Application of quaternary ammonium cation modified cellulose as talc inhibitor

Abstract

The invention discloses application of quaternary ammonium cation modified cellulose as a talc inhibitor, and belongs to the technical field of mineral separation. The quaternary ammonium cation modified cellulose has the following molecular structural formula: # imgabs0 #, R1, R2 and R3 are independently selected from hydrogen or quaternary ammonium salt groups, and at least one of R1, R2 and R3 is a quaternary ammonium salt group; and m / (m + n) is equal to 0.18-0.90. The talc flotation inhibitor has a good selective inhibition effect on talc flotation, and is particularly suitable for efficient flotation separation of metal sulfide ores (such as molybdenite, galena and sphalerite) and talc.

Description

Technical Field

[0001] The present invention relates to a new application of quaternary ammonium cation modified cellulose, in particular to an application of the quaternary ammonium cation modified cellulose as a talc inhibitor, belonging to the technical field of mineral processing. Background Art

[0002] Flotation is an important means of enriching low-grade ores. Flotation depressants used in the flotation process selectively regulate the hydrophilic and hydrophobic properties of minerals, making them a key component in separating useful minerals from gangue. Currently, the main depressants used for talc are water glass and organic polymer polysaccharides, but these also tend to have a certain inhibitory effect on sulfide ores. Therefore, developing highly selective depressants has become a challenge in this field.

[0003] At present, talc inhibitors are mostly polysaccharide inhibitors, such as cellulose inhibitors, gum inhibitors, etc. Studying the effect of polysaccharide inhibitors on talc is a hot topic in the research of talc inhibitors. Cellulose is an ideal source of talc inhibitors, with the characteristics of low price and wide source. Its inhibitory effect on talc is greatly affected by the flotation environment such as the acidity and alkalinity of the pulp and the concentration of metal ions. The literature ("The mechanism of action of carboxymethyl cellulose on the inhibition of talc flotation", Zhang Suojun, Journal of Luoyang Normal University, 2014, 33(05):62-64) believes that the carboxyl group in CMC can react with the Mg on the surface of talc. 2+ Forming chemical bonds At the same time, the hydroxyl groups can interact with the talc base surface through hydrogen bonds, the hydrophobicity of talc decreases, and the recovery rate decreases; the literature ("Effect of aluminum ions on the adsorption of carboxymethyl cellulose onto talc", Changbin Li, et al., Minerals Engineering, Volume 170, 2021, 107018) believes that the interaction between aluminum ions and talc changes the surface of talc, forming aluminum hydroxide on the surface of talc, thereby promoting the adsorption of CMC on talc. In summary, the existing carboxymethyl cellulose used for talc inhibition is an anionic inhibitor. So far, there has been no application of quaternary ammonium cation-modified cellulose for talc inhibition. Summary of the Invention

[0004] In response to the technical problems existing in the prior art, the purpose of the present invention is to provide an application of quaternary ammonium cation-modified cellulose, which can be used as a talc inhibitor. It can be used for the flotation separation of most metal sulfide minerals and talc, and is particularly suitable for the separation of talc and molybdenite. It has the characteristics of low inhibitor concentration, wide adaptability to pH range, and good inhibitory effect.

[0005] In order to achieve the above technical objectives, the present invention provides a quaternary ammonium cation-modified cellulose for use as a talc inhibitor, wherein the quaternary ammonium cation-modified cellulose has the following molecular structure:

[0006]

[0007] in,

[0008] R1, R2 and R3 are independently selected from hydrogen or a quaternary ammonium salt group, and at least one of R1, R2 and R3 is a quaternary ammonium salt group;

[0009] The structural formula of the quaternary ammonium salt group is as follows:

[0010]

[0011] R is a bonding group;

[0012] R4, R5 and R6 are independently selected from C1 to C4 alkyl groups;

[0013] m / (m+n)=0.18~0.90.

[0014] The quaternary ammonium cation-modified cellulose of the present invention has good compatibility with talc having a hydrophobic surface and is easily hydrophobicly attracted, thereby being adsorbed on the surface of the talc. At the same time, it can also interact with the negatively charged surface of the talc through its cationic properties, thereby greatly improving the selective inhibition of the quaternary ammonium cation-modified cellulose on the talc.

[0015] In the molecular structure of the quaternary ammonium cation-modified cellulose of the present invention, m / (m+n)=0.18-0.9, and the higher the ratio of m, the more the content of the quaternary ammonium salt group, thereby affecting its inhibitory effect on talc.

