WO2021128922A1

WO2021128922A1 - Application of 2-(3-substituted ureido)-n-hydroxy-2-oxoacetimide cyanide compound in flotation

Info

Publication number: WO2021128922A1
Application number: PCT/CN2020/112642
Authority: WO
Inventors: 曹建; 张晚佳; 高志勇; 冯知韬; 杨宇航; 孙伟; 胡岳华
Original assignee: 中南大学
Priority date: 2019-12-23
Filing date: 2020-08-31
Publication date: 2021-07-01
Also published as: ZA202206168B; CN111068925B; CN111068925A

Abstract

Provided is an application of a 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound in flotation, which is used as a flotation collector for the flotation separation of calcium-containing minerals, wherein the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound has excellent flotation separation effect and foaming performance of calcium-containing minerals, its compounding with auxiliary collectors will help to further reduce the dosage and improve the flotation performance; further provided is a calcium-containing mineral flotation agent, which includes the 2-(3-substituted ureido)-N-hydroxy- 2-oxoacetimide cyanide compound and auxiliary collectors. The flotation reagent can preferentially flotate fluorite and calcite; and under neutral conditions (pH = about 7), it can achieve high-efficiency separation of fluorite and calcite from scheelite, and can effectively purify the crude scheelite concentrate and improve the grade of scheelite concentrate and at the same time, a neutral flotation environment reduce its impact on the environment.

Description

Application of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compounds in flotation

Technical field

The invention belongs to the field of mineral flotation, and specifically relates to a high-separation flotation agent for calcium-containing minerals.

Background technique

Fluorite, calcite and scheelite are three common calcium-containing minerals. Among them, fluorite is widely used as a fluxing agent in the metallurgical industry. At the same time, fluorite is also the main source of hydrofluoric acid. In addition, fluorite is also used in glass, ceramics, optics and military industries due to its unique properties. Scheelite is one of the main sources of tungsten, and my country's demand for scheelite and fluorite is increasing.

The most effective and commonly used method for the separation and utilization of calcium-containing minerals at this stage is through flotation. Flotation is a beneficiation method that selectively separates minerals based on the difference in physical and chemical properties of the mineral surface. The flotation effect depends to a large extent on the use of flotation reagents, especially the use of flotation collectors. At this stage, one of the most important problems plaguing the flotation of calcium-containing minerals is fluorite, which is often accompanied by scheelite and calcite. At this stage, the commonly used collectors for calcium-containing minerals include fatty acids and their soaps, sulfates, sulfonates, etc. The most commonly used collector is oleic acid. Although oleic acid has good collecting performance, this collector There is almost no sorting, and it is impossible to sort fluorite, scheelite and calcite. At the same time, oleic acid also has disadvantages such as poor water solubility, high temperature and water quality requirements, low concentrate grade and large fluctuations in indicators. The cations of fluorite, scheelite and calcite are all Ca ²⁺ and have similar solubility. Therefore, in the flotation separation of calcium-containing minerals, inhibitors are often used to separate the minerals, but the addition of inhibitors will increase additional manpower and material resources. It also has an adverse impact on the environment, so it is of great significance to develop a collector that can efficiently separate fluorite, scheelite and calcite and has good foaming properties.

Summary of the invention

The purpose of the present invention is to provide an application of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound, aiming to pass 2-(3-substituted ureido)- The use of N-hydroxy-2-oxoacetimide cyanide compounds improves the flotation effect of calcium-containing minerals.

The second object of the present invention is to provide a flotation agent containing 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound.

The separation of calcium-containing minerals such as scheelite from calcium-containing gangue minerals, especially flotation separation from calcite and fluorite is one of the world's problems. The existing medicaments have poor selectivity for calcium-containing minerals and cannot achieve good flotation separation. For this reason, the present invention provides the following technical solutions:

An application of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound, which is used as a flotation collector for the flotation separation of calcium-containing minerals;

The 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound is at least one compound having the structural formula of Formula 1;

R is hydrogen, C ₁ -C ₁₅ alkyl, C ₃ -C ₁₅ cycloalkyl, propenyl, ethynyl, phenyl, benzyl or benzyloxy; wherein, phenyl, benzyl, benzyloxy Substituents are allowed on the aromatic ring of the group.

