Preparation method and application of xanthate or composite xanthate
By employing an automated alkali addition and reaction temperature interlocking control method in xanthate production, a composite xanthate was synthesized, solving the problems of product inhomogeneity and unstable flotation indicators in traditional methods. This achieved the preparation of a composite xanthate with stable performance, expanding its application range and reducing production costs.
Patent Information
- Application Number
- CN202310562114.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-18
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2043-05-18
AI Technical Summary
In traditional compound xanthate production methods, the product properties are uneven, leading to unstable flotation indicators, increased labor and production costs, and making it difficult to effectively apply to complex ores such as lean ores, sulfide ores with high oxidation rates, and polymetallic ores.
An automatic alkali addition and reaction temperature interlocking control method is adopted. The temperature parameters and automatic alkali addition switch logic are set through the DCS system to precisely control the reaction temperature and synthesize a composite xanthate. By mixing alcohols with different hydrocarbon chain lengths in a certain proportion, a one-step preparation method is achieved, ensuring stable product performance and uniform composition.
It improves the collection capacity and selectivity of compound xanthates, expands the application range, reduces production costs, reduces side reactions and free alkali content, simplifies the operation process, and improves the stability and economic benefits of flotation indicators.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of xanthate flotation reagents, in particular to a preparation method and application of xanthate or composite xanthate. BACKGROUND
[0002] Xanthate, also known as xanthate, was first synthesized by Zeise in 1815. Xanthate has a wide range of uses. In the rubber industry, it is used as a vulcanization accelerator. In analytical chemistry, ethyl sodium xanthate is used as a precipitant and colorimetric agent for copper, nickel and other metals. In the metallurgical industry, it is used as a reagent for precipitating copper, nickel and other metals in solution. Cellulose-based sodium xanthate is used for artificial fibers, and starch-based xanthate is used for sewage treatment. At the same time, xanthate is also the most widely used collector in the world. It is essential in the beneficiation and flotation process of heavy metal sulfide ores. In addition, it is also a common extractant in the recovery of precious metals.
[0003] The synthesis process of xanthate has a forward feeding method and a reverse feeding method. The alcohol and sodium hydroxide are first added to the kneader to react to form sodium alcoholate, and then carbon disulfide is slowly added for sulfonation to obtain xanthate powder.
[0004] This is the forward feeding method. If the feeding order is changed, the alcohol and carbon disulfide are mixed first, and then sodium hydroxide is slowly added for sulfonation to obtain xanthate powder. This is the reverse feeding method.
[0005] In addition, there are three types of methods for manufacturing xanthate, namely wet alkali method, dry method (or diluent method), and crystallization method. The wet alkali method adds a small amount of water to wet the caustic soda during the manufacturing process to avoid clumping and ensure complete reaction of the caustic soda. This method is suitable for local production and is simple and easy to operate, but it has the disadvantage of being prone to side reactions. The dry method (or diluent method) uses gasoline or benzene to wet the caustic soda instead of water. The crystallization method uses a large amount of gasoline or benzene as a solvent, and the generated xanthate is crystallized and separated from the solution. The advantages of this method are that the raw materials are fully mixed in the conventional stirring, the heat released during the reaction is easily cooled, and the product is easily separated from the solvent, resulting in good quality.
[0006] In the field of mineral flotation, composite reagents are often used according to the different properties of ores, especially composite xanthate, which utilizes the synergistic effect of long and short hydrocarbon chains and various functional groups to enhance the collecting performance. In recent years, there has been an increasing number of difficult-to-process ores such as lean ores, high-oxidation-rate sulfide ores, and polymetallic ores, and conventional xanthate has weak collecting ability for these ores.