[0016] As a preferred solution, the bonding group is C1 to C 10 The hydrocarbon chain or C2~C 10 of carbon, hydrogen and oxygen chains.

[0017] In the molecular structure of the quaternary ammonium cation modified cellulose of the present invention, R is a bonding group, that is, a bonding group to which the quaternary ammonium salt group is grafted onto the cellulose main chain, which can be C1 to C 10 The hydrocarbon chain or C2~C 10 C1~C 10 The hydrocarbon chain of C2~C 10The carbon-hydrogen-oxygen chain may contain an ether-oxygen bond, a hydroxyl substituent, an ester group, or the like. Specific examples include -CH2-CH(OH)-CH2-, -CH(OH)-CH2-, -(CH2)3-CH=CH-CH2-, -CH2-CH(CH3)C(=O)-O-CH2-CH2-, and the like. The bonding group primarily serves as a bonding agent and has relatively little effect on the activity of the quaternary ammonium salt active group.

[0018] As a preferred solution, the quaternary ammonium cation-modified cellulose is used as a talc inhibitor for flotation separation of metal sulfide ore and talc.

[0019] The quaternary ammonium cation-modified cellulose of the present invention has good compatibility with talc having a hydrophobic surface and is easily hydrophobicly attracted to be adsorbed on the surface of the talc. At the same time, the quaternary ammonium cation-modified cellulose can also interact with the negatively charged surface of the talc through its cationic properties, thereby avoiding the effect of flotation agents on the talc. The surface effect of the quaternary ammonium cation-modified cellulose on the metal sulfide ore is relatively weak, thereby greatly improving the selective inhibition of the quaternary ammonium cation-modified cellulose on the talc, which is conducive to the separation of the metal sulfide ore and the talc.

[0020] As a preferred solution, the metal sulfide ore includes at least one of molybdenite, galena, and sphalerite.

[0021] As a preferred solution, the flotation separation process is: after grinding and slurrying the metal sulfide ore, flotation reagents including quaternary ammonium cation modified cellulose, metal sulfide ore collector and frother are added to perform aeration flotation.

[0022] As a preferred solution, the slurry adjustment is to adjust the pH value of the slurry to 4.0-10.0.

[0023] As a preferred solution, the concentration of the quaternary ammonium cation-modified cellulose in the pulp is 100-500 mg / L.

[0024] As a preferred solution, the concentration of the metal sulfide ore collector in the ore slurry is 5 to 150 mg / L.

[0025] The preparation method of the quaternary ammonium cation modified cellulose of the present invention comprises the following steps:

[0026] 1) reacting cellulose and sodium hydroxide in an alcohol-water mixed solution at a temperature of 25-60° C. for 10-30 minutes to obtain alkalized cellulose; the concentration of the sodium hydroxide in the alcohol-water mixed solution is 0.1-1 mol / L;

[0027] The molar ratio of the cellulose to the sodium hydroxide is 1:(1.0-10.0), wherein the cellulose is measured based on the molar amount of the sugar units it contains; the structural formula of the sugar unit is as follows:

[0028]

[0029] 2) the alkalized cellulose is subjected to an etherification reaction with a halogenated organic quaternary ammonium salt, an alkenyl-containing organic quaternary ammonium salt, or an epoxy-containing organic quaternary ammonium salt to obtain the cellulose; the molar ratio of the cellulose to the halogenated organic quaternary ammonium salt is 1:(1.0-4.0), wherein the cellulose is measured based on the molar amount of the sugar units contained therein; and the etherification reaction is carried out at a temperature of 70-90° C. and for 1-1.5 hours.

[0030] The halogenated organic quaternary ammonium salts disclosed herein have the following molecular structure:

[0031]

[0032] Wherein, X is a halogen substituent, R is a bonding group, and R4, R5, and R6 are independently selected from C1-C4 alkyl groups; X is specifically a chlorine substituent or a bromine substituent. A specific example of a halogenated organic quaternary ammonium salt is 3-chloro-2-hydroxypropyltrimethylammonium chloride. The halogenated organic quaternary ammonium salt and the alkalized cellulose primarily form an ether bond through a substitution reaction.

