how to process copper ore: beneficiation methods and equipment | fote machinery
All available copper-bearing natural mineral aggregates are called copper mines. The high-grade copper concentrate can be obtained by the coarse grinding, roughing, scavenging of copper ore, then grinding and concentrating of coarse concentrate.
Due to the different types of ore, the nature of the ore is also different, so the beneficiation process needs to be customized. The specific process for selecting copper ore depends mainly on the material composition, structure and copper occurrence state of the original copper ore.
Before the beneficiation of copper ores, crushing and grinding are required. The bulk ores are crushed to about 12cm by a jaw crusher or a cone crusher. Then the crushed materials are sent to the grinding equipment, and the final particle size of the copper ore is reduced to 0.15-0.2mm.
Copper sulfide can be divided into single copper ore, copper sulfur ore, copper-molybdenum deposit, copper nickel, carrollite and so on. Basically, only flotation can be considered in its separation.
Almost all copper sulphide ores contain iron-bearing sulfides, so in a sense, the flotation of copper sulfide is essentially the separation of copper sulfide from iron sulfide. The common iron sulfide minerals in copper ore are pyrite and pyrrhotite.
1 Disseminated grain size and symbiotic relationship of copper and iron sulfide. Generally, pyrite has a coarse grain size, while copper ore, especially secondary copper sulfide, is closely associated with pyrite. Only when the copper ore is finely ground can it be dissociated from pyrite. This characteristic can be used to select copper-sulphur mixed concentrates, discard the tailings, and then grind and separate the mixed concentrate.
2 The influence of secondary copper sulfide minerals. When the secondary copper sulfide mineral content is high, the copper ions in the slurry will increase, which will activate the pyrite and increase the difficulty of Cu-S separation.
3 The influence of pyrrhotite. The high content of pyrrhotite will affect the flotation of copper sulfide. Pyrrhotite oxidation will consume the consumption of oxygen in the pulp. In severe cases, the copper minerals do not float at the beginning of flotation. This can be improved by increasing inflation.
Generally, copper is floated firstly and then sulfur. The content of pyrite in dense massive copper-bearing pyrite is quite high and high alkalinity (free CaO content> 600800g/m3) and high dosage of xanthine are often used to suppress the pyrite. There is mainly pyrite in its tailings with few gangues, so the tailings are sulfur concentrates.
For the disseminated copper-sulfur ore, the preferential flotation process is adopted, and the sulphur in the tailings must be re-floated. To reduce the consumption of sulfuric acid during the floatation and ensure safe operation, the process condition of low alkalinity should be adopted as far as possible.
It is more advantageous for copper sulfur ore containing less sulfur with copper easy to be floated. Carry out the bulk flotation firstly in the weakly alkaline pulp and then add lime to the mixed concentrate to separate the copper and sulfur in the highly alkaline pulp.
In semi-preferential bulk-separation flotation, Z-200, OSN-43 or ester-105 with good selectivity are used as collectors to float copper minerals firstly. The copper concentrate is then subjected to copper-sulfur bulk flotation and the obtained copper-sulfur mixed concentrate is subjected to separation flotation of floating copper and suppressing sulfur.
It avoids the inhibition of the easily floating copper under high lime consumption and does not require a large amount of sulfuric acid-activated pyrite. It has the characteristics of reasonable structure, stable operation, a good index and early recovery of target minerals.
3 The xanthate collector mainly plays the role of chemisorption together with the cation Cu (2 +), so minerals whose surface contains more Cu (2 +) minerals have a strong effect with the xanthate. The order of the effect is: chalcocite > covellite > porphyrite> chalcopyrite.
4 The floatability of copper sulfide minerals is also affected by factors such as crystal size, mosaic size, being original or secondary. The minerals with fine crystal and mosaic size are difficult to float. Secondary copper sulfide ore is easy to oxidize and more difficult to float than original copper ore.
As for the grinding and floating process, it is more advantageous to adopt the stage grinding and floating process for refractory copper ore, such as the re-grinding and re-separation of coarse concentrate, re-grinding and re-separation of bulk concentrate, and separate treatment of medium ore.
