Hydroximic acid-metal hydroxide coordination complex and preparation and application thereof

Abstract

A hydroxamic acid-metal hydroxide coordination complex and preparation and application thereof are disclosed. The hydroxamic acid-metal hydroxide coordination complex is formed by a coordination of hydroxamic acid with divalent or higher valent metal ions under an alkaline condition. The hydroxamic acid-metal hydroxide coordination complex has a strong selectivity and a strong collection ability for metal oxide minerals such as tungsten-containing minerals, ilmenite, rutile, cassiterite, and rare earth. The preparation method is simple and low in costs, and is beneficial to industrialized production.

Claims

1. A preparation method of a hydroxamic acid-metal hydroxide coordination complex, comprising: performing a coordination reaction between hydroxamic acid and divalent or higher valent metal ions in an alkaline solution system to obtain the hydroxamic acid-metal hydroxide coordination complex; wherein the hydroxamic acid has a structure of formula 1, and the formula 1 is expressed as: ##STR00003## wherein R is a hydrophobic organic group, wherein after the coordination reaction is completed, the hydroxamic acid-metal hydroxide coordination complex is separated and purified by a carrier adsorption-foam floatation method.

2. The preparation method according to claim 1, wherein R is an aliphatic hydrocarbon radical or an aryl.

3. The preparation method according to claim 2, wherein R is a C.sub.4-C.sub.12 alkyl, a C.sub.4-C.sub.12 unsaturated aliphatic hydrocarbon radical, phenyl, or substituted phenyl.

4. The preparation method according to claim 3, wherein R is the phenyl.

5. The preparation method according to claim 1, wherein the divalent or higher valent metal ions comprise at least one of Pb.sup.2+, Ca.sup.2+, Mn.sup.2+, Cu.sup.2+, Fe.sup.3+, and Al.sup.3+.

6. The preparation method according to claim 5, wherein the divalent metal ions are Pb.sup.2+.

7. The preparation method according to claim 1, wherein a coordination mole ratio of the divalent or higher valent metal ions to the hydroxamic acid is (1-4):(1-5).

8. The preparation method according to claim 7, wherein the coordination mole ratio of the divalent or higher valent metal ions to the hydroxamic acid is (1-2):(1-3).

9. The preparation method according to claim 1, wherein a pH value of the alkaline solution system is 8-11.

10. The preparation method according to claim 9, wherein the pH value of the alkaline solution system is 8.5-9.5.

11. The preparation method according to claim 1, wherein a temperature of the coordination reaction is 20-80 C., and a reaction time is 0.5-6 hours.

12. The preparation method according to claim 11, wherein the temperature of the coordination reaction is 55-65 C., and the reaction time is 1-2 hours.

13. The preparation method according to claim 1, wherein the carrier adsorption-foam floatation method comprises the steps of: adsorbing the hydroxamic acid-metal hydroxide coordination complex in a solution system by carrier particles; after the step of adsorbing is completed, recovering the carrier particles loading the hydroxamic acid-metal hydroxide coordination complex through a foam floatation; and obtaining a hydroxamic acid-metal coordination complex solution by an ultrasonic washing of the carrier particles loading the hydroxamic acid-metal hydroxide coordination complex.

14. The preparation method according to claim 13, wherein the carrier particles are quartz particles with a particle size of 10-37 m.

15. The preparation method according to claim 13, wherein absolute ethyl alcohol is used as a washing agent for the ultrasonic washing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of an adsorption model of floatation collection of scheelite by a benzohydroxamic acid-lead hydroxide coordination complex.

(2) FIG. 2 is an infrared spectrogram of a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiments 2-5 and benzohydroxamic acid.

(3) FIG. 3 is an XRD spectrogram of a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiments 3-5.

(4) FIG. 4 is a thermogravimetric analysis (TGA) spectrogram of a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiments 5-6.

