Inhibitor for copper-molybdenum separation and preparation method and application thereof

Abstract

The invention discloses an inhibitor for copper-molybdenum separation and a preparation method and application thereof.The inhibitor is a grafted copolymer DG-1 obtained after chitosan and sodium thioglycolate are grafted, the selectivity of sulfydryl to copper ions is enhanced through the product, the adsorption effect on the copper ions is enhanced, and molybdenite is not affected; secondly, a carboxyl group of a grafted product points to ore pulp and has more active sites, so that the solubility and the stability of single chitosan or sodium thioglycolate are enhanced; a third step; the copolymer is relatively simple to prepare and easy to realize, and the economic cost for inhibiting the chalcopyrite is effectively reduced. The inhibitor is used for separating copper and molybdenum and is environmentally friendly, the dosage is relatively small, and the process is simple and efficient.

Description

Technical Field

[0001] The invention relates to a copper-molybdenum separation inhibitor and a preparation method and application thereof, belonging to the technical field of ore dressing and flotation agents. Background Art

[0002] The effective separation of molybdenite and chalcopyrite in polymetallic sulfide deposits has always been a challenge. As the main mineral processing technology, the development of flotation reagents plays a decisive role in the separation efficiency of copper and molybdenum. Since the natural floatability of molybdenite is better than that of chalcopyrite, the industry currently often uses the method of copper suppression and molybdenum flotation to separate copper and molybdenum. However, most of the commonly used chalcopyrite depressants have problems such as large dosage, high cost, and environmental pollution, resulting in increasingly low economic benefits. Therefore, it is crucial to develop new, efficient and environmentally friendly chalcopyrite depressants.

[0003] Sodium thioglycolate is a common chalcopyrite inhibitor in copper-molybdenum separation, but it has the following problems: First, sodium thioglycolate has a certain complexing effect on copper and molybdenum during copper-molybdenum separation, resulting in low selectivity; second, sodium thioglycolate needs strong acid conditions to effectively complex copper ions, and acidic conditions often corrode experimental equipment, and the organic waste generated will pollute the environment; third, the reaction conditions of sodium thioglycolate are relatively harsh, and are easily affected by conditions such as pH and temperature, and the reaction conditions need to be carefully controlled; fourth, sodium thioglycolate is an organic sulfur compound, and the sulfur element or polysulfide compounds generated during use and treatment will cause environmental pollution problems; fifth, sodium thioglycolate has a high cost, with an average unit price of 4 yuan / g. In the process of inhibiting copper, sodium thioglycolate mainly plays a role in thiol and carboxyl groups. The carboxyl (-COOH) group is hydrophilic. When the thiol (-SH) group is adsorbed on the surface of chalcopyrite, the carboxyl (-COOH) group points to the slurry solution, thereby achieving the effect of inhibiting chalcopyrite. Chitosan, as a natural, biodegradable, non-toxic polysaccharide, is widely used in biomedicine, wastewater treatment, papermaking and textiles, and is also used in the field of copper-molybdenum separation. In the copper-molybdenum separation process, the advantages of chitosan are: first, it shows good selectivity for copper ions, but weak adsorption capacity for molybdenum ions; second, chitosan is derived from the shells of crustaceans, has good biocompatibility and biodegradability, and has little impact on the environment after use; third, the raw material cost of chitosan is low, easy to obtain, and is a renewable resource. However, there are still some problems with chitosan in industrial production, mainly manifested as: chitosan has limited adsorption capacity and poor performance when the copper ion concentration is high. Summary of the invention

[0004] In order to solve the above problems, one of the purposes of the present invention is to provide a new and efficient copper-molybdenum separation inhibitor DG-1, which is mainly aimed at the flotation separation of copper-molybdenum mixed concentrate and solves a series of problems existing when sodium thioglycolate is used as a chalcopyrite inhibitor.

