US2604207A - Apparatus for separating magnetic material - Google Patents

Description

July 22, 1952 w, J SCOTT 2,604,207

APPARATUS FOR SEPARATING MAGNETIC MATERIAL Filed Feb. 1, 1949 1 W III-lI IIIIIlllIlllllllllllllllllllllIllllll|lllllll| 3mlmmxaxmxmxmxmxmxmimxmlmxm JNVENTOR. WA/fEr' 1/, 5130f) Patented July 1952 Q t. APPARATUS FOR SEPARATING MAGNETIC MATERIAL 'Walter 'J Scott, Portland, Oreg. Application February 1, 1949, Serial No. 73,894

1 The-present invention has to do with the magnetic separation of valuable components of materials found in many types and forms. For example, in many sections there are tremendous "(repeats-smack sand, composed principally of silicates Yand magnetite with smaller percentages of such desirable elements" as gold; scheelite, ga-

lena, titanium oxides; tin 'oxides and platinum.

'Other'types of materials which maybe'treated inaccordanceswith my process are of the rock ore type bearing small percentages of gold; silver, platinum or other valuable minerals, which ores may be finely crushed and treated inaccordance with my process, provided thata portionfjofthe ore comprises magnetic materials.

Whether the material to be treated is found originally'in the form of'placer sands or solid bodies of ore which; are crushedand ground as 'a'pre- 'liminary to separation, an expensive, time-consuming step. in the recovery of the valuable components heretofore has been the requirement that the mineral must be dried in order that separation may be accomplished; An object of 'my invention is to eliminate this costly step, making it possible to achieve, separation with the material'lemaining in its original'wet condition." By

the use of my process magnetic sands may be sluiced ordredged-from a riverbed or coastal shelf and passed through the separator in the condition in which they are drawn from the placer-deposits. With the use of my process and apparatus the magnetic material may be entirely removed-before the sand is passed through the usual r'ifiles'when the-object is to obtain gold or the like fr'om the sand. In passing gold-bearing blacksand through a rifile device in accordance with' the prior practices, I have noted that the rifiles are rapidly clogged by the magnetite or similar heavy particles, since their specific gravity is such as to cause them to settle behind riffle barsf Goldparticles in such sands are usually Thus, ev'en'though the riflie does not appear to be dangerously filled, a great deal of the valuable elements arelost shortly after a riflie is placed in operation in a black sand area. With my invention themagnetite and othermagnetic'materials are entirely eliminated before the lighter, nonmagnetic materials such as. quartz sand are 1 Claim. (Cl. 209-218) passed through the riflle device, with the result that a high efficiency is achieved.

In other types of mining operations the object of my invention is to recover magnetic materials which have value in themselves. It may not pay to recover magnetite as a source ofiron orsteel, but in many. instances such sands contain minor percentages of oresof valuable elements suchas tin or titanium which havethe'property of being attracted magnetically but to a lesser extent than magnetite. v I am aware that many attempts have been made in the past to separate such material from the gangue by the use of magnetic separators, either wet or dry, and either singly or arranged in series of separators with different separating eflects. However, it has'been my observation that no such prior separating apparatus or process is successful, and I have concluded that it is due primarily to the tendency of the magnetic particles to build up clots of cohered particles which bind within themselves the non-magnetic or lesser magnetic particles, or form shelves or projections upon which the non-magnetic or lessermagnetic particles are supported, with the result that unwanted materials are trapped with the desired materials. With my invention I am able to cleanly separate relatively magnetic materials from relatively non-magnetic materials, either aggregating all materials having some degree of magnetism, or separating only a certain material having a certain degree of magnetic properties. I am thus able entirely to separate the unwanted magnetic materials from gold, platinum or silver-bearing quartz sand which may later be passed through riflles, or {first to separate magnetite from material bearing other ores of magnetic property which are desired and then to separate the other magnetic materials either from the residue which remains after separating the magnetite or from the magnetite itself. The present invention is extremely rapid in operation and adds very little to the cost of equipment necessary to dredge or mine and crush the value-bearing materials.

The objects and advantages of the present invention may be more readily understood by inspection of the following specification taken in connection with the accompanying drawing wherein like numerals refer to like parts throughout, while the features of novelty will be'more distinctly pointed out in the appended claim.

The drawing illustrates a schematic represen tation of a preferred embodiment of the mechanism by which the process is carried out. In the drawing a relatively deep tank I0 is filled 3 with a liquid, preferably water, as indicated, and the sand or crushed ore is directed downwardly into the relatively quiescent water through an inlet II, the sand or crushed ore preferably being carried along by a stream of water such as would be produced by the usual hydraulic dredge;

The Water level in the'tank is maintained fairly constant by regulating an adjustableoutlet 12 in the-bottom of thejta'nk. 7

At one side of the tank is located a pair of transverse drums I5, one located above the other, 5

either one or both of which may be driven by -power means (not shown); The drums".

are preferably provided with teeth or cogson" their surfaces capable of engaging a series of magnets I S strung together on a chain or chains H which are, receivable in guiding grooves .(not

shown) in the surfaces of the drums. The chains are endless and pass about the drums 15 so that an endless magnetic belt is thus provided. The