(5) FIG. 5 is a flow diagram of a desulfurization tailing tungsten separation process of using a benzohydroxamic acid-lead hydroxide coordination complex according to Embodiment 13 as a collector.

(6) FIG. 6 is influence of a pH value of ore pulp on floatability of scheelite when a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiment 1 is used as a collector.

(7) FIG. 7 is influence of a pH value of ore pulp on floatability of scheelite when a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiments 2-5 is used as a collector.

(8) FIG. 8 is influence of a pH value of ore pulp on floatability of scheelite when a benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 8 is used as a collector.

(9) FIG. 9 is influence of a pH value of ore pulp on floatability of scheelite when a salicyl hydroxamic acid-lead hydroxide coordination complex is used as a collector.

(10) FIG. 10 is influence of a pH value of ore pulp on floatability of scheelite when an octyl hydroxamic acid-lead hydroxide coordination complex is used as a collector.

(11) FIG. 11 is influence of a pH value of ore pulp on floatability of scheelite when an acetohydroxamic acid-lead hydroxide coordination complex is used as a collector.

(12) FIG. 12 is influence of a pH value of ore pulp on floatability of fluorite ore when a benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiments 2-5 is used as a collector.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(13) Embodiments below further illustrate contents of the present invention, and are not intended to limit the scope of the present invention claimed to be protected in claims.

(14) In the embodiments below, used agents and ore raw materials, unless otherwise specified, are all common raw materials directly obtained on the market in the art.

Embodiment 1

(15) 100 mL of 0.1 mol/L benzohydroxamic acid (BHA) ethyl alcohol solution and 8 mL of 0.5 mol/L lead nitrate solution were respectively prepared. Sodium hydroxide was added into the benzohydroxamic acid solution to regulate a pH value to 9. The solution was heated to 60 C. The lead nitrate solution was slowly added into the benzohydroxamic acid solution. A reaction time was 1.5 h. An obtained benzohydroxamic acid-lead coordination complex solution was transferred into a floatation cell with a volume of 100 mL. 30 g of quartz powder with a particle size of 10-37 m was added. Pulp conditioning and stirring were performed for 15 min. Then, inflation floatation was performed. Floatation foam was collected, and filtration was performed. Quartz products in the floatation foam were transferred into the ethyl alcohol solution. Oscillation washing was performed by an ultrasonic washing device so that the benzohydroxamic acid-lead hydroxide coordination complex adsorbed on the quartz surface was desorbed. A benzohydroxamic acid-lead hydroxide coordination complex-ethyl alcohol mixed solution was obtained, and might be used as a floatation collector. According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=1:2.5.

Embodiment 2

(16) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 80 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(17) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=4:1.

Embodiment 3

(18) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 40 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(19) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=2:1.

Embodiment 4

(20) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 20 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(21) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=1:1.

Embodiment 5

(22) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 10 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(23) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=1:2.

Embodiment 6

(24) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 5 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(25) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=1:4.

Embodiment 7

(26) Experiment conditions were identical to those in Embodiment 1. Only proportions of lead nitrate and hydroxamic acid were different: 4 mL of 0.5 mol/L lead nitrate solution and 100 mL of 0.1 mol/L benzohydroxamic acid ethyl alcohol solution.

(27) According to this embodiment, the benzohydroxamic acid-lead hydroxide coordination complex was prepared under a condition of C.sub.Pb/C.sub.BHA=1:5.

Embodiment 8

(28) Experiment conditions were identical to those in Embodiment 7. Only metal salt solution containing different metal ions was used: the lead nitrate solution was replaced by a solution containing Ca.sup.2+, Mn.sup.2+,

(29) Cu.sup.2+, Fe.sup.3+ or Al.sup.3+.

Embodiment 9

(30) Experiment conditions were identical to those in Embodiment 6. Only the benzohydroxamic acid was replaced by salicyl hydroxamic acid.

