A mineral flotation frother and its preparation method and use

Abstract

The invention discloses a mineral flotation frother, a preparation method and a use thereof. The invention comprises the following steps: feeding an ε-caprolactone byproduct and a small molecule alcohol in a certain proportion, adding a catalyst, reacting at 140-200 DEG C, reacting at a low vacuum degree at 140-200 DEG C in the middle and late stages of the reaction, and finally obtaining a liquid modified oligomer; then mixing the oligomer with X oil and octanol in a certain proportion, stirring the oligomer sufficiently and standing the mixture to obtain a mineral flotation frother. The invention can solve the problems that the caprolactone oligomer is easy to solidify and difficult to recycle, and is an efficient treatment method. The prepared mineral flotation frother has obvious synergistic effect among various components, good foaming performance, high mechanical strength of a foam film after foaming, and the foam can be kept stable. The invention has a small dosage during use, and is particularly suitable for the flotation of metal sulfide ores, metal oxide ores or non-metallic minerals.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparing frothers for mineral flotation, and in particular relates to a frother for mineral flotation, a preparation method and a use thereof Background Art

[0002] ε-Caprolactone is a non-toxic organic chemical intermediate. In synthetic compounds, it can provide many excellent chemical properties to the synthetic compounds; it also has many advantages such as good biodegradability, low temperature flexibility and hydrolysis resistance.

[0003] ε-caprolactone is a temperature-sensitive substance. The temperature requirements of the process in the production process of ε-caprolactone are relatively high. ε-caprolactone is easy to cause ring-opening self-polymerization at high temperature in the production process to form oligomers with a polymerization degree of 2-9, resulting in the generation of by-product waste and increased production costs. Analysis of the by-products shows that they contain about 10-20% of ε-caprolactone, 50-60% of low molecular weight terminal hydroxyl polycaprolactone, 10-15% of impurity acid, 4% of 6-hydroxycaproic acid, and about 1% of light components and heavy components.

[0004] The process of producing oligomers of ε-caprolactone: After completing the Bayer-Villiger reaction, cyclohexanone and peracid will enter the No. 1 distillation tower, and the light components will be removed from the top of the tower by distillation. The bottom temperature of the No. 1 distillation tower is relatively low, and ε-caprolactone and the remaining heavy components will be transferred from the bottom of the tower to another No. 2 distillation tower with a higher temperature for distillation again. ε-caprolactone will be produced from the top of the tower, and the heavy components will be produced from the bottom of the tower. The bottom temperature of the No. 2 distillation tower is relatively high. ε-caprolactone may undergo slight polymerization during the distillation process. This part of the polymerized ε-caprolactone will be produced from the by-product outlet after adsorption treatment together with the heavy components. The oligomers of ε-caprolactone, its main active ingredient is terminal hydroxyl polycaprolactone, and the secondary active ingredient is 6-hydroxycaproic acid.

[0005] The oligomers of ε-caprolactone are brown viscous liquids at about 80°C. They solidify and agglomerate after cooling, and cannot be completely melted even after being left for a period of time and baked at 100°C. They are difficult to handle and cannot be completely recycled, and will cause difficult environmental problems. Invention patent CN110016128A describes a method for recycling oligomers of ε-caprolactone to treat oligomers produced in the production process of ε-caprolactone; wherein the oligomers are reacted with alcohol according to the method described in the patent until the final acid value cannot reach 2mg KOH / g, and the final acid value is 40mg KOH / g, and a large amount of acid reducer needs to be added to meet the requirement; in addition, after adding a large amount of adsorbent and bleaching agent, the color of the product cannot be significantly improved, but the production cost is greatly increased.

