Chalcopyrite flotation process

Flotation technology is widely used in the enrichment and separation of sulfide ore, enabling the effective use of low-grade minerals. At the end of the 19th century, flotation technology realized industrial application. It experienced three stages of full oil flotation, surface flotation and foam flotation. The flotation collector was also developed by several simple mineral oils and tars, and yellow medicine appeared. aerofloat, thiophosphoric acid salts collector sulfide ores, flotation separation has been enhanced and improved. With brass mineral resources becoming "poor, fine heteroaryl", the flotation process and the conventional single collector it has been difficult to meet the requirements. In recent years, researchers have conducted extensive research on flotation processes and flotation collectors, especially in the development and application of high selectivity and strong capture capacity flotation reagents. This paper gives a brief overview of the research progress of the chalcopyrite flotation process and flotation collector.

1 Chalcopyrite mineral characteristics and flotation characteristics

1.1 Mineral characteristics of chalcopyrite

There are more than 280 copper-bearing minerals discovered in nature, mainly chalcopyrite, chalcopyrite and porphyrite, of which chalcopyrite accounts for about 70%. The crystal structure of chalcopyrite is tetragonal, with a lattice energy of 17500 kJ. Cu atoms and Fe atoms are at the apex angle of the tetrahedron. Each S atom is surrounded by two Cu atoms and Fe atoms, often in the form of dense blocks. Or granular. Chalcopyrite has good electrical conductivity and can promote the action of the agent and the mineral surface to enhance its floatability.

As of 2012, China has proven copper reserves of 30 million tons and basic reserves of 63 million tons, ranking sixth in the world, most of which are distributed in Jiangxi, Yunnan, Hubei, Anhui, Gansu, Inner Mongolia, Sichuan, Shanxi, etc. Provincial area. The main types of copper is chalcopyrite, bornite, tetrahedrite, etc., low-grade multi-metal refractory ore more, the average grade of ore is only 0.87%, and frequently with molybdenum, gold, silver and other precious metal Comprehensive recycling is difficult.

1.2 Flotation characteristics of chalcopyrite

Chalcopyrite is one of the minerals with good self-induced floatability and collector-induced floatability in nature. It has good hydrophobicity in weak alkaline and neutral environments, but it will be water in high alkali environment. Hydrogen bonds are formed to reduce their floatability. Gardner et al. studied the chalcopyrite flotation particles with a modified single-bubble flotation tube. Studies have shown that elemental sulfur attached to the mineral surface by anodic oxidation of the mineral surface is a key factor in changing the hydrophilicity of the mineral.

Heyes et al. studied the natural floatability of chalcopyrite and believed that the floatability of chalcopyrite is closely related to its redox potential and anodization. He conducted flotation studies on mixed single minerals by batch flotation experiments. The results show that chalcopyrite exhibits natural flotation in an oxidizing environment. In the flotation process using a ball mill made of iron will produce a strong reducing environment, thus affecting its flotation performance, followed by addition of an oxidizing agent or contact with air, it is possible to restore its flotation performance.

2 Chalcopyrite flotation process

The chalcopyrite flotation process varies according to the nature of the ore and the quality requirements of the concentrate. The current industrial processes are mainly mixed flotation, full priority flotation, partial priority-mixed flotation and floatable flotation. And other processes.

2.1 Mixed flotation process

The mixed flotation process first floshes the chalcopyrite and other useful minerals present in the ore, and then uses the preferred float copper to inhibit the flow of other minerals to obtain a qualified copper concentrate. The process is suitable for treating ore with low ore grade and simple ore property, and has the advantages of saving grinding cost, flotation reagent and flotation equipment ; however, the process has the disadvantages of difficult separation between useful minerals and low grade of concentrate. .

Ge et al. improved the flotation process of Jiudingshan copper-molybdenum ore, using a ball-milling mixed flotation process to obtain copper grade 19.23%, recovery rate 85.5%; molybdenum grade 48.53%, recovery rate 90.96% flotation index, and Compared with the re-grinding separation process of the original copper-molybdenum mixed concentrate, it can avoid the over-grinding phenomenon that may occur during re-grinding and improve the flotation index.

2.2 Full priority flotation process

Chrysanthemum's full-priority flotation process has two main forms. One is to suppress associated minerals such as pyrite by adding inhibitors such as lime. Although this process can achieve a good flotation effect, it usually requires a large amount of consumption. The lime will also reduce the grade of copper concentrate and the recovery of copper and associated rare metals such as Au, Ag, Mo. Yet another approach is to flocculate chalcopyrite under neutral to weak alkaline conditions using an agent that is highly selective for chalcopyrite. The full-priority flotation process is suitable for processing simple components, few kinds of useful minerals to be recycled, large differences in flotation between useful minerals, or minerals that coexist with chalcopyrite can be well suppressed against chalcopyrite Flotation has no significant impact on the ore.

