as shown in Fig. 3, by sewing in much the same manner aS the ordinary bed-quilts are made. When irst used, the loose weaving of these blankets or coverings, provide interstices which are of suiiicient size td permit the free passage of air or other gaseous medium, but after a short time, say three or four days, the fibers of the material become saturated and swell and the pores or interstices becomeous medium through the blanket increases from, say l pounds up to three (3) or four (4) pounds as the blanket is continued in use, and at the end of say several weeks, the interstices in the blanket become substantially clogged because of the minuteness of the interstices and the tendency of the settling material to clog the same. Experience has shown that at the end of several weeks, the blankets have to be dried out and flogged with a carpet beater, or the like, to make them operable; or, if this is not feasible, and the apparatus cannot be stopped for the purpose lof removing andrenewmg the blanket, recourse is had to the use of a stick, brush or paddle, with which to punch and beat the blankets to relieve them of the sedimentary deposit and to thereby open the pores suiiciently to permit passage of the gaseous medium. y

With the large volume of air or other gaseous medium (which may be ten cubic feet per square foot ofblanket per minute) passing through the blanket, it would not be expected that the blanket would become saturated, but that the issuing air, which is under considerable pressure, would tend to elevate the water in the pulp out of contact with the blanket and thus prevent the fibers of which the blanket is composed from absorbing moisture. It is found, however, that this is not the case, and the blankets in operation, do get wet, as their bers have a tendency to absorb moisture, and as a result, the fibers swell and tighten up the pores or yinterstices and thereby increase the resistance to the passage of air, or gaseous medium.

Furthermore, in my experiments I have been somewhat surprised to find on splitting open an old blanket (say one which has been in use for or 70 days), to Vnd that its pores or interstices have been more or less filled with fine ore particles, or slimes, which have blocked the passages or interstices. In another oase, where burned lime had been added to the ore pulp for the purpose of making the pulp alkaline (for metallurgical reasons well known in the art of'fioa'ting mineral particles), I have found a ine deposit 4of lime between the plies of the blanket. In a still further case, when operating on a certain lime ore, which had previously been roasted, I found a cement like@ accretion formed on the surfaceof"b the blanket which in twenty-four hours would renderthe blanket completely impervious to the passage of air at the pressures usually In my invention the apparatus is provided with a blanketv or septum B, which has been so treated as to render the bers wholly or partially non-absorbent to water, or to an alkali, or an acid, and which treat- Lacasse ment I have found in practice, prevents the formation of the cement-like accretion, or the entanglements of the slimes within the meshes of the canvas, or other material, or between the plies thereof. In fact, an apparatus provided with a blanket treated as I will hereinafter describe, has proved conclusively that when I render the canvas or the bers thereof wholly or partially non-absorbent to water, I eliminate the danger of the fibers swelling and thereby reduclng or closin the pores or interstices which are used fr the passage of the gaseous medium, and hence the pores or interstices do not clog up, but remain in their'normal open condition and provide free exits for the air or gaseous medium which lis admitted therethrough'into the tank for the purpose of inducing in its combination with the frothing agent, which is a constituent of the pulp under treatment, the formation 4of the air bubbles which serve as carriers for the mineral particles of the ore and which gradually accumulate on the surface of the pulp and overflow 'vinto a suitable launder, or other receiver.

In producing theblanket forming a part of my apparatus I may use any of the well known operations and substances heretofore employed for water-proofing fibers. For instance, such substances as wood-creosote; a solution of paraffin-wax and gasolene; rosin dissolved in ether; vaseline dissolved in gasolene; linseed-oil; neats-foot oil; or, in fact, any of the substances capable of rendering the fibers non-absorbent may be used to advantage; and hence my invention is not limited to any particular means for the treatment of the blanket, or the fibers therestantial reduction of the size of the pores due toan expansion or swelling of which .the blanket is composed.

My invention is distinctly related tothe metallurgical industryY and to the so-called otation' processes which treat mineral-bearing pulps, as the object of the treatment to which I refer is to render the blankets when combined with the other elements of a lotation apparatus less-absorbent to water and still leave their interstices free and open for the passage intothe otation apparatus of the air or other,` gaseous medium which is employed in flotation, processes.

The invention I have described is comparatively inexpensive and the practical use in combination with flotation apparatus of a blanket treated as I have described has shown that the life of the blanket in such apparatus is greatly prolonged and that the interstices remain open for the passage of the gaseous medium into the apparatus and the iibers of there is not the tendency of the pores clogging during use by a deposit of any character.

The foregoing results are obtainable wherever the otation apparatus is provided with a fibrous covering in association with an underlying or inclosed chamber C or passage into which a gaseous medium is admitted under pressure and is designed to be discharged outwardly through the covering and into a body of pulp containing particles which are to be separated one from the other and which pulp also contains an agent which induces the formation of a froth, or a bubble column, when acted on by the finely divided air admitted through said blanket or covering.

It will thus appear that my invention comprehends and includes an apparatus provided with such a covering as I have described lwhether the same shall form a bottom which is inclined or horizontal and whether the tank or compartment be of rectangular, square, circular, or other configuration, all of which are more or less common in the flotation art. Also, that the invention is broad enough to bring Within its scope any apparatus having a gas receiving chamber or member, whose discharg! ing surface is formed or provided with such a fibrous porous covering and where it is desirable and necessary that the pores of such covering should during operation be maintained in substantially their normal condltion to provide for the emission of numerous jets of gas into the liquid body or pulp containing articles to be recovered, and where the bla eting of the pores because of the saturation of the fibers and the conse uent closing of said pores would have a ten ency to close the pores against the admission of the ine gaseous streams, as above indicated.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. A flotation apparatus comprising, in

combination, a tank having a gas-receiving chamber, and a covering for said chamber, said covering bein formed of fibrous material porous for t e admission of the gas into the tank, and having the capacity to substantially maintain its normal porosity when submerged in the liquid contents of the tank.

2. In iotation apparatus, a tank having a gas-receiver and a porous fibrous covering between the same and the interior of the tank, said covering having means for subY stantially maintaining the porosity of the covering during the submergence of the lat ter in the liquid contents of the tank.

3. In flotation apparatus, a tank having a gas compartment in its bottom and a fibrous blanket or septum forming a porous cov ering therefor, said blanket or septum being liquid repellent to maintain substantially its normal porosity when 1n use 4. A otation apparatus provided with a water-proofed or water repellent fibrous blanket or covering pervious to air through which air or other gas is introduced.

5. A flotation apparatus having a porous bottom for the intrcduction of air or other gaseous flotation agent, said porous bottom being of water-proofed or water repellent fibrous material.

6. As an article of manufacture a metallurgical septum or blanket adapted for sub mersion and to form the bottom of a ota tion separatory cell and the top of a` cham ber containing a gaseous medium under pressure, said blanket consisting of lies of loosely-woven fibrous material unite one to the other and having its upper surface made liquid repellent the said blanket being of a nature to permit the passage upwardly therethrough of a gas under pressure from said' chamber.

In testimony whereof I affix my signature.

JOHN M. CALLOW.

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