[0006] At present, the difficulty in applying ε-caprolactone oligomers is that they are easy to solidify, have dark color and high acid value, making them difficult to apply in most industries. The present invention is committed to making the difficult-to-recycle by-products generated during the production of ε-caprolactone: ε-caprolactone oligomers into a frother for mineral flotation through reaction and proportioning, so as to recycle the ε-caprolactone oligomers and improve the economic benefits for enterprises. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a mineral flotation frother, a preparation method and a use thereof, which solve the problem that oligomers generated in the production process of ε-caprolactone are difficult to recover; the present invention utilizes the structural characteristics that one end of the oligomer of ε-caprolactone is a hydroxyl group and the other end is an ester bond after the reaction with a small molecular alcohol, esterification generates a liquid modified oligomer, and the flotation frother is prepared by proportioning. The product can form a mechanical membrane with external hydrophobicity and internal hydrophilicity in water, thereby achieving an emulsification effect, and is therefore used in the flotation of minerals; at the same time, the water generated by the esterification reaction can be removed by vacuum together with the unreacted octanol in the later stage of the reaction, and octanol and water are immiscible and can be separated into phases by standing, so that the octanol can be recovered.

[0008] To achieve the above purpose, the technical solution of the present invention is as follows:

[0009] A mineral flotation frother, a preparation method and a use thereof. The invention relates to an ε-caprolactone oligomer obtained by Bayer-Villiger reaction of cyclohexanone and peroxy acid. The acid value of the ε-caprolactone oligomer is tested before the reaction, and the content of the ε-caprolactone and other impurities is determined by gas chromatography; the molar number of carboxyl groups of terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer is determined by the acid value, and a small molecule alcohol is added in a molar ratio, and the amount of the small molecule alcohol added is usually 10-30% more than the theoretical value, and the reaction is carried out; after the reaction is completed, the temperature is lowered and the mixture is allowed to stand for 1 hour, and then filtered to obtain a modified oligomer; the modified oligomer is mixed with X oil and octanol in a certain proportion, and then stirred and allowed to stand and filtered to obtain a mineral flotation frother.

[0010] The specific experimental steps of the present invention are as follows:

[0011] Put ε-caprolactone oligomers into a four-necked flask, use a magnetic stirring oil bath pot, put a magnet in the flask and heat it up, use a circulating water pump to vacuum dehydrate at 80°C for 1-2h, the absolute pressure of the whole system is 1KPa, take samples to measure the acid value and record it; then calculate the input amount of small molecule alcohol according to the acid value result, and the actual input amount should be 10%-30% more than the theoretical input amount; after adding small molecule alcohol and catalyst, heat it up and react at 140-200°C; after reacting at normal pressure for 1h-2h, connect a condenser and a reflux bottle at the mouth of the flask, then use a circulating water pump to evacuate, remove the water produced by the esterification reaction through low vacuum, and make the reaction proceed in the direction of generating liquid modified oligomers; gradually reduce the vacuum degree, and continue the reaction for 1h-2h at the system absolute pressure of 1KPa until the acid value Av≤30mg KOH / g; after recording the final acid value of the reaction, cool it down and let it stand for 1 hour, then filter it with gauze, take the filtrate and mix it with X oil and octanol in a certain proportion, stir it well and let it stand for 15 minutes again, and filter it with gauze again. The purpose of filtering is to prevent residual impurities from affecting the emulsification effect of the foaming agent.

[0012] The above invention experiment content is further explained:

[0013] The added small molecule alcohol is selected from the monohydric alcohol n-octanol; the dihydric alcohols such as neopentyl glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, 1,5-pentanediol, 1,3-butanediol, etc.; the trihydric alcohols such as trimethylolpropane, glycerol, etc.; and the tetrahydric alcohol such as pentaerythritol, among which n-octanol, neopentyl glycol and trimethylolpropane are preferred.

[0014] The catalyst added in the reaction of preparing the modified liquid oligomer is one of stannous octoate, tetrabutyl titanate, benzenesulfonic acid, sulfuric acid, hydrochloric acid, boric acid, modified zeolite, solid acid catalyst and super solid acid catalyst, preferably benzenesulfonic acid or tetrabutyl titanate, and the addition amount is 100-500ppm.

