Drying-free xanthate collecting agent and preparation method and application thereof

Abstract

The invention belongs to the technical field of flotation collecting agents, and particularly discloses a drying-free xanthate collecting agent and a preparation method and application thereof. The preparation method comprises the following steps: adding an additive into a reaction system for synthesizing xanthogenate, wherein the addition amount of the additive is 0.1-10% of the mass of the finally obtained xanthogenate product; the additive is selected from at least one of sodium metasilicate, calcium oxide, metaaluminate, montmorillonite, anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, potassium sulfate, magnesium oxide, aluminum oxide, calcium lactate, molecular sieve and fumed silica. The collecting agent has the advantages of being free of drying, capable of being directly obtained, high in stability, excellent in physical property, capable of improving the flotation effect and the like. The preparation method provided by the invention can effectively improve the working environment of the production process of xanthate, and is easy to realize industrial production.

Description

Technical Field

[0001] This invention relates to the technical field of flotation collectors, and more particularly to a drying-free xanthate collector, its preparation method, and its application. Background Technology

[0002] Xanthates, also known as dithiocarbonates (commonly called xanthates), are the most widely used and consumed flotation collectors in the mineral processing industry. However, residual moisture in their industrially synthesized products can directly lead to chemical failure and deterioration of physical properties. Specifically, on the one hand, moisture triggers and accelerates the deterioration of xanthate ions (ROCSS). - The reversible hydrolysis reaction (producing alcohol, CS2 and OH) - The presence of water, along with oxidation reactions (generating biflavonoids, etc.), continuously consumes the active ingredients, reduces harvesting selectivity, and severely shortens the product's shelf life. Furthermore, the presence of free water easily causes severe powder agglomeration, leading to bridging and blockages during storage, transportation, and feeding, disrupting production continuity. In addition, improper moisture content control can cause granulation difficulties or dust pollution. Therefore, removing moisture to achieve chemical stability and a "low dust, high flowability" physical state has become an indispensable drying step in traditional production processes.

[0003] To overcome the shortcomings of traditional drying processes, recent technological improvements have mainly focused on the following three directions: (1) Drying process control and equipment optimization, for example, patent CN120292852A discloses an energy-saving control method for drying towers based on historical data modeling, patent CN118794218A discloses a multi-layer drying tower that optimizes airflow distribution using a stepped cavity and a guide structure, and patent CN117824328A discloses a belt vacuum drying device and process that can achieve continuous production and avoid agglomeration; (2) Enhancement of vacuum drying systems, such as patent CN216204710U discloses a technical solution to accelerate moisture removal and reduce agglomeration and wall adhesion by adding a Roots vacuum pump to increase the system vacuum level; (3) Dynamic drying and mechanical dispersion technology, patent CN114526589A discloses a dryer that integrates dispersing, scattering and drying functions, patent CN119374352A discloses a scattering dryer that uses a rotating scattering disc to enhance particle dispersion and circulation, and patent CN223460708U discloses a horizontal fluidized bed dryer that uses mechanical agitation to make the material evenly distributed in the fluidized bed.

[0004] However, while the aforementioned existing technologies have improved drying uniformity and energy efficiency to some extent, they still have not overcome the inherent limitations of traditional thermal drying technologies: the process still requires precise temperature and pressure control, is complex to operate, and is costly; due to the high heat sensitivity of xanthates, strict temperature control is required for drying, and uneven heating can easily lead to decomposition, oxidation, or "dry outside, wet inside" phenomena, resulting in particle pulverization, agglomeration, or decreased strength; at the same time, the sulfur-containing waste gas volatilized during the drying process also imposes an environmental treatment burden. Overall, the existing process is essentially a high-energy-consuming process that seeks to balance dehydration efficiency, product stability, and economic cost.

[0005] In summary, existing technologies still cannot fundamentally solve the multiple problems associated with xanthates, such as chemical instability and poor physical properties caused by moisture, as well as the high energy consumption, high pollution, and operational complexity of the drying process itself. Therefore, developing a new method for preparing xanthate collectors that can eliminate drying at the source and directly obtain products with high stability and excellent physical properties is of great significance and innovative value for promoting technological upgrading in the industry, reducing production costs, and achieving green manufacturing. Summary of the Invention

