US2962231A - Beneficiation of ores - Google Patents

Beneficiation of ores Download PDF

Info

Publication number
US2962231A
US2962231A US653240A US65324057A US2962231A US 2962231 A US2962231 A US 2962231A US 653240 A US653240 A US 653240A US 65324057 A US65324057 A US 65324057A US 2962231 A US2962231 A US 2962231A
Authority
US
United States
Prior art keywords
mill
product
concentrate
magnetic
ore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US653240A
Inventor
Weston David
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US653240A priority Critical patent/US2962231A/en
Application granted granted Critical
Publication of US2962231A publication Critical patent/US2962231A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
    • B03B9/00—General arrangement of separating plant, e.g. flow sheets

Definitions

  • This invention relates to methods of milling material in dry milling circuits and more particularly to a method of dry milling embodying concentration of values and the production of a beneficiated milling circuit product.
  • the method of the present invention while it applies particularly to the beneficiaation of ores containing com ponents amenable to magnetic separation has broad application to the beneficiation of all ore materials which are amenable to any form of concentration at a stage of reduction at which the values are contained in composite particles, rather than primary crystalline particles.
  • the milling operation is conducted in'a combined dry crushing and grinding unit wherein the'product is extracted in a stream of air.
  • the mill is so adjusted that a substantial proportion of the material carried away from the mill by the airstream is within a size range coarser than that desired as a final product and a fraction (which may be considered a middlings in relation to the operation being conducted) is removed by air and/ormechanical classification and passed through a dry magnetic concentrator.
  • the concentrate is returned to the'inlet side of the mill while the tailing may usually be discarded as a coarse tailing containing only a very small amount of values.
  • Figure l is a schematic illustration of a typical flow sheet for the beneficiation of magnetic iron ores operating according to previously known principles.
  • Figure 2 is a schematic illustration of a flow sheet according to one embodiment of the present invention.
  • Figure 3 is a schematic illustration of an alternative embodiment of the present invention.
  • feed 10 is delivered to the combined dry crushing and grinding unit 11 which is an airswept mill discharging into an air classifier 12 which removes the oversize and permits the main product to pass to cyclone 13.
  • air classifier 12 removes the oversize and permits the main product to pass to cyclone 13.
  • the air classifier 12 discharges on to the mechanical screen 16 and the oversize from the said screen is returned to the inlet side of the mill.
  • the through product from screen 16 is passed to magnetic separator 17 which produces a final tailing 18 of low metal content (20.0% Fe) and a rough concentrate of higher metal content which is passed to a second magnetic concentrator 19, which latter produces a final coarse concentrate 20 containing 51.3% Fe and a minor proportion of tailings and middlings which are combined and recirculated to the inlet side of the mill 11.
  • the main product from cyclone 13 is passed to a magnetic concentrator 21 which produces a final fine concentrate 22 of 63.5% Fe and fine tails 23 containing 17.0% Fe.
  • Example I.A 5 by 2' combined dry crushing and grinding unit was brought into operating balance in accordance with the flow sheet illustrated in Figure 1 using as feed a low grade magnetic iron ore obtained from a de posit in Northern Quebec with a feed rate of 057 ton per hour and a velocity of air through the mill corresponding to a water gauge reading 1.5" at the mill outlet.
  • the screen 16 was a 20 mesh screen and under balanced conditions the +20 mesh material returned to the mill from the top of screen 16 amounted to 5% by weight of the feed.
  • the combined coarse tails and middlings re: turned from the magnetic concentrator 19 amounted to 2% of the total feed.
  • Table I The results'of this run are illustrated in Table I:
  • Example 2 (see Figure 2).
  • the mill was brought into balance with a feed rate of 0.54 ton'per hour with a, velocityofair through the mill corresponding to 1.9' ',wa-; ter gauge at the outlet side thereof.
  • the magnetic concentrator 17 produces a middlings and a tailings which are combined and returned to the inlet side of the mill 11 and the concentrate from concentrator 17 is cleaned in asecond magnetic concentrator 19 which produces a coarse concentrate which is returned to the inlet side of the mill anda final coarse tailing 26 which is discarded.
  • the main product from the cyclone 13 passes to magnetic concentrator 21 which produces a fine concentrate 22 and a fine tailing which is passed to the further magnetic concentrator 21a where it is separated into a final fine tailing 23 and a middling which is recycled to a point just in advance of the cyclone 13.
  • Example 3 The same equipment was brought into balance with the same ore in accordance with the method of operation illustrated in Figure 3 which differs from that shown in Figure 2 in that the middlings from magnetic concentrator 21a is returned to the inlet side of the mill rather than to a point in the collection circuit.
  • the amount of the material returned from the concentrators 17, 19, 21a to the inlet side of the mill amounted to 100% of the feed while the mesh returned to the mill from screen 16 amounted to 4% of the feed 10.
  • the capacity of the mill was 0.54 ton per hour with a velocity of air through the mill corresponding to 2.2" of water at the outlet side thereof.
  • Examples 2 and 3 illustrate the advantages which may be gained in increased grade by the return of a coarse concentrate to the inlet side of the milling circuit. Comparable advantage may be achieved in similar manner on ores other than magnetic iron but which are subject to dry concentration when in a state of sub-division larger than their primary grain size.
  • magnetic concentration has been utilized, but it will be appreciated that, where applicable, use may be made of electrostatic concentration or any other form of dry concentration which may suit the particular material being treated.
  • a method of beneficiating magnetic iron ores containing aggregates of substantially barren gangue particles and a non-uniform distribution of aggregates of primary crystals of the mineral to be recovered comprising; passing the ore through a dry milling circuit, comprising a combined dry crushing and grinding mill and which is adapted to produce a substantial proportion of product in a size range larger than the primary crystal size of the contained mineral; collecting milling circuit product which is primarily of a particle size larger than the primary crystal size of said ore; subjecting said collected product to magnetic concentration to produce at least a coarse concentrate; and returning the coarse concentrate to the inlet side of said combined dry crushing and grinding mill.
  • a method of beneficiating magnetic iron ore of the type containing aggregates of substantially barren gangue particles and a non-uniform distribution of aggregates of primary crystals of the mineral to be recovered whereby magnetic concentration is eifective to produce a discardable tailing when the ore is in a state of sub-division larger than its primary crystal size said methodcomprising; passing the ore through a dry milling circuit comprising a combined dry crushing and grinding mill and which is adapted to produce a substantial proportion of product in a size range larger than the primary crystal size of the contained mineral; collecting milling circuit product which is primarily of a particle size larger than the primary crystal size of said ore; subjecting said collected product to magnetic concentration to produce at least a coarse concentrate and a discardable coarse tailing; and returning the coarse concentrate to the inlet side of said combined dry crushing and grinding mill.