[0015] Before the reaction of preparing the modified liquid oligomer, the temperature of the oligomer vacuum dehydration is 80°C and the time is 1-2h. After adding n-octanol and benzenesulfonic acid, the reaction is carried out between 140-200°C and the reaction time is 1h-2h. After reacting at normal pressure for 1h-2h, a low vacuum is used to remove the water generated by the esterification reaction. When the vacuum is reduced after the water is removed, the vacuum should not be reduced too quickly, otherwise the alcohol is easily extracted at high temperature and accompanied by liquid flooding. The vacuum of the reaction system is gradually reduced according to 60KPa, 50KPa, 40KPa, 30KPa, 20KPa, 10KPa, 5KPa and 1KPa. The basis for reducing the vacuum is that there is no distillate in the condenser and no violent liquid flooding occurs in the flask, then the vacuum can be reduced to carry out the second stage reaction.

[0016] When performing theoretical calculations for feeding, the molar number of hydroxyl groups of the small molecule alcohol should correspond to the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone, and 1 mole of hydroxyl groups corresponds to 1 mole of carboxyl groups; when actually feeding, the molar number of the small molecule alcohol should be more than the molar number of the terminal hydroxyl polycaprolactone; preferably, the molar number of the small molecule alcohol is 10%-30% more than the molar number of the terminal hydroxyl polycaprolactone, and the molar ratio of the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone to the molar number of hydroxyl groups of the small molecule alcohol is 1:1.1-1.3.

[0017] The ratio of the modified liquid oligomer to X oil and octanol after filtration is modified oligomer: X oil: n-octanol = 40:40:20; modified oligomer: X oil: n-octanol = 45:40:15; modified oligomer: X oil: n-octanol = 50:40:10; modified oligomer: X oil: n-octanol = 55:40:5.

[0018] The X oil in the above preferred embodiment is a byproduct of cyclohexane oxidation, comprising the following mass components in percentage: cyclohexanol derivatives 5%-10%; cyclohexenylcyclohexanone 20%-30%; cyclohexylcyclohexanone 2%-10%; cyclohexylether 20%-40%; the remainder is cyclohexanone and oligomers.

[0019] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0020] In terms of cost, the oligomers of ε-caprolactone are brown viscous liquids at about 80°C, which will solidify and agglomerate after cooling, and cannot be completely melted even after being left for a period of time and baked at 100°C; it is difficult to handle and cannot be completely recycled, and will cause difficult environmental problems, and can only be treated as hazardous waste, resulting in greatly increased production costs; the present invention esterifies the oligomers produced in the production process of ε-caprolactone with n-octanol to obtain modified liquid oligomers; another technical solution of the present invention mixes the oxidation by-product X oil of cyclohexane with the modified oligomer and n-octanol in proportion to produce a mineral flotation frother product with high economic value; it not only solves the environmental problem, but also generates economic value and has good economic prospects; the cyclohexane oxidation by-product X oil in the solution is currently difficult to recycle and is generally used as fuel, but it produces a large amount of black smoke when burned, polluting the environment.

[0021] The method for preparing the modified oligomer and mineral flotation frother of the present invention is simple, the process conditions are relatively mild, the reaction efficiency is high, it is beneficial to reduce the reaction energy consumption, and it is convenient to control the progress of the reaction, thus greatly reducing the production cost.

[0022] The mineral flotation frother prepared by the technical solution of the present invention has obvious synergistic effect among the components, good frothing performance, and high mechanical strength of the foam film after frothing, so that the foam film can remain stable; the dosage during use is small, and it is particularly suitable for the flotation of metal sulfide ores, metal oxide ores or non-metallic minerals.

[0023] In terms of storage stability, the modified oligomer was placed at room temperature for storage experiments. After 1 week, 1 month, 3 months, 6 months, and 12 months, there was no solidification or bottom sedimentation, and the acid value did not change significantly. After being stored at room temperature for 12 months, the prepared foaming agent still has good foaming performance, and the mechanical strength of the foam film after foaming is high, so that the foam film can remain stable. In terms of transportation, because the foaming agent and the modified oligomer are both liquid and do not contain waste residue, they can be transported by tank trucks, which can save more transportation costs compared to the original barrel transportation. DETAILED DESCRIPTION

[0024] The present invention is further described below with reference to the embodiments.