[0006] In view of the above-mentioned problems, this invention discloses a drying-free xanthate collector, its preparation method, and its application. This invention, by adding additives to the reaction system for synthesizing xanthate, inhibits the hydrolysis and oxidation side reactions of xanthate ions, improves antioxidant and deliquescence resistance, delays the degradation of active ingredients, extends product shelf life, and ensures its stability during flotation. It can play a synergistic promoting role in flotation, helping to improve overall separation efficiency; it enables low-dust clean granulation, enhancing particle strength and uniformity, thereby significantly improving the industrial operating environment and enhancing operational safety and convenience; it avoids complex temperature control and airflow regulation operations, greatly shortening the production cycle and improving production line continuity; it fundamentally avoids the decomposition, oxidation, or "externally dry, internally wet" phenomenon of xanthate caused by localized overheating during traditional drying processes, ensuring the chemical homogeneity and structural integrity of the product. The additives used are highly safe, with no sulfur-containing waste gas volatilization, reducing environmental and health risks and meeting green manufacturing requirements.

[0007] To address the aforementioned problems, this invention provides a method for preparing a drying-free xanthate collector. An additive is added to the reaction system for synthesizing xanthate, the amount of which is 0.1-10% of the final xanthate product mass. The additive is selected from at least one of sodium metasilicate, calcium aluminate, aluminate, montmorillonite, anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, potassium sulfate, magnesium oxide, aluminum oxide, calcium lactate, molecular sieve, and fumed silica.

[0008] It should be noted that among the above additives,

[0009] Additives that primarily function through physical adsorption: montmorillonite, molecular sieves, and alumina;

[0010] Additives that primarily function through chemical bonding: calcium oxide, anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, and aluminates;

[0011] Additives with synergistic effects of physical adsorption and chemical bonding: sodium metasilicate, potassium sulfate, magnesium oxide, calcium lactate, and fumed silica.

[0012] The above classification is based on the main characteristics of the interaction between each additive and the moisture in the system. However, in practical applications, the water absorption and stabilizing effects of most additives are the result of both physical and chemical mechanisms.

[0013] It should be noted that the addition of additives to the reaction system for synthesizing xanthates in this invention can form a stable inorganic adsorption / coating layer or porous network structure on the surface of xanthate particles. Specifically:

[0014] The main additives that form the inorganic adsorption / coating layer are: sodium metasilicate, calcium oxide, aluminate, calcium lactate, anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, and potassium sulfate;

[0015] The main additives that constitute the porous network structure are: molecular sieves, montmorillonite, alumina (activated alumina), magnesium oxide (light or active), and fumed silica.

[0016] The above classification is based on the dominant physical function of each additive in the xanthate particle system. In practical applications, multiple additives can synergistically construct a stable composite structure.

[0017] The additives of this invention are classified according to their functions as follows:

[0018] Hygroscopic additives (these additives can effectively absorb and fix free water in the system, improve the slurry environment or the physical state of the collector itself): anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, montmorillonite, molecular sieves and alumina.

[0019] Alkaline regulating additives (these additives can adjust the pH of the slurry, thereby inhibiting the target mineral): calcium oxide, sodium metasilicate, and aluminates.

[0020] Porous adsorption additives (these additives have high specific surface area or porous structure, and can selectively adsorb ions or molecules in the slurry, affecting the surface properties of minerals): molecular sieves, montmorillonite, and alumina;

[0021] Skeleton-filling additives (these additives mainly play a physical role in supporting, dispersing or improving the flowability of materials in solid mixtures): potassium sulfate, calcium lactate, magnesium oxide and fumed silica.

[0022] The above classification is based on the "most prominent or most likely to be utilized auxiliary function" of each additive. It should be noted that an additive may have multiple functional properties at the same time (for example, "montmorillonite" has both hygroscopic, adsorption and even ion exchange activation / inhibition capabilities).

[0023] Preferably, the amount of the additive added is 0.5-5% of the mass of the final xanthate product.

[0024] Preferably, the xanthate is prepared by reacting a raw material comprising an alcohol, carbon disulfide, and a caustic base; wherein the alcohol comprises C2~C64. 12 At least one of fatty alcohols, fusel oils, and hydroxyl ether alcohols.

[0025] Preferred, C2~C 12 The fatty alcohol is selected from at least one of ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, isoamyl alcohol, neopentyl alcohol, n-hexanol, isohexanol, methyl isobutyl methanol, n-octanol, isooctanol, and dodecanol.

[0026] The above C2~C 12 The reaction equation for the synthesis of xanthates from fatty alcohols by reacting with carbon sulfide and caustic alkali is shown in Reaction I below:

[0027] (I).

[0028] In the above formula, R 1 It is selected from one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, isopentyl, sec-pentyl, and neopentyl; M is Na or K.

[0029] Preferably, the caustic alkali is at least one of sodium hydroxide and potassium hydroxide, and is in powder, granule or flake form.

