Beneficiation method for ilmenite and associated minerals

Abstract

The invention relates to a beneficiation method for ilmenite and associated minerals, and belongs to the technical field of ilmenite beneficiation. The method comprises the following steps: S1, carrying out pre-flotation on associated sulfides, and carrying out flotation on the sulfides under a weakly alkaline condition by taking sulfolane as a sulfide collecting agent; s2, oxidizing and activating the surface of the ilmenite; s3, ilmenite roughing; and S4, ilmenite concentration. According to the method, efficient and green separation of ilmenite, associated sulfide and titanaugite is achieved through the process combination of sulfide pre-floating of the sulfolane sulfur-free collecting agent, sodium hypochlorite-sodium persulfate synergistic oxidation activation and N-phenylthiobenzamide-sodium oleate combined collecting, and the method has industrial application and popularization prospects. The problems that in the prior art, sulfide flotation is conducted through xanthate collecting agents, sulfide removal is not thorough, and residual sulfide interferes with ilmenite flotation are solved.

Description

TECHNICAL FIELD

[0001] The application relates to a beneficiation method for ilmenite and associated minerals and belongs to the technical field of ilmenite beneficiation. BACKGROUND

[0002] The ilmenite is often associated with sulfide minerals such as pyrite, pyrrhotite and chalcopyrite and titanic augite. The traditional process usually first uses xanthate collectors to float sulfides, and then uses hydroxamic acid or sodium oleate to float ilmenite, and has the following defects: 1. The sulfide removal is not complete, and residual sulfide interferes with the ilmenite flotation; 2. The surface of the ilmenite is low in activity, and the consumption of the collector is large; 3. The selectivity of ilmenite-titanic augite separation is poor; 4. The xanthate collector has heavy environmental load.

[0003] Therefore, it is of important industrial value to develop a new process of using a xanthate-free collector to collect sulfides, strengthening the surface oxidation activation of ilmenite and improving the selectivity of the collector. SUMMARY

[0004] The technical problem to be solved by the application is that the use of xanthate collectors to float sulfides in the prior art causes incomplete removal of sulfides and residual sulfides to interfere with the ilmenite flotation.

[0005] The technical scheme adopted by the application to solve the technical problem is a beneficiation method for ilmenite and associated minerals, comprising the following steps: S1. Pre-flotation of associated sulfides, using sulfolane as a sulfide collector to float sulfides under weak alkaline conditions; S2. Surface oxidation activation of ilmenite; S3. Ilmenite roughing; S4. Ilmenite cleaning.

[0006] In the above method, the pH value of the slurry in the step S1 is 7-9.

[0007] Further, in the above method, in the step S1, the raw ore is ground to 60-80 wt% of 0.074 mm, water is added to adjust the slurry to a concentration of 20-35 wt%, sulfolane is used as a sulfide collector at 25-45 DEG C, the dosage is 200-600 g / t, a foaming agent is added at 10-30 g / t, and the flotation is carried out for 3-6 min to obtain a sulfide rough concentrate and a desulfurization tailing.

[0008] The step S2 in the above method is that the desulfurization tailings obtained in the step S1 is concentrated to a slurry concentration of 30-50 wt%, and an oxidizing agent is added under the conditions of 20-40 DEG C and pH 8-10, with a total dosage of 200-800 g / t, and stirring and oxidizing for 5-15 min.

[0009] Further, the oxidizing agent in the step S2 in the above method is an oxidizing agent composition compounded from sodium hypochlorite and sodium persulfate at a mass ratio of 1:0.2-0.5.

[0010] The step S3 in the above method is that the slurry after the oxidation in the step S2 is sequentially added with sulfolane 50-300 g / t, N-phenyl thiobenzamide 50-150 g / t and sodium oleate 100-300 g / t, and rough flotation is carried out under the conditions of 25-40 DEG C and pH 8-10 for 4-8 min.

[0011] Further, the step S4 in the above method is that the rough flotation titanium concentrate obtained in the step S3 is again added with N-phenyl thiobenzamide 20-50 g / t and sodium oleate 50-100 g / t, and clean flotation is carried out under the conditions of 25-40 DEG C and pH 8-10 for 3-6 min.

