copper flotation, extraction of copper, copper processing, copper flotation process -xinhai
With more than 20 years of mineral processing experience, Xinhai constantly strengthens development and innovation of copper flotation reagent, flotation process, technology and equipment. According different types of copper ores and customer demand, Xinhai finally formed four main copper flotation process systems:
After the mine sample test, Xinhai Mine Design Institute concluded that the ore was skarn copper, the main minerals were chalcopyrite and bornite, then magnetite and pyrite.
Xinhai decided to adopt three stage opening circuit crushing, one stage grinding, differential flotation two stage dewatering process. Three stage opening circuit crushing adopted Xinhai jaw crusher, the crushing product was sent to cone crusher by belt conveyor for two or three stage crushing,then sent to Xinhai grid type ball mill for grinding and classifying,the mixed slurry was sent to Xinhai JJF flotation cell. Then Xinhai added collector to the pulp for copper differential flotation, and got qualified copper concentrate, then sulfur concentrate. The tailings were sent to Xinhai magnetic separator to separate qualified iron ore concentrate. Finally, copper and sulfur concentrate were transported to high efficient thickener, thickening underflow was filtered by plate press filter.
This process floats copper concentrate and other useful minerals together and gets mixed concentrate, then separates mixed concentrate to obtain qualified copper concentrate.
Shandong client commissioned Xinhai Mine Research Institute to conduct ore dressing experiment after collected 50kg samples on the scene. After tested the ore properties of sample ore, Xinhai lab concluded that the main metal minerals of the project were copper, lead, zinc, and a certain amount of magnetite.
Xinhai Mine Research Institute carried on preliminary exploration of its processing conditions and found that the copper recovery rate was the highest in bulk flotation process. Therefore, after discussed with client, Xinhai adopted two stage closed-circuit crushing, one stage closed-circuit grinding, middlings regrinding, copper lead bulk flotation - zinc flotation - copper lead separation process. Copper lead bulk flotation adopted a roughing, three scavenging, four cleaning process. Roughing and scavenging adopted Xinhai XCF flotation cell, cleaning used Xinhai BF flotation cell. Zinc flotation adopted a roughing, three scavenging, four cleaning process, roughing and scavenging adopted KYF flotation cell, and cleaning selected SF flotation cell BF flotation cell was used in copper lead separation process. The dewatering of copper, lead and zinc concentrates used Xinhai efficient deep cone thickener+ceramic filter. The concentrate moisture was about 12% after dewatering.
In recent years, the ore grade of this peoject has fallen, and the flotation index of technology was not good. Therefore, Xinhai upgraded its flotation technology: adopt Xinhai JJF flotation cell to replace original flotation column, then add collector and frother as PH regulator, which strengthened concentration process, increased floating ratio of coarse grain. The recovery rate of copper concentrate reached above 94%, and copper concentrate grade was improved by 3%.
Xinhai decided to adopt three stage opening crushing process, closed-circuit rod mill, ball mill and hydrocyclone, single copper flotation, concentrate scavenging and tailings reelection process. After crushing and screening, grinding, and classifying, qualified mineral particles were sent to Xinhai KYF flotation cell, BF flotation cell,the alkaline medium was adjusted to PH10 ~ 10.5. Then added copper inhibitors, which greatly improved foam properties. After a roughing, scavenging and cleaning, high-quality copper concentrate was obtained.
copper sulfide flotation
Copper, due to the present world demand and price, is of foremost interest to the mining industry. Many new properties are either in the process of being brought into production or are being given consideration. Copper minerals usually occur in low grade deposits and require concentration prior to smelting. The method and degree of concentration depends on smelter location and schedules, together with the nature of the ore deposit. Sulphide copper ores generally occur with pyrite, pyrrhotite, arsenopyrite and molybdenite, and with gold and silver. A complete copper-iron separation may not always be essential for the maximum economic recovery and often is tied to the distribution of the gold and silver values.
The above flowsheet is designed for the treatment by flotation of copper as chalcopyrite with gold and silver values. The ore, ranging from 60-65% silica, with pyrite, arsenopyrite, and calcite with 3 to 4% copper. This flowsheet, though simple, is adequate for tonnages of 100 to 500 tons or more per day, depending on the size of equipment selected. It can be readily expanded by duplicating units for increased tonnages. By minor circuit changes, it provides the flexibility to treat a range of ore conditions which are often encountered in any mining operation. Generally in these small plants the recovery of molybdenum is disregarded unless it is present in considerable amounts. Larger plants generally will incorporate a circuit for molybdenum recovery from the copper concentrate by flotation. Sub- A Flotation is standard for this service.
Crushing Section. The crushing section with two-stage reduction is suitable for smaller tonnages, depending on the ore characteristics. Three-stage reduction in either an open or closed circuit, with screens for the removal of fines can be employed where conditions warrant. The fines are removed by a grizzly or screen ahead of each reduction stage for higher efficiency and for reduced wear on crushing surfaces.