[0030] Preferably, the xanthate is prepared by reacting a raw material comprising an alcohol, carbon disulfide and a caustic alkali, wherein the alcohol is a hydroxyl ether alcohol.

[0031] Preferably, the molar ratio of alcohol to caustic alkali is 1:0.5-1:1.2, and the molar amount of carbon disulfide is not less than the molar amount of alcohol.

[0032] Preferably, the hydroxyl ether alcohol is selected from 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 2-tert-butoxyethanol, 2-hexyloxyethanol, 2-methoxypropanol, 2-ethoxypropanol, 2-butoxypropanol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, di ... diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, diethylene glycol monobutyl ether, One or more of the following: ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, diethylene glycol monopentyl ether, triethylene glycol monopentyl ether, tetraethylene glycol monopentyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, propylene glycol monopentyl ether, dipropylene glycol monopentyl ether, tripropylene glycol monopentyl ether, tetrapropylene glycol monopentyl ether.

[0033] Preferably, the hydroxyl ether alcohol is a propylene glycol ether; the propylene glycol ether is selected from at least one of propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, propylene glycol monopentyl ether, dipropylene glycol monopentyl ether, tripropylene glycol monopentyl ether, and tetrapropylene glycol monopentyl ether.

[0034] The reaction equations for the synthesis of xanthate from the above-mentioned propylene glycol ether with carbon sulfide and caustic alkali are shown in reaction equations II-VII below:

[0035] (II);

[0036] (III);

[0037] (IV);

[0038] (V);

[0039] (VI); (VII).

[0040] In the above formulas, R 1It is selected from one of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, isopentyl, sec-pentyl, and neopentyl; M is Na or K.

[0041] For example, the alcohol is at least one of the distillation residue from the ethylene oxide process for producing ethylene glycol ether and the distillation residue from the propylene oxide process for producing propylene glycol ether.

[0042] It should be noted that when the alcohol is the residue from the distillation vessel during the production of propylene glycol ethers using the propylene oxide process, the reaction formulas involved include I-VII.

[0043] Preferably, the additive is added before the reaction begins, during the reaction, or after the reaction is completed; and / or, the method for synthesizing xanthate includes at least one of the kneading method and the solvent method.

[0044] Preferably, the reaction temperature for synthesizing xanthate is 0-60℃ and the reaction time is 1-6h.

[0045] Preferably, in the solvent method, the raw materials further include a solvent, which includes at least one of dichloromethane, dichloroethane, carbon disulfide, ethanol, and tetrahydrofuran; after the reaction is completed, the solvent is recovered by atmospheric distillation or vacuum distillation, wherein the temperature of atmospheric distillation is 60-100℃ and the temperature of vacuum distillation is 30-80℃.

[0046] Preferably, the volume of the solvent is 2-10 times the volume of the alcohol.

[0047] Based on the same inventive concept, the present invention provides a drying-free xanthate collector prepared by any of the preparation methods described above.

[0048] Based on the same inventive concept, the present invention also provides an application of the above-described drying-free xanthate collector in mineral flotation.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] (1) Compared with products prepared by traditional kneading method, the present invention introduces additives, which effectively fix the free water in the system by means of the physical adsorption and chemical bonding of the additives, thereby significantly reducing the free water content. At the same time, the additives can form a stable inorganic adsorption / coating layer or porous network structure on the surface of xanthate particles, which plays a "buffer isolation" role for the active components, reducing their contact probability with oxygen and water vapor in the air, thereby inhibiting the hydrolysis and oxidation side reactions of xanthate ions, improving the antioxidant and deliquescence resistance, delaying the degradation of effective components, extending the shelf life of the product, and ensuring its stable performance in the flotation process.

[0051] (2) The additive of the present invention can be used as a solid carrier and a dispersion medium at the same time. It can absorb moisture and block the agglomeration and clumping between particles, so that the product remains in a uniform and loose powder or granular state, significantly improving the flowability of materials and effectively avoiding bridging and blockage during storage, transportation and feeding.

[0052] (3) The additives of the present invention are sodium metasilicate, calcium oxide, aluminate, montmorillonite, molecular sieve, etc., which can be used as flotation activators or gangue mineral inhibitors. According to different ore properties and flotation conditions, different types (hygroscopic, alkaline control, porous adsorption, skeleton filling, etc.) of additives and their combinations can be introduced into the flotation system to play a synergistic promoting role in the flotation process and help improve the overall separation efficiency.

[0053] (4) The preparation method provided by the present invention can achieve low dust clean granulation by adjusting the appropriate moisture content and with the help of the molding assistance of additives, thereby enhancing the strength and uniformity of the particles, thus significantly improving the industrial use environment and improving the safety and convenience of operation.