[0025] Example 1

[0026] The present invention provides a mineral flotation frother and a preparation method and use thereof, and the specific implementation methods are as follows:

[0027] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by acid value, and n-octanol was added in molar ratio, the molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of n-octanol was 1:1.1, and the amount of n-octanol added was 250 g calculated by molar ratio.

[0028] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the mixture was heated to 80°C under stirring, and the ε-caprolactone byproduct was vacuum dehydrated using a circulating water pump. After 1h, N2 was used to eliminate the vacuum, and the acid value was determined to be 249mg KOH / g; add 250g of n-octanol and 100ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 140℃ under stirring, react at this temperature under normal pressure for 1h, turn on the circulating water pump, evacuate and control the absolute vacuum of the reaction system to 50KPa, and remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa, and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 29mg KOH / g.

[0029] Place filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 20g of the filtered modified oligomer, mix it with 20g of X oil and 10g of n-octanol at a mass ratio of modified oligomer: X oil: n-octanol = 40:40:20, stir well and let stand for 30min, filter it with gauze to obtain the mineral flotation frother.

[0030] The effects produced by this embodiment are as follows:

[0031] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 94.55%, the yield of modified oligomers after filtration is 93.46%, and the acid value is 29 mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0032] The foaming agent prepared in this example and the commercial foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml graduated cylinder, and then the foam quality and half-life were measured. The results are shown in Table 1. Compared with the commercial foaming agent, the foaming agent prepared in this example has a foam quality improved by 15.9% and a half-life extended by 50 s.

[0033] Table 1

[0034]

[0035] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, and the mineral components included precious metals such as gold and silver. The results are shown in Table 2. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.4%.

[0036] Table 2

[0037]

[0038] Recovery rate refers to the ratio of the weight of gold contained in the concentrate to the content of Polygonatum in the original ore;

[0039] Example 2

[0040] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0041] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of n-octanol was 1:1.2. The amount of n-octanol added was 272 g, which was calculated by the molar ratio.

[0042] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the ε-caprolactone byproduct was heated to 80°C under stirring conditions, and a circulating water pump was used to vacuum dehydrate the ε-caprolactone byproduct. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was measured to be 252mg KOH / g; add 272g of n-octanol and 150ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 150℃ under stirring, react at this temperature under normal pressure for 1h, turn on the circulating water pump, evacuate and control the absolute vacuum degree of the reaction system to 50KPa, and remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum degree of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa, and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 27mg KOH / g.

[0043] Place the filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 22.5g of the filtered modified oligomer, mix it with 20g of X oil and 7.5g of n-octanol according to the mass ratio of modified oligomer: X oil: n-octanol = 45:40:15, stir it thoroughly and let it stand for 30 minutes, filter it with gauze to obtain the mineral flotation frother.

[0044] The effects produced by this embodiment are as follows:

[0045] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 93.24%, the yield of modified oligomers after filtration is 92.57%, and the acid value is 27mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0046] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 3. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 14.3%, and the half-life was extended by 45 s.

[0047] Table 3

[0048]

[0049] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 4. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the concentrate grade of gold by 0.55%.

[0050] Table 4

[0051]

[0052]

[0053] Example 3

[0054] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0055] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of trimethylolpropane was 1:1.1. The amount of trimethylolpropane added was calculated by the molar ratio to be 112 g.

[0056] 500g of caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the mixture was heated to 80°C under stirring, and the ε-caprolactone byproduct was vacuum dehydrated using a circulating water pump. After 1h, N2 was used to eliminate the vacuum, and the acid value was determined to be 251mg KOH / g; add 112g trimethylolpropane and 300ppm catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 160℃ under stirring, react at this temperature under normal pressure for 2h, turn on the circulating water pump, evacuate and control the absolute vacuum degree of the reaction system to 50KPa, and remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum degree of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa, and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 30mg KOH / g.

[0057] Place the filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 25g of the filtered modified oligomer, mix it with 20g of X oil and 5g of n-octanol according to the mass ratio of modified oligomer: X oil: n-octanol = 50:40:10, stir it thoroughly and let it stand for 30 minutes, filter it with gauze to obtain the mineral flotation frother.