Description

Nov. 29, 1960 Filed April 16, 1957 ORE a4. 82%
D. WESTON BENEFICIATION 0F ORES V 3 Sheets-Sheet 2 INVEN TOR. 04 W0 WES TON ,47'roz/vsys Nov. 29, 1960 D. WESTON 62,
BENEFICIATION OF ORES Filed April 16, 1957 5 Sheets-Sheet 3 ORE 34. 7% /0 114 IL 5 i006 p/vc.
ram:
ca/vc.
INVENTOR. JAM 0 WE 7'0 United States Patent F BENEFICIATION F onns David Weston, 129 Adelaid St. W., Toronto 1, Ontario, Canada Filed Apr. 16, 1957, Ser. No. 653,240
3 Claims. (Cl. 241-80) This invention relates to methods of milling material in dry milling circuits and more particularly to a method of dry milling embodying concentration of values and the production of a beneficiated milling circuit product.
The method of the present invention while it applies particularly to the benefication of ores containing com ponents amenable to magnetic separation has broad application to the beneficiation of all ore materials which are amenable to any form of concentration at a stage of reduction at which the values are contained in composite particles, rather than primary crystalline particles.
It has hitherto been the practice with such materials to continue comminution to a point where substantially all of the values have been reduced at least to the primary crystalline grain size (i.e. the particle size wherein the minerals are effectively liberated) and then to concentrate the values from the resulting primarily mechanical mixture of particles of values and gangue. The reduction of the material may be carried out according to these known methods either in a single pass through a series of reduction units or by employing one or more reduction units in which an oversize fraction of the product is recirculated.
' I have now found that in the case of many minerals and notably in the case of magnetic iron ores the distribution of values in particles consisting of aggregates of primary crystals is nonuniform in nature so that a substantial percentage of such particles consist for the most of aggregates of crystals of values and a substantial percentage of such particles consist for the most part of aggregates of substantially barren gangue particles. I have further found that in specific cases it is possible to take advantage of this fact to produce a higher grade of concentrate with a concurrent saving in milling costs by removing a substantial proportion of the material from the milling circuit at a size range considerably above that desired in the final product, subjecting the thus removed material to concentration, e.g. magnetic concentration in the case of magnetic iron ores, and then returning the concentrate to the inlet side of the milling circuit along with the normal feed thereto, and in many cases discarding the tailing.
Preferably, according to the present invention,.the milling operation is conducted in'a combined dry crushing and grinding unit wherein the'product is extracted in a stream of air. The mill is so adjusted that a substantial proportion of the material carried away from the mill by the airstream is within a size range coarser than that desired as a final product and a fraction (which may be considered a middlings in relation to the operation being conducted) is removed by air and/ormechanical classification and passed through a dry magnetic concentrator. The concentrate is returned to the'inlet side of the mill while the tailing may usually be discarded as a coarse tailing containing only a very small amount of values.
' The invention and its operation will be described in some detail as applied to the beneficiation of magnetic iron ores in the following detailed specification in which reference will be had to the accompanying drawings wherein:
, 2,962,231 Patented Nov. 29, 1960 Figure l is a schematic illustration of a typical flow sheet for the beneficiation of magnetic iron ores operating according to previously known principles.
Figure 2 is a schematic illustration of a flow sheet according to one embodiment of the present invention.
Figure 3 is a schematic illustration of an alternative embodiment of the present invention.