Wang Ligang et al. carried out research on flotation process technology of a copper-molybdenum mine in Mongolia. According to the difference of floatability of useful minerals in ore, the experiment was carried out by preferential flotation process, and copper-molybdenum mixed concentrate was preferentially obtained to inhibit pyrite. The copper concentrate grade and copper recovery rate were 24.32% and 96.77%, respectively. The recovery rates of molybdenum, gold and silver were 81.04%, 82.00% and 84.03%, respectively. The flotation index was ideal and the process flow was simple and easy to implement. The coarse concentrate does not need to be reground.

2.3 Partial priority-mixed flotation process

Partially preferred-mixed flotation process is to first flotation of easy-flotation copper ore, and then mix and float the mixed concentrate of copper and other useful minerals, followed by flotation separation of the mixed concentrate, and according to the actual The situation is combined or treated separately with copper concentrate. The process is suitable for treating some of the easily floatable chalcopyrites present in the ore. It can be preferentially floated under the condition that the fineness of the grinding is not very high, so that the copper is fast-receiving and early-receiving, and it is difficult to float. In the case of re-grinding or no-grinding, it is possible to use an ore with a highly collectable collector and other minerals. The process can reduce the amount of medicament used, eliminate the influence of excess medicament on the separation flotation, and improve the flotation index. The main disadvantage is that more flotation equipment is needed.

Liu et al. studied the flotation process and flotation reagents of a copper-molybdenum ore in Dexing. When using the partial priority-mixing flotation process, the MC-103 flotation was used to float the copper and molybdenum ore. The trapping ability of the agent flotation is difficult to float copper-molybdenum ore. The whole flotation process can increase the molybdenum grade and recovery rate to 48.83% and 90.60%, respectively, which solves the problem of low molybdenum recovery rate, and reduces the dosage and cost.

2.4 and other floatable flotation process

The floatable process is suitable for the treatment of polymetallic ores, and there is a mineral in the ore that has good floatability. Other ores can be divided into two parts: easy flotation and difficult flotation. Equal floatable flotation usually does not require the addition of modifiers, inhibitors and activators, keeping the minerals naturally buoyant. Minerals with better floatability can naturally float without being affected by the inhibitor, while avoiding the action of the activator to float the useful minerals together, resulting in the disadvantage of requiring a large amount of chemicals and equipment for mineral separation. The process generally achieves good technical specifications and can reduce the use of less chemicals and simplify the flotation equipment.

Liu et al. carried out flotation experiments on polymetallic copper, molybdenum, cobalt and iron ore with chalcopyrite as the main copper mineral. The distribution of copper minerals in ore is very large, reaching 91.36%, and cobalt and iron are closely symbiotic. The floatation and flotation process is used to float the copper-molybdenum mixed concentrate first, and then the cobalt concentrate and iron concentrate are floated from the tailings. The grades and recoveries of copper, molybdenum, cobalt and iron finally obtained were 21.25%, 45.78%, 0.46%, 63.73% and 93.38%, 45.72%, 46.42% and 38.26%, respectively.

In the actual production process, the flotation process is more flexible and often affected by the flotation performance of the agent. The company will adopt a process suitable for its own development based on the nature of the ore and production experience. With the development of lean, fine and miscellaneous chalcopyrite, and associated with a variety of metals, considering the recovery of useful elements, a single flotation process is difficult to obtain satisfactory indicators, generally using a combination of multiple flotation processes. For example, the step-by-step priority flotation process is based on the difficulty of the beneficial mineral flotation in the ore, and the preferential flotation is carried out in a certain order to obtain a separate qualified concentrate. This process typically achieves higher concentrate grades, simplifies process flow, and facilitates the recovery of rare metals associated with minerals.

3 chalcopyrite flotation collector

Chalcopyrite flotation collectors generally contain sulfur atoms inside the molecule, which only have the ability to capture sulfide ore, while the gangue minerals are basically not flotation. According to the functional group in the collector, common collectors can be divided into xanthate and its derivatives collectors, black drugs and their derivatives collectors, sulfur nitrogen collectors, mercapto compounds and The other five types of new chalcopyrite collectors, regardless of the flotation process, are designed to improve their capture capacity and selectivity.