Embodiment 10

(31) Experiment conditions were identical to those in Embodiment 5. Only the benzohydroxamic acid was replaced by octyl hydroxamic acid.

Embodiment 11

(32) Experiment conditions were identical to those in Embodiment 5. Only the benzohydroxamic acid was replaced by acetohydroxamic acid.

(33) An infrared spectrogram of a benzohydroxamic acid-lead hydroxide coordination complex (Pb-BHA) prepared according to Embodiments 2-5 and benzohydroxamic acid (BHA) is shown in FIG. 2. Absorption peaks of the BHA were 3295 cm.sup.1 and 3060.17 cm.sup.1, and these might be telescopic vibration absorption peaks of OH and NH. A broadband about 2747.24 cm.sup.1 was an intramolecular OHO extension band of the BHA. IR spectrum comparison of the Pb-BHA and the BHA showed that disappearance or decrease of the broadband (intramolecular OHO extension band) in a 2700 cm.sup.1 position and broadband position movement were caused by loss of OH in CONHOH. Meanwhile, a feature peak of OH in a 3295.33 position also disappeared, and some new peaks of 3200 cm.sup.1 to 3600 cm.sup.1 were generated, it might be Fermi resonance of OH induced by the Pb-BHA. CO or CN peaks in a 1665.50 cm.sup.1 position were separated, movement was performed in the complex to a certain degree, and it showed that the ligand performed coordination through O or N. In a region of 550-630 cm-1, two (or more) strong absorption peaks of the Pb-BHA were v (PbO or PbN). A plurality of PbO or PbN bands existed. This was more obvious on a mixed ligand complex. Different PbO or PbN bond lengths were reflected. It could be predicted that most Pb-BHA coordination complexes would exist in a form of CO and PbO to form stable five-membered rings, because the BHA mainly used a sealed (hydrogen bonded) Z structure in a water solution.

(34) An XRD spectrogram of the Pb-BHA prepared according to Embodiments 3, 4, and 5 is shown in FIG. 3. FIG. 3 shows an XRD spectrogram of the Pb-BHA at different Pb/BHA rates. Feature peaks of the BHA and Pb(NO.sub.3).sub.2 were not observed. Additionally, some strong peaks occurred in positions of 5.4578, 11.0964, and 12.2432. It showed that new Pb-BHA types were generated. The peak intensities of the Pb-BHA complex are different from each other relative to the Pb/BHA rates. It was discovered that more than one stable complex was formed in a reaction between the BHA and Pb.sup.2+.

(35) A thermogravimetric analysis (TGA) spectrogram of the Pb-BHA prepared according to Embodiments 5 and 6 is shown in FIG. 4. A molecular structure of the Pb-BHA coordination complex is PbBHA.sub.2.Math.2Pb(OH).sub.2 or Pb.sub.3(OH).sub.4BHA.sub.2. FIG. 4 is thermogravimetric analysis of the Pb-BHA in a temperature rise process of 30 C. to 600 C. It showed that Pb-BHA precipitates went through three stages. In the first stage (30-300 C.), the weight of the Pb-BHA was reduced through evaporation of water (such as free water and crystal water) and decomposition of absorbed BHA molecules. In the second stage (300-450 C.), exothermic decomposition peaks were prominent, and Pb(BHA).sub.2.Math.xPb(OH).sub.2 started to be decomposed into Pb(OH).sub.2. In the third stage (450-600 C.), the Pb(OH).sub.2 was decomposed into PbO. The reaction might be concluded as follows:
first stage: Pb(BHA).sub.2gxPb(OH).sub.2gmBHAgnH.sub.2O+O.sub.2Pb(BHA).sub.2gxPb(OH).sub.2+CO.sub.2+NO+H.sub.2O;
second stage: Pb(BHA).sub.2gxPb(OH).sub.2+H.sub.2O+O.sub.2Pb(OH).sub.2+CO.sub.2+NO.sub.2; and
third stage: Pb(OH).sub.2PbO+H.sub.2O.