[0005] The inhibitor of the present invention is a graft copolymer DG-1 obtained by grafting chitosan with sodium thioglycolate. The copolymer has the following characteristics: first, the product enhances the selectivity of thiol to copper ions and strengthens the adsorption effect on copper ions without affecting molybdenite; second, the carboxyl (-COOH) group of the graft product points to the ore pulp and has more active sites, thereby enhancing the solubility and stability of single chitosan or sodium thioglycolate; third, the preparation of the copolymer is relatively simple, easy to implement, and effectively reduces the economic cost of inhibiting chalcopyrite. The specific reaction formula is:

[0006]

[0007] The second object of the present invention is to provide a method for preparing the copper-molybdenum separation inhibitor, the preparation process is relatively simple and easy to implement, and the specific steps are as follows:

[0008] (1) firstly, a sodium thioglycolate solution and a sodium hydroxide solution in a volume ratio of 3:25 to 4:25 are mixed, heated and stirred for 4 hours to obtain a pre-reaction mixture;

[0009] (3) Then, 1.5 g to 2 g of chitosan was added to the pre-reaction mixture and stirred at room temperature for 12 h;

[0010] (4) After the reaction is completed, 50-60 mL of anhydrous ethanol is added to the reactant, and then the precipitate is collected by centrifugation;

[0011] (5) filtering the precipitate and then washing it repeatedly with anhydrous ethanol and deionized water alternately until the pH of the washing solution is neutral to obtain a modified material;

[0012] (6) Finally, the modified material was freeze-dried at -45°C to -50°C for 48 hours to obtain the final invention product, inhibitor DG-1.

[0013] The third object of the present invention is to apply the inhibitor of copper-molybdenum separation in copper-molybdenum separation, and the specific steps are as follows:

[0014] (1) Regrinding of copper-molybdenum mixed concentrate: Regrinding the copper-molybdenum mixed concentrate, the regrinding fineness is -0.038mm, accounting for 85% to 90%, the slurry concentration is adjusted to 35% to 40%, and the slurry is adjusted to pH = 12;

[0015] (2) Copper-molybdenum separation and roughing: adding inhibitor DG-1, collector kerosene, and foaming agent methyl isobutyl carbinol to the ore pulp obtained in step (1) in sequence, and performing a copper-molybdenum separation and roughing operation to obtain a separation roughing concentrate and a separation roughing tailings;

[0016] (3) separation and selection of copper and molybdenum: adding an inhibitor DG-1 to the separated rougher concentrate obtained in step (2), and performing four copper and molybdenum separation and selection operations, wherein the selection I operation obtains a selected I concentrate and a selected I middling, adding an inhibitor DG-1 and a collector kerosene to the selected I concentrate to perform a selection II operation to obtain a selected II concentrate and a selected II middling, and the selected I middling returns to the first rougher operation, adding an inhibitor DG-1 to the selected II concentrate to perform a selection III operation to obtain a selected III concentrate and a selected III middling, and the selected II middling returns to the selection I operation, adding an inhibitor DG-1 and a collector kerosene to the selected III concentrate to perform a selection IV operation to obtain a molybdenum concentrate and a selected IV middling, and the selected IV returns to the first selection III operation to form a closed loop;

[0017] (4) Copper-molybdenum separation and scavenging: The inhibitor DG-1, the collector kerosene, and the foaming agent methyl isobutyl carbinol are added to the separated roughing tailings obtained in step (1) in sequence to carry out a scavenging operation. The intermediate ore from the scavenging operation is returned to the roughing operation to form a closed loop to obtain a copper concentrate.

[0018] In step (2), the dosages of inhibitor DG-1, collector kerosene and foaming agent methyl isobutyl carbinol are 2000-2500 g / t, 500-600 g / t and 60-72 g / t respectively.

[0019] In step (3), the amount of inhibitor DG-1 added in the selection I operation is 400-440 / t, the amount of inhibitor DG-1 and collector kerosene added in the selection II operation is 200-220g / t and 80-100g / t, the amount of inhibitor DG-1 added in the selection III operation is 100-110g / t, and the amount of inhibitor DG-1 and collector kerosene added in the selection IV operation is 50-55g / t and 45-50g / t.