Feed control is essential to efficient grinding and helps reduce surges and fluctuations throughout the entire plant. The Ball Mill in closed circuit with a Spiral Classifier discharges the pulp at about 60% minus 200 mesh. The Ball Mill is equipped with a Spiral Screen on the discharge for removal of any tramp oversize, worn grinding balls, and wood chips from the circuit.
The pulp from the Conditioner is treated in a 10-cell Sub-A Flotation Machine and a 4-cell Sub-A Flotation machine. Sometimes conditioners are not provided; however, their use insures that reagents are thoroughly mixed into the pulp ahead of flotation. This gives a more uniform feed and effective use of reagents plus improved flotation conditions. The 10-cell Sub-A Flotation Machine is of the free-flow type. Weirs for the control of pulp level through the machine are provided at the fourth, eighth and tenth cells. This free-flow type provides ample volume for normal fluctuations in the feed rate without cell level adjustment. Sand relief ports help extend the long life of the molded rubber wearing parts.
The first eight cells produce a rougher concentrate while the last two cells act as scavengers. The concentrate or middling product from these two cells is returned by gravity back to the fifth cell. The rougher concentrate from the first eight cells is cleaned in two stages in the four-cell standard Sub-A Flotation Machine, of the cell-to-cell type. No pumps are needed for the return of these flotation products for cleaning. This feature in Sub-A Flotation Machines gives added flexibility by enabling the operator to change cleaning circuits readily, should conditions require. The tailings from the cleaner flotation section are pumped back to the ball mill for regrind. To control dilution a cone classifier is placed in this circuit with the coarse solids going to regrind and the overflow used as dilution in the mill and classifier. It is possible to eliminate this classification in some cases but control is less positive. A separate regrind section could be provided if the quantity of middling products were enough to make this section feasible.
The final cleaned flotation concentrate flows or is pumped to a Spiral Rake Thickener. A Adjustable Stroke Diaphragm Pump, mounted on the thickener superstructure, meters the thickened concentrate to the Disc Filter. The Thickeners are often used to store concentrates for filtration at fixed intervals. These units have heavy duty construction throughout, overload indicators and positive rake lifting features. The Diaphragm Pump is used for concentrate recirculation purposes during such periods.
Lime is added to the Ball Mill by a Cone Type Dry Reagent Feeder. Other reagents, such as cyanide, xanthate, and a frother are fed and controlled by No. 12A Wet Reagent Feeders to the classifier and to the conditioner ahead of flotation.
This flowsheet stresses simplicity without sacrifice of efficiency. The factors of flexibility are essential to meet changing ore and market conditions. The unit arrangement which can be expanded by sections for increased capacity is an important feature. The equipment indicated has been proven for long life and low maintenance, and to give superior results. The Sub-A Flotation Machines are designed for high capacity and with features of flexibility to handle fluctuating conditions with a minimum of operating attention. Low final tailings and high grade concentrate are assured through the selective action of the Sub-A in the roughing, cleaning, and recleaning circuits.
Large scale mining operations, of which the porphyry coppers are typical, must resort to concentration. This is necessary as the ores are generally low grade and require flotation to produce a concentrate acceptable to the smelters.
These large scale milling operations handling low grade ore must provide very careful planning in the design of their plant flowsheet and selection of equipment. Milling circuits must be as simple as possible and for large tonnages, as few as possible. It is for this reason grinding mills and flotation circuits arenow designed to handle these large tonnages at low cost.
Sub-A Flotation Machines are a basic part of large tonnage operations and their use assures maximum economic recovery. Particular emphasis has been placed on the design and operation of these machines for roughing, scavenging and cleaning. Mechanisms have been greatly simplified and molded rubber wearing parts are standard for maximum abrasion resistance.
Three stage crushing is illustrated in the flowsheet; however, it is possible and practical to eliminate the third stage by incorporating a rod mill in the grinding section. This is a very practical arrangement and often a necessity when handling wet, sticky ore. There is evidence that this combination of crushing and grinding results in lower costs for reducing large tonnages of ore to flotation size.
The flowsheet illustrates a typical grinding circuit with a rod mill in open circuit. Its discharge, usually all 14 mesh, goes to a classifier for removal of finished material. The classifier sands are ground in a ball mill in closed circuit with the same classifier. High speed rod milling with speeds up to 80% of critical has shown definite improvement in efficiency and grinding capacity. Proper selection of mill density and grinding charges are also factors of importance. Usually the rod mill is operated at lower density so it acts partially as its own classifier for retaining oversize for further size reduction.
Some conditioning of the pulp ahead of flotation is usually very beneficial and will result in more uniform and rapid flotation of a selective high grade concentrate. For this service the (patented) Super Agitator and Conditioner is standard. Reagents added at this point are thoroughly mixed and reacted with the pulp. Any tendency of the pulp to froth prematurely is readily overcome by the patented standpipe arrangement which also assures positive pulp circulation.