[0054] (5) The preparation method provided by the present invention completely eliminates the traditional hot drying process and related supporting equipment, avoids complex temperature control and airflow regulation operations, greatly shortens the production cycle, and improves the continuity of the production line. At the same time, by eliminating the high-energy-consuming drying process, the energy consumption and production cost per unit product are significantly reduced;

[0055] (6) The preparation method provided by this invention fundamentally avoids the decomposition, oxidation, or "external dry and internal wet" phenomenon of xanthates caused by local overheating during the traditional drying process, ensuring the chemical uniformity and structural integrity of the product. The additives used are highly safe, with no sulfur-containing waste gas volatilization, reducing environmental and health risks and meeting the requirements of green manufacturing;

[0056] (7) The additives of the present invention are mostly common inorganic salts / oxides / layered aluminosilicate materials, which are widely available, inexpensive, and stable in storage and transportation; their doping ratio is low and the process steps are simplified, making it easy to quickly transform and promote large-scale application in existing production lines. Attached Figure Description

[0057] Figure 1 This is a flow chart of the actual flotation process for copper sulfide ore according to the present invention;

[0058] Figure 2 The graphs show the changes in the effective content of the products synthesized in Examples 1, 4, 6, and 8 of the present invention and Comparative Examples 1-2 over time. Detailed Implementation

[0059] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or obtained by known methods.

[0060] To address the limitations of existing technologies in fundamentally resolving the chemical instability and poor physical properties of xanthates due to moisture, as well as the high energy consumption, high pollution, and operational complexity inherent in the drying process, this invention provides a drying-free xanthate collector, its preparation method, and its applications. The collector of this invention offers advantages such as drying-free operation, direct acquisition, high stability, excellent physical properties, and improved flotation performance. Furthermore, the preparation method of this invention effectively improves the working environment of the xanthate production process and is easily scalable for industrial production.

[0061] The following examples and comparative models further illustrate this point.

[0062] Example 1: Preparation of sodium isobutylxanate by kneading method with 1 wt.% calcium oxide added initially.

[0063] 1497.4 parts isobutanol and 1692.0 parts carbon disulfide were added to a 10L kneader at a speed of 60 rpm. Then, 38.4 parts calcium oxide were added, followed by 808.1 parts of powdered sodium hydroxide in three batches. After the addition was complete, the mixture was reacted at 30-35℃ for 2.5 hours. After the reaction was complete, 3788.5 parts of a yellow powdery solid xanthate were obtained. Analysis showed that the product contained sodium isobutylxanthate (86.7 wt.%) and calcium oxide (1.0 wt.%), with the calcium oxide coating the xanthate surface in the form of calcium salts such as CaCO3.

[0064] Example 2

[0065] 4 wt.% sodium metasilicate is added during the preparation of sodium isobutyl xanthate by the kneading method.

[0066] 1497.4 parts isobutanol and 1692.0 parts carbon disulfide were added to a 10L kneader at a speed of 60 rpm. Then, 808.1 parts powdered sodium hydroxide and 158.6 parts sodium metasilicate were added in three batches. After the addition was complete, the mixture was reacted at 30-35℃ for 2.5 hours. After the reaction was completed, 3908.7 parts of yellow powdered solid xanthate were obtained. Analysis showed that the product contained sodium isobutyl xanthate (85.3 wt.%) and sodium metasilicate (4.0 wt.%), and the sodium metasilicate existed in a stable metasilicate form.

[0067] Example 3: 5 wt.% calcium lactate was added at the end of the preparation of sodium isobutyl xanthate by the kneading method.

[0068] 1497.4 parts isobutanol and 1692.0 parts carbon disulfide were added to a 10L kneader at a speed of 60 rpm. Then, 808.1 parts of powdered sodium hydroxide were added in three batches. After the addition was complete, the mixture was reacted at 30-35℃ for 2.5 hours. After the reaction was complete, 200.3 parts of powdered calcium lactate were added, and the reaction was continued for 10 minutes to obtain 3908.4 parts of yellow powdered solid xanthate. Analysis showed that the product contained sodium isobutyl xanthate (84.6 wt.%) and calcium lactate (5.0 wt.%), and the calcium lactate existed in a stable lactate form.

[0069] Example 4: Solvent-based preparation of sodium isobutylxanthate, initially with the addition of 1 wt.% calcium oxide and 4 wt.% calcium lactate.