(36) According to weight loss at each stage, a structure of the Pb-BHA might be predicated into 2Pb(OH).sub.2.Math.Pb(BHA).sub.2.Math.mBHA.Math.nH.sub.2O. A most stable structure might be 2Pb(OH).sub.2.Math.Pb(BHA).sub.2. BHA molecules might be adsorbed onto the structure through hydrogen bonds.

Embodiment 12

(37) After Shizhuyuan wolframite and scheelite mixed ore in Hunan (containing a small amount of tungstite) was subjected to crushing, ore grinding, magnetic separation deferrization, and desulfurization, a pH regulator was added into desulfurization tailings to regulate the pH value of ore pulp to 9.6. Then, the benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. A terpenic oil foaming agent was added for inflation floatation. A foam product was a tungsten concentrate. An addition amount of the benzohydroxamic acid-lead hydroxide coordination complex relative to the raw ore was 400 g/t, and an addition amount of the foaming agent was 5 g/t. The pH regulator was sodium carbonate. The floatation temperature was 25 C. During concentration operation, water glass and aluminum sulfate were added to be used as inhibitors. A wolframite and scheelite mixed concentrate with the concentrate WO.sub.3 grade of 12.63% was obtained through one roughing and two concentrations. A recovery rate was 82.58% (as shown in Table 1).

(38) Table 1 Whole-Flow-Process Closed-Circuit Test Result of New Tungsten Separation Process of Desulfurization Tailings

(39) TABLE-US-00001 TABLE 1 WO.sub.3 CaF.sub.2 Sn CaCO.sub.3 WO.sub.3 CaF.sub.2 Sn CaCO.sub.3 Product Yield grade grade grade grade recovery recovery recovery recovery name (%) (%) (%) (%) (%) rate (%) rate (%) rate (%) rate (%) Tungsten 2.56 12.63 12.66 1.08 14.58 82.58 1.53 31.05 4.67 concentrate Tailings 97.44 0.07 21.37 0.11 7.82 17.42 98.47 68.95 95.33 Feeding 100.0 0.39 21.15 0.14 7.99 100 100 100 100

Embodiment 13

(40) After Chaishan single scheelite ore in Hunan was subjected to crushing, ore grinding, magnetic separation deferrization, and desulfurization, a pH regulator was added into desulfurization tailings to regulate the pH value of ore pulp to 9.6. Then, the benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. A terpenic oil foaming agent was added for inflation floatation. A foam product was a tungsten concentrate. An addition amount of the collector relative to the raw ore was 300 g/t, and an addition amount of the foaming agent was 5 g/t. The pH regulator was sodium carbonate. The floatation temperature was 25 C. During concentration operation, water glass and aluminum sulfate were added to be used as inhibitors. A scheelite concentrate with the concentrate WO.sub.3 grade of 16.43% was obtained through one roughing and two concentrations. A recovery rate was 92.64% (the floatation process flow process was as shown in FIG. 5).

(41) Table 2 Whole-Flow-Process Closed-Circuit Test Result of New Tungsten Separation Process of Desulfurization Tailings

(42) TABLE-US-00002 TABLE 2 Table 2 Whole-flow-process closed-circuit test result of new tungsten separation process of desulfurization tailings Product name Yield/% WO.sub.3 grade/% WO.sub.3 recovery rate/% Tungsten concentrate 1.51 16.43 92.64 Tailings 98.49 0.02 7.36 Feeding 100.00 0.27 100.00

Embodiment 14

(43) Operation steps were identical to those in Embodiment 13. Floatation effects of the benzohydroxamic acid-lead hydroxide coordination complex prepared according to Embodiment 7 on the scheelite under a condition of different pH values were investigated. The floatation effects are as shown in FIG. 6. It shows that under the alkaline condition, the floatation effect of benzohydroxamic acid-metal hydroxide on the scheelite is better, and the effect is particularly prominent when the pH value is 8-10.