For large tonnage circuits normally encountered in many of the copper operations the open or free flow type Sub-A Super Rougher Flotation Machine is recommended. Intermediate cell weirs are eliminated and circulation of pulp through the impeller is fixed to provide the desired agitation and aeration for rougher flotation conditions. Machines are usually arranged with up to six cells being open or free-flow without intermediate weirs. Two or more machines are always provided in series. This allows adequate volume for absorbing surges and fluctuation in feed without cell adjustment. Mineral and middlings in the teeter or quiescent zone of the cell are gradually forced upward to the froth removal zone. Only the coarser material in the agitation zone passes through the impeller for further conditioning and bubble attachment.
In the flowsheet each circuit consists of 16 or 18 cells in 4 or 6 cell units. These Sub-A Super Rougher Flotation Free-Flow Machines are in series. All of the mechanisms are of the single impeller type and are completely supported from the superstructure to facilitate maintenance. All heavy hoods and castings are eliminated and the impeller-diffuser clearance is pre-set and accurately maintained throughout the long life of the heavy duty moulded rubber wearing parts. The last two cells are the super scavenger type giving veryintense agitation and aeration to float the last trace of recoverable mineral or middling for re-treatment.
Rougher flotation concentrates are cleaned in a standard Sub-A Flotation Machine with cell to cell pulp level control. This arrangement for upgrading concentrates is universal in its acceptance by the ore dressing industry. Two or more stages of cleaning in the same machine are accomplished without auxiliary pumps and ideal flotation conditions for producing high-grade concentrates are easily maintained.
Cleaner flotation tailings are returned to the head of the rougher flotation circuit for retreatment. In many milling circuits, particularly if coarse grinding is used, the cleaner tailings will contain middlings or mineral with attached particles of gangue. In these cases it is necessary to thicken or classify and regrind this fraction. Centrifugal classifiers are being very successfully applied for the classification step although they do take considerable power and require more maintenance than a thickener with its underflow going to a regrind circuit.
The flowsheet incorporates thickening for both the concentrates and tailings for water reclamation and tailings disposal purposes. A Adjustable Stroke Diaphragm Pump on the concentrate thickener assures absolute control of the volumes delivered to the Disc Filter. When the filter is down temporarily for bag changes the concentrates may be recirculated to the thickener by this same pulp.
Flexibility and simplicity are the two most important points to design into any large tonnage flotation operation. The arrangement shown is flexible and will permit addition of extra milling sections up to the limit of the designed capacity of the crushing plant. Sub-A Flotation Machines are designed specifically for high tonnage installations and have been proven for all types of applications. Rugged construction will give years of service at lowest possible cost. This flowsheet is readily adaptable for the treatment of other ores. Note particularly the location and use of Automatic Sampler.
Copper, one of our most important minerals, is found in many parts of the world. One of the major sources of Copper is the so-called porphyry ores such as the large deposits in the west and southwestern United States, Mexico, South America and Europe.
Porphyry ores, with copper occurring in the form of Chalcocite and Chalcopyrite are normally low in grade and the copper minerals must be concentrated before smelting. In this flowsheet using Sub-A Cells the emphasis is on maximum economic recoveryhigh concentrating efficiency together with a premium smelter feed with a low alumina and magnesia content in the flotation concentrate.
To obtain lowest tailings from this ore usually requires scavenging of rougher flotation tails. This is performed ideally by the Sub-A Super Rougher Flotation Machine which was specially developed for this duty. This machine has a double impeller and gives tremendous aeration.
The flowsheet in this study is designed to get the maximum recovery from a large tonnage of porphyry copper ore.
The crushing section consists of three-stage ore reduction with either a grizzly or vibrating screen between each crushing stage. Removing fines before putting the ore through a crusher increases the efficiency of the crusher as it is then only working on material that must be reduced, and is not hampered by fines already reduced in size. Electromagnets and magnetic pulleys are used to remove tramp iron from the ore, the former to remove the iron near the surface and the magnetic pulley to remove the tramp iron close to the conveyor belt.
Porphyry copper ores usually are medium to medium hard and require grinding to about 65 mesh to economically liberate the copper minerals from the siliceous gangue. Sometimes a regrinding circuit is advantageous on the rougher concentrate and on the scavenger concentrate. This will liberate the mineral from the middling products and increase the recovery by putting those mineral particles into the concentrate. Rougher flotation may be accomplished at a relatively coarse grind and the subsequent regrind performed on a comparatively small tonnage.
Lime is usually added to the ball mill feed by a Dry Reagent Feeder. The frother and promoter are added in the classifier prior to flotation to realize the full effect of the reagent. Reagents can also be stage- added to the cells in the flotation circuit.