[0012] Further, the sulfolane in the above method has a purity of 99% or more, and a moisture content of 0.1% or less, the N-phenyl thiobenzamide has a purity of 95% or more, and the sodium oleate has a purity of 80% or more.

[0013] Further, the sodium hypochlorite in the step S3 in the above method has an effective chlorine content of 10% or more, and the sodium persulfate has a purity of 98% or more.

[0014] The flotation equipment for the steps S1-S4 in the above method is a mechanical stirring type flotation machine or an aerated flotation column.

[0015] The beneficial effects of the present application are that, by the process combination of the sulfolane sulfur-free collector for pre-floating sulfides, the sodium hypochlorite-sodium persulfate synergistic oxidation activation, and the N-phenyl thiobenzamide-sodium oleate combined collection, the efficient and green separation of ilmenite and associated sulfides and titanic augite is realized, and meanwhile, the present method is free of xanthate and cyanide in the whole process, is environmentally friendly, and has the prospect of industrial popularization and application. DETAILED DESCRIPTION

[0016] The present application is further described below in combination with examples.

[0017] A beneficiation method for ilmenite and associated minerals according to the present application comprises the following steps: S1, pre-flotation of associated sulfides, with sulfolane as a sulfide collector to float sulfides under weak alkaline conditions; S2, surface oxidation and activation of ilmenite; S3, ilmenite roughing; S4, ilmenite cleaning. It is understood by those skilled in the art that the process combination of sulfide pre-flotation by sulfolane non-sulfur collector, sodium hypochlorite-sodium persulfate synergistic oxidation activation, and N-phenyl thiobenzamide-sodium oleate combined collection realizes efficient and green separation of ilmenite and associated sulfides and titanic augite. The sulfone group of sulfolane in step S1 coordinates with the metal ions on the surface of sulfide minerals to form a hydrophobic film, realizing non-sulfur collector flotation. Sulfolane acts as a polar aprotic solvent and a sulfide collector, preferentially floating sulfides under weak alkaline conditions, and improving the removal rate of sulfides. Step S2 mainly realizes the transformation of sulfides in the ore slurry by oxidizing agents. → Steps S3 and S4 further remove impurities and improve recovery.

[0018] Preferably, in the above method, the pH of the ore slurry in step S1 is 7-9. It is understood by those skilled in the art that since sulfolane preferentially floats sulfides under weak alkaline conditions, the pH of the ore slurry in the method is preferably 7-9.

[0019] Preferably, in the above method, the ore in step S1 is ground to -0.074 mm accounting for 60-80 wt%, water is added to adjust the slurry concentration to 20-35 wt%, and sulfolane is used as a sulfide collector at a dosage of 200-600 g / t, and a foaming agent is added at a dosage of 10-30 g / t at 25-45 ℃, and the sulfide rough concentrate and desulfurization tailings are obtained after 3-6 min of flotation. It is understood by those skilled in the art that the specific content of step S1 is further limited and the order of addition is as follows: first, the ore is ground to -0.074 mm accounting for 60-80 wt%; then, the slurry is adjusted: slurry concentration 20-35 wt%, temperature 25-45 ℃, pH 7-9; addition of reagents: sulfolane (collector) 200-600 g / t, foaming agent 10-30 g / t; finally, flotation: mechanical stirring or flotation column, 3-6 min, to obtain the sulfide rough concentrate and desulfurization tailings.

[0020] Preferably, in the above method, the desulfurization tailings obtained in step S1 are concentrated to a slurry concentration of 30-50 wt% in step S2, and an oxidizing agent is added at a total dosage of 200-800 g / t at 20-40 ℃ and pH 8-10, and the slurry is stirred and oxidized for 5-15 min. It is understood by those skilled in the art that the desulfurization tailings obtained in step S1 are concentrated to 30-50 wt% in step S2; the conditions are: temperature 20-40 ℃, pH 8-10; the oxidizing agent can be preferably a mixture of sodium hypochlorite and sodium persulfate in a mass ratio of 1:0.2-0.5, with a total amount of 200-800 g / t; the oxidation time is 5-15 min, so that the → .