The present invention finds that the compound of formula 1 is a non-ionic calcium-containing mineral collector. Through its molecular structure and intramolecular interaction between groups, it gives the molecule good foamability and excellent collection performance. And selectivity; using it as a collector for calcium-containing minerals, it can show good flotation selectivity and recovery rate, and can solve the urgent need to solve calcium-containing minerals in the industry, such as scheelite-fluorite-calcite mixed minerals. The problem of high-efficiency flotation separation, and the problem of high-efficiency removal of scheelite coarse concentrate.

The alkyl group is, for example, a straight chain alkyl group or a branched chain alkyl group. The cycloalkyl group is preferably a three- to six-membered monocyclic alkyl group with the carbon number, or a bridged ring or spirocyclic alkyl group with six or more members. Phenyl, benzyl, substituted with, for example, allow the C ₁ ~ C ₃ alkyl group, an alkoxy group or a halogen on the aromatic ring benzyloxy.

Preferably, the R is a hydrogen group, a C ₂ -C ₆ alkyl group, a C ₃ -C ₆ propenyl group, a phenyl group, an ethynyl group or a benzyl group.

More preferably, R is hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, propenyl, allyl, phenyl, benzyl or benzyloxy.

Most preferably, R is methyl, ethyl, butyl, pentyl, hexyl or phenyl. Studies have found that the compound has better effects in the flotation process of calcium-containing minerals.

Preferably, the calcium-containing minerals are two or more minerals among scheelite and calcium-containing gangue.

Preferably, the calcium-containing gangue contains at least one of fluorite and calcite. According to the technical scheme of the present invention, the compound of formula 1 has good selectivity to two or more mixed ores of scheelite, fluorite and calcite, and can realize the selective flotation separation of the calcium-containing mixed ores; Improve the grade of useful minerals in flotation concentrates.

The preferred application is for the flotation separation of scheelite and calcium gangue. The research of the present invention found that the compound of formula 1 has better selectivity to scheelite and other calcium-containing gangue (for example, at least one of fluorite and calcite), and can realize the negative flotation of scheelite. And realize the positive flotation of calcium-containing gangue, so as to realize the efficient separation of scheelite and calcium-containing gangue.

Preferably, in the application, the calcium-containing mineral is crushed and slurried to obtain a slurry, and a compound containing 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide is added to the slurry. Of flotation reagents for flotation.

Preferably, the flotation agent also contains a collector assistant. The study found that the use of the existing collector assisting agent and the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound of the present invention can produce a synergistic effect and reduce 2 -(3-Substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound dosage, not only that, but also can improve the flotation selectivity and recovery rate.

The auxiliary collector includes at least one of hydroxamic acid compounds, fatty acid compounds, phosphoric acid compounds, dodecylamine compounds and amino acid compound collectors.

The study found that further control of the ratio of the components in the flotation reagent will help to further enhance the selectivity of the flotation reagent.

In the flotation reagent, the weight part of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector is 70 to 98 parts; the weight part of the auxiliary collector is not More than 30 servings;

Preferably, in the flotation agent, the weight parts of the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector is 80 to 98 parts, and the weight of the auxiliary collector is 80 to 98 parts. Parts by weight are 2-20 parts. In this preferred range, the flotation agent containing the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector of the present invention has a better synergistic effect, It is more conducive to effectively improve the recovery rate and concentrate grade of target calcium-containing minerals.

Preferably, the pH of the flotation process is 6-8. Controlling the pH of the slurry during the flotation process is within 6-8, which can further exert the performance of the collector and further improve the flotation selectivity and recovery rate.

Preferably, in the flotation process, the amount of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector is not less than 0.8×10 ^-4 mol/L ; It is preferably not less than 4×10 ^-4 mol/L.

Preferably, in the application, the calcium-containing mineral is a mixed calcium-containing mineral containing two or more of scheelite, fluorite and calcite. The 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound of the present invention is used in the flotation and purification of scheelite coarse concentrate containing fluorite and calcite impurities Has a better effect.

The present invention also provides a flotation agent for calcium-containing minerals, which includes 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compounds.

The preferred flotation reagent also contains a collector assistant. Studies have found that 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compounds and auxiliary collectors have good synergy, which can improve the flotation effect of calcium-containing minerals, such as , Improve the flotation selectivity, and enhance the grade of useful mineral concentrates.

