Preparation method of fluorite flotation collecting agent

Abstract

The invention relates to the technical field of fluorite flotation reagents, in particular to a preparation method of a fluorite flotation collecting agent. The specific preparation method comprises the following steps: carrying out sulfonation reaction on sulfuric acid and benzene to obtain sulfonation reaction liquid; the method comprises the following steps: by taking oleic acid or acid oil as a raw material, adding sulfonation reaction liquid at 10-20 DEG C, and carrying out stirring reaction; adding alkali liquor to carry out neutralization reaction, controlling the temperature to be less than or equal to 80 DEG C, and adjusting the pH value to be 7-8; and a water phase is separated and removed, and a mixture containing oleate, sulfated oleate, hydroxyl oleate and stearic acid benzene sulfonate is obtained and serves as the fluorite flotation collecting agent. By controlling the proportion of sulfuric acid to benzene and adding oleic acid, on the basis of reducing product benzene residues, the collecting capacity is improved, good selectivity is achieved, and the problem of aromatic hydrocarbon residues existing in a flotation collecting agent prepared from aromatic hydrocarbons such as benzene as raw materials is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorite flotation reagents, and particularly relates to a preparation method of a fluorite flotation collector. Background Art

[0002] Fluorite, as an important mineral resource, mainly consists of calcium fluoride. However, in nature, fluorite often contains various impurities and is often associated with other minerals such as calcite, for example, calcite-type fluorite ore. In order to obtain high-grade fluorite concentrate, a flotation process is usually required for separation and purification. The flotation process includes scavenging, roughing, and multiple cleaning steps, aiming to effectively separate fluorite from other minerals through physical and chemical means.

[0003] In the process of fluorite flotation, the selection of the collector is crucial. Oleic acid commonly used in the market is used as a fluorite collector. Oleic acid is a colorless to light yellow viscous liquid, and its purity is usually not less than 98.0%. However, although oleic acid has a certain collecting ability, there are still many problems in practical applications. For example, at low temperatures below 10°C, the collecting ability of oleic acid is relatively low, resulting in low flotation efficiency; at the same time, the foaming property of oleic acid is poor, and it is difficult to form a stable bubble layer, further affecting the flotation effect.

[0004] In order to overcome the deficiencies of oleic acid as a collector, researchers have begun to explore other alternative collectors. Among them, petroleum sulfonates and non-polar oils prepared by sulfonation reaction using aromatic hydrocarbons such as benzene as raw materials have received attention as a new type of flotation collector. This collector has the advantages of strong collecting ability and good flotation effect, and is expected to replace oleic acid to a certain extent.

[0005] However, it should be noted that in the process of preparing this new type of collector, due to the reversibility of the sulfonation reaction, a certain amount of aromatic hydrocarbons often remain in the collector. These residual aromatic hydrocarbons may bring a series of environmental safety problems in the process of fluorite flotation. For example, the residual aromatic hydrocarbons will be carried into the flotation waste liquid during the flotation process, which will bring great difficulties to the treatment of the flotation waste liquid. Summary of the Invention

[0006] In order to solve the problem of aromatic hydrocarbon residues in the flotation collector prepared from aromatic hydrocarbons such as benzene as raw materials, the purpose of the present invention is to provide a preparation method of a fluorite flotation collector.

[0007] To achieve the above purpose, the technical solution of the present invention is as follows.

[0008] The present invention provides a preparation method of a fluorite flotation collector, including the following steps:

[0009] The sulfonation reaction is carried out between sulfuric acid and benzene to obtain a sulfonation reaction solution; wherein, the mass ratio of benzene to sulfuric acid is 1:1.3 - 1.5; the sulfuric acid is concentrated sulfuric acid or fuming sulfuric acid with a concentration of 90wt% - 98wt%.

[0010] Using oleic acid or acidified oil as the raw material, the sulfonation reaction solution is added under the condition of 10°C - 20°C, and a stirring reaction is carried out; the acidified oil is the acidified oil obtained by acidolysis of the oil sludge and soap pod generated in refined vegetable oil; then an alkali solution is added for a neutralization reaction, controlling the temperature ≤ 80°C, and adjusting the pH to 7 - 8; the aqueous phase is separated and removed to obtain a mixture containing oleate, sulfated oleate, hydroxyoleate and stearic acid benzene sulfonate, which is used as a collector for fluorite flotation.

[0011] The specific reaction principle is as follows:

[0012] In the present invention, the sulfonation reaction of benzene is first carried out to replace the hydrogen on benzene with a sulfonic acid group to generate benzenesulfonic acid; since the sulfonation reaction is a reversible reaction, by controlling the mass ratio of benzene to sulfuric acid to be 1:1.3 - 1.5, the forward reaction is promoted by using excessive sulfuric acid. Among them, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid and unreacted benzene.

[0013] After that, the oleic acid or acidified oil is subjected to a stirring reaction with the sulfonation reaction solution. Since the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid and unreacted benzene, the addition of oleic acid or acidified oil can further convert the benzenesulfonic acid, excessive sulfuric acid and unreacted benzene in the sulfonation reaction solution into stearic acid benzene sulfonic acid and sulfated oleic acid; and they are converted into stearic acid benzene sulfonate and sulfated oleate during the subsequent neutralization reaction. Oleate and 2-hydroxyoleate are the products formed by oleic acid in an alkaline environment.