Standard Sub-A Flotation Machines are used for both the rougher and cleaner circuits, where their cell-to-cell principle gives both high recovery and a good grade of concentrate. The rougher concentration is accomplished in 6 or 8-cell flotation machines, with the concentrate from each goingto a separate bank for cleaning and re-cleaning. No. 30 Sub-A Flotation Machines are ideal for large tonnage operations, as each bank will handle from 1000 tons upward per day. Tails from the rougher circuit go to a scavenger circuit. Roughing, scavenging, cleaning and recleaning can be carried out in one bank of Sub-As. This is possible because of the distinctive gravity return of a product from any cell to any other cell of a bank without using pumps. In large installations, however, these steps are usually carried out in separate banks of cells. The scavenger flotation circuit consists of a 4-cell, Sub-A Super Rougher Flotation Machine with its super aeration. The concentrate from scavenger cells is returned to the head of the rougher cells and tails are sent to tailing pond. The new Sub-A Super Rougher Machine is designed especially to produce the lowest possible tailings in the mill circuit by scavenging off the last bit of recoverable and often difficult to float mineral. The Automatic Sampler is used on the flotation feed, concentrates and tailings to establish close mill control.
The flowsheet incorporates a thickener on the copper concentrates to thicken for optimum filtering. This also serves as a temporary storage space to accommodate operating requirements. The Adjustable-Stroke Diaphragm Pump on the thickener gives absolute control of volumes pumped to the filter. When the filter is shut down concentrates may be recirculated to the thickener by this same pump.
It is essential to have flexibility in any mill circuit, but particularly in large-tonnage operations such as this. Changing ore, changing market conditions and many other factors make this flexibility absolutely necessary. A slight change, easily made, in a flexible flowsheet may increase tonnage, improve recovery and lower grinding and reagent costs.
jjf flotation cell, flotation process, wemco flotation cell - xinhai
[Improvement]: Shallow groove, the stator lower than the impeller, large slurry circulation volume, low energy consumption; the stator is a cylinder with an elliptical hole which is conducive to the dispersion and mixing of pulp and air. Umbrella shaped dispersion cover with hole keeps the pulp surface stable.
When the JJF mechanical agitation flotation machine is working, vortexes are generated in the vertical tube and the draft tube. This vortex forms a negative pressure and sucks the air from the air inlet pipe. It is in the impeller and stator area with the slurry sucked in through the draft tube. mixing. The slurry-gas mixed flow is moved in a tangential direction by the impeller, and then converted into radial movement by the action of the stator, and is evenly distributed in the flotation cell. The mineralized bubbles rise to the froth layer and are scraped out unilaterally or bilaterally to form froth products.
the effect of surface oxidation of copper sulfide minerals on clay slime coating in flotation - sciencedirect
The industry is well aware of the difficulty in treating copper ores in the presence of clay minerals. In this study, the effect of bentonite on the flotation of chalcopyrite (a primary copper sulfide mineral) and chalcocite (a secondary copper sulfide mineral) was investigated in terms of surface coating. Based on the flotation of copper ores containing both chalcopyrite and chalcocite, the flotation of chalcopyrite and chalcocite single minerals in the presence and absence of bentonite, and the zeta potential measurement of chalcopyrite, chalcocite and bentonite, it was found that the oxidation of chalcopyrite and chalcocite had a different effect on their interaction with bentonite. Under the normal grinding and flotation condition, significant oxidation occurred on the surface of chalcocite which was electrostatically attractive to bentonite resulting in bentonite slime coating and the depressed flotation of chalcocite. The reduction of oxidation on chalcocite could mitigate bentonite slime coating due to electrostatic repulsion between unoxidized chalcocite and bentonite. Unlike chalcocite, chalcopyrite with and without surface oxidation exhibited an electrostatic repulsion to bentonite. Its flotation was less affected by bentonite slimes.
The oxidation of chalcopyrite and chalcocite under the normal grinding and flotation condition alters the electrical properties on the surfaces and their interaction with bentonite slimes.Download : Download full-size image
The flotation of chalcocite is more affected by bentonite than the flotation of chalcopyrite. Chalcocite is more oxidized than chalcopyrite under the normal grinding and flotation condition. An electrostatic attraction between the oxidized chalcocite and bentonite promotes the slime coating. Bentonite has less effect on the flotation of chalcopyrite with and without strong oxidation.
recovery of copper from the slag of khatoonabad flash smelting furnace by flotation method | springerlink
Copper loss in the slag of Khatoonabad flash smelting furnace is estimated to be about 13%. At present, the electric slag cleaning furnace is used for the recovery of copper from slag. However, due to low recovery efficiency of electric furnace along with high consumption of electrical energy and water, selection of a method to enable minimum energy consumption and maximum recovery of copper seems to be essential. Therefore, the aim of this study was to investigate the possibility of copper recovery from this slag using flotation method, and to determine the effective parameters involved in the process. Based on the experiments conducted, the best results were obtained for pH 11.5, 60g/tZ11 and R407 collectors with a weighing ratio of 32, 40g/t of MIBC and A65 frothers with an equal weighting ratio and grinding time of 45min. Under these conditions, the copper concentrate grade and recovery were 19 and 91.1% in the rougher step, 27.4 and 96.3% in the cleaner step, and 32 and 93% in the recleaner step, respectively.
