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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/001—Flotation agents
  • B03D1/004—Organic compounds
  • B03D1/016—Macromolecular compounds
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/001—Flotation agents
  • B03D1/004—Organic compounds
  • B03D1/008—Organic compounds containing oxygen
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/001—Flotation agents
  • B03D1/004—Organic compounds
  • B03D1/01—Organic compounds containing nitrogen
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2201/00—Specified effects produced by the flotation agents
  • B03D2201/02—Collectors
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2201/00—Specified effects produced by the flotation agents
  • B03D2201/06—Depressants
• • 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
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D2203/00—Specified materials treated by the flotation agents; specified applications
  • B03D2203/02—Ores

Definitions

• the present invention relates to froth flotation processes for recovery of value sulfide minerals from base metal sulfide ores. More particularly, it relates to a method for the depression of non-sulfide silicate gangue minerals in the beneficiation of value sulfide minerals by froth flotation procedures.
• Modifiers include, but are not necessarily limited to, all reagents whose principal function is neither collecting nor frothing, but usually one of modifying the surface of the mineral so that it does not float.
• modifiers more particularly depressants
• a depressant is a modifier reagent which acts selectively on certain unwanted minerals and prevents or inhibits their flotation.
• the depressants commonly used in sulfide flotation include such materials as inorganic salts (NaCN, NaHS, SO2, sodium metabisulfite etc) and small amounts of organic compounds such as sodium thioglycolate, mercaptoethanol etc. These depressants are known to be capable of depressing sulfide minerals but are not known to be depressants for non-sulfide minerals, just as known value sulfide collectors are usually not good collectors for non-sulfide value minerals. Sulfide and non-sulfide minerals have vastly different bulk and surface chemical properties. Their response to various chemicals is also vastly different.
• polysaccharides such as guar gum and carboxy methyl cellulose
• guar gum and carboxy methyl cellulose are used to depress non-sulfide silicate gangue minerals during sulfide flotation.
• Their performance is very variable and on some ores they show unacceptable depressant activity and the effective dosage per ton of ore is usually very high (as much as 1 to 10 lbs/ton).
• Their depressant activity is also influenced by their source and is not consistent from batch to batch.
• these polysaccharides are also valuable sources of food i.e. their use as depressants reduces their usage as food and, storage thereof presents particular problems with regard to their attractiveness as food for vermin.
• US-A-4,902,764 (Rothenberg et al.) describes the use of polyacrylamide-based synthetic copolymers and terpolymers for use as sulfide mineral depressants in the recovery of value sulfide minerals.
• US-A-4,720,339 (Nagaraj et al) describes the use of polyacrylamide-based synthetic copolymers and terpolymers as depressants for silicious gangue minerals in the flotation beneficiation of non-sulfide value minerals, but not as depressants in the remediation of sulfide value minerals.
• the '339 patent teaches that such polymers are effective for silica depression during phosphate flotation which also in the flotation stage uses fatty acids and non-sulfide collectors.
• the patentees do not teach that such polymers are effective depressants for non-sulfide silicate gangue minerals in the recovery of value sulfide minerals. In fact, such depressants do not exhibit adequate depressant activity for non-sulfide silicate minerals during the beneficiation of sulfide value minerals.
• polyhydroxyamines are useful as depressants for gangue minerals including silica, silicates, carbonates, sulfates and phosphates in the recovery of non-sulfide mineral values.
• Illustrative examples of the polyhydroxyamines disclosed include aminobutanetriols, aminopartitols, aminohexitols, aminoheptitols, aminooctitols, pentose-amines, hexose amines, amino-tetrols etc.
• US-A-4,360,425 (Lim et al) describes a method for improving the results of a froth flotation process for the recovery of non-sulfide mineral values wherein a synthetic depressant is added which contains hydroxy and carboxy functionalities. Such depressants are added to the second or amine stage flotation of a double float process for the purpose of depressing non-sulfide value minerals such as phosphate minerals during amine flotation of the siliceous gangue from the second stage concentrate.
• This patent relates to the use of synthetic depressant during amine flotations only.
• AU-B-502457 discloses the use of polyvinyl-alcohol, optionally in combination with cellulose derivatives, as depressant for silicate gangues in the froth flotation of value sulphide minerals.