3.1 xanthate and its derivatives collector

Xanthate and its derivatives collectors mainly include four kinds of compounds, xanthate, xanthate, xanthate and thiourethane. Xanthate is currently the most widely used chalcopyrite collector in the industry and has a strong ability to capture. Ordinary xanthate is poorly selective, and other sulfide minerals are floated together, which increases the subsequent separation process and causes inconvenience in the industry. Zhu Jisheng prepared methyl isoamyl alcohol, sodium hydroxide and carbon disulfide in a molar ratio of 1. 1 : 1. 1 : 1. 2 to prepare a novel methyl isoamyl xanthate which is odorless, stable in nature and excellent in water solubility. It has the advantages of fast flotation speed and good selectivity. It is combined with butyl xanthate to form a compound xanthate according to 1:1. The experiment is carried out on the winter melon mountain mixed copper-sulfur ore. The selectivity and collection ability of the compound xanthate are found. Better than methyl isoamyl xanthate, methyl isoamyl xanthate is better than butyl xanthate.

The xanthate collector is an excellent collector for flotation of Cu, Au, and sulfides such as Pb, Zn, Hg, and Mo. Cai Chunlin et al. studied the synthesis of ethyl butyl xanthate (BXEF) and its flotation properties for chalcopyrite. The optimum synthesis conditions for BXEF were determined as follows: butyl xanthate and chloroformate B The ester was reacted at a molar ratio of 1.04:1 at 25 °C for 200 min to give a yield of 94.5%. BXEF was used to study the Wushan copper mine, and the copper concentrate was 22.8% copper and the copper recovery rate was 82.40%. Compared with the flotation results of butyl xanthate under the same conditions, BXEF showed stronger harvesting power. And better selectivity, higher recovery and higher copper concentrate grades.

Thiocarbamate (ROCSNR 'R'') is characterized by strong selectivity and low dosage. Ethyl thiourethane (Z-200) is the most commonly used urethane collector. Yu Jihua has improved the synthesis process of Z-200. The Z-200 is prepared by one-step method. The purity of the product is more than 96%, and the yield is greater than 95%, the synthesis process is simple and easy to operate, and the yield and purity are high.

3.2 Black medicine and its derivatives collector

Black medicine and its derivatives collectors usually have good selectivity, but their ability to collect is slightly poor. It can be used for sorting copper ore containing pyrite, mainly including black medicine, double black medicine and black medicine. ester. Zhu Yimin synthesized a new type of isobutylammonium black drug by using phosphorus pentasulfide, isobutanol and liquid ammonia as raw materials. Were used as collector-butyl ammonium n-butylammonium black powder and black powder collector for zinc Bajiazi Liaoning Copper, Lead ore comparison experiments show that ammonium isobutyl aerofloat as collector, copper is obtained The recovery rates of lead, zinc, sulfur and silver are all improved, indicating that the absorption performance of isobutylammonium black drug is stronger than that of n-butylammonium black, and the price of raw material isobutanol is much cheaper than that of n-butanol. advantage.

3.3 Sulfur and nitrogen collectors

The application of sulfur-nitrogen collectors is more ethyl sulphide, which is based on the molar ratio of diethylamine, carbon disulfide, sodium hydroxide and water.

A ratio of 1.07:1:1:2 was prepared by reaction in an ice brine bath. The capture performance of ethion-nitrogen is similar to that of xanthate, but the effect is better than that of xanthate. It has stronger harvesting performance, which can make the dosage of the drug more than or even tens of times lower than that of xanthate, and has faster flotation speed and Better selectivity.

Sulfurazolides generally have stronger capture capacity and selectivity than the corresponding sulfur nitrogen. They are prepared by reacting sulfur nitrogen with olefinic compounds, mainly sulfur-sulfadienyl ester, sulfur-acrylonitrile ester, and sulfur-azepine. Ester (ester-105) and the like. Wang Caihong studied the effect of ester-105 on the selection of birch ditch copper ore in Jiugang, and compared it with butyl xanthate. Using ester-105 as a collector, a small amount of water glass can be used to obtain a copper concentrate grade of 22.51%, a copper recovery rate of 93.41%, and a butyl yellow drug as a collector copper concentrate of only 18.79. %, indicating that ester-105 has stronger harvesting ability and selectivity than butyl xanthate.

3.4 mercapto compounds

Sulfhydryl compounds mainly include mercaptans, thiophenols, white medicines, thiazoles, imidazole thiols, etc., and are generally used as sulfide mineral collectors, either alone or in combination with xanthate. PBM DONGCHUAN imidazole of chalcopyrite and bornite primary copper sulphide minerals selected from calcium magnesium difficult because people flotation ore small study, the results show that both an imidazole alone, or with The combination of xanthate can keep the grade of copper concentrate basically unchanged, but the recovery rate can be increased by 2.98%.

3.5 Other new collectors

Natarajan et al. synthesized and studied the application of several aryl hydroxamic acids on Cu-Zn sulfide ore, showing good selectivity, strong capture ability for chalcopyrite, and very good for zinc and iron. Weak, and the ability to capture increases with the number of carbon atoms in the acyl group on the acyl group, but when it is increased to six, it will reduce the flotation performance. Butyryl phenylhydroxylamine shows the best flotation performance. When the dosage of the agent is very low, the copper recovery rate is 93%, the copper grade is 32%, and the flotation effect is better.