[0020] In step (4), the dosages of inhibitor DG-1, collector kerosene, and foaming agent methyl isobutyl carbinol are 200-220 g / t, 100-150 g / t, and 24-30 g / t, respectively.

[0021] The beneficial effects of the present invention are:

[0022] 1. The chalcopyrite inhibitor prepared by the present invention can effectively inhibit chalcopyrite and make the molybdenite in the copper-molybdenum mixed concentrate float out with the foam.

[0023] 2. The chalcopyrite inhibitor prepared by the present invention enhances the selectivity of the mercapto group for copper ions and strengthens the adsorption effect on copper ions, while having no effect on molybdenite; the carboxyl (-COOH) group of the grafted product of the present invention points to the pulp and has more active sites, thereby enhancing the solubility and stability of a single chitosan or sodium thioglycolate; the preparation of the copolymer is relatively simple, easy to implement, and effectively reduces the economic cost of inhibiting chalcopyrite.

[0024] 3. The chalcopyrite inhibitor of the present invention is environmentally friendly and the usage amount is relatively small.

[0025] 4. The present invention adopts the inhibitor to separate copper and molybdenum, and the process is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with specific embodiments. The embodiments are only used to specifically illustrate the present invention, but the protection scope of the present invention is not limited to the contents described.

[0028] Example 1: The inhibitor for separation of copper and molybdenum in this example is obtained by grafting chitosan with sodium thioglycolate to obtain a graft copolymer DG-1, and its molecular reaction formula is as follows:

[0029]

[0030] The preparation method of the inhibitor of this embodiment is as follows:

[0031] (1) firstly, a sodium thioglycolate solution and a sodium hydroxide solution in a volume ratio of 4:25 are mixed, heated and stirred for 4 hours to obtain a pre-reaction mixture, wherein the sodium thioglycolate and the sodium hydroxide are respectively configured to be solutions with mass fractions of 15% and 5%;

[0032] (3) Then, 2 g of chitosan was added to the pre-reaction mixture and stirred for reaction at room temperature for 12 h;

[0033] (4) After the reaction is completed, 50 mL of anhydrous ethanol is added to the reactant, and then the precipitate is collected by centrifugation;

[0034] (5) filtering the precipitate and then washing it repeatedly with anhydrous ethanol and deionized water alternately until the pH of the washing solution is neutral to obtain a modified material;

[0035] (6) Finally, the modified material was freeze-dried at -45°C for 48 hours to obtain the final invention product, inhibitor DG-1.

[0036] The inhibitor prepared in this example was applied to the Pulang Copper Mine in Yunnan to separate copper and molybdenum. The mineral raw materials used were from the Pulang Copper Mine in Yunnan. The original ore had a Cu content of 0.28%, a Mo content of 0.018%, a CaO content of 2.26%, and a MgO content of 1.78%. 2 O 3 The content is 13.68%. Phase analysis shows that Cu minerals mainly exist in the form of chalcopyrite and pyrite. The specific steps of separation are as follows:

[0037] (1) Regrinding of copper-molybdenum mixed concentrate: Regrinding the copper-molybdenum mixed concentrate, the regrinding fineness is -0.038mm, accounting for 85%, the pulp concentration is adjusted to 35%, and the pulp is adjusted to pH = 12;

[0038] (2) Copper-molybdenum separation and roughing: 2000 g / t of inhibitor DG-1, 500 g / t of collector kerosene, and 60 g / t of foaming agent methyl isobutyl carbinol are added to the slurry obtained in step (1) in sequence, and a copper-molybdenum separation and roughing operation is performed to obtain a separation roughing concentrate and a separation roughing tailings;