[0070] 11.23 parts isobutanol and 46.1 parts carbon disulfide were added to a three-necked flask. 0.3 parts calcium oxide and 1.2 parts calcium lactate were added under ice bath and mechanical stirring. Then, 6.56 parts of powdered sodium hydroxide were added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was allowed to proceed for 2.5 hours. After the reaction was complete, excess carbon disulfide was recovered by rotary evaporation at 40°C for 45 minutes, yielding 29.52 parts of a yellow-green powdery solid xanthate. Analysis showed that the product contained sodium isobutylxanthate (85.2 wt.%), calcium oxide (1.0 wt.%), and calcium lactate (4.0 wt.%), with calcium oxide and calcium lactate existing as stable calcium salts such as CaCO3 and lactate, respectively.

[0071] Example 5: 2 wt.% anhydrous sodium sulfate was added at the end of the solvent method preparation of sodium isobutylxanate.

[0072] 11.23 parts isobutanol and 46.1 parts carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 6.56 parts powdered sodium hydroxide was added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was allowed to proceed for 2.5 hours. After the reaction was complete, 0.58 parts anhydrous sodium sulfate were added, and then excess carbon disulfide was recovered by rotary evaporation at 40°C for 45 minutes, yielding 28.60 parts of a yellow-green powdery solid xanthate. Analysis showed that the product contained sodium isobutylxanthate (86.5 wt.%) and anhydrous sodium sulfate (2.0 wt.%), with the anhydrous sodium sulfate existing in a stable sulfate form.

[0073] Example 6: Preparation of O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate by kneading method. At the end of the preparation, 1 wt.% calcium oxide and 4 wt.% sodium metasilicate were added.

[0074] 1200.0 parts of dipropylene glycol butyl ether and 576.0 parts of carbon disulfide were added to a 10L kneader at a speed of 60 rpm. Then, 409.0 parts of powdered potassium hydroxide were added in three batches. After the addition was complete, the mixture was reacted at 30-35℃ for 2.5 hours. After the reaction was completed, 21.00 parts of powdered calcium oxide and 83.9 parts of powdered sodium metasilicate were added, and the reaction was continued for 10 minutes to obtain 2105.7 parts of yellow powdered solid xanthate. Analysis showed that the above product contained O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate. Testing revealed that the above product contains O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate (85.1 wt.%), calcium oxide (1.0 wt.%), and sodium metasilicate (4.0 wt.%), with the sodium metasilicate existing in a stable metasilicate form.

[0075] Example 7: Solvent-based preparation of O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate. 1 wt.% calcium oxide and 1 wt.% fumed silica were added at the end of the preparation.

[0076] 9.71 parts of dipropylene glycol butyl ether and 23.07 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 3.47 parts of powdered potassium hydroxide (85%) was added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was carried out for 4 hours. After the reaction was completed, 0.17 parts of calcium oxide and 0.17 parts of fumed silica were added, and stirring was continued for 10 minutes. Then, the excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 16.34 parts of yellow powdered solid xanthate. Analysis showed that the above product contained O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate. Testing revealed that the above product contains O-[1-(2-butoxy-1-methylethoxy)-2-propyl] dithiocarbonate (87.2 wt.%), calcium oxide (1.0 wt.%), and fumed silica (1.0 wt.%), with calcium oxide and fumed silica existing in the form of stable calcium salts such as CaCO3 and SiO2 aggregates, respectively.

[0077] Example 8: Solvent-based preparation of O-[1-(2-butoxy-1-methylethoxy)-2-propyl]sodium dithiocarbonate ( Add 5 wt.% calcium oxide at the beginning.

[0078] 9.71 parts of dipropylene glycol butyl ether and 25.00 parts of carbon disulfide were added to a three-necked flask, followed by 0.81 parts of calcium oxide. Then, 2.19 parts of granular sodium hydroxide (96%) were added in three batches under ice bath and mechanical stirring. After the addition was complete, the temperature was raised to 25°C and the reaction was carried out for 6 hours. After the reaction was completed, excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 16.02 parts of a light yellow powdery solid xanthate. Analysis showed that the above product contained O-[1-(2-butoxy-1-methylethoxy)-2-propyl]sodium dithiocarbonate (…). (85.1 wt.%) and calcium oxide (5.0 wt.%), with calcium oxide coated on the xanthate surface in the form of stable calcium salts such as CaCO3.

[0079] Example 9: Solvent-based preparation of O-(2-(2-ethoxypropoxy)propyl)dithiocarbonate ( 3 wt.% sodium metasilicate is added during the process.