The auxiliary collector may be an existing collector in the field of calcium-containing mineral flotation, such as hydroxamic acid compounds, fatty acid compounds, phosphoric acid compounds, dodecylamine compounds and amino acid compound collectors. At least one of.

The study found that further control of the ratio of the components in the flotation reagent will help to further enhance the selectivity of the flotation reagent. Preferably, in the flotation agent, the weight part of the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector is 70 to 98 parts, more preferably 80 to 98 parts; the weight part of the auxiliary collector is not more than 30 parts, more preferably 2-20 parts.

The application method of the flotation agent of the present invention can adopt the existing conventional method. In the flotation process, the pH during the flotation process is preferably controlled to be 6-8.

Preferably, during the flotation process, the concentration of the flotation agent in the slurry is not less than (greater than or equal to) 1×10 ^-4 mol/L; preferably, it is not less than 5×10 ^-4 mol/L.

Beneficial effect

1. The present invention found that the use of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compounds as flotation collectors for calcium-containing minerals can exhibit good flotation performance. Select selectivity and recovery rate.

2. The research of the present invention also found that the compounding of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound and auxiliary collector has a synergistic effect, not only Synergistically increase the collection capacity of calcium-containing minerals, enhance the stability of the foam, and effectively reduce the amount of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector , And effectively improve the flotation concentrate grade and recovery rate.

Description of the drawings

Table 1 The original grade and origin of the minerals used in the examples;

Figure 1 is a flotation flow chart of Example 1;

Figure 2 is a graph of the recovery rate of the flotation reagent in Example 1;

Table 2 is a data table of the recovery rate of the flotation reagent in Example 1;

Figure 3 is the recovery rate table of the flotation reagent of Example 2;

Table 3 is the recovery rate table of the flotation reagent in Example 2;

Figure 4 is a graph of the recovery rate of the flotation reagent in Example 3;

Table 4 is the recovery rate table of the flotation reagent in Example 3;

Figure 5 is a flotation flow chart of Example 4 and Comparative Example 1;

Table 5 shows the composition and ratio of the artificial mixed minerals of Example 4 and Comparative Example 1.

Table 6 shows the flotation results of Example 4 and Comparative Example 1;

Table 7 is Example 5, the grade of each component in ^{artificial mixed mineral 1 #} -4 ^#

Table 8 Flotation results of Example 5

Figure 6 is the NMR H spectrum of the 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compound of the present invention (R is ethyl);

Fig. 7 is the NMR C spectrum of the 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compound of the present invention (R is an ethyl group).

Detailed ways

Taking scheelite, single minerals of fluorite and calcite and two or more mixed calcium-containing minerals of scheelite-fluorite-calcite as examples to illustrate the effect of the present invention.

The synthetic route of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compounds is as follows:

For example, include the following steps:

step 1):

N-R substituted urea (formula A) and 2-cyanoacetic acid (formula B) are added to anhydrous acetic acid and reacted at 70° C. to obtain an intermediate product (C).

Step (2):

The intermediate product obtained in step (1) and sodium nitrite are placed in acetonitrile, and hydrochloric acid is added to react at 45° C. to obtain the target product (the compound of formula 1).

In the following cases, except for special declarations, the ingredients of the minerals used are as shown in Table 1:

Table 1 Original grade and origin of minerals

Example 1

In order to verify the separation effect of the flotation collector in the calcium-containing mixed minerals of each component when used alone in this case, we used scheelite, fluorite and calcite concentrates from Hunan and Sichuan, and used the process shown in Figure 1. Divided into 3 groups, the flotation collector in this case is used as the flotation agent to flotate different calcium-containing minerals. The flotation process parameters of each group of cases are the same. The only difference is that the types of flotation calcium-containing minerals are different. Compare the flotation and separation effects of the flotation collector in this case.

The flotation collector of the present invention: 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compound (in formula 1, R is ethyl), terpineol Add 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of 0.095mol:0.005mol, and magnetically stir at 65°C for 30min to make the agent fully mixed and seal for use.