Referring now more particularly to the drawings in the conventional method of operation as illustrated in Figure l which is given for purposes of comparison, feed 10 is delivered to the combined dry crushing and grinding unit 11 which is an airswept mill discharging into an air classifier 12 which removes the oversize and permits the main product to pass to cyclone 13. After a deposit of the main product in cyclone 13 fines are collected in the multicyclone 14 and dust which is too fine for collection in the multicyclone 14 is collected in the bag filter 15. The air classifier 12 discharges on to the mechanical screen 16 and the oversize from the said screen is returned to the inlet side of the mill. The through product from screen 16 is passed to magnetic separator 17 which produces a final tailing 18 of low metal content (20.0% Fe) and a rough concentrate of higher metal content which is passed to a second magnetic concentrator 19, which latter produces a final coarse concentrate 20 containing 51.3% Fe and a minor proportion of tailings and middlings which are combined and recirculated to the inlet side of the mill 11. The main product from cyclone 13 is passed to a magnetic concentrator 21 which produces a final fine concentrate 22 of 63.5% Fe and fine tails 23 containing 17.0% Fe.
Typical results obtained operating in accordance with the flow sheet of Figure 1 are indicated in the following example. 7
Example I.A 5 by 2' combined dry crushing and grinding unit was brought into operating balance in accordance with the flow sheet illustrated in Figure 1 using as feed a low grade magnetic iron ore obtained from a de posit in Northern Quebec with a feed rate of 057 ton per hour and a velocity of air through the mill corresponding to a water gauge reading 1.5" at the mill outlet. The screen 16 was a 20 mesh screen and under balanced conditions the +20 mesh material returned to the mill from the top of screen 16 amounted to 5% by weight of the feed. The combined coarse tails and middlings re: turned from the magnetic concentrator 19 amounted to 2% of the total feed. The results'of this run are illustrated in Table I:
Table I v r Ironin Product lSoluble iron. in Percent product Weiht 5 Final Product Based on Total 'Percent. Percent Percent Percent Feed Iron in 'Weizht Iron in Wei ht 7 Product oi Feed Product of Feed Coarse Tails 18. 25.6 20.0 5. 1 7. 0 1. 8 (approx.) Coarse Gone. 20.... 20.1 51. 3 .10. 3 50.0 10.0 Fine Gone. 22. 17. 5 .63. 3 11.1. 62.3 10. Multicvcloue 24 4. 4 22. 2 0. 98 14.0 0. 62 Fine Tails 23 26. 5 17.0 4. 5 9.0 2. 38 Dust; 25 5. 9 24.4 1. 43 17.0 1.0
The same equipment was then operated under balanced c onditionsin accordance with the methodof the present invention, and the results of these runs using the same ore is set forth in Examples 2 and 3. H Example 2 (see Figure 2).The mill was brought into balance with a feed rate of 0.54 ton'per hour with a, velocityofair through the mill corresponding to 1.9' ',wa-; ter gauge at the outlet side thereof. In this case, the amount of +20 mesh returned to the mill from the top of screen 16 amounted to 4% of the mill feed. In this case, the magnetic concentrator 17 produces a middlings and a tailings which are combined and returned to the inlet side of the mill 11 and the concentrate from concentrator 17 is cleaned in asecond magnetic concentrator 19 which produces a coarse concentrate which is returned to the inlet side of the mill anda final coarse tailing 26 which is discarded. The main product from the cyclone 13 passes to magnetic concentrator 21 which produces a fine concentrate 22 and a fine tailing which is passed to the further magnetic concentrator 21a where it is separated into a final fine tailing 23 and a middling which is recycled to a point just in advance of the cyclone 13.
With conditions in balance the amount of coarse concentrate and middlings recycled to the inlet of mill 11 from the magnetic concentrators 17 and 19 amounted to 50% of the weight of the feed 10. Results of a typical run are shown in Table II.
It will be noted from Table II with respect to line concentrate 22 that 32.5% by weight of the product is obtained with an improved iron content of 67.5% by weight as compared to only 17.5% by weight of fine concentrate 22 in Table I with the lower iron content of 63.3% by weight. Thus, almost double the amount of a higher premium concentrate is obtained with the invention. Similar comparisons are indicated as to the soluble iron content.