[0039] (3) separation and concentration of copper and molybdenum: adding 400 g / t of inhibitor DG-1 to the separated roughing concentrate obtained in step (2) to carry out concentration I operation, the concentration I operation obtains concentrated I concentrate and concentrated I middlings, the concentrated I middlings are returned to the roughing operation once, adding 200 g / t of inhibitor DG-1 and 80 g / t of collector kerosene to the concentrated I concentrate to carry out concentration II operation to obtain concentrated II concentrate and concentrated II middlings, the concentrated II middlings are returned to the concentration I operation once, adding 100 g / t of inhibitor DG-1 to the concentrated II concentrate to carry out concentration III operation to obtain concentrated III concentrate and concentrated III middlings, the concentrated III middlings are returned to the concentration II operation, adding 50 g / t of inhibitor DG-1 and 45 g / t of collector kerosene to the concentrated III concentrate to carry out concentration IV operation to obtain molybdenum concentrate and concentrated IV middlings, the concentrated IV middlings are returned to the concentration III operation once, forming a closed loop;

[0040] (4) Copper-molybdenum separation and scavenging: to the separated roughing tailings obtained in step (1), an inhibitor DG-1200 g / t, a collector kerosene 100 g / t, and a foaming agent methyl isobutyl carbinol 24 g / t are added in sequence to carry out a scavenging operation. The intermediate ore from the scavenging operation is returned to the roughing operation to form a closed loop to obtain a copper concentrate.

[0041] The molybdenum concentrate obtained in this embodiment contains 46.89% Mo and 0.27% Cu, and the molybdenum recovery rate in the molybdenum concentrate is 87.62%; the copper concentrate contains 0.32% Mo and 19.68% Cu, and the copper recovery rate in the copper concentrate is 89.58%.

[0042] Example 2: The inhibitor preparation method of this example is the same as that of Example 1, except that the volume ratio of sodium thioglycolate solution to sodium hydroxide solution is 3:25, sodium thioglycolate and sodium hydroxide are respectively configured into solutions with mass fractions of 10% and 4%, the amount of chitosan is 1.5g, 60mL of anhydrous ethanol is added, and the freeze-drying temperature is -50°C. The specific separation steps are as follows:

[0043] (1) Regrinding of copper-molybdenum mixed concentrate: Regrinding the copper-molybdenum mixed concentrate, the regrinding fineness is -0.038mm, accounting for 90%, the slurry concentration is adjusted to 40%, and the slurry is adjusted to pH = 12;

[0044] (2) Copper-molybdenum separation and roughing: to the ore pulp obtained in step (1), an inhibitor DG-12500 g / t, a collector kerosene 600 g / t, and a foaming agent methyl isobutyl carbinol 72 g / t are added in sequence to perform a copper-molybdenum separation and roughing operation to obtain a separation roughing concentrate and a separation roughing tailings;

[0045] (3) separation and selection of copper and molybdenum: adding an inhibitor DG-1440 g / t to the separated rougher concentrate obtained in step (2) to carry out a selection I operation, wherein the selection I operation obtains a selection I concentrate and a selection I middling, and the selection I middling is returned to the rougher operation once; adding an inhibitor DG-1220 g / t and a collector kerosene 100 g / t to the selection I concentrate to carry out a selection II operation to obtain a selection II concentrate and a selection II middling, and the selection II middling is returned to the selection I operation once; adding an inhibitor DG-1110 g / t to the selection II concentrate to carry out a selection III operation to obtain a selection III concentrate and a selection III middling, and the selection III middling is returned to the selection II operation; adding an inhibitor DG-155 g / t and a collector kerosene 50 g / t to the selection III concentrate to carry out a selection IV operation to obtain a molybdenum concentrate and a selection IV middling, and the selection IV middling is returned to the selection III operation once, thereby forming a closed loop;

[0046] (4) Copper-molybdenum separation and scavenging: to the separated roughing tailings obtained in step (1), an inhibitor DG-1220 g / t, a collector kerosene 150 g / t, and a foaming agent methyl isobutyl carbinol 30 g / t were added in sequence to carry out a scavenging operation. The intermediate ore from the scavenging operation was returned to the roughing operation to form a closed loop to obtain a copper concentrate.