'magnets may be permanent magnets: or electromagnetic magnets supplied; with current in any ordinary fashion; An endless belt lil is trained about thedrums l5iand'o ffset drum" IS aBd'gfuide roll 20 so as to provideia portion'projecting laterally fromf'above t l e Ito'p" of the'tank. "liiagnetic material which is attracted to the upwardly traveling reach of the belt i3 by thema'gnetsflfi is held to the belt 'until the horizontal portion thereof is reachedwhereu'pon the belt leaves the area of magnetic attraction but the materialremains supported upon the horizontal section. 'As I the. belt travels about the drum l9 the'magnetic material falls into a hopper or chute, the action being augmented by a doctor blade or section of the hopper wall 2! scraping the returning portion of the belt. "The belt then travels'downwardly through the tank and the cycle is repeated. I In accordance with the-preferred embodiment of my invention, the distance between the drums "ble 'fal sewall 25, thepositi'on of which '-relative I5 is considerable so that as the sands settle'vertically through the water column alongside of the upwardly traveling belt the. magnetic, particles have sufiicient opportunity to be attractedlaterally. toward the magnets. In the event that-the purpose of the apparatus is to separate black sand from non-magnetic materials including gold flakes, perfect separation can be achieyediparticularly since the gold flakes flutter downwardly" through the water, turning from side to side just .as a dish settles into a body of water. In 7.

of lesser magnetic value to escape through the outlet I2. In a second operation, or in. aiseparate separator locatedinseries with the first one, the materials of lesser magnetic quality may then be separated from m so -ma n t c ma e a ,suchas quartz and clay; similarly, one material of lesser magnetic property than magnetit may be. separated from a second-niateriahor even lesser magnetic properties.

The degree of separation. may 'alsobe affected by shifting the relativeposition of the inlet H the position thereof being dictated in accordance atnolt-ime being 4 with the particular qualities of the material being treated. If it is desired to separate all magnetic materials which can be separated, the inlet H may be placed close to the upper extremity of the belt so that by the time the particles have reached the lower extremity of the belt only non-magnetic particles remain in suspension in thewater. If it is placed further away the apparatus maybe caused'to' separate only a magnetic material of a certain degree of magnetic strength. Similar results may be obtained by "altering the depth of the water.

Similar effects, to a'certain extent, may be achieved by controlli'ng the speed of travel of the belt, but it is preferred that the other means of achieving con trol 'be' utilized since increasing the speed beyond a certain point results in inefficient operation since the friction of the water washes material from the belt. A further degree of control maybe achieved-by providing an adjustato the wall facing the'upwardly traveling section of belt may be controlledflbyadjustment screws I 26; The purposeof the false wall is to confine the material toa relatively small portion of the tank so that there will be no tendency for material to; escape themagnetic field. However, in some fca'sesiit may be desirable to move the inlet II as faras possible away from the magnetic field, in which'case the wall'25might have to be similarly moved awayv fr'qmthemagnets. w

' ,The' presentinve'ntion has the distinction over all, prior apparatus within my knowledge in that themethodjembodiedtherein has the following characteristics; The m'aterial to be separated fall's; dov'smwa'rdly through a body of Water in free suspensionthere'in'and the material which is magnetically attracted to'the' magnetic portion'of' the apparatus is removed vertically upward in a thin sheet without clots, .fingers' or shelves of material holding within or upon themselves undesired Vmaterial-sp The apparatus is preferably controlled in any of the foregoing manners, so as-to prevent morethan the accumulation of a thin coating. or' sheetof magnetic material whichis incapable of holdingthe non-magnetic particles. Eurther than that the point of greatest accumulation is immediately adjacent the inlet to the tankso that only very ,strongly magneticmaterials will be. immediately tra ted t -.t e; e p ent ing h wat The result: isthat; at the lower extremity of the upwardly traveling sectionof; the belt avery, thin 7 layer of material beginsto-accumulate; this-layer increasing to its maximum extent-adjacent the point ;of' entry ofjtheundivided material, v.but

built-up to an undesirable extent. j

Having illustrated and described a preferred embodiment of my invention, it should be apparent to those skilled'in the art that thein- 'ventionpermits of modification in arrangement and details; 'I claim as myinvention allsuch modifications as come within the true spiritand scope-.ofithe appended claim.

Iclaim: g g;

Apparatus for effecting the separation of fine, relatively magnetic. and non-magnetic;particles comprisinga relatively deep-tank, an inlet{at thetopof; said-tankthroughwhich a mixtureof particlesmay be introducedina liquid carrier, an outlet fat' .thelbottom Ofjtlidtank capable Ioflpermitti'ngthfe escape ofliquid equal to the amount introduced with the'material whereby to'maintain'a fairly constant depth of relatively quiescent liquid in the tank, said inlet being arranged to direct the material into the top of the liquid in the tank whereby the particles may travel in freely falling suspension downwardly through the liquid in the tank, a traveling belt having a vertical portion thereof traveling upwardly through the'liquid in the tank at one side of the path of free falling movement of the particles, a closely spaced series of magnets traveling with said belt in close proximity thereto at the side of said vertical portion of the belt away from the falling particles for creating a magnetic field through which the particles fall whereby magnetic particles are attracted to and held onto the upwardly traveling portion of the belt, and means for guiding a portion of said belt laterally from the upper region of said tank whereby particles removed from suspension by the traveling belt may be removed from the belt.

WALTER J. SCOTT.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 228,329 Edison June 1, 1880 466,515 Reed Jan. 5, 1392 529,188 Pike Nov. 13, 1894 954,016 Bent Apr. 5, 1910 1,146,140 Dutton July 13, 1915 2,088,364 Ellis July 27, 1937 2,290,892 Queneau July 28, 1942 2,437,681 Crockett Mar. 16, 1948

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