The specific operation is: dry grind the concentrate ore (particle size 3mm-0.5mm) for 15 minutes (the particle size after grinding is 0.0740-0.0374mm, using a horizontal ball mill for dry grinding, the grinding concentration is 35-40%), Weigh 2g of the ground calcium-containing concentrate (fluorite, calcite or scheelite) from each group into a 40mL flotation tank, add 30mL of deionized water and then add the flotation collector described in this case to supplement the appropriate amount of deionization Water, stir for 3 minutes, start to scrape foam, scrape foam for 3 minutes, the concentrate is scraped to the concentrate basin with the foam, the tailings remain in the flotation tank, the concentrate and tailings are respectively weighed after being filtered and dried. The grade of the mine is tested and the recovery rate is calculated.

Figure 2 shows Example 1, the recovery rates of scheelite, fluorite and calcite concentrates under different dosages of medicaments. (The flotation collector in this case is a flotation reagent, and the pH of the slurry is 7).

It can be seen from Figure 2 that within the range of the tested reagent dosage, the flotation reagent described in this case has a strong selective collection capacity for complex calcium-containing minerals, especially for scheelite, which can be efficiently recovered. Scheelite is separated from fluorite and calcite, which can be used to remove impurities from scheelite concentrate in industry. This means that the flotation collector described in this case can efficiently separate fluorite and scheelite and to a certain extent can separate fluorite and calcite.

Table 2 Flotation results of Example 1

Example 2

Combine 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compound (in formula 1, R is an ethyl compound), benzyl hydroxamic acid, terpineol Add 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of 0.080mol:0.015mol:0.005mol, and stir it magnetically at 65°C for 30min to make the medicament fully mixed and seal for use.

It uses scheelite, fluorite and calcite concentrates from Hunan and Sichuan. Using the process shown in Figure 1, the experiment is divided into three groups. With the flotation reagent compounded in this case as the only flotation reagent, the flotation process parameters of the three groups of cases are the same. The only difference is that different types of oxidized ore single minerals are used. In order to compare the flotation separation effect of the compound flotation reagent in this case.

Dry the concentrate ore (particle size 3mm-0.5mm) for 15min (after grinding the particle size is 0.0740-0.0374mm, the grinding pH of fluorite and calcite scheelite are 7, 9 and 6, respectively, using a horizontal ball mill Dry grinding, grinding concentration is 35-40%), weigh 2g of each group and pour into 40mL flotation tank, add 30mL deionized water, add flotation reagent, add appropriate amount of deionized water, stir for 3min, start to scrape bubbles, scrape After soaking for 3 minutes, the concentrate is scraped to the concentrate basin with the foam, and the tailings remain in the flotation tank. After filtering and drying, the concentrate and tailings are weighed separately to calculate the recovery rate.

Figure 3 shows Example 1, the recovery rates of scheelite, fluorite and calcite concentrates under different dosages of medicaments. (The flotation reagent in this case is a flotation reagent, and the pH of the slurry is 7).

It can be seen from Figure 3 that within the range of the tested reagent dosage, the flotation reagent described in this case has a strong selective collection capacity for complex oxide ore, especially for scheelite, which can efficiently collect fluorescens. Scheelite is separated from stone and calcite, which can be used to remove impurities from scheelite concentrate in industry. When the dosage of the reagent is very low (1×10 ^-5 mol/L), the recovery rate of the compound flotation reagent in this case for fluorite reaches about 50%, and the recovery rate of the compound flotation reagent in this case is calcite It is only 4.89%, and the recovery rate for scheelite is only 0.71%, which means that the combined flotation reagent in this case can efficiently separate fluorite and scheelite and to a certain extent can separate fluorite and calcite.

As the concentration of the reagent increases from 1×10 ^-5 mol/L to 5×10 ^-4 mol/L, the recovery rate of fluorite by the compound flotation reagent in this case has increased by 43.97%, and the concentration of the reagent is 5×10 ^{The recovery rate at -4} mol/L was 94.38%. The recovery rate of calcite increased by 23.53%, and the recovery rate was 28.42% when the ^{concentration of the agent was 5×10 -4 mol/L.} The recovery rate of scheelite has been kept below 3%. This shows that with the increase of the dosage of the reagent, the flotation reagent compounded in this case can further improve the sorting performance of fluorite, calcite and scheelite.