F. Carranza, R. Romero, A. Mazuelos, N. Iglesias, O. Forcat, Biorecovery of copper from converter slags: slags characterization and exploratory ferric leaching tests. Hydrometallurgy 97(12), 3945 (2009)
Somerville, M., Norgate T., Jahanshahi, S., Single Stage Copper MakingAssessment of Slag Treatment Options, Proceedings Minprex 2000, International Conference on Mineral Processing and Extractive Metallurgy, The Australasian Institute of Mining and Metallurgy, Melbourne, 2000, pp. 453459
Karimi, N., Vaghar, R., Mohammadi, M.R.T. et al. Recovery of Copper from the Slag of Khatoonabad Flash Smelting Furnace by Flotation Method.
J. Inst. Eng. India Ser. D 94, 4350 (2013). https://doi.org/10.1007/s40033-013-0015-3
worlds largest flotation cells improve copper and molybdenum recovery in mexico - metso outotec
This is the highest recovery I have seen at BVC Concentrator 1 since my first site visit back in 1988, said Jose Romero, Head of Sales for Outotecs office in North Mexico. This is a huge benefit for Grupo Mexico, and they have been very happy with Outotecs technical approach.
Buenavista del Cobre is a copper-molybdenum mine located in the state of Sonora, Mexico. The mine has two concentrators: Concentrator 1 is a 90 ktpd plant which has been in operation since 1986 while Concentrator 2 is a 100 ktpd brand new plant design that started-up in 2014. The flotation improvement reported in this work with the latest TankCell e630 technology was carried out at Concentrator 1.
Concentrator 1 has been in operation for more than three decades and was originally designed for 72 ktpd. The ore is mined from an open pit, crushed, and fed to ten ball mills. The concentrator is divided into two parallel comminution-flotation sections, so that five ball mills feed each flotation section. Both sections consist of three bulk copper and molybdenum rougher flotation lines, and the rougher concentrate is transferred to a regrinding stage.
In 2015, personnel from Buenavista del Cobre and Outotec conducted a process assessment of the rougher flotation stage. The process assessment included detailed mineralogical characterization of an ore sample, a sampling campaign bank-by-bank and flotation pilot (TC5) tests and lab flotation tests with fresh process samples. Basis of the generated kinetic test data rougher flotation model was implemented using Outotec HSC Chemistry software. The simulation model indicated that increase of flotation volume will result in increase of Cu recovery. Various scenarios were simulated to define the best manner to implement the 630 m3flotation cells to the existing flotation sections. The recommendation was to install two TankCelle630 flotation units as the first cells of the existing bulk rougher stage for parallel Sections 1 and 2, as shown in the schematic flowsheet presented in Figure 2.
The existing Section 1 bulk rougher lines consist of three parallel lines of 18 cells per line with a total flotation capacity of approx. 1529 m3. Section 2 bulk rougher stage also consists of three parallel lines, two of the lines equivalent to the flotation lines in Section 1 and one line consists of 13 cells with a net volume of 38 m3resulting in a total flotation capacity for the full section of approx. 1513 m3.
In 2017, installation work for the two new flotation cells began, thus the rougher capacity was dramatically expanded from approx. 3043 m3to 4303 m3. The start-up of the new flotation cells took place during the first quarter of 2018. The installation includes two Outotec TankCell e630s with Outotec FloatForcemixing technology, continental blowers, Outotec GIW slurry pumps, a complete automation package including samplers, FrothSense, LevelSense, Cellstation and Advisory Services.
The TankCell e630 flotation cell has a nominal volume of 630 m3, and is equipped with a FloatForce mechanism with a diameter of 2200 mm. The mechanical design of TankCell e630 is a direct scale-up from TankCell e300 and TankCell e500.For testing purposes these flotation cells were equipped with an auxiliary impeller, called FlowBooster. This type of impeller is used to further enhance hydrodynamic conditions in the tank. Since the TankCell e630 units in Buenavista del Cobre are the first operational cells of their size, the installed motor power is 515 kW and the motors of the cells are connected to a Variable Speed Drive allowing the rotational speed control of the flotation mechanism. The air flow rate and froth height are controlled locally from a CellStationcontrol panel. Flotation air requirement is provided by dedicated centrifugal air blowers.
Its large capacity makes the Outotec TankCell e630 particularly suitable for rougher and scavenger duties in copper, copper-molybdenum, gold and other base metal applications. The unit has a diameter of 11 meters and a lip height of approximately seven meters.