Copper oxide (CuO) is insoluble in water, ethanol, soluble acid, ammonium chloride and potassium cyanide solutions. It can react with alkali when slowly dissolving in ammonia solution. The beneficiation methods of oxidized copper ore mainly include gravity separatio, magnetic separation (see details on copper ore processing plant), flotation and chemical beneficiation.
Flotation is one of the commonly used mineral processing techniques for copper oxide ores. According to the different properties of copper oxide ores, there are sulphidizing flotation, fatty acid flotation, amine flotation, emulsion flotation and chelating agent-neutral oil flotation method.
Process flow: The dosage of sodium sulfide can reach 1~2kg/t during vulcanization. Because the film produced by vulcanization is not stable and is easy to fall off after vigorous stirring, and sodium sulfide itself is easily oxidized, sodium sulfide should be added in batches.
Besides, the vulcanization speed of malachite and azurite is relatively fast, so the vulcanizing agent can be directly added to the first flotation cell with no need to stir in advance during vulcanization and adjust the amount of vulcanizing agent according to the foam state.
Fatty acids and their soaps are mainly used as collectors of fatty acid floatation, also known as direct flotation. During flotation, water glass (gangue inhibitor), phosphate, and sodium carbonate (slurry regulator) are also usually added.
There is a practice of mixing vulcanization and fatty acid methods. Firstly float the copper sulfide and part of the copper oxide with sodium sulfide and xanthate, and then float the residual copper oxide with fatty acid.
For example, the ore in the Nchanga processing plant in Zambia contains 4.7% copper. The copper content achieved to 50% ~ 55% through flotation by adding 500g/t of lime (pH 9 ~ 9.5), 10g/t of cresol (foaming agent), 60g/t of ethylxanthate, 35g/t of amyl xanthate, 1kg/t of sodium sulfide, 40g/t of palmitic acid and 75g/t of fuel oil.
It is mainly to sulfurize the copper oxide mineral firstly and then add the copper accessory ingredient to create a stable oil-wet surface. Then, the neutral oil emulsion is used to cover the mineral surface, resulting in a strong hydrophobic floating state. In this way, the mineral can be attached to the foams firmly to complete the separation.
Many problems should be paid attention to in the flotation of copper ore, such as the length of the vulcanization time, whether to add sodium sulphide in batches and the proportion of chemicals. Here is a brief introduction.
1 The vulcanization time. Different ores require different vulcanization times. Generally speaking, it should be short rather than longer. The suitable vulcanization time is 1 to 3 minutes. After 6 minutes, the recovery rate and concentrate grade will decrease.
2 Add sodium sulfide in batches. The roughing time for processing the ore in the concentrator is about ten minutes, while the ore contains a large amount of carbonaceous gangue and the divalent sulfur ions disappear quickly in the slurry. So the effect of adding sodium sulfide in batches is better than that of adding it once.
3 Add sodium sulfide proportionally. Generally, copper oxide floats in the liquid at a slower speed, and reduce the number of cycles of the mineral in the flotation process can obtain a higher recovery rate. It is of great significance to study the distribution ratio of sodium sulfide among different operations to catch the mineral at the right time.
The chemical beneficiation method is often used for refractory copper oxide and mixed copper. For some copper oxide minerals with high copper content, fine mosaic size and rich sludge, the chemical beneficiation method will be used to obtain good indicators because the flotation method is difficult to realize the separation.
The solution of ammonia and ammonium carbonate in a concentration of 12.5% was used as the solvent to leach for 2.5h at a temperature of 150, a pressure of 1925175~2026500Pa. The mother liquor can be distilled by steam at 90 to separate ammonia and carbon dioxide. Copper, on the other hand, is precipitated from the solution as black copper oxide powder.
Because some copper oxide minerals are not tightly combined with iron, manganese, etc., it is difficult to separate them by using the magnetic separation method alone, and flotation has a good separation effect.
