Polyalkylene modified cellulose as well as preparation method and application thereof

Abstract

The invention relates to polyene modified cellulose and a preparation method and application thereof, and the preparation method comprises the following steps: adding cellulose, a halogenated olefin compound, a catalyst, a ligand and an additive into a solvent, mixing, and reacting in a protective atmosphere to obtain the polyene modified cellulose, wherein the structural formula of the halogenated olefin compound is # imgabs0 # X = F, Cl, Br, I or OTf; r, R1 and R2 are respectively at least one of alkyl, aryl, ester group and halogen independently; according to the present invention, cellulose is subjected to polyenylation modification, such that the problem that the inhibition effect of the inhibitor on the carbonaceous or easily-floating gangue in the prior art is poor is solved, the inhibition effect of the polyenylation modified cellulose on the carbonaceous or easily-floating gangue is improved, and the stability and the selectivity of the polyenylation modified cellulose under different pH value conditions are enhanced; therefore, useful minerals in the carbon-containing nonferrous metal ore are better separated, and the ore dressing efficiency and the recovery rate are improved.

Description

Technical Field

[0001] The present invention relates to the fields of organic synthesis and mineral flotation, and more particularly to polyene-modified cellulose and a preparation method and application thereof. Background Art

[0002] In recent years, with the continuous discovery of carbonaceous non-ferrous metal deposits, their beneficiation has become a significant research topic. These deposits are mostly sedimentary or sedimentary metamorphic, with the carbon primarily derived from carbonaceous slate, shale, or other sedimentary rocks. The presence of carbon in the ore creates a high level of floatation, significantly interfering with the flotation separation of sulfide minerals, making beneficiation of these ores difficult. The deeper the carbonization, the higher the carbon content, and the finer the interpenetration of the carbonaceous and useful minerals, the greater the difficulty in beneficiation.

[0003] Conventional mineral processing methods are ineffective for treating carbon-containing nonferrous metal ores. Common carbon removal methods include: (1) pre-decarbonization of sulfide minerals before flotation, such as using frothers and kerosene flotation or other mechanical methods; (2) using highly selective inhibitors to suppress carbon; and (3) selecting a mixed product of sulfide and carbon and then separating it. However, these methods all have certain limitations. For example, pre-decarbonization may lead to the loss of useful minerals, and the effectiveness of existing inhibitors is not ideal.

[0004] In the beneficiation of carbonaceous, lead-zinc-sulfur ores, the presence of carbonaceous and buoyant gangue severely impairs the separation of valuable minerals such as lead, zinc, and sulfur. Therefore, the search for a reagent that can effectively suppress carbonaceous and buoyant gangue while maintaining the flotation of valuable minerals has become a research priority.

[0005] Existing research indicates that carboxymethyl cellulose (CMC) has a significant inhibitory effect on carbonaceous and buoyant gangue in carbonaceous, lead-zinc-sulfur ores. At a certain dosage, CMC can improve the preferential flotation separation of lead, zinc, and sulfur, achieving superior mineral processing performance. However, CMC's inhibitory effect still needs to be improved, and its stability and selectivity under varying pH conditions require further refinement. Summary of the Invention

[0006] In view of this, the present invention proposes a preparation method of polyene-modified cellulose. By polyene-modifying cellulose, the invention aims to solve the problem that inhibitors in the prior art have poor inhibitory effects on carbonaceous materials or easily floating gangue, improve the inhibitory effect of polyene-modified cellulose on carbonaceous materials and easily floating gangue, enhance its stability and selectivity under different pH conditions, thereby better realizing the separation of useful minerals in carbon-containing non-ferrous metal ores, and improving mineral processing efficiency and recovery rate.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A method for preparing polyene-modified cellulose, the reaction equation of which is as follows:

[0009]

[0010] The following steps are involved:

[0011] Cellulose, a halogenated olefin compound, a catalyst, a ligand, and an additive are added to a solvent and mixed, and reacted under an inert gas atmosphere to obtain polyene-modified cellulose; wherein the structural formula of the halogenated olefin compound is: X=F, Cl, Br, I or OTf; R, R 1 、R 2 Each is independently at least one of an alkyl group, an aryl group, an ester group, and a halogen group.