Example 3.-The same equipment was brought into balance with the same ore in accordance with the method of operation illustrated in Figure 3 which differs from that shown in Figure 2 in that the middlings from magnetic concentrator 21a is returned to the inlet side of the mill rather than to a point in the collection circuit. In this case under balanced conditions the amount of the material returned from the concentrators 17, 19, 21a to the inlet side of the mill amounted to 100% of the feed while the mesh returned to the mill from screen 16 amounted to 4% of the feed 10. Under balanced conditions, the capacity of the mill was 0.54 ton per hour with a velocity of air through the mill corresponding to 2.2" of water at the outlet side thereof.
Results of a typical run operating under the above conditions are given in Table III.
Once again it will be observed that compared to the method of operation illustrated in Figure 1 the grade of concentrate is higher and the tailing losses lower. Com- 4 pared to the method illustrated in Figure 2 the result is a slightly lower ratio of concentration, and slightly higher loss in the coarse tailings owing to the higher air velocity used.
Examples 2 and 3 illustrate the advantages which may be gained in increased grade by the return of a coarse concentrate to the inlet side of the milling circuit. Comparable advantage may be achieved in similar manner on ores other than magnetic iron but which are subject to dry concentration when in a state of sub-division larger than their primary grain size. In the foregoing examples, magnetic concentration has been utilized, but it will be appreciated that, where applicable, use may be made of electrostatic concentration or any other form of dry concentration which may suit the particular material being treated.
What I claim as my invention is:
1. A method of beneficiating magnetic iron ores containing aggregates of substantially barren gangue particles and a non-uniform distribution of aggregates of primary crystals of the mineral to be recovered, said method comprising; passing the ore through a dry milling circuit, comprising a combined dry crushing and grinding mill and which is adapted to produce a substantial proportion of product in a size range larger than the primary crystal size of the contained mineral; collecting milling circuit product which is primarily of a particle size larger than the primary crystal size of said ore; subjecting said collected product to magnetic concentration to produce at least a coarse concentrate; and returning the coarse concentrate to the inlet side of said combined dry crushing and grinding mill.
2. A method of beneficiating magnetic iron ore of the type containing aggregates of substantially barren gangue particles and a non-uniform distribution of aggregates of primary crystals of the mineral to be recovered whereby magnetic concentration is eifective to produce a discardable tailing when the ore is in a state of sub-division larger than its primary crystal size, said methodcomprising; passing the ore through a dry milling circuit comprising a combined dry crushing and grinding mill and which is adapted to produce a substantial proportion of product in a size range larger than the primary crystal size of the contained mineral; collecting milling circuit product which is primarily of a particle size larger than the primary crystal size of said ore; subjecting said collected product to magnetic concentration to produce at least a coarse concentrate and a discardable coarse tailing; and returning the coarse concentrate to the inlet side of said combined dry crushing and grinding mill.
3. The method as defined in claim 1 wherein the magnetic concentration stage produces a middliugs which is also returned to the inlet side of the milling circuit.
References Cited in the file of this patent UNITED STATES PATENTS 1,637,648 Kopf Aug. 2, 1927 1,905,780 Ahlmann Apr. 25, 1933 1,931,921 Breerwood Oct. 24, 1933 2,072,063 Alton Feb. 23, 1937 2,381,351 Hardinge Aug. 7, 1945 2,462,645 Knowland Feb. 22, 1949 2,595,117 Ahlmann Apr. 29, 1952 2,627,375 Grondal et a1 Feb. 3, 1953 2,674,413 Weston Apr. 6, 1954 2,692,677 Bosqui et a1. Oct. 26, 1954 2,712,902 Kennedy July 12, 1955 2,835,452 Cline et al May 20, 1958 OTHER REFERENCES Handbook of Mineral Dressing, by Taggart, 1945, p. 2-141, published by John Wiley and Sons, Incorporated, New York,