[0058] It is calculated that in the modification reaction of ε-caprolactone byproduct, the esterification rate of oligomers is 89.67%, the yield of modified oligomers after filtration is 85.26%, and the acid value is 30mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals. The effects produced by this embodiment are as follows:

[0059] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 5. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 9.7%, and the half-life was extended by 18 s.

[0060] Table 5

[0061]

[0062] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 6. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.25%.

[0063] Table 6

[0064]

[0065] Example 4

[0066] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0067] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of trimethylolpropane was 1:1.3. The amount of trimethylolpropane added was calculated by the molar ratio to be 130 g.

[0068] 500g of ε-caprolactone byproduct: ε-caprolactone oligomer (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the ε-caprolactone byproduct was heated to 80°C under stirring conditions, and a circulating water pump was used to vacuum dehydrate the ε-caprolactone byproduct. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was measured to be 250mg KOH / g; add 130g trimethylolpropane and 400ppm catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 170℃ with stirring, react at this temperature under normal pressure for 2h, turn on the circulating water pump, evacuate and control the absolute vacuum degree of the reaction system to 50KPa, and remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum degree of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa, and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 32mg KOH / g.

[0069] Place filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 20g of the filtered modified oligomer, mix it with 20g of X oil and 10g of n-octanol at a mass ratio of modified oligomer: X oil: n-octanol = 40:40:20, stir well and let stand for 30min, filter it with gauze to obtain the mineral flotation frother.

[0070] The effects produced by this embodiment are as follows:

[0071] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 87.46%, the yield of modified oligomers after filtration is 86.78%, and the acid value is 32 mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0072] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 7. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 10.5%, and the half-life was extended by 23 s.

[0073] Table 7

[0074]

[0075] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 8. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.33%.

[0076] Table 8

[0077]

[0078] Example 5

[0079] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0080] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of the neopentyl glycol was 1:1.1. The amount of neopentyl glycol added was 120 g, which was calculated by the molar ratio.

[0081] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the mixture was heated to 80°C under stirring, and the ε-caprolactone byproduct was vacuum dehydrated using a circulating water pump. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was determined to be 255mg KOH / g; add 120g neopentyl glycol, 500ppm catalyst benzenesulfonic acid, and connect the condenser and reflux flask; heat to 250℃ under stirring, react at this temperature and pressure for 2h, then turn on the circulating water pump, evacuate and control the absolute vacuum degree of the reaction system to 50KPa to remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum degree of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 37mg KOH / g.

[0082] Place filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 20g of the filtered modified oligomer, mix it with 20g of X oil and 10g of n-octanol at a mass ratio of modified oligomer: X oil: n-octanol = 40:40:20, stir well and let stand for 30min, filter it with gauze to obtain the mineral flotation frother.

[0083] The effects produced by this embodiment are as follows:

[0084] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 77.23%, the yield of modified oligomers after filtration is 69.65%, and the acid value is 37 mg KOH / g; while the esterification rate and yield decrease, the foaming property of the foaming agent is general, the dispersion rate is not high, the mechanical strength of the foam film after foaming is not high, the bubbles are easy to rupture, and the selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals decreases.

[0085] The foaming agent prepared in this example and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 9. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this example was improved by 11.7%, and the half-life was extended by 31 s.

[0086] Table 9

[0087]

[0088] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 10. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.37%.

[0089] Table 10

[0090]

[0091] Example 6

[0092] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0093] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of n-octanol was 1:1.3. The amount of n-octanol added was 294 g, which was calculated by the molar ratio.

[0094] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 264mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the ε-caprolactone byproduct was heated to 80°C under stirring conditions, and a circulating water pump was used to vacuum dehydrate the ε-caprolactone byproduct. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was measured to be 252mg KOH / g; add 294g of n-octanol and 200ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 160℃ under stirring, react at this temperature and pressure for 1h, then turn on the circulating water pump, evacuate and control the absolute vacuum of the reaction system to 50KPa to remove water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently reduce the absolute vacuum of the reaction system by 30KPa, 20KPa, 10KPa, 5KPa and 1KPa; when the absolute pressure of the reaction system drops to 1KPa, continue the reaction for 30min, then cool and let stand for 1h, and the acid value is determined to be 25mg KOH / g.