[0014] The specific chemical reaction formulas are as follows:

[0015]

[0016] In the present invention, sulfuric acid can not only react with benzene to carry out a sulfonation reaction to generate benzenesulfonic acid, but also act as an acid catalyst to make benzenesulfonic acid or unreacted benzene react with oleic acid under the catalysis of sulfuric acid to carry out a Friedel-Crafts alkylation reaction to generate stearic acid benzene sulfonic acid. At the same time, sulfuric acid and oleic acid will also generate sulfated oleic acid during the stirring process.

[0017] The collector for fluorite flotation prepared by the present invention is a mixture system. Among them, the sulfated oleate is an anionic surfactant. Oleate, hydroxyoleate and sulfated oleate have a dispersion and solubilization effect, can be used as collectors for flotation of calcium fluoride, improve the collecting ability, and have good selectivity. Stearic acid benzene sulfonate is an anionic surfactant that is relatively soluble in water, and the chain length is at C 13As described above, it has strong foaming performance and high collecting ability, and can be used for flotation of calcium fluoride. Therefore, the mixture system prepared by the present invention does not need to be separated and can be directly used as a collector for fluorite flotation.

[0018] In the present invention, by controlling the ratio of sulfuric acid to benzene, the forward reaction is promoted by using excessive sulfuric acid to reduce the residue of benzene; then oleic acid is added. On the basis of further reducing the residue of benzene, the sulfuric acid in the system is reduced to be converted into phenylsulfonic acid stearate and sulfated oleic acid, avoiding the destruction of the carbon chain of the oleic acid group due to too long neutralization reaction time and too high temperature. Thus, on the basis of reducing the benzene residue in the product, the collecting ability is improved and good selectivity is achieved.

[0019] In the present invention, the sulfuric acid is concentrated sulfuric acid with a concentration of 90wt% - 98wt% or fuming sulfuric acid. Preferably, the sulfuric acid is concentrated sulfuric acid with a concentration of 98wt% or fuming sulfuric acid. The sulfuric acid used in the present invention is high-concentration concentrated sulfuric acid, which avoids the influence of the water generated by the reaction on the forward progress of the reaction and can reduce the temperature of the sulfonation reaction. Of course, fuming sulfuric acid can also be used in other embodiments. For example, the fuming sulfuric acid is fuming sulfuric acid with a mass fraction of SO3 of 20%.

[0020] Preferably, the mass ratio of benzene to sulfuric acid is 1:1.3 - 1.4. Further preferably, the mass ratio of benzene to sulfuric acid is 1:1.36. In the present invention, by regulating the mass ratio of benzene to sulfuric acid, the forward reaction is promoted by using excessive sulfuric acid.

[0021] Preferably, the addition amount of oleic acid or acidified oil to the mass of benzene is 0.27 - 1.86:1.

[0022] Preferably, the temperature of the neutralization reaction is controlled ≤60°C. Preferably, the temperature of the neutralization reaction is 50°C - 60°C. If the temperature of the neutralization reaction is too high, side reactions may occur, resulting in the breakage of the oleic acid group and the generation of isooleic acid, which is not conducive to flotation.

[0023] Preferably, the alkali solution is sodium hydroxide solution or potassium hydroxide solution; the mass fraction of the alkali solution is 5wt% - 20wt%. Preferably, the mass fraction of the alkali solution is 5wt% - 10wt%.

[0024] In the present invention, by selecting a low-concentration liquid alkali, a large amount of heat release during the neutralization reaction is avoided. When the alkali solution is sodium hydroxide, the oleate is sodium oleate, and the 2-hydroxyoleate is sodium 2-hydroxyoleate. The molecular formula of sodium oleate is CH3(CH2)7CH=CH(CH2)7COONa, abbreviated as C 17 H 33 COONa; the molecular formula of sodium 2-hydroxyoleate is CH3(CH2)7CH2-CH(OH)(CH2)7COONa.

[0025] Preferably, the stirring reaction time is 1 h to 2 h.

[0026] Preferably, the temperature of the sulfonation reaction is 20°C to 60°C. Preferably, the time of the sulfonation reaction is 1 h to 10 h. In the present invention, by using excessive sulfuric acid to regulate the forward progress of the reaction and reducing the sulfonation reaction temperature to 20°C to 60°C, the volatilization loss of benzene caused by too high sulfonation reaction temperature is avoided.

[0027] Preferably, the specific process of the sulfonation reaction is as follows:

[0028] Under stirring conditions, sulfuric acid is added to benzene in 2 to 5 portions. During each addition of sulfuric acid, the reaction temperature is controlled to rise to 50°C to 60°C. After reacting for 1 h to 2 h, the temperature is lowered to below 30°C to obtain a sulfonation reaction solution.

[0029] For example, under stirring conditions, a portion of sulfuric acid is slowly added to benzene, and the reaction temperature is controlled to rise from 20°C to 50°C to 60°C. After reacting for 1 h to 2 h, the temperature is lowered to below 30°C; then sulfuric acid is continuously added, and the reaction temperature is controlled to rise to 50°C to 60°C. After reacting for 1 h to 2 h, the temperature is lowered to below 30°C; then sulfuric acid is continuously added, and the reaction temperature is controlled to rise to 60°C. After reacting for 1 h to 2 h, the temperature is lowered to 20°C to 30°C. The number of operations for adding sulfuric acid is 2 to 5 times to obtain a sulfonation reaction solution.

[0030] Preferably, the benzene is crude benzene, petroleum benzene or coking benzene. In the present invention, when using crude benzene as the raw material, since crude benzene contains impurities such as naphthalene, if sulfuric acid is continuously added, the reaction temperature will be too high and side reactions will occur. Therefore, by adding sulfuric acid in batches, side reactions caused by too high temperature are avoided.