After successful start-up, Outotecs metallurgical team is now working closely with Grupo Mexico for the tuning and optimization of the flotation cells. Grupo Mexico and Outotec are presenting the results from Concentrator 1 at Buenavista del Cobre at the Procemin-Geomet 2018 Conference in Santiago, Chile, November 28-30.
iron ore processing,crushing,grinding plant machine desgin&for sale | prominer (shanghai) mining technology co.,ltd
After crushing, grinding, magnetic separation, flotation, and gravity separation, etc., iron is gradually selected from the natural iron ore. The beneficiation process should be as efficient and simple as possible, such as the development of energy-saving equipment, and the best possible results with the most suitable process. In the iron ore beneficiation factory, the equipment investment, production cost, power consumption and steel consumption of crushing and grinding operations often account for the largest proportion. Therefore, the calculation and selection of crushing and grinding equipment and the quality of operation management are to a large extent determine the economic benefits of the beneficiation factory.
There are many types of iron ore, but mainly magnetite (Fe3O4) and hematite (Fe2O3) are used for iron production because magnetite and hematite have higher content of iron and easy to be upgraded to high grade for steel factories.
Due to the deformation of the geological properties, there would be some changes of the characteristics of the raw ore and sometimes magnetite, hematite, limonite as well as other types iron ore and veins are in symbiosis form. So mineralogy study on the forms, characteristics as well as liberation size are necessary before getting into the study of beneficiation technology.
1. Magnetite ore stage grinding-magnetic separation process
The stage grinding-magnetic separation process mainly utilizes the characteristics of magnetite that can be enriched under coarse grinding conditions, and at the same time, it can discharge the characteristics of single gangue, reducing the amount of grinding in the next stage.
In the process of continuous development and improvement, the process adopts high-efficiency magnetic separation equipment to achieve energy saving and consumption reduction. At present, almost all magnetic separation plants in China use a large-diameter (medium 1 050 mm, medium 1 200 mm, medium 1 500 mm, etc.) permanent magnet magnetic separator to carry out the stage tailing removing process after one stage grinding. The characteristic of permanent magnet large-diameter magnetic separator is that it can effectively separate 3~0mm or 6~0mm, or even 10-0mm coarse-grained magnetite ore, and the yield of removed tails is generally 30.00%~50.00%. The grade is below 8.00%, which creates good conditions for the magnetic separation plant to save energy and increase production.
2.Magnetic separation-fine screen process
Gangue conjoined bodies such as magnetite and quartz can be enriched when the particle size and magnetic properties reach a certain range. However, it is easy to form a coarse concatenated mixture in the iron concentrate, which reduces the grade of the iron concentrate. This kind of concentrate is sieved by a fine sieve with corresponding sieve holes, and high-quality iron concentrate can be obtained under the sieve.
There are two methods for gravity separation of hematite. One is coarse-grained gravity separation. The geological grade of the ore deposit is relatively high (about 50%), but the ore body is thinner or has more interlayers. The waste rock is mixed in during mining to dilute the ore. For this kind of ore, only crushing and no-grinding can be used so coarse-grained tailings are discarded through re-election to recover the geological grade.
The other one is fine-grain gravity separation, which mostly deals with the hematite with finer grain size and high magnetic content. After crushing, the ore is ground to separate the mineral monomers, and the fine-grained high-grade concentrate is obtained by gravity separation. However, since most of the weak magnetic iron ore concentrates with strong magnetic separation are not high in grade, and the unit processing capacity of the gravity separation process is relatively low, the combined process of strong magnetic separation and gravity separation is often used, that is, the strong magnetic separation process is used to discard a large amount of unqualified tailings, and then use the gravity separation process to further process the strong magnetic concentrate to improve the concentrate grade.
Due to the complexity, large-scale mixed iron ore and hematite ore adopt stage grinding or continuous grinding, coarse subdivision separation, gravity separation-weak magnetic separation-high gradient magnetic separation-anion reverse flotation process. The characteristics of such process are as follows:
(1) Coarse subdivision separation: For the coarse part, use gravity separation to take out most of the coarse-grained iron concentrate after a stage of grinding. The SLon type high gradient medium magnetic machine removes part of the tailings; the fine part uses the SLon type high gradient strong magnetic separator to further remove the tailings and mud to create good operating conditions for reverse flotation. Due to the superior performance of the SLon-type high-gradient magnetic separator, a higher recovery rate in the whole process is ensured, and the reverse flotation guarantees a higher fine-grained concentrate grade.
(2) A reasonable process for narrow-level selection is realized. In the process of mineral separation, the degree of separation of minerals is not only related to the characteristics of the mineral itself, but also to the specific surface area of the mineral particles. This effect is more prominent in the flotation process. Because in the flotation process, the minimum value of the force between the flotation agent and the mineral and the agent and the bubble is related to the specific surface area of the mineral, and the ratio of the agent to the mineral action area. This makes the factors double affecting the floatability of minerals easily causing minerals with a large specific surface area and relatively difficult to float and minerals with a small specific surface area and relatively easy to float have relatively consistent floatability, and sometimes the former has even better floatability. The realization of the narrow-level beneficiation process can prevent the occurrence of the above-mentioned phenomenon that easily leads to the chaos of the flotation process to a large extent, and improve the beneficiation efficiency.