[0080] 16.55 parts of dipropylene glycol monoethyl ether and 61.53 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 6.93 parts of powdered potassium hydroxide (85%) and 0.91 parts of powdered sodium metasilicate were added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was carried out for 6 hours. After the reaction was completed, excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 29.47 parts of a yellow powdery solid xanthate. Analysis showed that the above product contained O-(2-(2-ethoxypropoxy)propyl)dithiocarbonate (…). (84.8 wt.%) and sodium metasilicate (3.0 wt.%), with sodium metasilicate existing in a stable metasilicate form.

[0081] Example 10: Solvent-based preparation of O-(1-methyl-2-butoxy)dithiocarbonate ( Add 0.5 wt.% calcium oxide at the end.

[0082] 6.68 parts of propylene glycol butyl ether and 30.76 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 3.47 parts of granular potassium hydroxide (85%) was added in three batches. After the addition was complete, the temperature was raised to 20°C and the reaction was carried out for 5 hours. After the reaction was completed, 0.08 parts of calcium oxide were added, and stirring was continued for 10 minutes. Then, excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 13.64 parts of a yellowish-white powdery solid xanthate. Analysis showed that the above product contained O-(1-methyl-2-butoxy)dithiocarbonate (…). (86.4 wt.%) and calcium oxide (0.5 wt.%), with calcium oxide coated on the xanthate surface in the form of calcium salts such as CaCO3.

[0083] Example 11: Solvent-based preparation of O-(1-[2-(2-methoxy-1-methylethoxy)-1-methylethoxy]-2-propyl)potassium dithiocarbonate ( Add 1 wt.% montmorillonite during the process.

[0084] 21.05 parts of tripropylene glycol methyl ether and 61.53 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 6.93 parts of powdered potassium hydroxide (85%) and 0.34 parts of montmorillonite were added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was carried out for 6 hours. 34.12 parts of a yellow powdery solid xanthate were obtained. Analysis showed that the above product contained O-(1-[2-(2-methoxy-1-methylethoxy)-1-methylethoxy]-2-propyl)potassium dithiocarbonate (…). (83.1 wt.%) and montmorillonite (1.0 wt.%), with montmorillonite existing in the form of layered aluminosilicate.

[0085] Example 12: Solvent-based preparation of O-(2-ethoxypropyl)dithiocarbonate ( Add 1% calcium oxide and 1% montmorillonite at the beginning.

[0086] 5.48 parts of 2-ethoxypropanol and 19.23 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, 0.12 parts of calcium oxide and 0.12 parts of montmorillonite were added, followed by 3.47 parts of powdered potassium hydroxide (85%) in three batches. After the addition was complete, the mixture was heated to 25°C and reacted for 4 hours. 12.08 parts of a yellowish-white powdery solid xanthate were obtained. Analysis showed that the above product contained O-(2-ethoxypropyl) dithiocarbonate (…). (88.1 wt.%), calcium oxide (1.0 wt.%) and montmorillonite (1.0 wt.%), with calcium oxide and montmorillonite existing as calcium salts and layered aluminosilicates, respectively.

[0087] Example 13: Solvent-based preparation of O-(2-(2-methoxypropoxy)propoxypropyl)potassium dithiocarbonate ( Add 1 wt.% calcium oxide at the end.

[0088] 10.52 parts of tripropylene glycol methyl ethyl ether and 17.30 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 3.47 parts of powdered potassium hydroxide (85%) was added in three batches. After the addition was complete, the temperature was raised to 30°C and the reaction was carried out for 6 hours. After the reaction was completed, 0.17 parts of calcium oxide were added, and stirring was continued for 10 minutes. Then, excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 17.02 parts of yellow powdered solid xanthate. Analysis showed that the above product contained O-(2-(2-methoxypropoxy)propoxypropyl)potassium disulfide (…). (82.6 wt.%) and calcium oxide (1.0 wt.%), with calcium oxide coated on the xanthate surface in the form of calcium salts such as CaCO3.

[0089] Comparative Example 1: Preparation of Sodium Isobutylxanthate by Solvent Method

[0090] 11.23 parts isobutanol and 46.1 parts carbon disulfide were added to a three-necked flask. Then, 6.56 parts of powdered sodium hydroxide were added in three batches under ice bath and mechanical stirring. After the addition was complete, the temperature was raised to 25°C and the reaction was allowed to proceed for 2.5 hours. After the reaction was complete, excess carbon disulfide was recovered by rotary evaporation at 40°C for 45 minutes, yielding 28.04 parts of a yellow-green powdery solid xanthate, with a yield of 94.22%. Analysis showed that the product contained sodium isobutylxanthate.