[0031] The beneficial effects of the present invention:

[0032] 1. By controlling the ratio of sulfuric acid to benzene, the present invention uses excessive sulfuric acid to promote the forward progress of the reaction and reduce the residual benzene; then oleic acid is added. On the basis of further reducing the residual benzene, the sulfuric acid in the system is reduced to be converted into phenylsulfonic acid stearate and sulfated oleic acid, avoiding the carbon chain of the oleic acid group being damaged due to too long and too high temperature in the subsequent neutralization reaction. Thus, on the basis of reducing the residual benzene in the product, the collecting ability is improved and good selectivity is achieved.

[0033] 2. By regulating the addition amount of sulfuric acid, the present invention helps to adjust the amount of oleic acid used, and further regulates the foaming ability and selectivity of the prepared fluorite flotation collector.

[0034] 3. The present invention utilizes sulfuric acid, benzene, and oleic acid, and combines with a neutralization reaction to prepare a mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium benzenesulfonate stearate as a collector for fluorite flotation. On the basis of reducing the viscosity of the collector and improving its solubility in water, it can improve the collecting ability and is used for fluorite flotation.

[0035] 4. The collector for fluorite flotation prepared by the present invention is a mixture system. Among them, sulfated oleate is an anionic surfactant. Oleate, hydroxyoleate, and sulfated oleate have a dispersing and solubilizing effect, can be used as collectors for flotation of calcium fluoride, improve the collecting ability, and have good selectivity. Sodium benzenesulfonate stearate is an anionic surfactant that is relatively soluble in water, with a chain length of C 13 above, having strong foaming performance and high collecting ability, and can be used for flotation of calcium fluoride. Therefore, the mixture system prepared by the present invention does not need to be separated and can be directly used as a collector for fluorite flotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a process flow chart of a fluorite flotation process provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0039] The present invention provides a method for preparing a collector for fluorite flotation, which includes the following steps:

[0040] Step 1, perform a sulfonation reaction on sulfuric acid and benzene to obtain a sulfonation reaction solution; wherein, the mass ratio of benzene to sulfuric acid is 1:1.3 - 1.5; the sulfuric acid is concentrated sulfuric acid or fuming sulfuric acid with a concentration of 90wt% - 98wt%. The temperature of the sulfonation reaction is 20°C - 60°C.

[0041] Step 2: Using oleic acid or acidified oil as raw materials, adding a sulfonation reaction solution under the condition of 10°C to 20°C, and carrying out a stirring reaction; the acidified oil is the acidified oil obtained by acidolysis of the oil sludge and soap pod produced in refined vegetable oil; then adding an alkali solution for a neutralization reaction, controlling the temperature ≤ 80°C, and adjusting the pH to 7 - 8; separating and removing the aqueous phase to obtain a mixture containing oleate, sulfated oleate, hydroxyoleate, and stearic acid benzenesulfonate as a collector for fluorite flotation. Among them, the mass ratio of the addition amount of oleic acid or acidified oil to benzene is 0.27 - 1.86:1. The alkali solution is sodium hydroxide solution or potassium hydroxide solution; the mass fraction of the alkali solution is 5wt% - 20wt%.

[0042] In step 1 of the present invention, mainly using sulfuric acid as a sulfonating agent to carry out a sulfonation reaction on benzene, so that the hydrogen on benzene is replaced by a sulfonic acid group to generate benzenesulfonic acid; since the sulfonation reaction is a reversible reaction, by controlling the mass ratio of benzene to sulfuric acid to be 1:1.3 - 1.5, the excess sulfuric acid is used to promote the forward progress of the reaction. Among them, the sulfonation reaction solution contains benzenesulfonic acid, excess sulfuric acid, and unreacted benzene.

[0043] In step 2 of the present invention, mainly using oleic acid or acidified oil to carry out a stirring reaction with the sulfonation reaction solution. Since the sulfonation reaction solution contains benzenesulfonic acid, excess sulfuric acid, and unreacted benzene, the addition of oleic acid or acidified oil can further convert the benzenesulfonic acid, excess sulfuric acid, and unreacted benzene in the sulfonation reaction solution into stearic acid benzenesulfonic acid and sulfated oleic acid; and they are converted into stearic acid benzenesulfonate and sulfated oleate during the subsequent neutralization reaction. Oleate and 2-hydroxyoleate are the products generated by oleic acid in an alkaline environment.

[0044] In step 2 of the present invention, the addition amount of oleic acid is mainly determined according to the addition amount of sulfuric acid in step 1. A part of the added oleic acid is used to neutralize sulfuric acid to generate sulfated oleic acid, and the other part is used to carry out a Friedel - Crafts alkylation reaction with benzenesulfonic acid or unreacted benzene under the catalysis of sulfuric acid to generate stearic acid benzenesulfonic acid. The generated stearic acid benzenesulfonic acid and sulfated oleic acid are converted into stearic acid benzenesulfonate and sulfated oleate during the subsequent neutralization reaction. The excess oleic acid generates oleate and 2-hydroxyoleate in an alkaline environment.