[0021] Preferably, the oxidant in step S2 of the above method is an oxidant composition prepared by compounding sodium hypochlorite and sodium persulfate at a mass ratio of 1:0.2-0.5. Those skilled in the art will understand that this method employs a synergistic oxidation of sodium hypochlorite and sodium persulfate: sodium hypochlorite rapidly oxidizes the surface layer. Sodium persulfate provides a continuous oxidation potential, preventing... Reduction; further specified that sodium hypochlorite and sodium persulfate are in a mass ratio of 1:0.2 to 0.5.

[0022] Preferably, in step S3 of the above method, 50-300 g / t of sulfolane, 50-150 g / t of N-phenylthiobenzamide, and 100-300 g / t of sodium oleate are sequentially added to the slurry obtained after oxidation in step S2, and roughing flotation is performed for 4-8 min at 25-40 °C and pH 8-10. Those skilled in the art will understand that the benzene ring-thioamide structure of N-phenylthiobenzamide can be related to... It forms stable pentacyclic or hexacyclic chelates with better selectivity than traditional fatty acids; using N-phenylthiobenzamide as the main collector and sodium oleate as the auxiliary collector, it achieves efficient separation of gangue minerals such as ilmenite and titanopyroxene. Sulfolane acts as a polar aprotic solvent in step C, reducing the strength of the hydration film and promoting collector diffusion, but it does not directly collect sulfides. The order of reagent addition is as follows: 1. Sulfolane 50-300 g / t (to further adjust the polarity of the slurry, not for collecting), adjust the slurry for 1-3 min; 2. N-Phenylethiobenzamide (main collector) 50-150 g / t, slurry preparation 2-5 min; 3. Sodium oleate (auxiliary collector) 100-300 g / t, stir for 2-4 min; Re-flotation: 25-40 ℃, pH 8-10, 4-8 min, to obtain roughed titanium concentrate and roughed tailings.

[0023] Preferably, in step S4 of the above method, the rough titanium concentrate obtained in step S3 is subjected to further flotation at 25–40 °C and pH 8–10, with the addition of 20–50 g / t of N-phenylthiobenzamide and 50–100 g / t of sodium oleate, for 3–6 min. Those skilled in the art will understand that further defining the processing object and operating steps of step S4 involves: pulp: the rough titanium concentrate obtained in step S3; reagents: 20–50 g / t of N-phenylthiobenzamide and 50–100 g / t of sodium oleate; flotation: 25–40 °C, pH 8–10, 3–6 min, to obtain the final titanium concentrate; and if necessary, the flotation can be repeated 1–2 times to ensure… Grade ≥48%, recovery rate ≥85%.

[0024] Preferably, in the above method, the purity of sulfolane is ≥99%, the moisture content is ≤0.1%, the purity of N-phenylthiobenzamide is ≥95%, and the purity of sodium oleate is ≥80%. Those skilled in the art will understand that further limiting the reagent parameters to improve the effectiveness of the method specifically preferably results in a purity of sulfolane ≥99%, a moisture content ≤0.1%, a purity of N-phenylthiobenzamide ≥95%, and a purity of sodium oleate ≥80%.

[0025] Preferably, in step S3 of the above method, the available chlorine content of sodium hypochlorite is ≥10%, and the purity of sodium persulfate is ≥98%. Those skilled in the art will understand that the sodium hypochlorite-sodium persulfate composite oxidant will oxidize the surface of ilmenite. Oxidized to To improve the stability of the collector complexed with ilmenite; to ensure the oxidation effect, this method preferably uses sodium hypochlorite with available chlorine ≥10% and sodium persulfate with purity ≥98%.

[0026] Preferably, the flotation equipment in steps S1 to S4 of the above method is a mechanically stirred flotation machine or an aerated flotation column. Those skilled in the art will understand that this method only specifies the preferred structure of the flotation equipment, and the aforementioned mechanically stirred flotation machine or aerated flotation column are existing technologies. Simultaneously, the froth products obtained from the secondary flotation are concentrated, filtered, and dried to obtain sulfide concentrate and titanium concentrate, respectively.

[0027] Example 1 Raw ilmenite: 8.6%, pyrite 4.2%.