Therefore, the flotation method is used to obtain high-grade concentrates, the magnetic separation is for tailings and wet smelting is carried out finally. This process combines flotation, magnetic and wet smelting very well, which greatly increases the recovery rate and reduces the beneficiation cost.
The above are several common beneficiation methods for copper oxide minerals. For the selection of copper oxide minerals, it is best to conduct a professional beneficiation test and customize the process according to the report.
Flotation is the most widely used method in copper mine production. The copper ore pulp is stirred and aerated, and the ore particles adhere to the foams under the action of various flotation agents. The foams rise to form a mineralized foam layer, which is scraped or overflowed by the scraper. This series of flotation processes are all completed in the flotation machine. (Contact Manufacturer)
The internal magnetic system of the barrel adopts a short circuit design to ensure that the barrel skin has no magnetic resistance at high speeds, and the stainless-steel barrel skin does not generate high temperatures, extending the life of the magnetic block.
Since it adopts a dynamic magnetic system design, the roller does not stick to the material, which is conducive to material sorting. The selected grade can be increased by 3-6 times to more than 65%.
Copper mines are generally purified by flotation, but for the beneficiation of copper minerals with coarser grain size and higher density, the pre-selection by the gravity separation method will greatly reduce the cost and achieve flotation indicators.
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flotation of copper oxide ore - fodamon machinery
The floatability of copper oxide ores is generally worse than that of copper sulfide ores, and is greatly influenced by the existing form of copper in minerals and gangue composition. For example, when copper is in the form of carbonate (malachite, blue copper ore), the flotability is relatively good, while the flotability of silicate (silica malachite) is poor, free copper oxide is easy to float, and copper oxide can not be recovered by a single flotation method. Copper oxide minerals in a separate state are called free copper oxide. All free copper oxide can dissolve in cyanide solution. When copper and gangue (e.g. iron hydroxide) are cemented together, copper oxide minerals in a certain form are called bound copper oxide. Their cementation patterns are various and can be mechanical. The method can be used as inclusion of extremely fine dispersed copper minerals in gangue, isomorphism in chemical way, and adsorption-type chromophore. All bound copper oxide can not be dissolved in cyanide solution. The percentage of bound copper in copper oxide is called the binding rate. Gangue minerals are mainly siliceous (e.g. quartz) and carbonate (e.g. calcite, dolomite) are easier to flotation. It is more difficult to separate gangue minerals when they contain more iron hydroxide and clay slime, especially when they are closely combined.
The flotation of oxidized minerals is mostly carried out by a vulcanization process. Because of the high flotation speed of oxidized ore after sulfidation, concentrate products are directly produced in the first 1-2 tank of the first roughing. Addition of reagents is of special significance to the flotation of copper oxide ores, especially sodium sulfide, which is not only an activator of copper oxide ores, but also an inhibitor of copper sulfide ores. Therefore, it is not appropriate to add enough reagents at one time, usually in batches and stages. Therefore, the first operation (roughing) in the flotation process is to add reagents in batches and stages. ) The addition of sodium sulfide is 70-80% of the total amount, which ensures that the concentration of sodium sulfide is sufficient and not excessive. When sodium sulfide is used to sulfide, lime is used as the adjusting agent of PH, and PH 8.5-9.5. Only when sodium sulfide is used can the ideal effect be obtained. When sodium sulfide is used, appropriate amount of ammonium sulfate and 1:1 sodium sulfide are added. It can improve the recovery of copper oxide ore. The reason is that the decrease of PH value after adding ammonium sulfate is beneficial to the increase of HS concentration, the acceleration of sulfidation reaction and the flotation of copper oxide ore. However, when sulfide and oxidize mixed ores are beneficiated, ammonium sulfate can inhibit sulfide minerals when the amount of ammonium sulfate is too large. Therefore, the dosage of ammonium sulfate should be strictly controlled.
Adding hydroxamate and butyl xanthate in combination, it has strong ability to collect refractory minerals such as chrysocolla and copper-bearing limonite ore. Sodium hydroxysulphate has very good sulphide ore at PH10~11. Good harvesting effect, but when the pH is lower than 8, it is unfavorable for the selection of sulfide ore.