[0045] The collector for fluorite flotation prepared by the present invention is a mixture system. Among them, sulfated oleate is an anionic surfactant. Oleate, hydroxyoleate, and sulfated oleate have a dispersion and solubilization effect, can be used as collectors for flotation of calcium fluoride, improve the collection ability, and have good selectivity. Stearic acid benzenesulfonate is an anionic surfactant that is relatively soluble in water, and the chain length is at C 13As described above, it has strong foaming performance and high collecting ability, and can be used for flotation of calcium fluoride. Therefore, the mixture system prepared by the present invention does not need to be separated and can be directly used as a collector for fluorite flotation.

[0046] In summary, the present invention controls the ratio of sulfuric acid to benzene, uses excessive sulfuric acid to promote the forward progress of the reaction and reduce the residual benzene; then oleic acid is added to further reduce the residual benzene and reduce the sulfuric acid in the system to be converted into phenylsulfonic acid stearate and sulfated oleic acid, avoiding the carbon chain of the oleic acid group being damaged due to too long neutralization reaction time and too high temperature. Thus, on the basis of reducing the residual benzene in the product, the collecting ability is improved and it has good selectivity. In addition, by regulating the addition amount of sulfuric acid, the present invention helps to adjust the amount of oleic acid used, and further regulate the foaming ability and selectivity of the prepared collector for fluorite flotation.

[0047] The technical solution of the present invention will be further described below through specific examples.

[0048] In the following examples, unless otherwise specified, the methods are all conventional methods; the reagents and materials, unless otherwise specified, can be purchased on the market.

[0049] In the following examples, the sulfuric acid is sulfuric acid with a mass fraction ≥ 90%, and sulfuric acid with a corresponding concentration can be selected according to the actual situation. Benzene can be crude benzene, petroleum benzene or coking benzene; crude benzene is a mixture recovered from coke oven gas, and its main components include benzene and its homologues, and the content of benzene and its homologues in crude benzene is between 80% and 95%; petroleum benzene is a benzene compound refined from petroleum; coking benzene is a product obtained by further processing the crude benzene recovered from coke oven gas by a coking plant, and the benzene content in coking benzene is not less than 99%. Oleic acid is a colorless to light yellow viscous liquid with a purity ≥ 98.0%.

[0050] Taking sulfuric acid with a mass fraction of 98%, coking benzene conforming to the national standard of coking benzene GB / T 2283-2019 and oleic acid with a purity ≥ 98.0% as examples below, the preparation method of the collector for fluorite flotation will be further described.

[0051] Example 1

[0052] A preparation method of a collector for fluorite flotation, comprising the following steps:

[0053] Step 1: Weigh 100 g of sulfuric acid with a mass fraction of 98% and 130 g of benzene according to the mass ratio of benzene to sulfuric acid of 1:1.3. Under stirring conditions, add benzene into the enamel reaction kettle, and then slowly add a part of sulfuric acid along the wall of the enamel reaction kettle. Control the reaction temperature to rise from 20 °C to 50 °C, keep the temperature for 2 h, and then cool down to below 30 °C; then continue to slowly add a part of sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50 °C, keep the temperature for 2 h, and then cool down to below 30 °C; continue to slowly add the remaining sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50 °C, keep the temperature for 2 h, and then cool down to below 30 °C. Keep stirring during the reaction process; by adding sulfuric acid in batches, side reactions caused by too high temperature are avoided. After the reaction is completed, a sulfonation reaction solution is obtained.

[0054] Since water is generated during the sulfonation reaction, as the reaction proceeds, the water content gradually increases, causing partial dissociation of sulfonic acid groups to generate benzene, which is the reverse reaction of the sulfonation reaction. Therefore, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid, and unreacted benzene.

[0055] Step 2: Use oleic acid as the raw material, and weigh oleic acid according to the mass ratio of the benzene addition amount in Step 1 to the oleic acid addition amount of 1:0.27, and add it into the enamel reaction kettle. Adjust the temperature of the enamel reaction kettle to 10 °C; under stirring conditions, slowly add the sulfonation reaction solution obtained in Step 1 along the wall of the enamel reaction kettle, and control the reaction temperature between 10 °C and 20 °C. This is mainly because when the temperature is too low and lower than 10 °C, it is easy to form a semi-solid; after all the sulfonation reaction solution is added, continue to stir and react for 1 h.

[0056] Then, add a 10 wt% sodium hydroxide solution in 2 batches for the neutralization reaction, and control the neutralization reaction temperature ≤ 60 °C. Specifically: add the first sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C, stagnate for 2 hours, then discharge the generated waste liquid, add the sodium hydroxide solution again, and control the neutralization reaction temperature ≤ 60 °C; finally adjust the pH to 7 - 8. After the neutralization reaction is completed, separate and remove the lower-layer wastewater and the middle impurity layer to obtain a viscous mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium stearate benzenesulfonate as a fluorite flotation collector.

[0057] Example 2

[0058] A preparation method of a fluorite flotation collector, comprising the following steps:

[0059] Step 1: According to the mass ratio of benzene to sulfuric acid being 1:1.33, weigh 100 g of sulfuric acid with a mass fraction of 98% and 133 g of benzene. Under stirring conditions, add benzene into the enamel reaction kettle, and then slowly add a part of sulfuric acid along the inner wall of the enamel reaction kettle. Control the reaction temperature to rise from 20 °C to 55 °C, keep it warm for 1 h, and then cool it down to below 30 °C. After that, continue to slowly add the remaining sulfuric acid along the inner wall of the enamel reaction kettle, control the reaction temperature to rise to 55 °C, keep it warm for 2 h, and then cool it down to below 30 °C. Keep stirring during the reaction process; by adding sulfuric acid in batches, side reactions caused by too high temperature are avoided. After the reaction ends, a sulfonation reaction solution is obtained.