• US-A-2740522 discloses various anionic linear (co)polymers to be used as gangue depressants.
• the polymer depressants used in the present invention may comprise, as the grafted monomers, such acrylamides as acrylamide per se and alkyl acrylamides such as methacrylamide and ethacrylamide.
• the comonomers may comprise any monoethylenically unsaturated monomer copolymerizable with the acrylamide monomer such as hydroxyalkylacrylates and methacrylates, e.g. 1,2-dihydroxypropyl acrylate or methacrylate and hydroxyethyl acrylate or methacrylate; glycidyl methacrylate, acrylamido glycolic acid; hydroxyalkylacrylamides such as N-2-hydroxyethylacrylamide, N-1-hydroxypropylacrylamide, N-bis(1,2-dihydroxyethyl)acrylamide and N-bis(2-hydroxypropyl)-acrylamide; acrylic acid; methacrylic acid; alkali metal or ammonium salts of acrylic and/or methacrylic acid; vinyl sulfonate; vinylphosphate; 2-acrylamido-2-methyl propane sulfonic acid; styrene sulfonic acid; maleic acid; fumaric acid; crotonic acid;
• the effective weight average molecular weight range of the polyvinylalcohols is surprisingly very wide but is preferably at least ten thousand, more preferably at least thirty thousand, and up to millions, e.g. 2 million but preferably up to about 1 million.
• polysaccharides useful as an optional component in the depressant compositions used in the process of the present invention include guar gums, modified guar gums, cellulosics such as carboxymethyl cellulose and starches. Guar gums are preferred.
• the ratio of the polysaccharide to the grafted polymer in the depressant composition generally ranges from 9:1 to 1:9, respectively, preferably from 7:3 to 3:7, respectively, most preferably from 3:2 to 2:3, respectively.
• the dosage of depressant useful in the method of the present invention generally ranges from 0.01 to 10 pounds (1 pound ⁇ 0.454 kg) of depressant per ton of ore, preferably from 0.1 to 5 lb/ton, most preferably from 0.1 to 1.0 lb/ton of ore.
• mixtures of the grafted polyvinylalcohol polymers discussed above are used as the depressant, they may be used in ratios of 9:1 to 1:9, preferably 3:1 to 1:3, most preferably 3:2 to 2:3, respectively.
• the weight ratio of the acrylamide to the polyvinyl alcohol in the depressants used herein preferably ranges from 99 to 1 to 1 to 1, more preferably from 10 to 1 to 4 to 1, respectively.
• the concentration of the optional copolymerizable comonomers is preferably less than 50%, as a weight percent fraction, more preferably from 1% to 30% of the total monomers.
• the acrylamide monomer grafted polyvinylalcohol may be prepared by any method known to those skilled in the art such as that taught in EP-A-117978; Melnik et al; Dokl. Akad. Nauk Uter, SSR, Ser B; Geol. Khim. Brol. Nanki (6), 48-51, Russian 1987; and Burrows et al, J. Photochem, Photobiol. A,63(1), 67-73, English, 1992.
• the acrylamide monomer, alone or in conjunction with the optional comonomer may be grafted onto the polyvinylalcohol in the presence of ceric ion catalyst, e.g.
• ceric ammonium nitrate at a temperature ranging from about 10-50° with intermittent cooling for from about 2-6 hours. Termination of the reaction is effected after a constant solution viscosity is reached by raising the pH with diluted caustic solution to neutral or above.
• the amount of catalyst employed should range from about 0.3% to about 5.0%, by weight, based on the combined weight of monomers to be grafted, preferably from about 0.8% to 4.0%, same basis, the preferred range resulting in a grafted polymer having a more effective depressant activity.
• the new method for beneficiating value sulfide minerals employing the synthetic depressants according to the present invention provides excellent metallurgical recovery with improved grade.
• a wide range of pH and depressant dosage are permissible and compatibility of the depressants with frothers and sulfide value mineral collectors is another advantage.
• the present invention is directed to the selective removal of non-sulfide silicate gangue minerals that normally report to the value sulfide mineral flotation concentrate, either because of natural floatability or hydrophobicity or otherwise. More particularly, the instant method effects the depression of non-sulfide magnesium silicate minerals while enabling the enhanced recovery of sulfide value minerals.
• such materials may be treated as, but not limited to, the following:
• graft copolymers of AMD and PVA of higher molecular weight i.e., 20,000 and 50,000 are also prepared.
• a graft terpolymer is prepared by adding 30.9 parts of a 52% acrylamide monomer solution and 7.2 parts of acrylic acid monomer to a solution of 5.0 parts of PVA (mol. wt. 50,000) in 150 parts water. A total of 10 parts of ceric catalyst solution are used for this preparation.
• Other copolymers are prepared similarly, e.g. using acrylonitrile and vinyl butyl ether.
• An ore containing approximately 3.3% Ni and 16.5% MgO (in the form of Mg silicates) is ground in a rod mill for 5 min. to obtain a pulp at a size of 81% -200 mesh.