Embodiment 15

(44) Operation steps were identical to those in Embodiment 13. Benzohydroxamic acid-lead hydroxide coordination complexes in Embodiments 2-5 were respectively used. Floatation effects of these coordination complex collectors on the scheelite under a condition of different pH values were investigated. The floatation effects are as shown in FIG. 7. From the figure, it can be seen that the benzohydroxamic acid-lead hydroxide coordination complexes with the pH value of 3-12 had floatation effects on the scheelite, and the floatation effects were better under the alkaline condition, such as a pH of 7-10.

(45) Control experiment group: operation steps were identical to those in Embodiment 13. Benzohydroxamic acid-lead hydroxide coordination complexes in Embodiments 2-5 were respectively used. Floatation effects of these coordination complex collectors on the fluorite ore under a condition of different pH values were investigated. The floatation effects are as shown in FIG. 13.

(46) Through the control experiment group, it can be seen that the selectivity ability of the benzohydroxamic acid-lead hydroxide coordination complexes on the scheelite under the alkaline condition is much higher than that of calcium-containing minerals such as fluorite. Efficient separation of the scheelite from the minerals such as fluorite can be realized.

Embodiment 16

(47) Operation steps were identical to those in Embodiment 13. Various benzohydroxamic acid-metal hydroxide coordination complexes in Embodiments 8 were respectively used. Floatation effects on the scheelite under a condition of different pH values were investigated. The floatation effects are as shown in FIG. 8. From FIG. 8, it can be seen that hydroxamic acid-lead complexes formed by divalent lead ions showed better selectivity and strong collection ability on the floatation collection of the scheelite through being compared with hydroxamic acid-metal hydroxide coordination complexes formed by other metal ions such as Ca.sup.2+, Mn.sup.2+, Cu.sup.2+, Fe.sup.3+, and Al.sup.3+. AsPb.sup.2+ is better than Ca.sup.2+, Ca.sup.2+ is better than Mn.sup.2+, Fe.sup.3+ and Al.sup.3+, and Mn.sup.2+, Fe.sup.3+ and Al.sup.3+ are better than Cu.sup.2+, the metal ions were most preferably Pb.sup.2+.

Embodiment 17

(48) Operation steps were identical to those in Embodiment 13. Various hydroxamic acid-lead hydroxide coordination complexes in Embodiments 9-11 were respectively used. Floatation effects on the scheelite under a condition of different pH values were investigated. The floatation effects are as shown in FIG. 9-11. From the figures, it can be seen that under the same conditions, the floatation effects on the scheelite when the hydroxamic acid-lead hydroxide coordination complexes prepared from benzohydroxamic acid, salicyl hydroxamic acid, and octyl hydroxamic acid were used as collectors were higher than those of acetohydroxamic acid-lead hydroxide coordination complexes.

Embodiment 18

(49) After Wenshan fine particle tin ore in Yunnan was subjected to crushing, ore grinding, magnetic separation deferrization, and desulfurization, a pH regulator was added into desulfurization tailings to regulate the pH value of ore pulp to 8.5. Then, the benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. An octanol foaming agent was added for inflation floatation. A foam product was a tin concentrate. An addition amount of the collector relative to the raw ore was 400 g/t, and an addition amount of the foaming agent was 10 g/t. The pH regulator was sodium carbonate. The floatation temperature was 25 C. During concentration operation, 50 g/t of carboxymethylcellulose was added to be used as an inhibitor. A tin concentrate with the concentrate SnO.sub.2 grade of 40.15% was obtained through one roughing and three concentrations. A recovery rate was 83.89%.