[0060] Since water is generated during the sulfonation reaction process, as the reaction progresses, the water content gradually increases, causing partial dissociation of sulfonic acid groups to generate benzene, which is the reverse reaction of the sulfonation reaction. Therefore, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid, and unreacted benzene.

[0061] Step 2: Using oleic acid as the raw material, according to the mass ratio of the benzene addition amount in Step 1 to the oleic acid addition amount being 1:0.69, weigh oleic acid and add it into the enamel reaction kettle, and adjust the temperature of the enamel reaction kettle to about 20 °C; under stirring conditions, slowly add the sulfonation reaction solution obtained in Step 1 along the inner wall of the enamel reaction kettle, and control the reaction temperature to be between 10 °C and 20 °C. This is mainly because when the temperature is too low and lower than 10 °C, it is easy to form a semi-solid; after all the sulfonation reaction solution is added, continue to stir and react for 1 h.

[0062] After that, add the sodium hydroxide solution with a mass fraction of 5 wt% in 3 batches for the neutralization reaction, and control the neutralization reaction temperature ≤ 60 °C. Specifically: add the first sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C, stagnate for 2 hours, then discharge the generated waste liquid, add the sodium hydroxide solution again, control the neutralization reaction temperature ≤ 60 °C, stagnate for 2 hours, and then discharge the generated waste liquid; finally add the remaining sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C; finally adjust the pH to 7 - 8. After the neutralization reaction ends, separate and remove the lower-layer wastewater and the middle impurity layer to obtain a mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium stearate benzenesulfonate as the fluorite flotation collector.

[0063] Example 3

[0064] A preparation method of a fluorite flotation collector, comprising the following steps:

[0065] Step 1: Weigh 100 g of sulfuric acid with a mass fraction of 98% and 136 g of benzene according to the mass ratio of benzene to sulfuric acid of 1:1.36. Under stirring conditions, add benzene into the enamel reaction kettle, and then slowly add a part of sulfuric acid along the wall of the enamel reaction kettle. Control the reaction temperature to rise from 20°C to 50°C, keep the temperature for 1.5 h, and then cool down to below 30°C. After that, continue to slowly add sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50°C, keep the temperature for 2 h, and then cool down to below 30°C. Then continue to slowly add sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50°C, keep the temperature for 2 h, and then cool down to below 30°C. Then continue to slowly add sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50°C, keep the temperature for 2 h, and then cool down to below 30°C. Keep stirring during the reaction process; by adding sulfuric acid in batches, side reactions caused by too high temperature can be avoided. After the reaction is completed, a sulfonation reaction solution is obtained.

[0066] Since water is generated during the sulfonation reaction, and as the reaction progresses, the water content gradually increases, causing partial dissociation of sulfonic acid groups to form benzene, which is the reverse reaction of the sulfonation reaction. Therefore, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid, and unreacted benzene.

[0067] Step 2: Use oleic acid as the raw material, weigh oleic acid according to the mass ratio of the benzene addition amount in Step 1 to the oleic acid addition amount of 1:0.89, and add it into the enamel reaction kettle. Adjust the temperature of the enamel reaction kettle to 18°C; under stirring conditions, slowly add the sulfonation reaction solution obtained in Step 1 along the wall of the enamel reaction kettle, and control the reaction temperature to be below 30°C, specifically between 10°C and 20°C. This is mainly because when the temperature is too low and below 10°C, it is easy to form a semi-solid; after all the sulfonation reaction solution is added, continue to stir and react for 1 h.

[0068] Then add a 10 wt% sodium hydroxide solution in 3 batches for the neutralization reaction, and control the neutralization reaction temperature ≤ 60°C. Specifically: add the first sodium hydroxide solution, control the neutralization reaction temperature ≤ 60°C, stagnate for 2 hours, then discharge the generated waste liquid, add the sodium hydroxide solution again, control the neutralization reaction temperature ≤ 60°C, stagnate for 2 hours, and then discharge the generated waste liquid; finally add the remaining sodium hydroxide solution, control the neutralization reaction temperature ≤ 60°C; finally adjust the pH to 7 - 8. After the neutralization reaction is completed, separate and remove the lower-layer wastewater and the middle impurity layer to obtain a mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium stearate benzenesulfonate as the fluorite flotation collector.

[0069] Example 4

[0070] A preparation method of a fluorite flotation collector, comprising the following steps:

[0071] Step 1: Weigh 100 g of sulfuric acid with a mass fraction of 98% and 140 g of benzene according to the mass ratio of benzene to sulfuric acid of 1:1.4. Under stirring conditions, add benzene into the enamel reaction kettle, and then slowly add a part of sulfuric acid along the inner wall of the enamel reaction kettle. Control the reaction temperature to rise from 20 °C to 60 °C, keep the temperature for 1.5 h, and then cool down to below 30 °C. Then continue to slowly add the remaining sulfuric acid along the inner wall of the enamel reaction kettle, control the reaction temperature to rise to 60 °C, keep the temperature for 2 h, and then cool down to below 30 °C. Keep stirring during the reaction process; by adding sulfuric acid in batches, side reactions caused by too high temperature can be avoided. After the reaction is completed, a sulfonation reaction solution is obtained.

[0072] Since water is generated during the sulfonation reaction, as the reaction progresses, the water content gradually increases, causing partial dissociation of sulfonic acid groups to form benzene, which is the reverse reaction of the sulfonation reaction. Therefore, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid, and unreacted benzene.