Claims (1)

1. A METHOD OF BENIFICIATING MAGNETIC IRON ORES CONTAINING AGGREGATES OF SUBSTANTIALLY BARREN GANGUE PARTICLES AND A NON-UNIFORM DISTRIBUTION OF AGGREGATES OF PRIMARY CRYSTALS OF THE MINERAL TO BE RECOVERED, SAID METHOD COMPRISING, PASSING THE ORE THROUGH A DRY MILLING CIRCUIT, COMPRISING A COMBINED DRY CRUSHING AND GRINDING MILL AND WHICH IS ADAPTED TO PRODUCE A SUBSTANTIAL PROPORTION OF PRODUCT IN A SIZE RANGE LARGER THAN THE PRIMARY CRYSTAL SIZE OF THE CONTAINED MINERAL, COLLECTING MILLING CIRCUIT
US653240A 1957-04-16 1957-04-16 Beneficiation of ores Expired - Lifetime US2962231A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US653240A US2962231A (en) 1957-04-16 1957-04-16 Beneficiation of ores

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US653240A US2962231A (en) 1957-04-16 1957-04-16 Beneficiation of ores

Publications (1)

Publication Number Publication Date
US2962231A true US2962231A (en) 1960-11-29

Family

ID=24620047

Family Applications (1)

Application Number Title Priority Date Filing Date
US653240A Expired - Lifetime US2962231A (en) 1957-04-16 1957-04-16 Beneficiation of ores

Country Status (1)