[0047] The molybdenum concentrate obtained in this embodiment contains 46.24% Mo and 0.41% Cu, and the molybdenum recovery rate in the molybdenum concentrate is 86.94%; the copper concentrate contains 0.36% Mo and 19.48% Cu, and the copper recovery rate in the copper concentrate is 89.42%.

[0048] Example 3: The inhibitor preparation method of this example is the same as that of Example 1, except that the volume ratio of sodium thioglycolate solution to sodium hydroxide solution is 7:50, sodium thioglycolate and sodium hydroxide are respectively configured into solutions with mass fractions of 12% and 4.5%, the amount of chitosan used is 1.75g, and the mineral raw material used is copper-molybdenum mixed concentrate, in which the Cu content is 22.74%, the Mo content is 1.68%, and it also contains gangue minerals such as quartz and feldspar.

[0049] The specific separation steps are as follows:

[0050] (1) Regrinding of copper-molybdenum mixed concentrate: Regrinding the copper-molybdenum mixed concentrate, the regrinding fineness is -0.038mm, accounting for 85%, the slurry concentration is adjusted to 40%, and the slurry is adjusted to pH = 12;

[0051] (2) Copper-molybdenum separation and roughing: to the ore pulp obtained in step (1), 300 g / t of inhibitor DG-12, 550 g / t of collector kerosene, and 66 g / t of foaming agent methyl isobutyl carbinol were added in sequence to carry out a copper-molybdenum separation and roughing operation to obtain a separation roughing concentrate and a separation roughing tailings;

[0052] (3) separation and concentration of copper and molybdenum: add 420 g / t of inhibitor DG-1 to the separated rougher concentrate obtained in step (2) to carry out concentration I operation, the concentration I operation obtains concentrated I concentrate and concentrated I middlings, the concentrated I middlings are returned to the rougher operation once, add 210 g / t of inhibitor DG-12 and 90 g / t of collector kerosene to the concentrated I concentrate to carry out concentration II operation to obtain concentrated II concentrate and concentrated II middlings, the concentrated II middlings are returned to the concentrated I operation once, add 1105 g / t of inhibitor DG-11 to the concentrated II concentrate to carry out concentration III operation to obtain concentrated III concentrate and concentrated III middlings, the concentrated III middlings are returned to the concentrated II operation, add 33 g / t of inhibitor DG-15 and 45 g / t of collector kerosene to carry out concentration IV operation to obtain molybdenum concentrate and concentrated IV middlings, the concentrated IV middlings are returned to the concentrated III operation once, forming a closed loop;

[0053] (4) Copper-molybdenum separation and scavenging: to the separated roughing tailings obtained in step (1), an inhibitor DG-1210 g / t, a collector kerosene 125 g / t, and a foaming agent methyl isobutyl carbinol 27 g / t were added in sequence to carry out a scavenging operation. The intermediate ore from the scavenging operation was returned to the roughing operation to form a closed loop to obtain a copper concentrate.

[0054] The molybdenum concentrate obtained in this embodiment contains 50.36% Mo and 0.42% Cu, and the molybdenum recovery rate in the molybdenum concentrate is 82.16%. The copper concentrate contains 0.28% Mo and 25.16% Cu, and the copper recovery rate in the copper concentrate is 86.92%.

Claims

1. An inhibitor for separation of copper and molybdenum, characterized in that The inhibitor is obtained by grafting chitosan with sodium thioglycolate to obtain a graft copolymer DG-1, and its molecular reaction formula is as follows:

2. The method for preparing the copper-molybdenum separation inhibitor according to claim 1, characterized in that: The specific steps are as follows: (1) firstly, a sodium thioglycolate solution and a sodium hydroxide solution in a volume ratio of 3:25 to 4:25 are mixed, heated and stirred for 4 hours to obtain a pre-reaction mixture; (2) then adding 1.5 g to 2 g of chitosan to the pre-reaction mixture and stirring the reaction at room temperature for 12 h; (3) After the reaction is completed, 50-60 mL of anhydrous ethanol is added to the reactant, and then the precipitate is collected by centrifugation; (4) filtering the precipitate and then washing it repeatedly with anhydrous ethanol and deionized water alternately until the pH of the washing solution is neutral to obtain a modified material; (5) Finally, the modified material was freeze-dried at -45°C to -50°C for 48 hours to obtain the final invention product, inhibitor DG-1.