[0095] Place the filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 25g of the filtered modified oligomer, mix it with 20g of X oil and 5g of n-octanol according to the mass ratio of modified oligomer: X oil: n-octanol = 50:40:10, stir it thoroughly and let it stand for 30 minutes, filter it with gauze to obtain the mineral flotation frother.

[0096] The effects produced by this embodiment are as follows:

[0097] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 93.55%, the yield of modified oligomers after filtration is 92.49%, and the acid value is 25mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0098] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 11. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 12.3%, and the half-life was extended by 37 s.

[0099] Table 11

[0100]

[0101] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 12. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.44%.

[0102] Table 12

[0103]

[0104] Example 7

[0105] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0106] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of n-octanol was 1:1.1. The amount of n-octanol added was 248 g, which was calculated by the molar ratio.

[0107] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the ε-caprolactone byproduct was heated to 80°C under stirring conditions, and a circulating water pump was used to vacuum dehydrate the ε-caprolactone byproduct. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was measured to be 252mg KOH / g; add 248g of n-octanol and 300ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 170℃ under stirring, react at this temperature and pressure for 1h, then turn on the circulating water pump, evacuate and control the absolute vacuum of the reaction system to 50KPa to remove water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently reduce the absolute vacuum of the reaction system by 30KPa, 20KPa, 10KPa, 5KPa and 1KPa; when the absolute pressure of the reaction system drops to 1KPa, continue the reaction for 30min, then cool and let stand for 1h, and the acid value is measured to be 28mg KOH / g.

[0108] Place the filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 27.5g of the filtered modified oligomer, mix it with 20g of X oil and 2.5g of n-octanol according to the mass ratio of modified oligomer: X oil: n-octanol = 55:40:5, stir it thoroughly and let it stand for 30 minutes, filter it with gauze to obtain the mineral flotation frother.

[0109] The effects produced by this embodiment are as follows:

[0110] It is calculated that in the modification reaction of ε-caprolactone byproduct, the esterification rate of oligomers is 93.04%, the yield of modified oligomers after filtration is 92.16%, and the acid value is 28mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0111] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 13. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 7.6%, and the half-life was extended by 36 s.

[0112] Table 13

[0113]

[0114] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 14. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.34%.

[0115] Table 14

[0116]

[0117] Example 8

[0118] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0119] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone was determined by acid value, and n-octanol was added in molar ratio, the molar ratio of the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone to the molar number of hydroxyl groups of n-octanol was 1:1.3, and the amount of n-octanol added was 272 g calculated by molar ratio.

[0120] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 259mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the ε-caprolactone byproduct was heated to 80°C under stirring conditions, and a circulating water pump was used to vacuum dehydrate the ε-caprolactone byproduct. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was measured to be 252mg KOH / g; add 272g of n-octanol and 400ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 180℃ under stirring, react at this temperature and pressure for 1h, then turn on the circulating water pump, evacuate and control the absolute vacuum of the reaction system to 50KPa to remove water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently reduce the absolute vacuum of the reaction system by 30KPa, 20KPa, 10KPa, 5KPa and 1KPa; when the absolute pressure of the reaction system drops to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 27mg KOH / g.

[0121] Place filter cloth on the funnel, pour the modified ε-caprolactone oligomer after standing and filter it, take 20g of the filtered modified oligomer, mix it with 20g of X oil and 10g of n-octanol at a mass ratio of modified oligomer: X oil: n-octanol = 40:40:20, stir well and let stand for 30min, filter it with gauze to obtain the mineral flotation frother.

[0122] The effects produced by this embodiment are as follows:

[0123] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 93.20%, the yield of modified oligomers after filtration is 92.27%, and the acid value is 27 mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0124] The foaming agent prepared in this example and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured, and the results are shown in Table 15. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this example was improved by 14.1%, and the half-life was extended by 42 s.

[0125] Table 15

[0126]

[0127] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 16. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.45%.