Country Link
US (1) US2962231A (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3037711A (en) * 1957-06-18 1962-06-05 Metallwerke Refonda Wiederkehr Method of and installation for processing dross of non-ferrous metals
US3221998A (en) * 1963-04-29 1965-12-07 Microcyclomat Co Pulverizer and classifier
US3231204A (en) * 1962-10-05 1966-01-25 Koppers Co Inc Beneficiation means and methods for autogenous grinding systems
US3291398A (en) * 1964-02-03 1966-12-13 Aerofall Mills Inc Beneficiation of magnetic iron ores
US3337328A (en) * 1964-06-19 1967-08-22 Univ Minnesota Iron ore beneficiation process
US3396913A (en) * 1963-08-06 1968-08-13 Jackering Gunter Means for comminuting thermoplastic materials
US3490702A (en) * 1966-10-24 1970-01-20 D Ore Mills Inc Method of accelerating production of portland cement and similar material
US3672579A (en) * 1970-08-10 1972-06-27 Univ Minnesota Process for beneficiating magnetite iron ore
US3754713A (en) * 1970-03-28 1973-08-28 Bayer Ag Separation of magnetizable particles
US3878994A (en) * 1973-11-28 1975-04-22 Urban Wood & Fiber Products In Apparatus and process for treating waste wood
US4252638A (en) * 1977-12-07 1981-02-24 Klockner-Humboldt-Deutz Ag Method for the desulfurization of coal
US4416768A (en) * 1982-04-02 1983-11-22 Quebec Cartier Mining Company Ore beneficiation
US20050072273A1 (en) * 2003-08-11 2005-04-07 Egbert Burchardt Method and apparatus for grinding iron ore or iron ore concentrate
WO2012000785A1 (en) * 2010-07-02 2012-01-05 Akw Apparate + Verfahren Gmbh Method for the wet processing of materials, in particular ores or similar materials by means of a closed circuit grinding process
US20140117125A1 (en) * 2012-10-26 2014-05-01 Vale S.A. Iron ore concentration process with grinding circuit, dry desliming and dry or mixed (dry and wet) concentration

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1637648A (en) * 1926-10-01 1927-08-02 Jabez Burns & Sons Inc Coffee product and method for making it
US1905780A (en) * 1929-10-24 1933-04-25 Smidth & Co As F L Apparatus for grinding materials which contain particles of iron
US1931921A (en) * 1932-12-01 1933-10-24 Valley Forge Cement Company Manufacture of cement
US2072063A (en) * 1933-09-30 1937-02-23 Vanderbilt Co R T Manufacture of pyrophyllite
US2381351A (en) * 1942-04-23 1945-08-07 Hardinge Co Inc Method and means of feeding material to grinding mills
US2462645A (en) * 1945-07-10 1949-02-22 Boston Woven Hose & Rubber Co Method of treating rubber scrap
US2595117A (en) * 1950-03-08 1952-04-29 Smidth & Co As F L Method and apparatus for grinding
US2627375A (en) * 1948-01-05 1953-02-03 Weyerhaeuser Timber Co Separation of bark components
US2674413A (en) * 1951-10-16 1954-04-06 Weston David Closed circuit air swept rotating drum material reduction system with air drawoff todust collector and air entry control means adjacent mill inlet
US2692677A (en) * 1951-02-09 1954-10-26 Dorr Co Process for classifying magnetized or magnetizable solids
US2712902A (en) * 1951-09-12 1955-07-12 Joseph E Kennedy Disintegrating apparatus having a discharge arranged to separate oversized material from the air-borne material
US2835452A (en) * 1954-06-28 1958-05-20 Du Pont Process for granulating urea-formaldehyde fertilizer compositions

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1637648A (en) * 1926-10-01 1927-08-02 Jabez Burns & Sons Inc Coffee product and method for making it
US1905780A (en) * 1929-10-24 1933-04-25 Smidth & Co As F L Apparatus for grinding materials which contain particles of iron
US1931921A (en) * 1932-12-01 1933-10-24 Valley Forge Cement Company Manufacture of cement
US2072063A (en) * 1933-09-30 1937-02-23 Vanderbilt Co R T Manufacture of pyrophyllite
US2381351A (en) * 1942-04-23 1945-08-07 Hardinge Co Inc Method and means of feeding material to grinding mills
US2462645A (en) * 1945-07-10 1949-02-22 Boston Woven Hose & Rubber Co Method of treating rubber scrap
US2627375A (en) * 1948-01-05 1953-02-03 Weyerhaeuser Timber Co Separation of bark components
US2595117A (en) * 1950-03-08 1952-04-29 Smidth & Co As F L Method and apparatus for grinding
US2692677A (en) * 1951-02-09 1954-10-26 Dorr Co Process for classifying magnetized or magnetizable solids
US2712902A (en) * 1951-09-12 1955-07-12 Joseph E Kennedy Disintegrating apparatus having a discharge arranged to separate oversized material from the air-borne material
US2674413A (en) * 1951-10-16 1954-04-06 Weston David Closed circuit air swept rotating drum material reduction system with air drawoff todust collector and air entry control means adjacent mill inlet
US2835452A (en) * 1954-06-28 1958-05-20 Du Pont Process for granulating urea-formaldehyde fertilizer compositions