[0033] The alkenyl-containing organic quaternary ammonium salt of the present invention has the following molecular structure:

[0034] Wherein, R8 is methyl or hydrogen; R7 can be a C1-C8 hydrocarbon chain or a C1-C8 hydrocarbon oxygen chain; and R4, R5, and R6 are independently selected from C1-C4 alkyl groups. Specific examples of alkenyl-containing organic quaternary ammonium salts include dimethyldiallylammonium chloride and methacryloyloxyethyltrimethylammonium chloride. Ether bonds are primarily formed between the alkenyl-containing organic quaternary ammonium salt and the alkalized cellulose through an addition reaction.

[0035] The epoxy-containing organic quaternary ammonium salt of the present invention has the following molecular structure:

[0036] R9 can be a C1-C8 hydrocarbon chain or a C1-C8 hydrocarbon-oxygen chain; R4, R5, and R6 are independently selected from C1-C4 alkyl groups. Specific examples of epoxy-containing organic quaternary ammonium salts include di-2,3-epoxypropyltrimethylammonium chloride. The ether bond between the epoxy-containing organic quaternary ammonium salt and the alkalized cellulose is primarily formed through a ring-opening addition reaction.

[0037] The present invention is specifically described by taking the substitution reaction between a halogenated organic quaternary ammonium salt and alkalized cellulose to form an ether bond as an example, and the reaction formula is as follows:

[0038]

[0039] wherein R1, R2 and R3 are independently selected from hydrogen or a quaternary ammonium salt group, and at least one of R1, R2 and R3 is a quaternary ammonium salt group;

[0040] The structural formula of the quaternary ammonium salt group is as follows:

[0041] R is a bonding group; R4, R5 and R6 are independently selected from C1 to C4 alkyl groups; m / (m+n)=0.18 to 0.90.

[0042] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0043] The quaternary ammonium cation-modified cellulose provided by the present invention can be used as a talc inhibitor for efficient flotation separation of metal sulfide ores and talc, has a wide applicable pulp pH value, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is the UV spectrum of CAC.

[0045] Figure 2 is the UV spectrum of CDC.

[0046] Figure 3 is the UV spectrum of CGC.

[0047] Figure 4 The left figure shows the effect of CGC concentration on molybdenite and talc respectively: the left figure shows the inhibitory effect of CGC on talc and molybdenite under different pH conditions; the right figure shows the inhibitory effect of CGC on talc and molybdenite under different reagent conditions (MIBC dosage is 1.5×10 -4 mol / L).

[0048] Figure 5 The left figure shows the effect of CDC concentration on molybdenite and talc respectively: the left figure shows the inhibitory effect of CDC on talc and molybdenite under different pH conditions; the right figure shows the inhibitory effect of CDC on talc and molybdenite under different reagent conditions (MIBC dosage is 1.5×10 -4 mol / L). DETAILED DESCRIPTION

[0049] The technical solutions of the present invention are described in detail below through specific embodiments, but the following specific embodiments do not limit the protection scope of the claims of the present invention.

[0050] In the following examples, unless otherwise specified, all the drugs used are commercially available products. The concentrations or contents in each example are expressed in percentage by mass.

[0051] The cellulose of the present invention is a commercially available microcrystalline cellulose product: CAS: 9004-34-6.

[0052] Example 1

[0053] To a three-necked flask, 0.01 mol of cellulose and 30 g of isopropanol were added sequentially. The reaction system was maintained at 25°C. After 10 minutes, 0.4 g of sodium hydroxide solution was added. After the addition of alkali, the temperature was raised to 55°C and the alkalization reaction was carried out for 1.5 hours. Subsequently, (2,3-epoxypropyl)trimethylammonium chloride, dimethyldiallylammonium chloride, and 3-chloro-2-hydroxypropyltrimethylammonium chloride (in a 1:1 ratio with sodium hydroxide) were added, and isopropanol was added as solvent. The etherification reaction was carried out for 3 hours. After the reaction, the reaction system was cooled to room temperature, and the filtrate and filter cake were separated by filtration. The filter cakes obtained were crude products of CGC, CDC, and CAC, respectively. The crude products of CGC, CDC, and CAC were placed in a beaker, washed three times with ethanol, and dried under vacuum to obtain pale yellow powders of CGC, CDC, and CAC.