[0012] In some embodiments, the mass ratio of the cellulose to the halogenated hydrocarbon compound is 10:1-10.

[0013] In some embodiments, the ligand comprises at least one of oxazoline, oxazole, pyridine, bipyridine, and phenanthroline.

[0014] In some embodiments, the catalyst includes at least one of copper chloride, copper bromide, copper acetate, copper sulfate, copper trifluoromethanesulfonate, palladium acetate, and palladium dichloride.

[0015] In some embodiments, the additive includes at least one of NaOH, NaBH4, Na2CO3, NaHCO3, KOH, K2CO3, molecular sieves, and (NH4)2HPO4.

[0016] In some embodiments, the cellulose is at least one of microcrystalline cellulose, powdered cellulose, cellulose with a particle size of 90 μm, and cellulose with a particle size of 250 μm.

[0017] In some embodiments, the solvent includes at least one of ethyl acetate, dimethyl sulfoxide, dichloromethane, methanol, ethanol, water, N,N-dimethylformamide, diethyl ether, acetone, and acetonitrile.

[0018] In some embodiments, the reaction temperature is 0-150°C; preferably, 20-80°C.

[0019] In some embodiments, the reaction time is 0-48 h; preferably, 10-36 h.

[0020] In some embodiments, the inert atmosphere is one of argon atmosphere, nitrogen atmosphere, and helium atmosphere.

[0021] The present invention also provides polyene-modified cellulose obtained by the preparation method of any of the above embodiments.

[0022] The present invention also provides the use of the polyolefin-modified cellulose in mineral flotation.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention can significantly improve the inhibition effect on carbonaceous and easily floating gangue by polyene modification of cellulose, and at the same time enhance its stability and selectivity under different pH conditions, which can effectively improve the separation effect of useful minerals in carbon-containing non-ferrous metal ores and improve mineral processing efficiency and recovery rate.

[0025] The preparation method of the present invention uses cellulose and a halogenated olefin compound as raw materials, reacts under the action of a catalyst, a ligand and an additive, and directly and efficiently produces polyene-modified cellulose through a one-step synthesis. The raw materials used are common reagents and the cost is low. In addition, the synthesis process is simple and does not require complex equipment and conditions. Conventional experimental conditions can be used. The reaction conditions are mild and the reaction has a wide range of applicability. DETAILED DESCRIPTION

[0026] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] Example 1

[0029] 100g powdered cellulose, 100g methyl bromocyclopentenecarboxylate (CAS: 320608-71-7), 5mol% Pd2(dba)3-CHCl3 catalyst, 15mol% 2,2'-bipyridine, 1g The mixture was stirred and reacted with 200 mL of tetrahydrofuran in a nitrogen atmosphere at room temperature for 12 hours, and then the stirring was stopped. The solvent was removed by rotary evaporation under reduced pressure, and the product was separated and purified by column chromatography to obtain the target product.

[0030] Example 2

[0031] 100g microcrystalline cellulose, 50g ethyl bromide cyclopentene carboxylate, 10mol% Pd2Cl2 catalyst, 20mol% oxazoline, 1g The mixture was stirred and reacted with 200 mL of tetrahydrofuran in a nitrogen atmosphere at room temperature for 12 hours, and then the stirring was stopped. The solvent was removed by rotary evaporation under reduced pressure, and the product was separated and purified by column chromatography to obtain the target product.

[0032] Example 3

[0033] 100 g of microcrystalline cellulose, 50 g of methyl chlorocyclopentenecarboxylate (CAS: 66839-38-1), 5 mol% CuCl2 catalyst, 10 mol% pyridine, 1 g of NaBH4, and 200 mL of N,N-dimethylformamide were added to a reaction tube in sequence. After stirring at 80°C under a nitrogen atmosphere for 12 hours, stirring was stopped, the solvent was removed by rotary evaporation under reduced pressure, and then the target product was separated and purified by column chromatography to obtain the target product.

[0034] Example 4

[0035] 100g 250μm particle size cellulose, 100g chlorocyclopentene carboxylic acid methyl ester, 5mol% Pd2(dba)3-CHCl3 catalyst, 15mol% 2,2'-bipyridine, 1g The mixture was stirred at room temperature for 12 hours under a nitrogen atmosphere, and the solvent was removed by rotary evaporation under reduced pressure. The product was then separated and purified by column chromatography to obtain the target product.