[0091] Comparative Example 2: Preparation of O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate by solvent method

[0092] 9.71 parts of dipropylene glycol butyl ether and 25.00 parts of carbon disulfide were added to a three-necked flask. Under ice bath and mechanical stirring, a total of 2.19 parts of granular sodium hydroxide (96%) was added in three batches. After the addition was complete, the temperature was raised to 25°C and the reaction was carried out for 4 hours. After the reaction was completed, excess carbon disulfide was recovered by rotary evaporation at 40°C for 2 hours, yielding 15.22 parts of a yellow powdery solid xanthate, with a yield of 94.18%. The product was identified as O-[1-(2-butoxy-1-methylethoxy)-2-propyl]sodium dithiocarbonate (…). ).

[0093] Performance testing and results analysis:

[0094] The odor of the products synthesized in Examples 1-13 and Comparative Examples 1-2 was evaluated according to the direct olfactory method in GB / T15549-1995. Specifically, 5g of sample was placed in a 25mL serum bottle and sealed for 1 hour. Five evaluators then evaluated and scored the odor, with 1 being no odor, 2 being a slight odor, 3 being an odor but not irritating, 4 being an irritating odor, 5 being a strong irritating odor, and 6 being an unbearable odor. The evaluation results are shown in Table 1.

[0095] Table 1:

[0096]

[0097] As shown in Table 1, the xanthate collectors prepared using the method of this invention have lower odor intensity than the control samples without additives. This is mainly due to the following synergistic mechanisms: First, the additives can form a coating layer on the surface of xanthate particles, inhibiting the volatilization of active components and their contact with water molecules, thereby reducing the generation of xanthate molecules and their decomposition products that cause odor at the source; second, some additives can effectively fix free water in the system through physical or chemical actions, reducing the degree of xanthate hydrolysis induced by water molecules; finally, alkaline additives such as calcium oxide help maintain the alkalinity of the local microenvironment, inhibiting the conversion of xanthate to unstable xanthic acid, thereby slowing down its decomposition process. In summary, the additives significantly reduce the characteristic odor of the product through multiple synergistic mechanisms of physical isolation, water fixation, and pH regulation.

[0098] The products synthesized in Examples 1, 4, 6, and 8, Comparative Examples 1 and 2, and the product synthesized in Comparative Example 2 plus additives were used as collectors in actual copper sulfide ore flotation experiments.

[0099] The ore sample was from the Pulang copper mine in Yunnan Province, with a raw ore content of 0.47% copper and 0.87% sulfur. The following methods were used: Figure 1The flotation process involves a roughing stage. For each experiment, 500g of ore powder, 300mL of water, and a certain amount of lime are added to a ball mill and ground until the mineral particle size meets the requirements for beneficiation. The slurry is then transferred to a 1.5L single-cell flotation unit for flotation experiments. After the flotation cell is installed, the flotation unit is turned on and stirred for 3 minutes, then the collector is added and stirred for another 3 minutes. A frother is then added and stirred for another 1 minute. The foam is collected for 5 minutes as the concentrate, and the product in the water tank is the tailings. The concentrate is thoroughly dried, ground, and samples are prepared for copper content analysis. The yield and recovery rate are calculated. The reagent formulation was as follows: grinding fineness was -200 mesh (66%), lime dosage was 400 g / t, frother was 24 g / t of No. 2 oil, and collectors were the xanthate products prepared in Examples 1, 4, 6, 8, and Comparative Example 1, the xanthate product prepared in Comparative Example 2, and the xanthate product prepared in Comparative Example 2 plus calcium oxide (calculated by converting the content of O-[1-(2-butoxy-1-methylethoxy)-2-propyl]dithiocarbonate in the xanthate product prepared in Comparative Example 2 to 85.1 wt.%, and the amount of calcium oxide added was 5.0 wt.%). The flotation results are shown in Table 2.

[0100] Table 2:

[0101]

[0102] As shown in Table 2, in xanthate systems with the same structure, Examples 1, 4, 6, and 8, which incorporated the additives of this invention, exhibited higher flotation recoveries and copper concentrate grades for copper sulfide ore than Comparative Examples 1-2, which did not contain the additives. Specifically, the indicators for Examples 1 and 4 were higher than those for Comparative Example 1, and the indicators for Examples 6 and 8 were higher than those for Comparative Example 2. This demonstrates that adding additives to the system for synthesizing xanthate collectors can effectively improve flotation performance. Comparing the results of flotation of copper sulfide ore using the product of Example 8 and Comparative Example 2 with calcium oxide as a collector, it can be seen that the flotation effect of adding the same amount of additive alone in the subsequent flotation process is significantly worse than the flotation effect of the product obtained by adding the additive provided by the present invention during or at the end of xanthate synthesis. This may be because when added to the xanthate reaction system, additives such as calcium oxide (and their hydration products) are more likely to form a uniform composite and "isositu" distribution with xanthate at the microscopic level. After entering the pulp, they tend to be released and act synergistically near the mineral particles, which is conducive to improving the effective contact and adsorption efficiency of the collector on the surface of the target mineral. At the same time, it may also reduce the ineffective consumption or local excessive fluctuation of the collector in the slurry phase to a certain extent, so as to improve the overall collection and selectivity performance.