[0073] Step 2: Use oleic acid as the raw material, weigh oleic acid according to the mass ratio of the benzene addition amount in Step 1 to the oleic acid addition amount of 1:1.34, and add it into the enamel reaction kettle. Adjust the temperature of the enamel reaction kettle to below 20 °C. Under stirring conditions, slowly add the sulfonation reaction solution obtained in Step 1 along the inner wall of the enamel reaction kettle, and control the reaction temperature to be below 30 °C, specifically between 10 °C and 20 °C. This is mainly because when the temperature is too low and below 10 °C, it is easy to form a semi-solid. After all the sulfonation reaction solution is added, continue to stir and react for 2 h.

[0074] Then add the sodium hydroxide solution with a mass fraction of 10 wt% in 3 batches for the neutralization reaction, and control the neutralization reaction temperature ≤ 60 °C. Specifically: add the first sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C, let it stand for 2 hours, then discharge the generated waste liquid, add the sodium hydroxide solution again, control the neutralization reaction temperature ≤ 60 °C, let it stand for 2 hours, then discharge the generated waste liquid; finally add the remaining sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C; finally adjust the pH to 7 - 8. After the neutralization reaction is completed, separate and remove the lower-layer wastewater and the middle impurity layer to obtain a mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium stearate benzenesulfonate as the fluorite flotation collector.

[0075] Example 5

[0076] A preparation method of a fluorite flotation collector, comprising the following steps:

[0077] Step 1: According to the mass ratio of benzene to sulfuric acid being 1:1.5, weigh 100 g of sulfuric acid with a mass fraction of 98% and 150 g of benzene. Under stirring conditions, add benzene into the enamel reaction kettle, and then slowly add a part of sulfuric acid along the wall of the enamel reaction kettle. Control the reaction temperature to rise from 20 °C to 50 °C, keep the temperature for 1.5 h, and then cool down to below 30 °C. After that, continue to slowly add the remaining sulfuric acid along the wall of the enamel reaction kettle, control the reaction temperature to rise to 50 °C, keep the temperature for 1.5 h, and then cool down to below 30 °C. Keep stirring during the reaction process; by adding sulfuric acid in batches, avoid side reactions caused by too high temperature. After the reaction ends, obtain the sulfonation reaction solution.

[0078] Since water is generated during the sulfonation reaction, as the reaction proceeds, the water content gradually increases, causing partial dissociation of sulfonic acid groups to generate benzene, which is the reverse reaction of the sulfonation reaction. Therefore, the sulfonation reaction solution contains benzenesulfonic acid, excessive sulfuric acid, and unreacted benzene.

[0079] Step 2: Using oleic acid as the raw material, according to the mass ratio of the benzene addition amount in Step 1 to the oleic acid addition amount being 1:1.86, weigh oleic acid and add it into the enamel reaction kettle, and adjust the temperature of the enamel reaction kettle to below 20 °C. Under stirring conditions, slowly add the sulfonation reaction solution obtained in Step 1 along the wall of the enamel reaction kettle, control the reaction temperature to be below 30 °C, specifically between 10 °C and 20 °C. This is mainly because when the temperature is too low and below 10 °C, it is easy to form a semi-solid. After all the sulfonation reaction solution is added, continue to stir and react for 1 h.

[0080] Then add the sodium hydroxide solution with a mass fraction of 10 wt% in 3 batches for the neutralization reaction, and control the neutralization reaction temperature ≤ 60 °C. Specifically: add the first sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C, stagnate for 2 hours, then discharge the generated waste liquid, add the sodium hydroxide solution again, control the neutralization reaction temperature ≤ 60 °C, stagnate for 2 hours, and then discharge the generated waste liquid; finally add the remaining sodium hydroxide solution, control the neutralization reaction temperature ≤ 60 °C; finally adjust the pH to 7 - 8. After the neutralization reaction ends, separate and remove the lower-layer wastewater and the middle impurity layer to obtain a semi-solid mixture containing sodium oleate, sodium sulfated oleate, sodium hydroxyoleate, and sodium stearate benzenesulfonate as the fluorite flotation collector.

[0081] Table 1 Raw material ratio of fluorite flotation collector

[0082]

[0083] Note: A represents benzene; B represents sulfuric acid; C represents oleic acid; A:B:C represents the mass ratio of benzene, sulfuric acid, and oleic acid. The yield of the fluorite flotation collector is calculated based on sodium stearate benzenesulfonate.

[0084] The structural formula of sodium stearate benzenesulfonate is

[0085] As can be seen from the results in Table 1, in Examples 1 to 5, excessive sulfuric acid was used to promote the forward progress of the sulfonation reaction. With the increase in the amount of sulfuric acid, the amount of oleic acid also increased to reduce the free sulfate ions and hydrogen ions in the system. The amount of sulfuric acid had little effect on the yield of sodium stearate benzene sulfonate. However, excessive sulfuric acid would make the foaming ability of the fluorite flotation collector too strong and the selectivity decrease, thus reducing the collecting ability. Therefore, the mass ratio of benzene, sulfuric acid, and oleic acid was preferably 1:1.3 - 1.36:0.27 - 0.89. According to the standard YB_T 5217-2019 "Fluorite", the organic matter content of special grade, first grade, and second grade in fluorite concentrate powder shall not exceed 0.10%. The benzene residue in the fluorite flotation collector obtained by the method of the examples of the present invention all meets the standard requirements.