[0007] The traditional production method of composite xanthate is to simply physically mix several xanthate products in a proportion in a batching kettle, which has the following disadvantages: the xanthate products have different product properties, different densities and different colors due to different functional groups, and it is difficult to achieve uniformity by simply mixing, and in the actual application process, the flotation index is unstable. Moreover, this production method of re-compounding after synthesis increases the labor of workers and directly increases the production cost of enterprises. SUMMARY
[0008] The present application aims to provide a preparation method and application of xanthate or composite xanthate, which links the automatic alkali addition with the reaction temperature, sets the logic between the temperature parameters and the automatic alkali addition switch in the DCS system, uses the alkali addition amount to control the reaction temperature, realizes the complete reaction of the xanthate product through the control of the front peak, the middle flat and the rear peak temperature, reduces the occurrence of side reactions on the one hand, greatly reduces the free alkali content in the product, and on the other hand, the use of the automatic alkali addition system can achieve precise control of the temperature, which completely changes the dependence of traditional xanthate production on the experience of alkali addition workers.
[0009] According to the principle of the different molecular structures, functional group properties and ore action of various xanthates, the present application designs a unique molecular structure, mixes different alcohol chain lengths into a complex alcohol in a proportion from the source, and makes the complex xanthate by one-step method, which has stable performance and uniform composition. The complex xanthate synthesized by this method expands the application range of xanthate, a common mineral collector, and can be applied to lead, zinc, copper, iron and other sulfide ores, and some refractory oxidized ores, precious metals gold, silver, etc. In the mineral processing process, it shows many performance differences, fully plays the synergistic effect between the effective functional groups in various xanthate molecules, and plays their own advantages, so as to fully utilize mineral resources and improve economic benefits. Thus, the problems in the above background technology are solved.
[0010] The technical scheme adopted by the present application is as follows:
[0011] A preparation method of xanthate or composite xanthate, comprising the following steps:
[0012] Step one, first add the weighed carbon disulfide into the self-made kneading machine with a jacket, start stirring, then add a certain proportion of complex alcohol, open the cooling brine, and continue stirring;
[0013] Step two, open nitrogen protection, the weighed caustic soda is added into the kneader of step one, the first time of adding caustic soda needs to make the reaction temperature rise to 20-50℃, stop adding caustic soda, the reaction reaches the first peak temperature, when the reaction temperature drops to about 10-15℃, the automatic caustic soda adding system is opened, the temperature rises to 20-30℃, so repeat the process until the remaining amount of caustic soda is 1 / 5 of the total amount, the cooling brine valve is closed, the remaining caustic soda is added into the kneader, when the second peak temperature is reached, the cooling brine valve is opened, the reaction is kept for 10-120 minutes, then continue stirring until the reaction temperature drops to below 20℃, close the nitrogen, and discharge the product.
[0014] The complex alcohol in step one is one or a combination of methanol, ethanol, propanol, isopropanol, n-butanol, isobutyl alcohol, sec-butyl alcohol, n-pentanol, isoamyl alcohol, neopentyl alcohol, n-hexyl alcohol, isohexyl alcohol, sec-hexyl alcohol, methyl isobutyl carbinol, n-heptyl alcohol, isoheptyl alcohol, n-octanol, isooctyl alcohol, sec-octyl alcohol, the purity of the complex alcohol is greater than or equal to 85%, the carbon disulfide is an industrial grade, and the purity is greater than or equal to 95%; the caustic soda in step two is one or several of industrial grade sodium hydroxide or potassium hydroxide, the shape is granular, flaky or powdery, and the purity is greater than or equal to 95%; the molar ratio of raw materials is carbon disulfide: alcohol: caustic soda = 1-2: 1.1: 1.
[0015] In step one, the stirring speed is 20-80 r / min, and the temperature of the cooling brine is 10-25℃.
[0016] In step two, the purity of nitrogen is greater than or equal to 99%, the first peak temperature of adding caustic soda is 20-50℃, the subsequent leveling temperature is 10-30℃, and the second peak temperature is 20-50℃. This step realizes the interlocking control of automatic caustic soda addition, temperature and cooling brine valve opening degree, and the reaction temperature is automatically and accurately controlled by using the amount of caustic soda through the logic between the temperature parameters and the automatic caustic soda switch in the DCS system, the logic of the temperature and the cooling brine valve opening degree.