Jiao Fen et al. studied the capture properties of collectors Mac-10, Ding Huang and 680 under different experimental conditions. The results show that the Mac-10 has better selectivity and enhanced trapping performance, enabling the use of less collector, achieving copper-sulfur separation at a wide pulp pH, and achieving better flotation.

Gu Guohua et al. studied the capture mechanism of chalcopyrite and pyrite by collector DLZ through a single mineral flotation experiment. The results show that the collector DLZ has a weak ability to capture pyrite under neutral and weak alkaline conditions, and can achieve copper-sulfur separation. FTIR analysis showed that DLZ was chemisorbed on the surface of chalcopyrite, while only physical adsorption occurred on the surface of pyrite.

Sun Xiaojun et al. studied the capture mechanism of the collector CSU31 for chalcopyrite and pyrite. Single mineral experimental studies have shown that CSU31 has good flotation performance for chalcopyrite in the whole pH range, and is not affected by lime under weak alkaline conditions, but the flotation ability of yellow iron is relatively Weak and much. The potentiodynamic test of CSU31 and minerals showed that CSU31 can be adsorbed more on the surface of chalcopyrite and has selectivity to pyrite. It can be used in copper-sulfur flotation separation experiments.

Qi Zhongxu studied the flotation performance of the new ore with different ore properties, high sulfur content, similar floatability of various minerals, and difficulty in separating copper and sulfur. In the experiment, DY-1 was combined with butyl xanthate. The copper grade of copper concentrate was 20.54% and the copper recovery rate was 72.96%. The mineral processing technical index was ideal.

Qi Wenqing et al. compared the selective flotation of copper-zinc ore with different collectors Z-200, Ding Huang, dibutyl dithiophosphate and new collector MBT. Experiments show that MBT is in flotation of brass. Mine and iron sphalerite show the best selectivity. Cyclic voltammetry and polarization curves have shown that zinc hydroxide and iron hydroxide are formed on the surface of the iron sphalerite, which causes the mineral surface to be hydrophilic and hinders MBT from flotation, while on the chalcopyrite surface. Hydrophobic substances (MBT) 2 and Cu(MBT) 2 are formed to promote flotation of chalcopyrite. Therefore, MBT can be used for flotation and separation of copper-zinc sulfide ore.

Conventional sulphide ore collectors have a strong ability to capture brass, but generally have poor selectivity, resulting in low separation efficiency between chalcopyrite and other minerals, and it is difficult to obtain satisfactory flotation indicators. Some collectors exist. The disadvantages of large toxicity and poor water solubility also limit their application in the gauze flotation. For this reason, the design and preparation of a new type of highly efficient and applicable chalcopyrite collector according to the capture mechanism of the drug has been extensive attention.

In recent years, the use of combined collectors has also been used more and more, generally using a combination of strong collection performance and another selective collector, not only can save the cost of chemicals, but also improve the float Selected indicators. Hangone studied the application of xanthate, dithiophosphate, dithiocarbamate and their blends in the flotation of copper sulfide in the Okiep mine. The results show that using a single collector, 2- Ethyl-dithiocarbamate has the worst flotation performance, 2-ethyl-dithiophosphate has the highest recovery and foaming; 90% ethylxanthate and Combination of 10% 2-ethyl-dithiophosphate can achieve the highest copper recovery; 90% ethyl xanthate and 10% dithiocarbamate combination can obtain the highest copper concentrate grade. The experimental results show that the reasonable ratio of the combination agent can show better flotation index than the single agent, and can be well applied in industry.

4 Conclusion

There are many kinds of chalcopyrite collectors, and the flotation performance is different. Among them, the xanthate collectors will be widely used in the future due to factors such as convenient raw materials, low price and strong flotation ability, but their existence The poor selectivity, odor, and the need to use a large amount of lime together need to be properly recognized and improved. Designing and preparing a new type of xanthate with selectivity, weak smell, tasteless and environmentally friendly will be the future yellow. Key areas of drug research.

In the face of increasingly scarce copper resources, the efficient use of poor, fine and miscellaneous copper ore has become an inevitable trend. In recent years, domestic and foreign mineral processing researchers have conducted extensive research on complex and difficult-to-select copper sulfide ore, researched and developed some highly efficient new collectors, and obtained industrial applications, creating huge economic value for some old floats. The selection process has been modified, and a more rational new process has been used to improve resource utilization. Develop a new type of chalcopyrite collector with high efficiency, low toxicity and high selectivity according to the action mechanism of chemicals and minerals, and study new process flow to improve the recovery rate of useful minerals and the separation efficiency of polymetallic minerals, so as to realize the full resources available. Utilization should receive more and more attention.

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