[0128] Table 16

[0129]

[0130] Example 9

[0131] The implementation is repeated on the basis of Example 1, and the specific implementation method is as follows:

[0132] For the ε-caprolactone oligomer obtained after the Bayer-Villiger reaction of cyclohexanone and peracid, the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the ε-caprolactone oligomer were determined by gas chromatography, the carboxyl molar number of the terminal hydroxyl polycaprolactone was determined by the acid value, and n-octanol was added in a molar ratio. The molar ratio of the carboxyl molar number of the terminal hydroxyl polycaprolactone to the hydroxyl molar number of n-octanol was 1:1.3. The amount of n-octanol added was 294 g, which was calculated by the molar ratio.

[0133] 500g of ε-caprolactone byproduct: oligomer of ε-caprolactone (acid value: 261mg KOH / g) was added to a 1000mL four-necked flask, a magnet was placed, and a magnetic stirring oil bath was used to heat; the mixture was heated to 80°C under stirring, and the ε-caprolactone byproduct was vacuum dehydrated using a circulating water pump. After 1 hour, N2 was used to eliminate the vacuum, and the acid value was determined to be 252mg KOH / g; add 294g of n-octanol and 500ppm of catalyst benzenesulfonic acid, connect the condenser and reflux flask; heat to 200℃ under stirring, react at this temperature under normal pressure for 1h, turn on the circulating water pump, evacuate and control the absolute vacuum degree of the reaction system to 50KPa, and remove the water produced by the reaction; when no more liquid is distilled out of the condenser and no more violent flooding occurs in the flask, reduce the absolute pressure of the reaction system to 40KPa; subsequently, the absolute vacuum degree of the reaction system is gradually reduced by 30KPa, 20KPa, 10KPa, 5KPa, and 1KPa; when the absolute pressure of the reaction system is reduced to 1KPa, continue the reaction for 30min, then cool down and let stand for 1h, and the acid value is measured to be 21mg KOH / g.

[0134] Place the filter cloth on the funnel, pour the modified caprolactone byproduct after standing and filter it, take 22.5g of the filtered modified oligomer, mix it with 20g of X oil and 7.5g of n-octanol according to the mass ratio of modified oligomer: X oil: n-octanol = 45:40:15, stir it thoroughly and let it stand for 30 minutes, filter it with gauze to obtain the mineral flotation frother.

[0135] The effects produced by this embodiment are as follows:

[0136] It is calculated that in the modification reaction of ε-caprolactone by-product, the esterification rate of oligomers is 93.86%, the yield of modified oligomers after filtration is 93.06%, and the acid value is 21mg KOH / g; at the same time, the foaming performance of the foaming agent is good, the dispersion rate is high, and the mechanical strength of the foam film after foaming is high, so that the foam can remain stable, and it has excellent selectivity for metal sulfide ores, metal oxide ores or non-metallic minerals.

[0137] The foaming agent prepared in this embodiment and the commercially available foaming agent were respectively prepared into 100 ml of a 1% aqueous solution, stirred at a high speed of 10000 r / min, and then poured into a 250 ml measuring cylinder. The foam quality and half-life were measured and the results are shown in Table 17. Compared with the commercially available foaming agent, the foam quality of the foaming agent prepared in this embodiment was improved by 15.3%, and the half-life was extended by 47 s.

[0138] Table 17

[0139]

[0140] The frother prepared in this embodiment and the commercially available frother were used to float gold ore, the mineral components of which included precious metals such as gold and silver. The results are shown in Table 18. Compared with the commercially available frother, the frother prepared in this embodiment can carry the ore powder better and increase the gold concentrate grade by 0.49%.

[0141] Table 18

[0142]

[0143] Example 10

[0144] On the basis of Example 1, a storage experiment was conducted for twelve months on the foaming agent and the modified oligomer in Example 1, and the acid value, foam quality and half-life were monitored in real time to determine the storage stability of the foaming agent and the modified oligomer. The results are shown in the following table:

[0145] Table 19

[0146]

[0147] It can be seen from the above table that the acid value of the modified oligomer only changed slightly during the twelve-month storage experiment. The foam quality and half-life of the foaming agent prepared from the modified oligomer were able to maintain a high level during the twelve-month storage experiment. It can be seen that the modified oligomer and the foaming agent have good storage stability and can be stored for a long time without deterioration.