Table 3 Flotation results of Example 2

Example 3

Pulp pH is one of the most important parameters to control the flotation process, and it may have a direct impact on mineral surface electrical properties, cationic hydrolysis, reagent flotation activity, adsorption properties, and sludge dispersion and agglomeration. By performing flotation experiments at different solution pHs, the optimal pH of the flotation agent of the present invention for separating fluorite, scheelite, and calcite is explored.

Combine 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compounds (in formula 1, R is ethyl), benzyl hydroxamic acid, and terpineol according to 0.085 Add 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of mol:0.010mol:0.005mol, and magnetically stir at 65°C for 30min to make the agent fully mixed and seal for use.

The specific operation is: dry grinding the concentrate ore (particle size 3mm-0.5mm) for 15 minutes (after grinding the particle size 0.0740-0.0374mm), dry grinding with a horizontal ball mill, and the grinding concentration is 35-40%. Each group weighs 2g of the ground concentrate and pours it into a 40mL flotation tank, adds 30mL of deionized water and then adds the flotation agent. The dosage of the two flotation agents is 5×10-4mol/L, and an appropriate amount of deionized water is added. Stir for 3 minutes, add pH adjuster (hydrochloric acid or sodium hydroxide) to adjust the flotation system to a specific pH, stir for 3 minutes, start to scrape foam, scrape foam for 3 minutes, the concentrate is scraped to the concentrate basin with the foam, and the tailings remain in the float In the selection tank, the concentrate and tailings are filtered and dried and weighed separately to calculate the recovery rate.

The pH gradient set in the experiment is: 4,5,6,7,8,9,10. Among them, the main component of calcite is CaCO3, which means that calcite will decompose under acidic conditions. After adding calcite, the pH of the solution cannot be stable under acidic conditions, so the pH gradient of calcite is: 6, 7, 8, 9, 10.

Figure 4 shows the recovery rates of Example 3 scheelite, fluorite and calcite concentrates at different pHs. (The concentration of the flotation reagent in this case is 5×10 ^-4 mol/L, the initial pH value of fluorite flotation is 7, the initial pH value of calcite flotation is 9, and the initial pH value of scheelite flotation is 6, all adjusted to pH The flotation experiment was carried out at 7, and the pH adjusting agent was sodium hydroxide solution and hydrochloric acid solution).

It can be seen from Example 3 that the collection performance of the flotation agent of the present invention on the three oxides of fluorite, calcite and scheelite tends to be stable between pH=6-8. In this pH range, this case The recovery rate of useful mineral fluorite is higher than 75%, while the recovery rate of scheelite is lower than 5%. It shows that the flotation reagent in this case can collect complex calcium-containing minerals with high efficiency and high separation in the green neutral acid-base range (pH between 6-8).

Table 4 Flotation results of Example 3

Example 4

In order to verify the separation effect of the flotation agent in the calcium-containing mixed minerals of each component, we used scheelite, fluorite and calcite concentrates from Hunan and Sichuan, mixed uniformly in different proportions, and obtained three artificial mixed minerals1 ^# -4 ^# , using the process shown in Figure 5, the experiment is divided into 4 groups, using the benzyl hydroxamic acid compound agent (comparative example 1) as the flotation agent to compare with the flotation agent of the present invention, each group of cases flotation The parameters of the selection process are the same, the only difference is that the types of flotation reagents are different, so as to compare the flotation effect of benzyl hydroxamic acid and the series of flotation reagents in this case.

The flotation agent of the present invention: 2-(3-ethylureido)-N-hydroxy-2-oxoacetimide cyanide compound (in formula 1, R is ethyl), benzyl hydroxamic acid , Terpineol is added to 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of 0.090mol:0.005mol:0.005mol, and magnetically stirred at 65°C for 30min to make the agent fully mixed and sealed for use.

Benzyl hydroxamic acid compound medicament (comparative example 1): Add benzyl hydroxamic acid and terpineol into 1L deionized water (concentration of 0.1mol/L) at the ratio of 0.095mol:0.005mol, Stir magnetically at ℃ for 30 minutes to make the medicines mix well and seal for use.