[0054] The reaction equations are shown below (1)(2)(3), where Cell-OH is the cellulose monomer structure in general formula 1:

[0055]

[0056]

[0057] Cellulose modified with quaternary ammonium cations exhibits characteristic absorption peaks in the ultraviolet region. Therefore, UV spectrophotometry is used to determine the absorbance of CGC, CDC, and CAC and calculate the degree of cationic substitution. For example, standard cationic monomer solutions of varying concentrations are prepared, their absorbances measured, and a standard curve plotted. Dissolve 0.5g of CAC in 50mL of deionized water and measure its UV absorbance.

[0058] Depend on Figure 1 、 2 As can be seen from Figures 3 and 4, CAC, CDC and CGC all have characteristic UV peaks at 266 nm, 310 nm and 266 nm, respectively. The yields of CAC, CDC and CGC obtained by the above experimental steps are 85%, 86% and 83%, respectively.

[0059] Example 2

[0060] The flotation performance of the cationic cellulose inhibitor prepared in Example 1 on a single mineral was studied. Under natural pH conditions, after stirring for 2 minutes, a pH adjuster (such as sodium hydroxide) was added for 2 minutes, the inhibitor was added and stirred for 3 minutes, the collector was added and stirred for 3 minutes, and a foaming agent (methyl isobutyl carbinol) 1×10 -4mol / L, stirred for 1 min, floated for 3 min, and the inhibitor concentration was 5-150 mg / L to obtain the flotation product.

[0061] from Figures 2-3 As shown in the figure, CGC and CDC have a good inhibitory effect on talc, and the talc recovery rate decreases with increasing inhibitor concentration. When the concentration of CGC and CDC is 200 mg / L, the talc recovery rate can be reduced from 85% to 35% and 52% respectively, and this is not affected over a wide pH range.

[0062] Example 3

[0063] The flotation performance of the depressant prepared in Example 1 on mixed minerals was investigated. After stirring the slurry for 2 minutes, a pH adjuster (e.g., sodium hydroxide) was added for 2 minutes. The depressant was then stirred for 3 minutes. A collector was added and stirred for 3 minutes. A frother was added and stirred for 1 minute. The mixture was then flotated for 3 minutes. The depressant concentration was selected to be between 5 and 150 mg / L to obtain a flotation product. At an depressant concentration of 100 mg / L, the depressant achieved a flotation recovery of 29.83% for talc and 81.57% for chalcopyrite. See Table 1 for details.

[0064] In artificial mixed ore flotation, CAC at a concentration of 50 mg / L effectively separated molybdenite from talc. When SIBX and kerosene were used as collectors, the molybdenite content reached a maximum of 78.52% and 77.20%, respectively. The difference in molybdenite and talc recoveries reached nearly 40%, with separation efficiencies of 39% and 36%, respectively. In summary, CAC is effective in separating molybdenite and talc.

[0065] Table 1 Separation effect of CAC on molybdenite-talc mixed ore under different reagent systems

[0066]

[0067] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A quaternary ammonium cation modified cellulose as a talc inhibitor, characterized in that: The quaternary ammonium cationic modified cellulose has the following molecular structural formula: in, R1, R2 and R3 are independently selected from hydrogen or a quaternary ammonium salt group, and at least one of R1, R2 and R3 is a quaternary ammonium salt group; The structural formula of the quaternary ammonium salt group is as follows: R is a bonding group; R4, R5 and R6 are independently selected from C1 to C4 alkyl groups; m / (m+n)=0.18~0.

90.

2. The use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 1, characterized in that: R is C1~C 10 The hydrocarbon chain or C2~C 10 of carbon, hydrogen and oxygen chains.

3. Use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 1 or 2, characterized in that: As a talc inhibitor, it is used in the flotation separation of metal sulfide ores and talc.

4. The use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 3, characterized in that: The metal sulfide ore includes at least one of molybdenite, galena and sphalerite.

5. The use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 3, characterized in that: The flotation separation process is as follows: after grinding and slurrying the metal sulfide ore, flotation reagents including quaternary ammonium cation modified cellulose, metal sulfide ore collector and frother are added to perform aeration flotation.

6. The use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 5, characterized in that: The slurry adjustment is to adjust the pH value of the slurry to 4.0-10.

0.

7. The use of a quaternary ammonium cation modified cellulose as a talc inhibitor according to claim 5, characterized in that: The concentration of the quaternary ammonium cation modified cellulose in the slurry is 100 to 500 mg / L; The concentration of the metal sulfide ore collector in the ore pulp is 5 to 150 mg / L.

Images