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CN-121972302-A - Nano lignin-based positive flotation desilication collecting agent and preparation method and application thereof

CN121972302ACN 121972302 ACN121972302 ACN 121972302ACN-121972302-A

Abstract

The application relates to a nano lignin-based positive flotation desilication collector and a preparation method and application thereof, belonging to the technical field of mineral flotation. According to the application, the novel collector with excellent selectivity and high-efficiency collecting capability is successfully prepared by loading the carboxyl/hydroxamic acid functional groups with high selectivity on the surfaces of the nano lignin particles in a chemical grafting manner and assisting a stable and controllable synthesis process. In the low-grade bauxite direct flotation desilication operation, the collecting agent can accurately capture diasporite through selective chemical adsorption of functional groups, effectively float the diasporite through the hydrophobic effect of a nano carrier, and simultaneously reduce the entrainment of siliceous gangue minerals, thereby remarkably improving the aluminum-silicon separation efficiency and effectively solving the problems of poor selectivity and poor adaptability to micro-fine ore in the prior art.

Inventors

  • ZHANG JIANQIANG
  • Du wuxing
  • XU KE
  • ZHANG MENG
  • GUO XIN
  • ZHANG ZHANYUN
  • MA JUNWEI
  • LIU ZHONGYUAN
  • WEI ZHAOBIN
  • ZHANG NAN
  • LI SHASHA
  • YAO JIE

Assignees

  • 中铝郑州有色金属研究院有限公司

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. The preparation method of the nano lignin-based positive flotation desilication collector is characterized by comprising the following steps of: carrying out first mixing on a first part of nano lignin dispersion liquid, a quaternary ammonium salt type surfactant and deionized water to obtain a first mixture; heating the first mixture to 50-80 ℃ under the protection of inert atmosphere, and performing first stirring at a rotating speed of 300-600 rpm to form a pre-dispersion system; Performing secondary mixing on the aqueous solution of the water-soluble free radical initiator and the pre-dispersion system to perform an initiation reaction so as to obtain an activation reaction system; dissolving carboxyl and/or hydroxamic acid functional group medicaments in an alkaline aqueous solution to obtain a saponification functional group solution; Thirdly mixing the second part of nano-sized lignin dispersion liquid with the saponification functional group solution to obtain a functionalized mixed liquid; And (3) dropwise adding the functionalized mixed solution into the activation reaction system within 2-6 hours, and continuously reacting for 12-24 hours after the dropwise adding is finished, so as to realize grafting of carboxylic acid and/or hydroxamic acid functional groups on the surface of the nano lignin, thereby obtaining the nano lignin-based direct flotation desilication collector.
  2. 2. The method of claim 1, wherein the first and second portions of the nano-sized lignin dispersion each satisfy the conditions that the average particle size of the nano-particles is 50nm to 200nm, the mass fraction of lignin contained is 0.05% to 5%, and/or, The mass ratio of the first part of nano lignin dispersion liquid to the second part of nano lignin dispersion liquid is 1 (1-5).
  3. 3. The method of claim 1, wherein the temperature of the initiation reaction is 50 ℃ to 80 ℃ and the time of the initiation reaction is 20 minutes to 80 minutes.
  4. 4. The method according to claim 1, wherein the first mixture comprises, in parts by mass, 20-40 parts of nano lignin dispersion, 0.5-2 parts of quaternary ammonium salt type surfactant and 90-110 parts of deionized water.
  5. 5. The method according to claim 1, wherein the alkaline aqueous solution is prepared from sodium hydroxide or potassium hydroxide, the pH value of the alkaline aqueous solution is 9-12, and the temperature of the alkaline aqueous solution is 50-90 ℃.
  6. 6. The method according to claim 1, wherein the quaternary ammonium salt type surfactant is at least one of dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium bromide, and/or, The water-soluble free radical initiator is one of ammonium persulfate, potassium persulfate and azo diisobutyl amidine hydrochloride, the mass concentration of the water solution of the water-soluble free radical initiator is 5% -20%, and/or, The carboxyl and/or hydroxamic acid functional group medicament is at least one of oleic acid, tall oil, oxidized paraffin soap, salicylic hydroxamic acid, benzoic hydroxamic acid and C5-C9 alkyl hydroxamic acid, and the mass ratio of the carboxyl and/or hydroxamic acid functional group medicament to the total solid content of the nano lignin dispersion is 9-15.
  7. 7. A nano lignin-based positive flotation desilication collector, characterized in that the collector is prepared by the method of any one of claims 1-6.
  8. 8. The collector of claim 7, wherein the collector is a nanoparticle grafted with carboxylic acid and/or hydroxamic acid functional groups on the surface, and the average particle size of the nanoparticle is 50-300 nm.
  9. 9. Use of the nano lignin-based direct flotation desilication collector of claim 7 or 8 in mineral flotation, wherein the nano lignin-based direct flotation desilication collector is used for selective flotation enrichment of diasporite in low grade bauxite direct flotation desilication operations.
  10. 10. The use according to claim 9, wherein the total amount of collector used in the selective flotation process for enriching diaspore is 1000g/t raw ore to 1300 g/t raw ore, and the pH of the flotation pulp is 8.0 to 9.5.