[0103] The products synthesized from Examples 1, 4, 6, and 8, and Comparative Examples 1-2, were subjected to stability testing, and the results are as follows: Figure 2 As shown. By Figure 2 It is evident that the addition of the additive of this invention significantly improves the stability of xanthate products; within three months, its effective content decreases by less than 3%, which can basically meet the requirements of general storage and usage cycles. Furthermore, from Figure 2 As can be seen from the comparison of Examples 6, 8 and Comparative Example 2, the additive of the present invention has a significant effect on the stability of the xanthate collector synthesized by the reaction of propylene glycol ether with carbon sulfide and caustic alkali. It can increase the relative content of the xanthate collector by more than 10% within three months (compared to no additive).

[0104] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a drying-free xanthate collector, characterized in that, An additive is added to the reaction system for synthesizing xanthate, wherein the amount of the additive added is 0.1-10% of the mass of the final xanthate product; the additive is selected from at least one of sodium metasilicate, calcium oxide, aluminate, montmorillonite, anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous sodium sulfate, potassium sulfate, magnesium oxide, aluminum oxide, calcium lactate, molecular sieve, and fumed silica.

2. The method for preparing the drying-free xanthate collector according to claim 1, characterized in that, The amount of the additive added is 0.5-5% of the mass of the final xanthate product.

3. The method for preparing the drying-free xanthate collector according to claim 1, characterized in that, The xanthate is prepared by reacting a raw material comprising an alcohol, carbon disulfide, and a caustic base; wherein the alcohol comprises C2~C64. 12 At least one of fatty alcohols, fusel oils, and hydroxyl ether alcohols.

4. The method for preparing the drying-free xanthate collector according to claim 1, characterized in that, The xanthate is prepared by reacting a raw material comprising an alcohol, carbon disulfide and a caustic base, wherein the alcohol is a hydroxyl ether alcohol.

5. The method for preparing the drying-free xanthate collector according to claim 4, characterized in that, The hydroxyl ether alcohol is selected from 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 2-tert-butoxyethanol, 2-hexyloxyethanol, 2-methoxypropanol, 2-ethoxypropanol, 2-butoxypropanol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, tetraethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, di ... One or more of the following: butyl ether, ethylene glycol monopentyl ether, diethylene glycol monopentyl ether, triethylene glycol monopentyl ether, tetraethylene glycol monopentyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, propylene glycol monopentyl ether, dipropylene glycol monopentyl ether, tripropylene glycol monopentyl ether, tetrapropylene glycol monopentyl ether.

6. The method for preparing the drying-free xanthate collector according to claim 4, characterized in that, The hydroxyl ether alcohol is a propylene glycol ether; the propylene glycol ether is selected from at least one of propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetrapropylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monoethyl ether, tetrapropylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, tetrapropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether, propylene glycol monopentyl ether, dipropylene glycol monopentyl ether, tripropylene glycol monopentyl ether, and tetrapropylene glycol monopentyl ether.

7. The method for preparing the drying-free xanthate collector according to claim 1, characterized in that, The additive is added before the reaction begins, during the reaction, or after the reaction is completed; and / or, the method for synthesizing xanthate includes at least one of kneading method and solvent method.

8. The method for preparing the drying-free xanthate collector according to claim 7, characterized in that, The reaction temperature for synthesizing xanthate is 0-60℃, and the time is 1-6h. In the solvent method, the raw materials also include a solvent, which includes at least one of dichloromethane, dichloroethane, carbon disulfide, ethanol, and tetrahydrofuran. After the reaction is completed, the solvent is recovered by atmospheric distillation or vacuum distillation. The temperature of atmospheric distillation is 60-100℃, and the temperature of vacuum distillation is 30-80℃.

9. A drying-free xanthate collector prepared by any one of the preparation methods described in claims 1-8.

10. The application of a drying-free xanthate collector according to claim 9 in mineral flotation.

Images