Aug. 22, 1967 J‘ E. LAWVER 3,337,328 IRON ORE BENEFICIATION PROCESS Filed June 19, 1964 6 Sheets-Sheet l Heavy Media Tailings Tailing Pond Fines or Semitaconite 25 to 50% Iron FIG. 1 I Crush and/or Grind to Free the Iron Oxide Partial Concentration to Separate Iron Mineral from Waste Product by one of Following Processes or or A B C High Intensity Wet Froth Gravity Magnetic Separation Flotation Separation l l I I Partial Waste Partial Waste Partial Waste Concentrate Product Concentrate Product Concentrate Product L I I . Gravity Gravity Concentrates or Separation of Partial‘ Concentrates Low-grade Hematitic Ore From "An or “all or "ch 40 to 58%‘.Iron Crush and Grind to Liberate Silica Coarse Fraction Minus O. 010" plus 0.003" Fine Fraction‘ Less than 0.003" G to 75% Weight @ 25 to 100% Weight Electrodynamic Process to Separate Froth Flotation Process to Separate Iron Oxides and Silica Iron Oxides and Silica Silica Product to Waste Silica Product to Waste Iron Oxide Concentrate 62 to 65% Iron 5% Silica ' INVENTOR J9me; E. L’ AWl/ER 14 T TORNE Y! Aug. 22, 1967 J. e. LAWVER 3,337,328 IRON ORE BENEFICIATION PROCESS Filed ‘June 19, 1964 6 Sheets-Sheet 2 Crude Ore %Wt. 100. O0 FIG.' 2 %Fe%Insol.4l.l9 39 . 35 4" Screen -4" Ore +4" Ore %wt.84.45 %Wt. 15.39 %E‘e 4O. 19 %E'e 34. 75 %Inso]l . 48. 57 Crush 8 Screen %Fe Rec.l3.59 _ -___.______ +14 Mesh ~~14 Mesh Heavy Media Sands Slimes Separation '7‘Wt- 9-58 Spirals %E‘e 11.78 Sinks Floats ' Concentrate r(‘ailing %Wt. 11.31 %Wt. 14.12 57 . 00 %Fe I28. 00 Grind to 100% -—48 Mesh Grlnd —48 +325 Mesh ~325 Mesh (several sizes) Flotation High Tension ' Flotation Concentrate ‘Failing 7m, 17.48 %wc. 16.70 Concen- Concen- %Fe 50.00 %Fe 5. 0O trate Tailing trate Tailing High Tension Concentrate Tailing Concentrate ‘Failing Wt. 30.04 %Wt. 10.81 %Wt . 10.93 %Wt. 6. 55 Insol.Fe 65.5.0+ 00 %Fe l 34.41 %Insol.%Fe 65.005.0+ %Fe i 25. 0O if Combined Concentrate Combined ‘Failing %Wt. 40.97 %Wt. 43. 56 %Fe 65.00 %E‘e 16.81 %Insol_ 5. 0+ %Inso1. 72. 5O Crude %Fe Rec. 67. 68 %§V‘e Rec. 18.73 ~4" Ore %Fe Rec. 78. 32 INVENTOR. JAMES/f. LAWl/ER ‘ 311%WM ‘ A?‘ TORNEK: Aug- 2'2, 1967 J. E. LAWVER I 3,337,328 IRON ORE BENEFICIATION PROCESS Filed June 19, 1964 6 Sheets-Sheet 3 ‘Tailings F 3 l.__._.__‘-__.______~—>Grind'through 28 to 48 Mesh Sizing I I Gravity Separations El/Iiddlingv cencet-ltrate 'l‘ai*1 ling I Open Circuit Rod Mill waste I Filter and Dry I I é-xElectrostatiéc Separation I Tailing Conceitrate l To Waste To Briquetting Plant I@—GravityI orSeparation to Tail‘ings |~-— -— -— —— —-—,—- Grind throughv 35 to 48 Mesh l I . I Float with Fatty Acid, Fatty Acid Soap, I or with Petrolpeum Sulfonate I I Iron Oxide Froth Product ' SilicJCell Product I Open Circuit Rod Mill > Waste I Float with Fatl’q}v Acid or Soap . Y I ‘*Silica Cell Product Iron Oxide Froth Product I Filter Iand. Dry 4 I Electrostatilc Separation I Tailing Final Concentrate I To Waste ' To Briquetting Plant L or to I Gravity Separation INVENTOR JJ‘IMESE. LA WVER‘ BY mil/Ah 147- TaR/vE Ks‘ Aug- 2.2, 1967' J. E. LAWVER 3,337,328 _ ’ IRON ORE BENVEFICIATION PROCESS Filed June 19, 1964 6 Sheets-Sheet 4 _ F165 Tailings Grind through 35 to 48 Mesh Float with Fatty Acid, Fatty Acid Soap, or with Petroleum Sulfonate Iron Oxide Froth Product Silica Cell ‘Product Open Circuit Rod Mill Waste Scrub with 10 lb Sulfuric Acid/Ton Ore Wash Float with Calcium Ion and Fatty Acid. l Iron Oxide Cell Product Silica Froth Product Filter and Dry Waste Electrostatic Separation Final Concentratq To Briquetting Plant INVENTOR. JZMEJELAWVER’ ATTORNEY! Aug- 22, 1967 J. E. LAWVER 3,337,328 IRON ORE BENEFICIATION PROCESS Filed June 19, 1964 ' 6 Sheets-Sheet 5 ‘ Crude Ore ' Wt. 100. 00 FIG_ 6 ‘ %Fe 31.31 Crush 5. Grind to Liberation Wet or Dry Low Intensity Magnetic Separation magnetite Magnetite Free Concentrate Product % Wt. 1.00 % Wt. 99.00 % Fe 60. 0O % Fe 30.01 High Intensity Wet Magnetic Rougher Separator Rouqher 'I‘ailing Rougher Concentrate %‘ Wt. 34. 95 % Wt. 64.05 % Fe 8. 63 % Fe 43.24 --»-~£@¥1Ye __.___ __ __j_ High Intensity Wet Magnetic Cleaner Separator Cleaner Concentrate Cleaner ‘Failing % Wt. 46. 23 ‘7.. Wt . 17. 82 % Fe 52.29 % Fe 19. 76 High Intensity wet Magnetic Recleaner Separator Recleaner Concentrate Recleaner 'I‘ailing ‘7. Wt, 37. 22 % Wt. 9. 01 % Fe 58. 23 % Fe 27. 76 A or I B Silica Flotation by Silica Flotation Calcium Activation Using an Amine Final Conc. Tailing Final Conc. Tailing % Wt. 29.45 % Wt. 7. 77 % Wt. 26.85 ‘ % Wt. 10. 37 % Fe 64. 16 % Fe 35. 75 % Fe 64. 16 % Fe 42.87 % Insol . 5.02 % Insol. ' 5. 01 %Fe Rec. 62 . 34 %Fe Rec. 56.84 INVENTOR. $4ME5E. ZAWVER B Y 1} if x47- TOR'NE v)" Aug.