[0036] Example 5

[0037] 100g microcrystalline cellulose, 100g iodocyclopentenecarboxylic acid methyl ester (CAS: 149512-06-1), 5mol% Pd2(dba)3-CHCl3 catalyst, 10mol% oxazoline, 1g The mixture was stirred at room temperature for 12 hours under a nitrogen atmosphere, and the solvent was removed by rotary evaporation under reduced pressure. The product was then separated and purified by column chromatography to obtain the target product.

[0038] Example 6

[0039] An example of the application of the reagent prepared in Example 2 of the present invention in a flotation method for recovering low-grade lead and antimony includes the following steps:

[0040] 1. Mineral raw materials:

[0041] The raw mineral used is low-grade lead-antimony ore, with a lead content of 0.93% and an antimony content of 1.57%. Phase analysis shows that the lead-antimony minerals are primarily galena, stybite, and stibnite, with minor amounts of antimony sulphite and cerussite. The ore has a lead oxidation rate of 3.84%, an antimony oxidation rate of 2.57%, and a carbon content of 4.28%.

[0042] 2. Flotation reagents and operating conditions:

[0043]

[0044] During flotation, the ore is ground until the mineral monomers are fully dissociated. Sodium hexametaphosphate is then added as a mineral dispersant to improve the dispersion of the minerals. The reagent prepared in Example 2 of the present invention is then added as a carbonaceous gangue inhibitor. Lead nitrate is added as a lead-antimony mineral activator, and aniline and butylamine black powders are used as lead-antimony mineral collectors. The entire process includes a primary roughing process, three scavenging processes, and a secondary cleaning process, ultimately yielding a high-quality lead-antimony mixed concentrate.

[0045] Experimental verification demonstrates that the agent produced by the process of the present invention can improve the grade and recovery efficiency of lead-antimony ore as an inhibitor. In a given ore, the lead content was 0.93% and the antimony content was 1.57%. Through a single roughing process, three scavenging processes, and two fine cleaning processes, a mixed lead-antimony concentrate with a lead grade of 18.48%, an antimony grade of 34.05%, and a carbon content of 0.48% was obtained. The lead and antimony recoveries reached 83.41% and 91.05%, respectively.

[0046] Comparative Example 1

[0047] 1. Mineral raw materials:

[0048] The raw mineral used was low-grade lead-antimony ore from the same batch as that used in Example 6. The ore contained 0.93% lead and 1.57% antimony. Phase analysis showed that the lead-antimony minerals were primarily galena, stybite, and stibnite, with minor amounts of cerussite and galena. The ore had a lead oxidation rate of 3.84%, an antimony oxidation rate of 2.57%, and a carbon content of 4.28%.

[0049] 2. Flotation reagents and operating conditions:

[0050]

[0051] During flotation, after the ore is ground until the mineral monomers are fully dissociated, sodium hexametaphosphate is added as a mineral dispersant to improve its dispersion. CMC is then added as a carbonaceous gangue inhibitor, lead nitrate as an activator for lead-antimony minerals, and aniline and butylamine black medicines as collectors. The entire process includes a primary roughing, three scavenging, and secondary cleaning, ultimately yielding a high-quality lead-antimony mixed concentrate.

[0052] Experimental verification showed that, given ore containing 0.93% lead and 1.57% antimony, a mixed lead-antimony concentrate with a lead grade of 15.20%, an antimony grade of 30.52%, and a carbon content of 0.89% was obtained through a single roughing, three scavenging, and two concentrating stages. The recoveries for lead and antimony were only 80.10% and 85.62%, respectively.

[0053] Example 7

[0054] Another application example of the reagent prepared in Example 4 of the present invention in a flotation method for recovering low-grade lead and antimony comprises the following steps:

[0055] 1. Mineral raw materials:

[0056] The raw mineral used is low-grade lead-antimony tailings, with a lead content of 0.38% and an antimony content of 0.27%. Phase analysis shows that the lead-antimony minerals are primarily pyroxenite, with minor amounts of galena, stibnite, antimony chalcanthite, and cerussite. The ore has a lead oxidation rate of 17.24%, an antimony oxidation rate of 12.60%, and a carbon content of 2.85%.