• the ground pulp is then transferred to a flotation cell and is conditioned at natural pH ( ⁇ 8-8.5) with 150 parts/ton of copper sulfate for 2 min., 50 to 100 parts/ton sodium ethyl xanthate for 2 min. and then with the desired amount of a depressant and an alcohol frother for 2 min.
• First stage flotation is then conducted by passing air at approximately 3.5-5 l/min. and a concentrate is collected.
• the pulp is conditioned with 10 parts/ton of sodium ethyl xanthate, and specified amounts of the depressant and the frother for 2 min. and a concentrate is collected.
• the conditions used in the second stage are also used in the third stage and a concentrate is collected. All of the flotation products are filtered, dried and assayed.
• a reduction in Ni recovery is to be expected in the process of reducing MgO recovery since there is invariably some mineralogical association of Ni minerals with the Mg-silicates and, when the latter are depressed, some Ni minerals are also depressed.
• the graft copolymers of the present invention are used, there is a much greater reduction in the MgO recoveries compared to that with guar gum.
• the Ni recoveries are also slightly lowered compared with that of guar gum, but the Ni grades in the concentrate are much higher than those obtained with guar gum.
• Example Depressant % Recovery (Gangue Silicate) 11C None 85 12C Polyvinyl alcohol 75 13C Guar 3.4 14 60/40 AMD/PVA 8.9 15 75/25 AMD/PVA 8.7 16 80/20 AMD/PVA 3.0 17 87/13 AMD/PVA 1.3 18 90/10 AMD/PVA 0 19 92.5/7.5 AMD/PVA 7.9 20 97.5/2.5 AMD/PVA 7.8
• a PVA graft copolymer is prepared in accordance with Background Examples 1-5 above, with varying amounts of ceric iron catalyst. The results are shown in Table III, below, following the flotation procedure of Examples 11-20.
• Example Depressant % Recovery (Gangue Silicate) 25 AMD/AN/PVA 80/10/10 7.75 26 AMD/AN/PVA 85/5/10 3.28 27 AMD/AA/PVA 66/24/10 16.60 28 AMD/VBE/PVA 80/10/10 14.70
• An ore containing approximately 3.3% Ni and 16.5% MgO (in the form of Mg silicates) is ground in a rod mill for 5 min. to obtain a pulp at a size of 81% -200 mesh.
• the ground pulp is then transferred to a flotation cell and is conditioned at natural pH ( ⁇ 8-8.5) with 150 parts/ton of copper sulfate for 2 min., 50 to 100 parts/ton sodium ethyl xanthate for 2 min. and then with the desired amount of depressant blend and an alcohol frother for 2 min.
• First stage flotation is then conducted by passing air at approximately 3.5-5 l/min. and a concentrate is collected.
• the pulp is conditioned with 10 parts/ton of sodium ethyl xanthate, and specified amounts of the depressant blend and the frother for 2 min. and a concentrate is collected.
• the conditions used in the second stage are also used in the third stage and a concentrate is collected. All of the flotation products are filtered, dried and assayed.
• a reduction in Ni recovery is to be expected in the process of reducing MgO recovery since there is invariably some mineralogical association of Ni minerals with the Mg-silicates and, when the latter are depressed, some Ni minerals are also depressed.
• AMD/PVA graft copolymer at the same dosage, there is significant reduction in MgO recovery compared with that of guar gum.
• the blend of guar gum and synthetic polymer at the same dosage, however, there is further increase in the depressant activity compared with that of the two components individually.
• the grade of the Ni in concentrate also increases. The results also suggest that much lower dosages of the blend can be used; in this case the Ni recoveries would improve while maintaining the low MgO recoveries.
• Feed Assay 3.31% Ni and 17.58% MgO Example Depressant Parts/Ton Ni Rec. Ni Grade MgO Rec. 39C None 0 96.6 4.7 61.4 40C Guar Gum 350+70+80 93.0 7.7 28.3 41C AMD/PVA (23K) 75/25 350+70+80 90.0 8.3 20.7 42 Guar Gum and AMD/PVA (23K) 75/25; 1:1 350+70+80 88.6 9.2 18.7

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• Silicates, Zeolites, And Molecular Sieves (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Paper (AREA)
• Silicon Compounds (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)

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• 1996
  • 1996-05-07 RU RU98100227A patent/RU2140329C1/ru active
  • 1996-05-07 AU AU57332/96A patent/AU693029B2/en not_active Ceased
  • 1996-05-07 DE DE69603727T patent/DE69603727D1/de not_active Expired - Lifetime
  • 1996-05-07 WO PCT/US1996/006481 patent/WO1996040439A1/en active IP Right Grant
  • 1996-05-07 AT AT96915590T patent/ATE183115T1/de not_active IP Right Cessation
  • 1996-05-07 BR BR9609098A patent/BR9609098A/pt active Search and Examination
  • 1996-05-07 EP EP96915590A patent/EP0830209B1/en not_active Expired - Lifetime
  • 1996-05-07 PL PL96323918A patent/PL180626B1/pl unknown
  • 1996-05-07 CA CA002222871A patent/CA2222871A1/en not_active Abandoned
  • 1996-05-07 CN CN96194427A patent/CN1186455A/zh active Pending
• 1997
  • 1997-12-05 OA OA70154A patent/OA10640A/en unknown
  • 1997-12-11 BG BG102113A patent/BG62124B1/bg unknown

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