Description

Nano lignin-based positive flotation desilication collecting agent and preparation method and application thereof Technical Field The application relates to the technical field of mineral flotation, in particular to a nano lignin-based positive flotation desilication collector and a preparation method and application thereof. Background Bauxite is a main raw material for alumina production, and along with the increasing exhaustion of high-quality bauxite resources, the efficient utilization of low-grade bauxite is a focus of industry attention. The main core of the method is that the collecting agent is added to selectively float and enrich the aluminum-containing minerals (mainly diasporite) and inhibit the silicon-containing minerals (such as kaolinite, illite and the like) in ore pulp, so that the aluminum-silicon separation is realized and the concentrate quality is improved. Currently, the collectors commonly used for bauxite direct flotation desilication mainly comprise fatty acids and derivatives thereof. The collecting agent has wide sources and relatively low price, and has certain collecting capacity for oxidized ores. However, the fatty acid collector has poor selectivity, and is easy to perform nonspecific adsorption with metal ions on the surface of the siliceous mineral while collecting diasporite, so that the content of silicon in the concentrate is higher, the aluminum-silicon ratio is limited to be improved, and in addition, the collection capacity and selectivity of the fatty acid collector are difficult to meet the process requirements of efficient desilication for low-grade bauxite with high fine particle embedding and dissociation degree requirements. Disclosure of Invention The application provides a nano lignin-based forward flotation desilication collector and a preparation method and application thereof, and aims to solve the technical problem of how to develop a novel desilication collector. In a first aspect, an embodiment of the present application provides a method for preparing a nano lignin-based positive flotation desilication collector, the method comprising: carrying out first mixing on a first part of nano lignin dispersion liquid, a quaternary ammonium salt type surfactant and deionized water to obtain a first mixture; heating the first mixture to 50-80 ℃ under the protection of inert atmosphere, and performing first stirring at a rotating speed of 300-600 rpm to form a pre-dispersion system; Performing secondary mixing on the aqueous solution of the water-soluble free radical initiator and the pre-dispersion system to perform an initiation reaction so as to obtain an activation reaction system; dissolving carboxyl and/or hydroxamic acid functional group medicaments in an alkaline aqueous solution to obtain a saponification functional group solution; Thirdly mixing the second part of nano-sized lignin dispersion liquid with the saponification functional group solution to obtain a functionalized mixed liquid; And (3) dropwise adding the functionalized mixed solution into the activation reaction system within 2-6 hours, and continuously reacting for 12-24 hours after the dropwise adding is finished, so as to realize grafting of carboxylic acid and/or hydroxamic acid functional groups on the surface of the nano lignin, thereby obtaining the nano lignin-based direct flotation desilication collector. Optionally, the first part and the second part of the nano-sized lignin dispersion liquid both meet the condition that the average particle size of the nano particles is 50 nm-200 nm, and the mass fraction of the lignin is 0.05% -5%. Optionally, the mass ratio of the first part of nano lignin dispersion liquid to the second part of nano lignin dispersion liquid is 1 (1-5). Optionally, the temperature of the initiation reaction is 50-80 ℃, and the time of the initiation reaction is 20-80 minutes. Optionally, the first mixture comprises 20-40 parts of nano lignin dispersion liquid, 0.5-2 parts of quaternary ammonium salt type surfactant and 90-110 parts of deionized water in parts by weight. Optionally, the alkaline aqueous solution is prepared from sodium hydroxide or potassium hydroxide, the pH value of the alkaline aqueous solution is 9-12, and the temperature of the alkaline aqueous solution is 50-90 ℃. Optionally, the quaternary ammonium salt type surfactant is at least one of dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide and octadecyl trimethyl ammonium bromide. Optionally, the water-soluble free radical initiator is one of ammonium persulfate, potassium persulfate and azo diisobutylamidine hydrochloride, and the mass concentration of the water solution of the water-soluble free radical initiator is 5% -20%. Optionally, the carboxyl and/or hydroxamic acid functional group medicament is at least one of oleic acid, tall oil, oxidized paraffin soap, salicylic hydroxamic acid, benzoic hydroxamic acid and C5-C9 alkyl