100tpd copper oxide flotation processing plant in tanzania - copper - news - xi'an desen mining machinery equipment co.,ltd
In 2015, a copper mine customer came to our company and hoped that we could help him flotation of the copper mine in Tanzania. Before doing the formal beneficiation, the customer brought his ore to our factory and did the ore taste analysis and flotation experiment. The experimental results are as follows:
Combining the above experimental results and the customer's strength of our factory, the customer decided to choose us to do the copper ore dressing test for him. The experiment process is as follows: feeding-crushing-grinding-flotation.
The main equipment included are:Feeder-Jaw Crusher-Hammer Crusher-Ball Mill-Spiral Classifier-Mixing Barrel-Flotation MachineAt the same time, flotation reagents are also used.The project began infrastructure construction in April 2016 and successfully ran in May. The highest taste of copper and gold powder can reach 52%.
flotation copper oxide - froth flotation (sulphide & oxide) - metallurgist & mineral processing engineer
Is there a way for flotation of copper oxide? Is it possible to recovery up to 75 percent achieved? I have sample that about 45% of copper oxide and about 40% recovery was achieved with the SIPX and Sodium Mercaptobenzothiazole Dithiophoishate collector. I need to know how to increase copper recovery.
Radio Hill in Australia successfully used the Ausmelt reagent AM28 (an alkyl hydroxamate) to float mixed sulphide/oxide copper ore, increasing recovery from a low of 40 to 50% up to 70%.They used AM28 to replace sulphidisation of oxide minerals, in conjunction with standard sulphide collectorsto recover sulphide minerals. Oxide minerals floated were cuprite, malachite and azurite. AM28 is a much safer reagent than mercaptaobenzothiazole as well (and smells a whole lot better!). Cytec (now Solvay) also make hydroxamates, as does Clariant.
I suggest that you engage a flotation reagent supplier to conduct screening tests on a sample of your ore rather than going to a commercial lab initially.You should also do some XRD and QEMSCAN to understand what the minerals are in relative abundance andmineral associations with gangue, including degree of locking to understand what is happening in your plant.
yes Mahdi. You best use a hydroxamate. I got great results using Oxflohttps://www.911metallurgist.com/blog/copper-oxide-flotationYour ore better be of good grade becausehydroxamates andsulphidisationreagents are expensive. Chrysocolla,malachite and azurite was what I had.
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copper oxide flotation
Oxflo selectivity advantage comes in with 75% Cu Recovery with only 10% Mass VS Axis at around 30% Recovery accompanied by an excessive 35 to 55% Mass. On its last try, Axis did manage to bring in a %Cu Recovery of %60 at a %50 Mass.
Cleaner Tests: It must be noted that Oxflo had not performed cleaner tests for the Sample Ore Type. For comparison purpose however is displayed/included one data point from Oxflos rougher test that had cleaner-like qualities.
Oxide copper minerals generally do not respond well to traditional methods of concentration using known sulfide copper collectors. Their recovery in a froth flotation circuit requires special treatment. The traditional method involves sulfidization (at-500 to -600 mV vs. a combination Sulfide Ion Electrode) using sodium sulfide (Na2S), sodium hydrosulfide (NaSH), or ammonium sulfide ((NH4)2S) followed by flotation using xanthate or other sulfide collectors. In principle, this method is quite attractive, but in practice it suffers from two major disadvantages: a) it is difficult to control the dosage of the sulfidizing agent; an excess causes depression of both sulfide and oxide minerals, and an insufficient amount produces poor recoveries, and b) the different oxide minerals respond differently to sulfidization, and frequently sulfidization simply fails to provide acceptable oxide copper recovery.
A wide variety of collectors has been proposed for oxide copper flotation without sulfidization in the past six decades. These include a large number of organic complexing agents, fatty acids, fatty amines, and petroleum sulfonates. Except for a very limited use of fatty acids (which are quite non-selective), none of the proposed reagents has been used in an operating plant, though a large number of collectors have shown considerable promise in laboratory tests. The high cost, high consumption, and inadequate performance are three important drawbacks for the majority of the proposed collectors. Alkyl hydroxamates, however, are among the very few collectors that have shown the most promise.