(3) The combined application of high-gradient strong magnetic separation and anion reverse flotation process achieves the best combination of processes. At present, the weak magnetic iron ore beneficiation plants in China all adopt high-gradient strong magnetic separation-anion reverse flotation process in their technological process. This combination is particularly effective in the beneficiation of weak magnetic iron ore. For high-gradient strong magnetic separation, the effect of improving the grade of concentrate is not obvious. However, it is very effective to rely on high-gradient and strong magnetic separation to provide ideal raw materials for reverse flotation. At the same time, anion reverse flotation is affected by its own process characteristics and is particularly effective for the separation of fine-grained and relatively high-grade materials. The advantages of high-gradient strong magnetic separation and anion reverse flotation technology complement each other, and realize the delicate combination of the beneficiation process.
The key technology innovation of the integrated dry grinding and magnetic separation system is to "replace ball mill grinding with HPGR grinding", and the target is to reduce the cost of ball mill grinding and wet magnetic separation.
HPGRs orhigh-pressure grinding rollshave made broad advances into mining industries. The technology is now widely viewed as a primary milling alternative, and there are several large installations commissioned in recent years. After these developments, anHPGRsbased circuit configuration would often be the base case for certain ore types, such as very hard, abrasive ores.
The wear on a rolls surface is a function of the ores abrasivity. Increasing roll speed or pressure increases wear with a given material. Studs allowing the formation of an autogenous wear layer, edge blocks, and cheek plates. Development in these areas continues, with examples including profiling of stud hardness to minimize the bathtub effect (wear of the center of the rolls more rapidly than the outer areas), low-profile edge blocks for installation on worn tires, and improvements in both design and wear materials for cheek plates.
With Strip Surface, HPGRs improve observed downstream comminution efficiency. This is attributable to both increased fines generation, but also due to what appears to be weakening of the ore which many researchers attribute to micro-cracking.
As we tested , the average yield of 3mm-0 and 0.15mm-0 size fraction with Strip Surface was 78.3% and 46.2%, comparatively, the average yield of 3mm-0 and 0.3mm-0 with studs surface was 58.36% and 21.7%.
These intelligently engineered units are ideal for classifying coarser cuts ranging from 50 to 200 mesh. The feed material is dropped into the top of the classifier. It falls into a continuous feed curtain in front of the vanes, passing through low velocity air entering the side of the unit. The air flow direction is changed by the vanes from horizontal to angularly upward, resulting in separation and classification of the particulate. Coarse particles dropps directly to the product and fine particles are efficiently discharged through a valve beneath the unit. The micro fines are conveyed by air to a fabric filter for final recovery.
Air Magnetic Separation Cluster is a special equipment developed for dry magnetic separation of fine size (-3mm) and micro fine size(-0.1mm) magnetite. The air magnetic separation system can be combined according to the characteristic of magnetic minerals to achieve effective recovery of magnetite.
After rough grinding, adopt appropriate separation method, discard part of tailings and sort out part of qualified concentrate, and re-grind and re-separate the middling, is called stage grinding and stage separation process.
According to the characteristics of the raw ore, the use of stage grinding and stage separation technology is an effective measure for energy conservation in iron ore concentrators. At the coarser one-stage grinding fineness, high-efficiency beneficiation equipment is used to advance the tailings, which greatly reduces the processing volume of the second-stage grinding.
If the crystal grain size is relatively coarse, the stage grinding, stage magnetic separation-fine sieve self-circulation process is adopted. Generally, the product on the fine sieve is given to the second stage grinding and re-grinding. The process flow is relatively simple.
If the crystal grain size is too fine, the process of stage grinding, stage magnetic separation and fine sieve regrind is adopted. This process is the third stage of grinding and fine grinding after the products on the first and second stages of fine sieve are concentrated and magnetically separated. Then it is processed by magnetic separation and fine sieve, the process is relatively complicated.
At present, the operation of magnetic separation (including weak magnetic separation and strong magnetic separation) is one of the effective means of throwing tails in advance; anion reverse flotation and cation reverse flotation are one of the effective means to improve the grade of iron ore.
In particular, in the process of beneficiation, both of them basically take the selected feed minerals containing less gangue minerals as the sorting object, and both use the biggest difference in mineral selectivity, which makes the two in the whole process both play a good role in the process.
Based on the iron ore processing experience and necessary processing tests, Prominer can supply complete processing plant combined with various processing technologies, such as gravity separation, magnetic separation, flotation, etc., to improve the grade of TFe of the concentrate and get the best yield. Magnetic separation is commonly used for magnetite. Gravity separation is commonly used for hematite. Flotation is mainly used to process limonite and other kinds of iron ores
Through detailed mineralogy study and lab processing test, a most suitable processing plant parameters will be acquired. Based on those parameters Prominer can design a processing plant for mine owners and supply EPC services till the plant operating.