[0148] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, makes any simple modifications, equivalent changes and modifications to the above embodiments based on the technical essence of the present invention, which still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a mineral flotation frother, characterized in that: The steps include: Step 1, after dehydrating the ε-caprolactone byproduct, adding a small molecule alcohol and a catalyst to carry out a first-stage reaction at 140° C.-200° C. under normal pressure for 1 h-2 h, gradually reducing the absolute vacuum after the first-stage reaction time, and after the absolute vacuum is reduced to 1 KPa, carrying out a second-stage reaction for 1 h-2 h until the acid value Av of the reaction product is ≤30 mg KOH / g, and finally obtaining a liquid modified oligomer; the ε-caprolactone byproduct is an ε-caprolactone oligomer with a degree of polymerization of 2-9; Step 2: Mix the liquid modified oligomer with X oil and octanol in a ratio of 40-55:40:5-20, and filter to obtain a mineral flotation frother.

2. The method for preparing a mineral flotation frother according to claim 1, characterized in that: The specific steps of step one are as follows: The oligomer of ε-caprolactone is dehydrated for 1h-2h in a vacuum reaction system at an absolute pressure of 1KPa and a temperature of 80°C, and after N2 is introduced to eliminate the vacuum and increase the pressure, a sample is taken to determine the acid value and record it, and the contents of ε-caprolactone and terminal hydroxyl polycaprolactone in the oligomer of ε-caprolactone are determined by gas chromatography, and the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone is determined by the acid value, and a small molecule alcohol is added in a molar ratio, and the molar ratio of the molar number of carboxyl groups of the terminal hydroxyl polycaprolactone to the molar number of hydroxyl groups of the small molecule alcohol is 1:1.1-1.3, and a small molecule is added 100-500ppm of catalyst is added after the alcohol, and the temperature is raised to 140-200°C after the catalyst is added. The oligomers of ε-caprolactone and the small molecule alcohol are subjected to a first-stage reaction and dehydration in a normal pressure reaction system at 140-200°C under the action of the catalyst for 1h-2h; after the first-stage reaction time is completed, the absolute vacuum is gradually reduced to 1Kpa, and the second-stage reaction is continued for 1h-2h in the reaction system with an absolute vacuum of 1Kpa, and finally a liquid modified oligomer is obtained.

3. The method for preparing a mineral flotation frother according to claim 2, characterized in that: After the first stage reaction is completed and before the second stage reaction begins, the absolute vacuum degree of the reaction system is gradually reduced according to: 60KPa, 50KPa, 40KPa, 30KPa, 20KPa, 10KPa, 5KPa, 1KPa, and finally the absolute vacuum degree of the system reaches 1KPa.

4. The method for preparing a mineral flotation frother according to claim 1, characterized in that: The specific steps of step 2 are as follows: the modified liquid oligomer is mixed with X oil and octanol in a mass ratio of modified oligomer: X oil: octanol = 40:40:20 or 45:40:15 or 50:40:10 or 55:40:5, the mixture is stirred until uniform and then allowed to stand for 1 hour, and the mixed solution is filtered through a filter screen and the filtrate is taken, wherein the filtrate is a frother in the mineral flotation agent.

5. The method for preparing a mineral flotation frother according to claim 1, characterized in that: The octanol is n-octanol.

6. The method for preparing a mineral flotation frother according to claim 1, characterized in that: The catalyst is benzenesulfonic acid, and the input amount is 100-500ppm.

7. The method for preparing a mineral flotation frother according to claim 5, characterized in that: The small molecule alcohol is n-octanol, neopentyl glycol or trimethylolpropane.

8. A use of a mineral flotation frother, characterized in that: The method for preparing the mineral flotation frother is as described in any one of claims 1 to 7. The mineral flotation frother is used for the flotation of precious metals, and the precious metals include gold and silver.

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