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3037711A (en) * 1957-06-18 1962-06-05 Metallwerke Refonda Wiederkehr Method of and installation for processing dross of non-ferrous metals
US3231204A (en) * 1962-10-05 1966-01-25 Koppers Co Inc Beneficiation means and methods for autogenous grinding systems
US3221998A (en) * 1963-04-29 1965-12-07 Microcyclomat Co Pulverizer and classifier
US3396913A (en) * 1963-08-06 1968-08-13 Jackering Gunter Means for comminuting thermoplastic materials
US3291398A (en) * 1964-02-03 1966-12-13 Aerofall Mills Inc Beneficiation of magnetic iron ores
US3337328A (en) * 1964-06-19 1967-08-22 Univ Minnesota Iron ore beneficiation process
US3490702A (en) * 1966-10-24 1970-01-20 D Ore Mills Inc Method of accelerating production of portland cement and similar material
US3754713A (en) * 1970-03-28 1973-08-28 Bayer Ag Separation of magnetizable particles
US3672579A (en) * 1970-08-10 1972-06-27 Univ Minnesota Process for beneficiating magnetite iron ore
US3878994A (en) * 1973-11-28 1975-04-22 Urban Wood & Fiber Products In Apparatus and process for treating waste wood
US4252638A (en) * 1977-12-07 1981-02-24 Klockner-Humboldt-Deutz Ag Method for the desulfurization of coal
US4416768A (en) * 1982-04-02 1983-11-22 Quebec Cartier Mining Company Ore beneficiation
US20050072273A1 (en) * 2003-08-11 2005-04-07 Egbert Burchardt Method and apparatus for grinding iron ore or iron ore concentrate
US7775465B2 (en) * 2003-08-11 2010-08-17 Polysius Ag Method and apparatus for grinding iron ore or iron ore concentrate
WO2012000785A1 (en) * 2010-07-02 2012-01-05 Akw Apparate + Verfahren Gmbh Method for the wet processing of materials, in particular ores or similar materials by means of a closed circuit grinding process
US20140117125A1 (en) * 2012-10-26 2014-05-01 Vale S.A. Iron ore concentration process with grinding circuit, dry desliming and dry or mixed (dry and wet) concentration
US10207275B2 (en) * 2012-10-26 2019-02-19 Vale S.A. Iron ore concentration process with grinding circuit, dry desliming and dry or mixed (dry and wet) concentration

Similar Documents

Publication Publication Date Title
US2962231A (en) Beneficiation of ores
US3337328A (en) Iron ore beneficiation process
US3502271A (en) Iron ore treating process
US5338337A (en) Beneficiation process
CN107096638A (en) A kind of iron ore composite ore point mill, sorting, magnetic-gravity separation technique
CN110624686A (en) Magnetite beneficiation process capable of fully releasing mill capacity
US3791595A (en) Method for processing iron ore concentrates
US4206878A (en) Beneficiation of iron ore
CN108212504A (en) A kind of method that pre-selection-roasting-magnetic floats technique recycling magnetic tailing
US2990124A (en) System for separating magnetic susceptible particles
CN107252730A (en) A kind of composite ore high pressure roller mill wind is classified again, tower mill, magnetic weight sorting process
US3291398A (en) Beneficiation of magnetic iron ores
US2388471A (en) Beneficiation of magnetite concentrates by flotation
AU2020101235A4 (en) Method for the Beneficiation of Iron Ore Streams
US3017993A (en) Air classification system
US4860957A (en) Treatment of middlings
EP0267170B1 (en) Treatment of middlings
CN107321492B (en) Composite ore high pressure roller mill wet type pre-selecting, strong magnetic-roasting-magnetic separation process
US2950007A (en) Concentration of potash ores
CN109550587A (en) The red composite ore ore-dressing technique of magnetic
JPS63205164A (en) Production of high purity quartz concentrate
US2307064A (en) Ore dressing
US3414201A (en) Talc beneficiation method
US2441584A (en) Closed circuit grinding with twostage classification
US3456792A (en) Method for recovering chalcopyrite and pyrite from complex magnetite ores