3. The method for preparing the copper-molybdenum separation inhibitor according to claim 2, characterized in that: In step (1), sodium thioglycolate and sodium hydroxide are respectively prepared into solutions with mass fractions of 10% to 15% and 4% to 5%.

4. The inhibitor for separation of copper and molybdenum according to claims 1 to 3 is used in separation of copper and molybdenum, characterized in that: The specific steps are as follows: (1) Regrinding of copper-molybdenum mixed concentrate: Regrinding the copper-molybdenum mixed concentrate, the regrinding fineness is -0.038mm, accounting for 85% to 90%, the slurry concentration is adjusted to 35% to 40%, and the slurry is adjusted to pH = 12; (2) Copper-molybdenum separation and roughing: adding inhibitor DG-1, collector kerosene, and foaming agent methyl isobutyl carbinol to the ore pulp obtained in step (1) in sequence, and performing a copper-molybdenum separation and roughing operation to obtain a separation roughing concentrate and a separation roughing tailings; (3) separation and selection of copper and molybdenum: adding inhibitor DG-1 to the separated rougher concentrate obtained in step (2), and performing four copper and molybdenum separation and selection operations, wherein the selection I operation obtains the selection I concentrate and the selection I middlings, and the selection I middlings are returned to the rougher operation once, and the inhibitor DG-1 and the collector kerosene are added to the selection I concentrate to perform the selection II operation to obtain the selection II concentrate and the selection II middlings, and the selection II middlings are returned to the selection I operation once, and the inhibitor DG-1 is added to the selection II concentrate to perform the selection III operation to obtain the selection III concentrate and the selection III middlings, and the selection III middlings are returned to the selection II operation, and the inhibitor DG-1 and the collector kerosene are added to the selection III concentrate to perform the selection IV operation to obtain the molybdenum concentrate and the selection IV middlings, and the selection IV middlings are returned to the selection III operation once, thereby forming a closed loop; (4) Copper-molybdenum separation and scavenging: The inhibitor DG-1, the collector kerosene, and the foaming agent methyl isobutyl carbinol are added to the separated roughing tailings obtained in step (1) in sequence to carry out a scavenging operation. The intermediate ore from the scavenging operation is returned to the roughing operation to form a closed loop to obtain a copper concentrate.

5. The use of the inhibitor for separation of copper and molybdenum according to claim 4 in separation of copper and molybdenum, characterized in that: In step (2), the dosages of inhibitor DG-1, collector kerosene and foaming agent methyl isobutyl carbinol are 2000-2500 g / t, 500-600 g / t and 60-72 g / t respectively.

6. Use of the inhibitor for separation of copper and molybdenum according to claim 4 in separation of copper and molybdenum, characterized in that: In step (3), the amount of inhibitor DG-1 added in the selection I operation is 400-440 / t, the amount of inhibitor DG-1 and collector kerosene added in the selection II operation is 200-220g / t and 80-100g / t, the amount of inhibitor DG-1 added in the selection III operation is 100-110g / t, and the amount of inhibitor DG-1 and collector kerosene added in the selection IV operation is 50-55g / t and 45-50g / t.

7. Use of the inhibitor for separation of copper and molybdenum according to claim 4 in separation of copper and molybdenum, characterized in that: In step (4), the dosages of inhibitor DG-1, collector kerosene, and foaming agent methyl isobutyl carbinol are 200-220 g / t, 100-150 g / t, and 24-30 g / t, respectively.

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