[0086] Next, the fluorite flotation was carried out with the fluorite flotation collector prepared in the above examples. Among them, oleic acid and water glass were purchased from Jiangsu Bost Chemical Technology Co., Ltd.

[0087] The fluorite ore was selected from a certain fluorite ore in Inner Mongolia, and the component contents and particle size ranges of the fluorite ore are shown in Table 2 and Table 3.

[0088] Table 2 Content of various components in fluorite ore

[0089] Name <![CDATA[CaF2]]> <![CDATA[SiO2]]> <![CDATA[CaCO3]]> Others Total Content 25％ 56％ 6％ 13％ 100％

[0090] Table 3 Particle size range of fluorite ore

[0091] Particle size / mm +0.10 0.10～0.074 0.074～0.038 0.038～0.019 ～0.019 Proportion / % 0.10 9.17 20.26 25.37 45.10

[0092] Application Example 1

[0093] Using the fluorite flotation collector prepared in Example 3 for fluorite flotation, the method of the fluorite flotation process is as follows:

[0094] S1. Grinding process: After crushing the fluorite ore, it was added to a ball mill and water was added for grinding. The overflow pulp concentration of the grinding was 30%, and the undersize product with a particle size of -0.074 mm in the overflow reached more than 80 wt% of the raw material to obtain a fluorite ore pulp.

[0095] S2. Rough selection process: The fluorite ore pulp after grinding was added with 200 g / t of the fluorite flotation collector per ton of raw ore and subjected to rough selection at room temperature to obtain rough selection foam and rough selection tailings. The flotation machine used for rough selection was an XCF / KYF8 cubic air-inflated mechanical agitation flotation machine.

[0096] S3. Cleaning process:

[0097] The rough-selected tailings are scavenged; the scavenging is carried out twice, denoted as scavenging 1 and scavenging 2 respectively.

[0098] Scavenging 1 is to mix the rough-selected tailings, a part of the first-stage concentrated middlings, and oleic acid of 10 g / t of the original ore, and then conduct the first scavenging to obtain the first scavenging foam and the first scavenging tailings; the first scavenging foam is transferred to the rough-selection process.

[0099] Scavenging 2 is to conduct the second scavenging on the tailings from the first scavenging to obtain the second scavenging concentrate and the second scavenging tailings; the second scavenging concentrate is transferred to the first scavenging process, and at the same time, the second scavenging tailings are discarded.

[0100] The flotation machine used for scavenging is the XCF / KYF8 cubic aerated mechanical agitation flotation machine.

[0101] S4. Concentration process:

[0102] The concentration is carried out six times, denoted as concentration 1, concentration 2, concentration 3, concentration 4, concentration 5, and concentration 6 respectively.

[0103] Concentration 1: Sodium silicate of 120 g / t of the original ore is added to the rough-selection foam per ton of the original ore as an inhibitor, and at the same time, a fluorite flotation collector of 100 g / t of the original ore is added to conduct the first concentration to obtain the first concentration foam and the first concentration middlings. The flotation machine used for the first concentration is the XCF / KYF8 cubic aerated mechanical agitation flotation machine. Among them, the first concentration middlings are transferred to the rough-selection process.

[0104] Concentration 2: Sodium silicate of 100 g / t of the original ore is added to the first concentration foam per ton of the original ore as an inhibitor, and at the same time, a fluorite flotation collector of 80 g / t of the original ore is added to conduct the second concentration to obtain the second concentration foam and the second concentration middlings. The flotation machine used for the second concentration is the XCF / KYF4 cubic aerated mechanical agitation flotation machine. The second concentration middlings are transferred to the first concentration process.

[0105] Concentration 3: Sodium silicate of 80 g / t of the original ore is added to the second concentration foam per ton of the original ore as an inhibitor, and at the same time, a fluorite flotation collector of 60 g / t of the original ore is added to conduct the third concentration to obtain the third concentration foam and the third concentration middlings. The flotation machine used for the third concentration is the XCF / KYF4 cubic aerated mechanical agitation flotation machine. The third concentration middlings are transferred to the second concentration process.

[0106] Concentration 4: The fourth concentration is carried out on the third concentration foam to obtain the fourth concentration foam and the fourth concentration middlings. The flotation machine used for the fourth concentration is the XCF / KYF4 cubic aerated mechanical agitation flotation machine. The fourth concentration middlings are transferred to the third concentration process.

[0107] Fine Selection Five: Conduct the fifth fine selection on the fourth fine selection foam to obtain the fifth fine selection foam and the fifth fine selection middlings. The flotation machine used for the fifth fine selection is an XCF / KYF 4-cubic-meter air-inflated mechanical agitation flotation machine. The fifth fine selection middlings are transferred to the fourth fine selection process.

[0108] Fine Selection Six: Conduct the sixth fine selection on the fifth fine selection foam to obtain fluorite concentrate powder and the sixth fine selection middlings. The flotation machine used for the sixth fine selection is an XCF / KYF 4-cubic-meter air-inflated mechanical agitation flotation machine. The sixth fine selection middlings are transferred to the fifth fine selection process.

[0109] The fluorite flotation collector described in the above application examples is the fluorite flotation collector prepared in Examples 1 to 5, and the flotation temperature range is 20°C.

[0110] Application Example 2

[0111] Perform fluorite flotation with the fluorite flotation collector prepared in Example 1, following the method of Application Example 1, with the difference being the dosage of the fluorite flotation collector, as shown in Table 4 specifically.

