Synthetic method of sec-heptyl xanthate

Abstract

The invention relates to a synthetic method of sec-heptyl xanthate. The synthetic method comprises the following steps: the xanthate is synthesized by directly reacting sec-heptanol, carbon disulfide and sodium hydroxide or potassium hydroxide according to a molar ratio of 0.98: 1.02: 1.05; the preparation method comprises the following steps: adding sec-heptanol and carbon disulfide into a reactor, uniformly stirring, adding powdered alkali in batches while stirring, controlling the reaction temperature at 20 + / -1 DEG C, adding the rest powdered alkali at one time, continuously stirring, keeping the temperature at 36-38 DEG C, continuously keeping the temperature for 30-40 minutes, cooling after the temperature is kept, and discharging after the temperature is reduced to 25 DEG C or below, thereby obtaining the product. According to the synthetic method of the sec-heptyl xanthate, the sec-heptyl xanthate meeting the industrial application requirement can be synthesized, the sec-heptyl xanthate is widely applied to mineral separation of non-ferrous metals such as copper, lead and zinc and precious metal minerals such as gold and silver, and due to the selectivity and collecting capacity different from those of other xanthate, an optional reagent can be newly added for the mineral separation process; and optimization of beneficiation process indexes and economic indexes is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of xanthate flotation agents, and in particular relates to a method for synthesizing a secondary heptyl xanthate. Background Art

[0002] Alkyl xanthate (commonly known as xanthate) is a broad-spectrum and high-efficiency flotation agent with the widest application range and the largest amount of non-ferrous metal beneficiation. Ethyl xanthate, propyl xanthate, butyl xanthate, isopentyl xanthate are commonly found in the market, and hexyl xanthate and sec-octyl xanthate are used in small quantities. According to the different ion groups, it is divided into sodium xanthate and potassium xanthate. Sodium xanthate is generally used in China, and some foreign customers will use potassium xanthate. The chemical name of the sec-heptyl xanthate of the present invention is sodium (potassium) sec-heptyl xanthate and sodium (potassium) 2-heptyl xanthate, and the chemical formula is C7H 15 OCSSNa (K), chemical structure is as follows:

[0003] According to many years of mineral processing practice, xanthate has the following rules in most cases: the collection capacity (ore processing recovery rate) shows a gradual increase trend with the increase of carbon chain, and the collection capacity of various xanthates is: ethyl xanthate < propyl xanthate < butyl xanthate < isopentyl xanthate < hexyl xanthate < heptyl xanthate < octyl xanthate; the selectivity (ore processing concentrate grade) shows a gradual decrease trend with the increase of carbon chain, and the selectivity of various xanthates is: ethyl xanthate > propyl xanthate > butyl xanthate > isopentyl xanthate > hexyl xanthate > heptyl xanthate > octyl xanthate. In many application scenarios, there are several xanthates or xanthates are used in combination with other functional group reagents in order to achieve the best mineral processing indicators and higher economic benefits.

[0004] At present, there is a lack of research on heptyl xanthate from the perspective of product series, product performance and application, and there is no relevant existing technology in the industry. Therefore, a synthesis method of secondary heptyl xanthate is proposed through research, providing a new type of available agent for the mineral processing agent industry. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for synthesizing secondary heptyl xanthate.

[0006] The specific technical scheme is: a method for synthesizing a secondary heptyl xanthate, comprising the following steps: the xanthate is synthesized by direct reaction of secondary heptyl alcohol, carbon disulfide, sodium hydroxide or potassium hydroxide in a molar ratio of 0.98:1.02:1.05; firstly, secondary heptyl alcohol and carbon disulfide are added into a reactor and stirred evenly, then caustic soda is added in batches under stirring, the reaction temperature is controlled at 20±1°C, the remaining caustic soda is added at one time, stirring is continued, at this time, the temperature is kept at 36-38°C, and the temperature is kept continuously for 30-40 minutes, the temperature is lowered after the temperature is maintained, and the material is discharged after the temperature is lowered to below 25°C to obtain the product.

[0007] Furthermore, the content of secondary heptanol is ≥98%, and the remaining components are alcohols.

[0008] Furthermore, the water content of the secondary heptanol is less than 0.2%.

[0009] Furthermore, the carbon disulfide content is ≥98%.

[0010] Furthermore, the content of sodium hydroxide or potassium hydroxide is ≥99%, and the crushing particle size is <60 mesh.

[0011] Beneficial effects of the present invention: The method for synthesizing the sec-heptyl xanthate proposed in the present invention can synthesize the sec-heptyl xanthate that meets industrial applications, and is widely used in the beneficiation of non-ferrous metals such as copper, lead, zinc, and precious metal minerals such as gold and silver. Its selectivity and capture capacity, which are different from other xanthates, can add a new optional agent to the beneficiation process, thereby promoting the optimization of beneficiation process indicators and economic indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a system diagram of the synthesis process of a secondary heptyl xanthate of the present invention; DETAILED DESCRIPTION

[0013] In order to make the technical problems and technical solutions solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and 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. Embodiment 1:

[0014] This embodiment is a small-scale test.

[0015] Synthesis equipment: -20℃ frozen brine water bath for cooling, 200ml stoppered conical flask as reaction equipment, 100℃ range alcohol thermometer as stirring and temperature measuring equipment, 0.01g electronic balance as weighing equipment, 2ml glass dropper for adding liquid raw materials, 180㎜ stainless steel single-head medicine spoon as manual powder alkali lifting equipment.

[0016] The synthesis steps include: (1) Take 22.7 g of sec-heptyl alcohol, 15.8 g of carbon disulfide and 8.5 g of powdered sodium hydroxide and set aside.