Prominer has been devoted to mineral processing industry for decades and specializes in mineral upgrading and deep processing. With expertise in the fields of mineral project development, mining, test study, engineering, technological processing.
imhoflot pneumatic flotation technology maelgwyn
The technology was introduced to the mining industry more than 25 years ago and the technology has since branched into various designs including V-cells, the patented as Imhoflot G-Cell and H-cell as the latest design.
The flotation cells are designed for a variety of throughput requirements, ranging from small pilot sized cells with a diameter of 0.8m, processing 6 10 m3/h of feed; to cells with a diameter of 6.5m, handling feeds of 1500 m3/h.
MMS has extensive experience in plant layouts regarding pneumatic flotation systems. Since the conception of pneumatic flotation in the 1980s, a large database of information has been accumulated. Our design layouts are based on standard laboratory tests. The mineral being floated determines the number and size of cells in series required to achieve optimal recovery, and the desired grade of the mineral will determinethe number of steps required.
Considerable savings in energy and cost are achieved when compared to other forms of flotation. Three conventional cleaning stages, required to produce market / smelter grades of a base metal or pyrite, can be replaced with one cleaning stage using the Imhoflot process.
Testing of an ore is done by using a pilot scale G08 cell with a throughput of 2 t/h. The ore is tested by milling it to the required size, conditioning with the correct chemicals andprocessed through the G-cell to achieve flotation. The flotation tailings is passed through the cell a number of times and the assay results of the products and their mass recoveries are used in a flotation simulation package.
Our engineering staff members are specialists in various types of flotation process operations, from a broad range of industries.We provide a complete range of customer services, from pilot scale testing, process design, manufacturing, installation, commissioning and after-sales service.
Technical backup is exceptional due to a world-wide network of agents and associates with expert advice. Liaison with the client throughout the project stages ensures an optimum solution for the specific application.
column flotation | flsmidth
Our modernised product line offers improved metallurgical performance and modular, customisable designs through our configure-to-order (CTO) program, designed to fit the individual needs of each process.
Expanding on the historic supply of Pyramid flotation columns, our modernised column cell offering includes design elements focused on improved metallurgical performance and enhanced mechanical design. This approach considers the main elements of column flotation: froth washing, froth recovery, residence time, cross-sectional area requirements, aspect ratio and column sparging. The end goal is to combine each into an overall design that becomes more than the sum of its parts. Following a configured-to-order design approach, the Column Flotation Cell minimises engineering at order and reduces CAPEX and supply lead times.
Fundamental understanding of column cell operation allows for effective column sizing and selection of functional features to ensure proper operation and integration into customers flow sheets. This integration can extend as far as inclusion of expert control systems to allow for enhanced overall flotation circuit operation and performance. Further circuit optimization is possible by combining the Column Flotation Cell with other FLSmidth flotation products.
A modular construction design minimises engineering costs and improved delivery timing. Fabrication costs are also reduced and Column Flotation Cell components can be readily containerised for delivery to site.
A stable and deep froth layer is maintained by level sensing elements that allow for advanced controls to ensure effective froth washing. This effectively removes gangue material, improving the grade in the process producing on-specification final product.
High recoveries are made possible by the Column Flotation Cells ideal hydrodynamic environment. Grade performance is enhanced by the Column Flotation Cells ability to maintain a deeper froth layer and improve washing to remove gangue material.
The design elements of column flotation make it unique among flotation techniques. Considerations include froth washing effects, froth recovery, residence time, cross-sectional area requirements, aspect ratio and column sparging.
Primary contacting occurs among relatively quiescent plug flow conditions within the vessel to promote recovery specifically for coarser particle sizes. Secondary, external, high-intensity contacting promotes bubble-particle collision, which result in attachment rates that optimise fine particle recovery.
FLSmidth columns feature venturi-style inline spargers. As the slurry is pumped into the slurry header, it distributes evenly between the spargers. The air header injects air individually into each sparger.
Air is sheared into the slurry under dynamic pressure changes, providing high-intensity contacting with the bubbles. Compared to traditional jet-nozzle spargers, this method enhances collision and attachment rates, greatly improving fines recovery.
The externally mounted sparging system, including a recirculation pump and spargers, offers ease of maintenance by eliminating the need to enter the tank. Optional sparger isolation valves allow the spargers to be serviced online.
Column flotation produces very well-defined, deep and stable froth layers that are washed with the application of percolating water from above, displacing gangue particles such as silicates and carbonates. Thorough washing results in superior final product quality.
Our Column Flotation Cell solutions are equipped with unparalleled monitoring controls. Normally, these types of controls supervise critical operating parameters like froth depth, wash water flow control, air supply and more to ensure the process is always optimised.
FLSmidth provides sustainable productivity to the global mining and cement industries. We deliver market-leading engineering, equipment and service solutions that enable our customers to improve performance, drive down costs and reduce environmental impact. Our operations span the globe and we are close to 10,200 employees, present in more than 60 countries. In 2020, FLSmidth generated revenue of DKK 16.4 billion. MissionZero is our sustainability ambition towards zero emissions in mining and cement by 2030.