The specific operation is: dry grind the concentrate ore (particle size 3mm-0.5mm) for 15 minutes (the particle size after grinding is 0.0740-0.0374mm, using a horizontal ball mill for dry grinding, the grinding concentration is 35-40%), Each group weighs 2g of the concentrate, which has been ground and evenly mixed in proportion, and poured into a 40mL flotation tank. After adding 30mL of deionized water, add benzyl hydroxamic acid and the series of flotation reagents described in this case, and add an appropriate amount of deionization. The concentration of water and flotation reagent are both 5×10 ^-4 mol/L, the pH of the pulp is 7, stirring for 3 minutes, start to scrape foam, scrape foam for 3 minutes, the concentrate is scraped to the concentrate basin with the foam, and the tailings remain in the flotation In the tank, the concentrate and tailings are filtered and dried and weighed separately. The grade of the concentrate is detected and the recovery rate is calculated.

The series of artificial mixed minerals 1 ^# -4 ^{# in} this case The specific mixing ratio is as follows:

^{Artificial mixed mineral #} 1 in this case: 1g of fluorite, 1g of calcite, mechanically stirred at room temperature for 10 minutes, so that the minerals are fully mixed, and sealed for use;

Artificial mixed mineral 2 ^{# in} this case: 1g of fluorite, 1g of scheelite, mechanically stirred at room temperature for 10 minutes, so that the minerals are fully mixed, and sealed for use;

Artificial mixed mineral 3 ^{# in} this case: 1g of calcite, 1g of scheelite, mechanically stirred at room temperature for 10 minutes, so that the minerals are fully mixed and sealed for use;

^{Artificial mixed mineral #} 4 in this case: 0.5g of fluorite, 0.5g of calcite, 1g of scheelite, mechanically stirred at room temperature for 10 minutes, so that the minerals are fully mixed and sealed for use;

Table 5 is Example 4, the grade of each component in the ^{artificial mixed mineral 1 #} -4 ^#.

Table 5 Composition and proportion of artificial mixed minerals

Table 6 shows Example 4, the flotation recovery rate and grade of fluorite, calcite and scheelite.

Table 6 Flotation results of Example 4

([Flotation agent of the present invention/benzyl hydroxamic acid compound agent] = 5×10 ^-4 mol/L; pH=7)

(The concentration of flotation reagent in this case is all 5×10 ^-4 mol/L, and the initial pH value of fluorite, calcite and scheelite is adjusted to 7)

It can be seen from Table 7 that when the concentration of the flotation agent is 5×10 ^-4 mol/L, the flotation agent in this case has a significantly stronger collection capacity for the fluorite and calcite in ^{the artificial mixed ore 1 #} -4 ^# Benzyl hydroxamic acid. At the same time, the collection capacity of the flotation reagent in this case for scheelite is obviously weaker than that of benzyl hydroxamic acid. According to the flotation results, compared with the traditional sulfide flotation agent benzyl hydroxamic acid, the separation effect of the flotation agent in this case has been significantly improved, and the recovery rate of useful minerals has also been significantly improved. It can be seen that the flotation reagent in this case is more effective than the traditional oxide ore flotation reagent benzyl hydroxamic acid, and the separation effect is better.

Example 5

In order to verify the separation effect of the flotation agent in the calcium-containing mixed minerals of each component, we used scheelite, fluorite and calcite concentrates from Hunan and Sichuan, mixed uniformly in different proportions, and obtained three artificial mixed minerals1 ^# -4 ^# , using the process shown in Figure 5, the experiment is divided into 4 groups, using different R groups corresponding to the compound flotation agent of the collector of the present invention as the flotation agent and compared, each group of case flotation The parameters of the selection process are the same. The only difference is that the types of flotation reagents are different, so as to compare the flotation effect of the series of flotation reagents in this case.

The flotation agent 1# of the present invention: Combine 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound (in formula 1, R is pentyl), benzyl hydroxyoxime Acid and terpineol were added to 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of 0.090mol:0.005mol:0.005mol, and magnetically stirred at 65°C for 30min to make the agent fully mixed and sealed for use.

The flotation agent 2# of the present invention: Combine 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound (in formula 1, R is phenyl), benzyl hydroxyoxime Acid and terpineol were added to 1L of deionized water (with a concentration of 0.1mol/L) in the ratio of 0.090mol:0.005mol:0.005mol, and magnetically stirred at 65°C for 30min to make the agent fully mixed and sealed for use.