‘ 22, 1967 J. E. LAWVER 3,337,328 IRON ORE BENEFIGIATION PROCESS ‘ Filed June 19, 1964 e Sheets~$heet e " 108 .L 5 ‘\ 9%‘<2 ' ‘ m \V) . \, __ aO ‘gIn iL \ g I Q 1 _, 5f I E’ "J wlu / aE: a /- - k / m z (L 9 / E ' k / i1’ § / __ w B‘. / z a; / n ,k / ? / 3: ‘m ./ __ g >& N i A. : : : : 8 h. we 1r.» ‘t n. w 0 O Q Q Q Q )4 -LN5IJI.=/d§0_) NOLL var/d9!‘ ' \?IMESELAWl/ER’. INVENTOR. BY97/WMM /4 T TOR/YE v5 3,337,328 United States Patent 0 ICC Patented Aug. 22, 1967 1 2 3,337,328 Concentration is also possible by gravity methods, IRON ORE BENEFICIATION PROCESS using such devices as spirals, tables or vanning concen James E. Lawver, Edina, Minn., assignor to The Regents trators. In general, however, gravity concentration of the of the University of Minnesota, Minneapolis, Minn, a ?ner sizes produces a concentrate high in silica unless corporation of Minnesota numerous recleaning stages and large circulating loads Filed June 19, 1964, Ser. No. 376,338 are used. 19 Claims. (Cl. 75-3) It is also known that many of these ores can be concen trated by using high intensity magnetic separators. High This invention relates to a process for the bene?ciation intensity dry magnetic separators have been used com or upgrading of low grade iron-containing minerals and, 10 mercially for years. However, low grade semi-taconite more particularly, to the bene?ciation of semi-taconite cannot be economically concentrated in this manner due ores or altered taconites which have become partially to the high capital costs of such separators and to the leached and oxidized, present plant concentrates produced drying costs implicit in such a process. by gravity separation which are of marginal usefulness Electrodynamic concentration can also be used to bene because of unfavorable physical and chemical properties, 15 ?ciate ores of this type provided that the feed is thor and tailing stock piles from prior gravity separation op oughly deslimed and that the ore is thoroughly dry. In erations. There are huge reserves in the Western Mesabi such a process, however, drying costs are high because a range of Minnesota, and elsewhere, of these relatively low large portion of the original feed would eventually be dis grade iron ores, unsaleable concentrates and tailings carded as a tailing. The problem is to produce a high dumps which are becoming of increasing interest and im 20 grade concentrate at high iron recovery with a minimum portance in our nation’s economy as richer ores and more capital and operating cost. easily concentrated minerals are becoming less readily In view of the known capabilities and the known dis available. Although methods are known by which these advantages of various prior art bene?ciation methods, it low grade minerals may be concentrated and upgraded, is apparent that no single bene?ciation process can be they are unsatisfactory in many instances, either because 25 found which will lend itself to an economically feasible the upgraded or concentrated product is not saleable be ?ow sheet for the production of acceptable saleable con cause it does not meet the minimum and increasingly centrates from semi-taconite ore, from low grade concen' strict requirements of the steel mills, or because it is trates and waste products from previous separations, and prohibitively expensive, or both. other similar services of low grade iron minerals. Accord The principal object of the present invention is to pro ingly, the present invention is based upon the utilization vide an economical iron ore bene?ciation process for the of the advantageous characteristics of a combination of production of saleable concentrates which are acceptable concentrating procedures. By utilizing several types of to the steel mills because they meet the requirements of processing equipment, it is possible to sort the minerals the mills. Such concentrates should contain more than in the ore so that advantage can be taken of the particular about 60% iron and less than about 7% silica. The pres physical and chemical properties of each ore group by out process provides for the highest iron recovery with using a combination of concentrating procedures. minimum capital and operating costs. The process is The invention is illustrated in the accompanying draw‘ adapted to the upgrading of present heavy density and ings in which: spiral concentrates and to the ‘concentration of present FIGURE 1 is an exemplary schematic ?ow sheet of a plant waste products as well as crude semi-taconite ores, process for the bene?ciation of crude semi-taconite ore; and in some cases, even ?ne-grained oxidized taconite.