It must be noted here that the discussion in this paper pertains to oxide copper that is typically associated with economical amounts of sulfide copper (the so called mixed sulfide-oxide ores) and, consequently, not treated by leaching-SX (the latter is widely practiced on low-grade ores from the oxide zone that are not treated by flotation). In specific cases where the oxide content in the mixed sulfide-oxide ore is relatively high, the tailings produced after maximum sulfide recovery, and partial oxide recovery, may be leached to recover oxide minerals that were not recovered in flotation. But for the majority of porphyry ores, this is not practiced.
Reasons 2-4 can be addressed together. In spite of the large amount of literature that exists on alkyl hydroxamates, they still appear to be rather restricted to academic research. Sulfidization-flotation has been practiced in the industry, often with some degree of success, depending on the mineralogy of the oxide minerals in the ore. Such is not the case with alkyl hydroxamates. Studies on actual ore samples from operating plants are limited. Information is lacking on the relevant practical aspects and guidelines for using alkyl hydroxamates in industrial applications. One of the objectives of this paper is to provide such practical guidelines.
Reasons 5 and 6 are related to the perceived performance of alkyl hydroxamates on real ores (as opposed to well-defined single minerals used in most studies) and are, therefore, of direct interest to the plant metallurgists. The extensive studies conducted by us have clearly identified conditions under which both Reasons 5 and 6 may be valid. The sometimes perceived poor performance of hydroxamates is closely related to the mineralogy of the ore, and highlights the fact that in the past investigations there was no attempt made to characterize or describe the various oxide minerals present in the ore under study. This aspect will be discussed fully in the paper along with supporting data from flotation and microscopy studies.
Reason 7 is also valid because there has been insufficient efforts made in the past to demonstrate the efficacy and cost benefits of using alkyl hydroxamates for a given ore type, both of which are a prerequisite for any large scale use of alkyl hydroxamates.
mechanism and application on sulphidizing flotation of copper oxide with combined collectors - sciencedirect
The effect of sodium butyl xanthate (NaBX) and dodecylamine (DDA) as combined collector on the sulphidizing flotation of copper oxide was investigated by flotation test, fluorescent pyrene probe, zeta potential, and infrared spectroscopy analyses. The micro-flotation results show that combined use of NaBX+DDA yields better effect than using NaBX at pH 7-11 only, and the optimal molar ratio of NaBX to DDA is 2: 1. The actual ores flotation shows that when the dosage of NaBX+DDA is (100+54) g/t, the copper concentrate grade and recovery are 15.93% and 76.73%, respectively. The fluorescent pyrene probe test demonstrates that the NaBX+DDA can reduce the micelle concentration in the pulp. The zeta potential and the infrared spectroscopy analyses indicate that chemical adsorption, hydrogen-bonding and electrostatic interaction can help to adsorb NaBX+DDA on the surface of malachite. Meantime, copper xanthate and copper-amine complexes may be generated during the adsorption process.
improving copper recovery from oxide sources in flotation process using sodium dodecyl sulfate modified zno nanoparticles as new collector | springerlink
This study aims to investigate the best route to increase the recovery of oxide-sulfide copper ore. Among various methods, using nanoparticles is more desirable because of their high efficiency. So, ZnO nanoparticles were synthesized and surface modified via anionic sodium dodecyl sulfate (SDS) surfactants. The results showed a recovery increased increase from 27.37 to 38% using the ZnO nanoparticles. Moreover, it was observed that changing pH could leads to some changes in the recovery value. According to the results, because of changing the surface charge of ZnO nanoparticles with pH and anionic SDS, the recovery will vary in various PH values. Besides, it was found that increasing the concentration of nanoparticles modified with SDS (from 2.25 to 7.5ml) leads to an increase in the recovery (from 77 to 88%), indicating the synergistic effect of SDS on nanoparticles.
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Chem. Pap. 75, 43714379 (2021). https://doi.org/10.1007/s11696-021-01677-w