[0028] Grinding: 70% of particles are 0.074 mm, pulp concentration is 30 wt%, pH is 8.5; Step S1: Sulfolane 400 g / t, frother MIBC 20 g / t, flotation for 4 min; Step S2: Sodium hypochlorite-sodium persulfate (1:0.3) 500 g / t, oxidation for 10 min; Step S3: 150 g / t sulfolane, 100 g / t N-phenylthiobenzamide, 200 g / t sodium oleate, rough selection for 6 min; Step S4: N-phenylthiobenzamide 30 g / t, sodium oleate 60 g / t, finely selected for 5 min.

[0029] Results: Titanium concentrate 49.1%, recovery rate 86.4%; sulfide removal rate 95.7%.

[0030] Example 2 Raw ore: 12.5%, pyrrhotite 3.8%.

[0031] Step S1: grinding - 0.074 mm accounts for 75%, the rest of the reagent dosage is increased by 20% in the same proportion as example 1, and the rest of the parameters and subsequent steps are the same as example 1.

[0032] Result: titanium concentrate 51.8%, recovery rate 89.2%; sulfide removal rate 97.6%.

Claims

1. A method of beneficiation of ilmenite and associated minerals, characterised in that The method comprises the following steps: S1, pre-flotation of associated sulfide, using sulfolane as sulfide collector, and floating sulfide under weak alkaline conditions; S2, surface oxidation activation of ilmenite; S3, rough flotation of ilmenite; S4, clean flotation of ilmenite.

2. A method of beneficiation of ilmenite and associated minerals according to claim 1, characterised in that: The pH value of the slurry in the step S1 is 7-9.

3. A method of beneficiation of ilmenite and associated minerals according to claim 2, characterised in that: In the step S1, the raw ore is ground to 60-80 wt% of 0.074 mm, water is added to adjust the slurry concentration to 20-35 wt%, and the sulfide rough concentrate and desulfurization tailings are obtained by flotation at 25-45 DEG C using sulfolane as the sulfide collector in an amount of 200-600 g / t, and adding a frother in an amount of 10-30 g / t, and floating for 3-6 min.

4. A method of beneficiation of ilmenite and associated minerals according to claim 1, characterised in that: In the step S2, the desulfurization tailings obtained in the step S1 are concentrated to a slurry concentration of 30-50 wt%, and an oxidizing agent is added in a total amount of 200-800 g / t under the conditions of 20-40 DEG C and pH 8-10, and stirring oxidation is performed for 5-15 min.

5. A method of beneficiation of ilmenite and associated minerals according to claim 4, characterised in that: The oxidizing agent in the step S2 is an oxidizing agent composition compounded from sodium hypochlorite and sodium persulfate in a mass ratio of 1:0.2-0.

5.

6. A method of beneficiation of ilmenite and associated minerals according to claim 1, characterised in that: In the step S3, sulfolane 50-300 g / t, N-phenylthiobenzamide 50-150 g / t and sodium oleate 100-300 g / t are sequentially added to the slurry after the oxidation in the step S2, and rough flotation is performed at 25-40 DEG C and pH 8-10 for 4-8 min.

7. A method of beneficiation of ilmenite and associated minerals according to claim 6, characterised in that: In the step S4, N-phenylthiobenzamide 20-50 g / t and sodium oleate 50-100 g / t are added again to the rough ilmenite concentrate obtained in the step S3 at 25-40 DEG C and pH 8-10, and clean flotation is performed for 3-6 min.

8. A method of beneficiation of ilmenite and associated minerals according to claim 7, characterised in that: The purity of the sulfolane is ≥99%, the moisture content is ≤0.1%, the purity of the N-phenylthiobenzamide is ≥95%, and the purity of the sodium oleate is ≥80%.

9. A method of beneficiation of ilmenite and associated minerals according to claim 5, characterised in that: In the step S3, the effective chlorine content of the sodium hypochlorite is ≥10%, and the purity of the sodium persulfate is ≥98%.

10. A method of beneficiation of ilmenite and associated minerals according to claim 1, characterised in that: The flotation equipment in the steps S1-S4 is a mechanical stirring type flotation machine or an aerated flotation column.