[0017] The application of xanthate or complex xanthate to the flotation of non-ferrous metal sulfide ore and oxidized ore and gold and silver.
[0018] As described above, by adopting the technical scheme, the application has the following beneficial effects:
[0019] 1. The raw material complex alcohol of the application participates in the synthesis reaction of carbon disulfide and caustic soda according to purity, ratio and sequence in the synthesis stage, the synthesis method is more complete than the traditional end physical mixing, the performance of the complex xanthate product is stable, and each component is uniform.
[0020] 2. The whole process is carried out in one reactor, without the need to put into another reactor when the complex is needed, the operation process is simplified, and the product production cost is reduced.
[0021] 3. The synthetic process of the present application uses nitrogen protection throughout, greatly reducing the overflow of reaction gas, improving the safety factor, and meeting the national safety and environmental protection requirements;
[0022] 4. The present application reduces the purity requirement of raw material alcohol, and the purity of the alcohol involved is ≥ 85%, which is an industrial standard, which is conducive to reducing the production cost of enterprises;
[0023] 5. The preparation method of the present application automatically adds alkali and controls the reaction temperature, sets the relationship between the temperature parameters and the automatic alkali adding switch in the DCS system, uses the alkali dosage to control the reaction temperature, realizes the complete reaction of xanthate product through the control of the front peak, the middle flat and the rear peak temperature, on the one hand, reduces the occurrence of side reactions, greatly reduces the free alkali content in the product, on the other hand, the use of automatic alkali adding system can realize precise control of temperature, completely changing the dependence of xanthate production on alkali adding workers' experience.
[0024] In summary, the raw materials of the present application are widely available, the process is simple, the cost is controllable, and the prepared composite xanthate has strong collecting ability and selectivity, and good flotation indexes are obtained in flotation tests DETAILED DESCRIPTION
[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.
[0026] Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.
[0027] EMBODIMENT
[0028] Table 1: Complex alcohol compounding scheme (mol)
[0029]
[0030]
[0031] The present embodiment provides a preparation method of xanthate or composite xanthate, comprising the following steps,
[0032] Step one, first to self-made jacketed kneader 346.9~693.8 g carbon disulfide, open stirring, stirring rate of 20~80 r / min, then add 371.6 g of complex alcohol (complex scheme see table 1), open cooling brine, cooling brine temperature is 10~-25℃, continue to stir;
[0033] Step two, open nitrogen protection, nitrogen purity ≥ 99%, 182.6 g of caustic soda is added in the above kneader in batches, under the stirring state (stirring rate is 20~80 r / min), the first time to add alkali to make the reaction temperature rise to 20~50℃, stop adding alkali, the reaction reaches the first peak temperature of 20~50℃, when the reaction temperature drops to about 10~15℃, the automatic alkali adding system is opened, and the temperature is raised to 20~30℃, so the temperature is repeated to run flat, and the running flat temperature is 10~30℃, until the remaining amount of alkali is about 1 / 5 of the total amount, the cooling brine valve is closed, the remaining alkali is added into the kneader, when the second peak temperature of 20~50℃ is reached, the cooling brine valve is opened, and the reaction is kept for 10~120 min, then the stirring is continued until the reaction temperature drops to below 20℃, the nitrogen is closed, and the material is discharged. This step realizes the interlocking control of automatic alkali addition, temperature and cooling brine valve opening degree. Through the logic between temperature parameters and automatic alkali opening switch in DCS system, the logic of temperature and cooling brine valve opening degree, and the amount of alkali added, the reaction temperature can be automatically and accurately controlled.