The specific operation is: dry grind the concentrate ore (particle size 3mm-0.5mm) for 15 minutes (the particle size after grinding is 0.0740-0.0374mm, using a horizontal ball mill for dry grinding, the grinding concentration is 35-40%), Each group weighs 2g of the concentrate, which has been ground and evenly mixed in proportion, and poured into a 40mL flotation tank. After adding 30mL of deionized water, add benzyl hydroxamic acid and the series of flotation reagents described in this case, and add an appropriate amount of deionization. The concentration of water and flotation agent are both 5×10 ^-4 mol/L, the pH of the slurry is 7, stirring for 3 minutes, start to scrape foam, scrape foam for 3 minutes, the concentrate is scraped to the concentrate basin with the foam, and the tailings remain in the flotation In the tank, the concentrate and tailings are filtered and dried and weighed separately. The grade of the concentrate is detected and the recovery rate is calculated.

Table 7 shows the grade of each component in the artificial mixed mineral 1 ^# -4 ^{# in Example 5.}

Table 7 Composition and proportion of artificial mixed minerals

Table 8 shows Example 5, the flotation recovery rate and grade of fluorite, calcite and scheelite.

Table 8 Flotation results of Example 5

([The flotation reagent of the present invention]=5×10 ^-4 mol/L; pH=7)

In summary, the flotation agent of Formula 1 of the present invention has good positive flotation collection for fluorite and calcite, reverse flotation effect for scheelite, and can selectively separate scheelite and calcium-containing gangue (Such as fluorite and calcite).

Claims

An application of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound, which is characterized in that it is used as a flotation collector for calcium-containing minerals Flotation separation;

The 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound is at least one compound having the structural formula of Formula 1;

R is hydrogen, C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, propenyl, ethynyl, phenyl, benzyl or benzyloxy; wherein, phenyl, benzyl, benzyloxy Substituents are allowed on the aromatic ring of the group.
The application according to claim 1, wherein the R alone is a hydrogen group, a C 2 -C 6 alkyl group, a C 3 -C 6 propenyl group, a phenyl group, an ethynyl group or a benzyl group.
The application according to claim 1, wherein the calcium-containing minerals are scheelite and calcium-containing gangue.
The application according to claim 3, wherein the calcium-containing gangue contains at least one of fluorite and calcite.
The application according to claim 3, characterized in that it is used for flotation separation of scheelite and calcium gangue.
The application according to claim 1, wherein the calcium-containing mineral to be processed is crushed and slurried to obtain a slurry, and the slurry containing 2-(3-substituted ureido)-N-hydroxy-2-oxyacetyl is added to the slurry. Flotation reagent for imino cyanide compounds for flotation.
The application according to claim 6, wherein the flotation reagent further contains a collector assistant;

The auxiliary collector includes at least one of hydroxamic acid compounds, fatty acid compounds, phosphoric acid compounds, dodecylamine compounds and amino acid compound collectors.
The application according to claim 6, characterized in that, in the flotation agent, the weight part of the collector of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound is 70-98 parts; the weight part of the auxiliary collector is not more than 30 parts.
The application according to claim 8, characterized in that, in the flotation agent, the weight part of the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound collector is 80-98 parts, the weight part of the auxiliary collector is 2-20 parts.
The application according to any one of claims 1-9, wherein the pH of the flotation process is 6-8.
The application according to claim 1, characterized in that, in the flotation process, the dosage of formula 1 is not less than 0.8×10 -4 mol/L; preferably, the dosage of formula 1 is not less than 4×10 -4 mol /L.
A calcium-containing mineral flotation agent containing the 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound described in any one of claims 1-11.
The flotation reagent according to claim 12, characterized in that it further comprises a collector assisting agent;

The auxiliary collector includes at least one of hydroxamic acid compounds, fatty acid compounds, phosphoric acid compounds, dodecylamine compounds and amino acid compound collectors.
The flotation agent according to claim 13, wherein the weight of the collector of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound in the flotation agent The parts are 70-98 parts; the weight parts of the collector assistant is not more than 30 parts.
The flotation reagent according to claim 14, wherein the weight of the collector of 2-(3-substituted ureido)-N-hydroxy-2-oxoacetimide cyanide compound in the flotation reagent The part is 80-98 parts, and the weight part of the auxiliary collector is 2-20 parts.