(50) Table 3 Whole-Flow-Process Closed-Circuit Test Result of New Cassiterite Floatation Process of Desulfurization Tailings

(51) TABLE-US-00003 TABLE 3 Table 3 Whole-flow-process closed-circuit test result of new cassiterite floatation process of desulfurization tailings Product Yield/% SnO.sub.2/% SnO.sub.2 recovery rate/% Tin concentrate 0.90 40.15 83.89 Tailings 99.10 0.07 16.11 Feeding 100.00 0.43 100.00

Embodiment 19

(52) Panzhihua fine particle ilmenite in Sichuan was treated by this process method. A pH regulator was added into desulfurization tailings to regulate a pH value of ore pulp to 5.6. Then, the benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. An octanol foaming agent was added for inflation floatation. A foam product was an ilmenite concentrate. An addition amount of the collector relative to the raw ore was 600 g/t, and an addition amount of the foaming agent was 10 g/t. The pH regulator was sulfuric acid. The floatation temperature was 25 C. During concentration operation, 100 g/t of acidified water glass was added to be used as an inhibitor. An ilmenite concentrate with the grade of 49.80% was obtained through one roughing and three concentrations. A recovery rate was 67.93%.

(53) Table 4 Whole-Flow-Process Closed-Circuit Test Result of New Ilmenite Floatation Process of Desulfurization Tailings

(54) TABLE-US-00004 TABLE 4 Table 4 Whole-flow-process closed-circuit test result of new ilmenite floatation process of desulfurization tailings Product Yield/% TiO.sub.2 grade/% TiO.sub.2 recovery rate/% Ilmenite concentrate 28.15 49.80 67.93 Tailings 71.85 9.21 32.07 Feeding 100.00 20.64 100.00

Embodiment 20

(55) Baotou heavy rare earth ore was treated by this process method. A pH value of raw ore was regulated by a pH regulator to 8.0. Then, the benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. An octanol foaming agent was added for inflation floatation. A foam product was a heavy rare earth concentrate. An addition amount of a metal ion coordination complex collector relative to the raw ore was 300 g/t, and an addition amount of the foaming agent was 10 g/t. The pH regulator was sodium carbonate. The floatation temperature was 25 C. During concentration operation, 150 g/t of acidified water glass was added to be used as an inhibitor. A heavy rare earth concentrate with the coarse concentrate grade of 52.24% was obtained through one roughing and four concentrations. A recovery rate was 53.68%.

(56) Table 5 Whole-Flow-Process Closed-Circuit Test Result of New Heavy Rare Earth Floatation Process

(57) TABLE-US-00005 TABLE 5 Table 5 Whole-flow-process closed-circuit test result of new heavy rare earth floatation process Product Yield/% Grade(REO)/% Yield/% Heavy rare earth concentrate 6.57 52.24 53.68 Tailings 93.43 3.17 46.32 Feeding 100.00 6.39 100.00

Embodiment 21

(58) Hubei low-grade rutile ore was treated by this process method. Raw ore was subjected to crushing and ore grinding. Then, a pH regulator was added for regulating a pH value of ore pulp to 5.0. Then, the benzohydroxamic acid-metal hydroxide coordination complex prepared according to Embodiment 1 was added for stirring and pulp conditioning. An octanol foaming agent was added for inflation floatation. A foam product was a rutile concentrate. An addition amount of a collector relative to the raw ore was 400 g/t, and an addition amount of the foaming agent was 10 g/t. The pH regulator was sulfuric acid. The floatation temperature was 25 C. During concentration operation, 100 g/t of acidified water glass was added to be used as an inhibitor. A rutile concentrate with the grade of 63.70% was obtained through one roughing and three concentrations. A recovery rate was 81.09%.

(59) Table 6 Whole-Flow-Process Closed-Circuit Test Result of New Rutile Floatation Process

(60) TABLE-US-00006 TABLE 6 Table 6 Whole-flow-process closed-circuit test result of new rutile floatation process Product Yield/% TiO.sub.2 grade/% TiO.sub.2 recovery rate/% Rutile concentrate 2.94 63.70 81.09 Tailings 97.06 0.45 18.91 Feeding 100.00 2.31 100.00