[0034] The example is investigated by orthogonal experiment method, and the specific contents are shown in table 2. The six factors and five levels involved in the investigation are as follows: the molar ratio of raw materials n (carbon disulfide): n (alcohol): n (caustic soda) = 1~2:1.1:1, and the specific investigation in this experiment is 1:1:1, 1.1:1.1:1, 1.2:1.1:1, 1.5:1.1:1, 2:1.1:1, the stirring rate is 20~80 r / min, and the specific investigation in this experiment is 20, 30, 50, 60, 80 r / min, the first peak temperature is 20~50℃, and the specific investigation in this experiment is 20, 25, 30, 40, 50℃, the intermediate running flat temperature is T10-15~T20-30℃, and the specific investigation in this experiment is 10~20, 10~25, 10~30, 15~25, 15~30℃, the last peak temperature is 20~50℃, and the specific investigation in this experiment is 20, 25, 30, 40, 50℃, the reaction time is 10~120 min, and the specific investigation in this experiment is 10, 30, 60, 90, 120 min.
[0035] Table 2 orthogonal experiment
[0036]
[0037] Example 1
[0038] The embodiment provides a preparation method of xanthate or composite xanthate, and comprises the following steps:
[0039] Step one, first, 416.3g of carbon disulfide is added into a self-made jacketed kneader, stirring is started, then 371.6g of complex alcohol (see Table 1 for a complex scheme, code F2-F12) is added, cooling brine is opened, and stirring is continued.
[0040] Step two, nitrogen protection is started, 182.6g of flaky alkali is added into the above kneader in batches, under the stirring state (the stirring rate is 50r / min), the first time of adding alkali needs to make the reaction temperature rise to 50 DEG C, the adding of alkali is stopped, the reaction reaches the first peak temperature, when the reaction temperature drops to about 10 DEG C, the automatic alkali adding system is started, the temperature is raised to 25 DEG C, and the above process is repeated until the remaining amount of alkali is about 1 / 5 of the total amount, the cooling brine valve is closed, the remaining alkali is added into the kneader, when the second peak temperature 40 DEG C is reached, the cooling brine valve is opened, the reaction is kept for 10 minutes, then the stirring is continued until the reaction temperature drops to below 20 DEG C, the nitrogen is closed, and the material is discharged.
[0041] The experimental results of the complex alcohol with different proportions under the optimal synthesis condition are shown in Table 3.
[0042] Table 3: Experimental results of complex alcohol synthesis
[0043] Code Main grade Free base Appearance F2 87.5 0.1 Light yellow F3 88.9 0.1 Light yellow F4 87.2 0.2 Light yellow F5 88.3 0.2 Light yellow F6 88.9 0.2 Light yellow F7 88.5 0.1 Light yellow F8 88.8 0.1 Yellow F9 89.8 Not detected Yellow F10 88.4 0.2 Yellow F11 88.5 0.2 Yellow F12 88.4 0.2 Yellow Light yellow
[0044] Example 3
[0045] The embodiment provides a preparation method of xanthate or composite xanthate, and comprises the following steps:
[0046] Step one, first, 416.3g of carbon disulfide is added into a self-made jacketed kneader, stirring is started, then 371.6g of complex alcohol (see Table 1 for a complex scheme, code F2-F12) is added, cooling brine is opened, and stirring is continued.
[0047] Step two, nitrogen protection is started, 182.6g of flaky alkali is added into the above kneader in batches, under the stirring state (the stirring rate is 50r / min), the first time of adding alkali needs to make the reaction temperature rise to 50 DEG C, the adding of alkali is stopped, the reaction reaches the first peak temperature, when the reaction temperature drops to about 10 DEG C, the automatic alkali adding system is started, the temperature is raised to 25 DEG C, and the above process is repeated until the remaining amount of alkali is about 1 / 5 of the total amount, the cooling brine valve is closed, the remaining alkali is added into the kneader, when the second peak temperature 40 DEG C is reached, the cooling brine valve is opened, the reaction is kept for 10 minutes, then the stirring is continued until the reaction temperature drops to below 20 DEG C, the nitrogen is closed, and the material is discharged.