[0057] 2. Flotation reagents and operating conditions:

[0058]

[0059]

[0060] During flotation, the ore is ground until the mineral monomers are fully dissociated. Sodium hexametaphosphate is then added as a mineral dispersant to improve the dispersion of the minerals. The reagent prepared in Example 4 of the present invention is then added as a carbonaceous gangue inhibitor. Lead nitrate is added as a lead-antimony mineral activator, and aniline and butylamine black powders are used as lead-antimony mineral collectors. The entire process includes a primary roughing process, three scavenging processes, and a secondary cleaning process, ultimately yielding a high-quality lead-antimony mixed concentrate.

[0061] Experimental verification demonstrates that the reagent produced by the process of this invention can improve the grade and recovery efficiency of lead-antimony ore. A given ore contained 0.38% lead and 0.27% antimony. Through a single roughing process, three scavenging processes, and two fine cleaning processes, a mixed lead-antimony concentrate with a lead grade of 18.47%, an antimony grade of 12.59%, and a carbon content of 0.36% was obtained. The lead and antimony recoveries reached 69.73% and 66.91%, respectively.

[0062] Comparative Example 2

[0063] 1. Mineral raw materials:

[0064] The raw mineral used was low-grade lead-antimony tailings from the same batch as in Example 7. The ore contained 0.38% lead and 0.27% antimony. Phase analysis revealed that the lead-antimony minerals were primarily stybausite, with minor amounts of galena, stibnite, antimony chalcanthite, and cerussite. The ore had a lead oxidation rate of 17.24%, an antimony oxidation rate of 12.60%, and a carbon content of 2.85%.

[0065] 2. Flotation reagents and operating conditions:

[0066]

[0067]

[0068] During flotation, after the ore is ground until the mineral monomers are fully dissociated, sodium hexametaphosphate is added as a mineral dispersant to improve its dispersion. CMC is then added as a carbonaceous gangue inhibitor, lead nitrate as an activator for lead-antimony minerals, and aniline and butylamine black medicines as collectors. The entire process includes a primary roughing, three scavenging, and secondary cleaning, ultimately yielding a high-quality lead-antimony mixed concentrate.

[0069] Experimental verification revealed that the lead content of the ore was 0.38% and the antimony content was 0.27%. Through a single roughing process, three scavenging processes, and two concentrating processes, a mixed lead-antimony concentrate with a lead grade of 15.33%, an antimony grade of 10.87%, and a carbon content of 0.66% was obtained. The lead and antimony recoveries were only 65.22% and 61.54%, respectively.

[0070] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing polyene-modified cellulose, characterized in that: The following steps are involved: Cellulose, halogenated olefin compound, catalyst, ligand and additive are added to a solvent and mixed, and reacted under an inert atmosphere to obtain polyene-modified cellulose; wherein the halogenated olefin compound has the structural formula: X=F, Cl, Br, I or OTf; R, R 1 , R 2 Each is independently at least one of an alkyl group, an aryl group, an ester group, and a halogen group.

2. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The mass ratio of the cellulose to the halogenated hydrocarbon compound is 10:1-10.

3. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The ligand includes at least one of oxazoline, oxazole, pyridine, bipyridine and phenanthroline.

4. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The catalyst includes at least one of copper chloride, copper bromide, copper acetate, copper sulfate, copper trifluoromethanesulfonate, palladium acetate and palladium dichloride.

5. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The additive includes at least one of NaOH, NaBH4, Na2CO3, NaHCO3, KOH, K2CO3, molecular sieves, and (NH4)2HPO4.

6. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The solvent includes at least one of ethyl acetate, dimethyl sulfoxide, dichloromethane, methanol, ethanol, water, N,N-dimethylformamide, ether, acetone, and acetonitrile.

7. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The reaction temperature is 0-150°C.

8. The method for preparing polyolefin-modified cellulose according to claim 1, characterized in that: The inert atmosphere is one of argon atmosphere, nitrogen atmosphere and helium atmosphere.

9. The polyene-modified cellulose obtained by the method for preparing the polyene-modified cellulose according to any one of claims 1 to 8.

10. Use of the polyene-modified cellulose according to claim 9 in mineral flotation.

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