[0017] (2) Add 22.7 g of sec-heptyl alcohol and 15.8 g of carbon disulfide into a conical flask, place the conical flask in a chilled brine water bath to cool, and stir using a thermometer; (3) Then, add powdered sodium hydroxide in small amounts in batches while stirring, and control the reaction temperature at 20±1°C; (4) Finally, add the remaining 1g of powdered sodium hydroxide into the conical flask at once and continue stirring. Move the conical flask out of the refrigerated brine water bath for insulation. The insulation temperature is controlled at 36-38°C and is maintained for 30-40 minutes. (5) After the insulation is completed, the conical flask is placed in a refrigerated brine water bath again to cool down. When the temperature drops below 25°C, the material is discharged to obtain sodium sec-heptyl xanthate. Embodiment 2:

[0018] This embodiment is an industrial test, and the specific process system is as follows Figure 1 shown.

[0019] Synthesis equipment: -20℃ frozen brine cooling system is used for cooling; 1m³ rake-type reactor is used as the reactor; sec-heptyl alcohol metering tank, carbon disulfide metering tank, caustic soda metering tank and caustic soda adding temperature control device are used to add sec-heptyl alcohol, carbon disulfide and caustic soda respectively, among which the caustic soda adding temperature control device can adjust the adding speed of caustic soda according to the reaction temperature.

[0020] The synthesis steps include: (1) Add 170 kg of sec-heptyl alcohol and 118 kg of carbon disulfide from the sec-heptyl alcohol metering tank and the carbon disulfide metering tank into the reactor respectively, start the reactor to stir, and weigh 64 kg of powdered sodium hydroxide in the powdered caustic soda metering tank; (2) Start the -20℃ frozen brine cooling system to cool the reactor, start the powdered alkali temperature control device to add powdered sodium hydroxide in small batches, and control the reaction temperature at 20±1℃ during the addition process; (3) Add the remaining 10 kg of powdered sodium hydroxide into the reactor at one time, close the circulating chilled brine outlet valve for insulation, control the insulation temperature at 36-38°C, and keep it warm for 40 minutes; (4) After the insulation is completed, open the circulating refrigerated brine outlet valve to cool the water down, and discharge the material when the temperature drops below 25°C to obtain sodium sec-heptyl xanthate. Embodiment 3:

[0021] This embodiment is an industrial test, and the specific process system is as follows Figure 1 shown.

[0022] Synthesis equipment: Different from Example 2, this example uses a 1m³ double-shaft kneader as a reactor, and other synthesis equipment is the same as Example 2.

[0023] The synthesis steps include: (1) Add 170 kg of sec-heptyl alcohol and 118 kg of carbon disulfide from the sec-heptyl alcohol metering tank and the carbon disulfide metering tank into the biaxial kneader respectively, start the biaxial kneader for stirring, and weigh 89 kg of powdered potassium hydroxide from the powdered alkali metering tank; (2) Start the -20℃ frozen brine cooling system to cool the biaxial kneading machine, start the powdered alkali temperature control device to add powdered potassium hydroxide in small batches, and control the reaction temperature at 20±1℃ during the addition process; (3) Add the remaining 10 kg of powdered potassium hydroxide into the biaxial kneading machine at one time, close the circulating chilled brine outlet valve for insulation, control the insulation temperature at 36-38°C, and keep it warm for 40 minutes; (4) After the insulation is completed, open the circulating refrigerated brine outlet valve to cool the water down, and discharge the material when the temperature drops below 25°C to obtain potassium sec-heptyl xanthate.

[0024] The product synthesized in the above-mentioned small-scale tests and industrial tests, sodium (potassium) sec-heptyl xanthate, was tested in accordance with YS / T271.1~271.3 "Chemical Analysis Methods for Xanthate", and the results showed that the grade of heptyl xanthate was 65%~67%, the appearance was light yellow powder, and the free base was 0.5%~1.0%, which can meet industrial applications.

[0025] In summary, the method for synthesizing the secondary heptyl xanthate proposed in the present invention can synthesize the secondary heptyl xanthate that meets industrial applications, and is widely used in the beneficiation of non-ferrous metals such as copper, lead, zinc, and precious metal minerals such as gold and silver. Its selectivity and capture capacity, which are different from other xanthates, can add a new optional agent to the beneficiation process, thereby promoting the optimization of beneficiation process indicators and economic indicators.

[0026] The present invention is described in detail above through specific and preferred embodiments, but those skilled in the art should understand that the present invention is not limited to the embodiments described above, and any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for synthesizing a secondary heptyl xanthate, characterized in that: The method comprises the following steps: the xanthate is synthesized by direct reaction of sec-heptyl alcohol, carbon disulfide, sodium hydroxide or potassium hydroxide in a molar ratio of 0.98:1.02:1.05; firstly, sec-heptyl alcohol and carbon disulfide are added into a reactor, stirred evenly, then powdered alkali is added in batches under stirring, the reaction temperature is controlled at 20±1 DEG C, the remaining powdered alkali is added at one time, stirring is continued, the temperature is kept at 36-38 DEG C, and the temperature is kept continuously for 30-40 minutes, the temperature is lowered after the temperature is kept, and the material is discharged after the temperature is lowered to below 25 DEG C to obtain the product.

2. The method for synthesizing a secondary heptyl xanthate according to claim 1, characterized in that: The content of the secondary heptanol is ≥98%, and the remaining components are alcohols.

3. The method for synthesizing a secondary heptyl xanthate according to claim 2, characterized in that: The water content of the secondary heptanol is less than 0.2%.

4. The method for synthesizing a secondary heptyl xanthate according to claim 1, characterized in that: The carbon disulfide content is ≥98%.

5. The method for synthesizing a secondary heptyl xanthate according to claim 1, characterized in that: The sodium hydroxide or potassium hydroxide content is ≥99%, and the crushing particle size is <60 mesh.

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