[0048] Example 4
[0049] The present embodiment provides an application of xanthate or composite xanthate, and a small-scale test is carried out using ore of a certain copper mine in Tibet to compare the flotation effects of newly synthesized composite xanthate and on-site xanthate. The analysis of the main elements of the raw ore sample shows that the valuable elements in the raw ore are copper and molybdenum, among which the copper grade is 0.61% and the molybdenum grade is 0.054%. The phase analysis of copper and molybdenum shows that the copper minerals and molybdenum minerals in the raw ore mainly exist in the form of sulfides, among which the copper minerals are mainly bornite and chalcopyrite, and the molybdenum minerals are mainly molybdenite.
[0050] The on-site process currently uses "copper-molybdenum bulk flotation-mixed concentrate regrinding-copper-molybdenum separation", in the copper-molybdenum bulk flotation stage, the on-site uses butyl xanthate as the collector, 2 # oil as the frother; in the copper-molybdenum separation stage, sodium sulfide is used as the copper depressant, kerosene is used as the molybdenum mineral collector, 2 # oil as the frother. The test only replaces the on-site butyl xanthate with the synthesized composite xanthate in the copper-molybdenum bulk flotation stage to compare the closed-circuit flotation indexes of the two collectors.
[0051] Table 4 Comparison test results of composite xanthate and on-site xanthate (%)
[0052]
[0053]
[0054] The test results show that the copper recovery rate of the copper concentrate is increased by 1.19 percentage points compared with the on-site reagent, the molybdenum recovery rate of the molybdenum concentrate is increased by 4.97 percentage points compared with the on-site reagent, the copper content and molybdenum content in the tailings of the composite xanthate (F1 production) scheme are significantly reduced, which shows that the composite xanthate has good selectivity and collecting power, and the collecting effect on the target minerals in the copper-molybdenum bulk flotation process is more significant, effectively reducing the loss of copper and molybdenum metals in the tailings, and creating good prerequisites for the improvement of the recovery rates of the copper concentrate and the molybdenum concentrate obtained in the subsequent copper-molybdenum separation.
Claims
1. A method for preparing a xanthate or a compound xanthate, characterized in that, Includes the following steps: Step 1: First, add the weighed carbon disulfide to the homemade jacketed kneader, turn on the stirring, then add a certain proportion of compound alcohol, turn on the cooling brine, and continue stirring. Step 2: Turn on nitrogen protection and add the weighed caustic alkali in batches to the kneader from Step 1. When adding alkali for the first time while stirring, the reaction temperature should be raised to 20-50℃. Stop adding alkali and wait for the reaction to reach the first peak temperature. When the reaction temperature drops to about 10-15℃, turn on the automatic alkali adding system and raise the temperature to 20-30℃. Repeat this process until the remaining amount of alkali is 1 / 5 of the total amount. Close the cooling brine valve and add all the remaining alkali to the kneader. When the second peak temperature is reached, open the cooling brine valve and keep the reaction at this temperature for 10-120 minutes. Continue stirring until the reaction temperature drops below 20℃. Turn off the nitrogen and discharge the material. The complex alcohol mentioned in step one is one or a combination of several of the following: methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, sec-butanol, n-pentanol, isopentanol, neopentanol, n-hexanol, isohexanol, sec-hexanol, methyl isobutyl methanol, n-heptanol, isoheptanol, n-octanol, isooctanol, and sec-octanol. The purity of the complex alcohol is ≥85%, and the carbon disulfide is industrial grade with a purity ≥95%. The caustic alkali mentioned in step two is one or more of industrial grade sodium hydroxide or potassium hydroxide, in granular, flake, or powder form, with a purity ≥95%. The molar ratio of the raw materials is carbon disulfide: alcohol: caustic alkali = 1~2:1.1:
1. In step one, the stirring rate is 20–80 r / min, and the temperature of the cooling brine is 10–-25℃; In step two, the nitrogen purity is ≥99%, the peak temperature of the first addition of alkali is 20-50℃, the leveling temperature is 10-30℃, and the peak temperature from the second addition is 20-50℃.