[0112] Application Example 3

[0113] Perform fluorite flotation with the fluorite flotation collector prepared in Example 2, following the method of Application Example 1, with the difference being the dosage of the fluorite flotation collector, as shown in Table 4 specifically.

[0114] Application Example 4

[0115] Perform fluorite flotation with the fluorite flotation collector prepared in Example 4, following the method of Application Example 1, with the difference being the dosage of the fluorite flotation collector, as shown in Table 4 specifically.

[0116] Application Example 5

[0117] Perform fluorite flotation with the fluorite flotation collector prepared in Example 5, following the method of Application Example 1, with the difference being the dosage of the fluorite flotation collector, as shown in Table 4 specifically.

[0118] Application Comparative Example 1

[0119] Perform fluorite flotation using oleic acid as the fluorite flotation collector, following the method of Application Example 1, with the difference being the dosage of oleic acid, as shown in Table 4 specifically.

[0120] Table 4 Dosage of fluorite flotation collector, g / t of raw ore

[0121] Fluorite flotation collector Rougher flotation process First cleaning Second cleaning Third cleaning Total dosage Example 1 210 105 90 65 470 Example 2 206 109 88 62 465 Example 3 200 100 80 60 440 Example 4 205 100 85 60 450 Example 5 210 110 78 63 461 Oleic acid 260 160 130 120 670

[0122] Taking the first-class fluorite concentrate FC-97 as the flotation quality standard, the flotation indexes are: CaF2≥97.00%, SiO2≤1.50%, CaCO3≤1.10%, S≤0.05%, P≤0.05%, As≤0.0005%, organic matter≤0.10%, H2O≤14.00%.

[0123] The flotation comparison results of oleic acid and the fluorite flotation collector prepared in Examples 1 to 5 are shown in Table 5, and the flotation temperature is 20°C.

[0124] Table 5 Flotation comparison results of oleic acid and fluorite flotation collector

[0125] Collector <![CDATA[Grade of CaF2 in Concentrate]]> Concentrate recovery rate Fluorite flotation collector of Example 1 97.37％ 86.36％ Fluorite flotation collector of Example 2 97.42％ 86.30％ Fluorite flotation collector of Example 3 97.51％ 86.27％ Fluorite flotation collector of Example 4 97.26％ 85.09％ Fluorite flotation collector of Example 5 97.17％ 85.22％ Oleic acid 97.09％ 80.54％

[0126] It can be seen from Table 5 in combination with Table 4 that compared with oleic acid as the collector, the fluorite flotation collectors in Examples 1 to 5 of the present invention all have good flotation collecting ability, and the dosage of the fluorite flotation collector is relatively small. The grade of CaF2 in the concentrate is above 97.00%, and the recovery rate of the concentrate is increased by about 5 percentage points, reaching more than 85%. Among them, for the fluorite flotation collectors prepared in Examples 4 and 5, due to the excessive addition of sulfuric acid, the amount of oleic acid also increases, resulting in too strong foaming ability of the fluorite flotation collector, a slight decrease in selectivity, and a decrease in collecting ability.

[0127] In addition, the fluorite flotation collectors prepared in Examples 1 to 5 of the present invention can be applied to the flotation temperature range of 10°C to 25°C and have good collecting ability.

[0128] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a fluorite flotation collector, characterized in that, It includes the following steps: Perform a sulfonation reaction on benzene and sulfuric acid to obtain a sulfonation reaction solution; wherein, the mass ratio of benzene to sulfuric acid is 1:1.3 - 1.5; the sulfuric acid is concentrated sulfuric acid or fuming sulfuric acid with a concentration of 90wt% - 98wt%. Using oleic acid or acidified oil as the raw material, add the sulfonation reaction solution under the condition of 10°C - 20°C and carry out a stirring reaction; the acidified oil is the acidified oil obtained by acidolysis of the oil sludge saponin produced in refined vegetable oil; then add an alkali solution for a neutralization reaction, control the temperature ≤ 80°C, adjust the pH to 7 - 8; separate and remove the aqueous phase to obtain a mixture containing oleate, sulfated oleate, hydroxyoleate and stearic acid benzene sulfonate as a collector for fluorite flotation.

2. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, In the acidified oil, the acid value ≥ 165mg KOH / g, the iodine value ≥ 110gI2 / 100g oil, the saponification value ≥ 185mg KOH / g, and the water impurity content ≤ 5%.

3. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, The mass ratio of benzene to sulfuric acid is 1:1.3 - 1.

4.

4. The preparation method of the fluorite flotation collector according to claim 3, characterized in that, The mass ratio of benzene to sulfuric acid is 1:

36.

5. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, The addition amount of oleic acid or acidified oil to benzene is 0.27 - 1.86:1 in terms of mass ratio.

6. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, Control the temperature of the neutralization reaction ≤ 60°C.

7. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, The alkali solution is sodium hydroxide solution or potassium hydroxide solution; the mass fraction of the alkali solution is 5wt% - 20wt%.

8. The preparation method of the fluorite flotation collector according to claim 1, characterized in that, The temperature of the sulfonation reaction is 20°C - 60°C.

9. The preparation method of the fluorite flotation collector according to claim 8, characterized in that, The specific process of the sulfonation reaction is as follows: Under stirring conditions, add sulfuric acid to benzene in 2 - 5 times. During each addition of sulfuric acid, control the reaction temperature to rise to 50°C - 60°C. After reacting for 1h - 2h, cool down to below 30°C to obtain the sulfonation reaction solution.

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