Gravity separation method is the earliest method that applied in mineral processing. According to the density difference among mines and the difference of gravity, fluid power and mechanical force in moving medium, mines realizes mineral grains separation by density difference, gravity separation still occupies an important position in the contemporary mineral processing methods.
Since founded in 1997, Xinhai Mining has constantly increased scientific research and technology of gravity separation method. During more than 20 years of exploration, Xinhai constantly improved gravity separation method, aims at providing customers with more environmental and efficient gravity concentration and gravity separator.
Gravity separation method is widely applied in gold ore, tungsten ore, tin ore, manganese ore, mercury ore, titanium ore, lead ore, tantalum-niobium ores, galena, barite, fluorite ore, pyrite, limonite, hematite, antimony, chromium ore and ferrous metal.
Xinhai gravity separation method simplifies the production process and avoids over-cycles; Tailings has less environmental pollution; Xinhai gravity separator has a simple manufacture, better stability, which saves energy and reduces cost.
In recent years, due to the rapid rise of gold price, the economic benefits of gold mining and production companieshave been significantly improved, and a large number of advanced world-renownedmineral processing equipment have been applied in China,due to their advantages of high equipment efficiency, low failure rate and easy operation, as well as simple process configurationand so on, they are generally recognized by mine and industry experts, these equipment include: crushingand screening equipmentproduced by Metro and Sandvik, Knelson Concentrator, etc. They have brought revolutionary development to China's mineral processing production, and the scale and technical indicators of mineral processing have also been greatly improved.
ShanDongYinGeZhuang Gold Mine was the first to importthe KnelsonConcentrator into China for recovery the coarse gold.Later, HeNan JinQu Gold Mine and Shanxi YiXingZhai Gold Mine alsosuccessively applied it in coarse goldrecovery. Since then, the Knelson Concentratorhas been rapidly promoted and applied in other mines in China, and configuration forms of Knelson Concentrators in gravity separation process has also been developed.
The Knelson Concentratorcan be configured before classification or after classification. Because the spiral classifier is often used in the classification of gold mineral processing plantsin China, the former configurationis more used in China.However, hydrocyclones are often used for classification abroad, therefore, Knelson Concentrator is usually used to separate coarse gold from underflow by hydrocyclones. Knelson Concentrator uses a large amount of water, resulting in a large water content of tailing after separation, so it must be concentrated before returning to the ball mill for regrinding.
Since the feed size of Knelson Concentrator must be less than 6 mm, it is necessary to separate the material larger than 6 mm with a sieve and return it directly to the classification equipment or ball mill.This paper will discuss the advantages and disadvantages of several configuration forms of Knelson Concentrator in China for reference.
In this way, the discharged of ball mill is divided into undersizematerial and oversizematerial through a fixed sieve installed at the discharging port of ball mill. The oversizematerial goes directly into the spiralclassifier for classification. The undersizematerial is fed into the KnelsonConcentrator for gravity separation and recovery of coarsegold. The tailing of Knelson Concentrator are pumped to the classifier for classification.The configurationformis shown in Figure 3.
The advantage of this kind of configuration form is to make full use of the height difference between the ball mill and the classifier, and directly feed the large-grain ore into the classifier, which reduces the wear of the pump caused by the large-grain ore. The disadvantage is that the screening effect of minerals is unstable due to the frequent blockage of the screen hole, the amount of undersize minerals is unstable, the screening efficiency is low, and the recovery index of Knelson Concentrator is not as good as expected.(This configuration form is used in JinQu Gold Mine in HeNan Province)
This configuration can realize the recovery of coarsegold from the ore by KnelsonConcentratordirectly, and maximize the recovery rate of gravity separation. Gravity tailing ispumped tospiralclassifier for classification. However, due to the height difference between ball mill and spiral classifier, a lot of mineral processing plantscan not directly install linear vibrating screen, and result that this configuration formis not easy to achieve and has fewpractical application.
Thisconfiguration can make full use of the height difference between different equipment to realize the slurry self-flow. In this way, the use of pumps can be reduced, the process operation is simpler, the automation control can be easily realized, the sanitary conditions can be better, the recovery of coarse gold is more thorough, and the recovery rate of gravity separation is higher. When using this configuration form, it is better to use overflow ball mill grinding and install reverse winch screen at the discharging end of ball mill to avoid discharging large ore and crushed steel balls, and reduce the wear of pump, as well as ensure the better classification efficiency of hydrocyclone (This configuration form is used in YiXingZhai Gold Mine of Shanxi Province).
This configuration is to feed the concentrate of jig into Knelson Concentrator and enrich the super-concentrate. The tailing of jig ispumped to spiral classifier for classification. That is to say, the jig is used not only as separation equipment, but also for classification.When this configuration is applied in practice, the yield of the jig is enlarged and the function of the jig as a sieve is brought into play. In this way, the influence of large particles on gravity separation is solved, and the recovery rate of simple jig gravity separation is improved.
But its disadvantage is that the limitation of recovering fine coarse gold by jig prevents some of the fine coarse gold from entering Knelson Concentratorfor separation, which affects the recovery rate of gravity separation. The use of jigs increases water consumption. Sometimes concentration/dewatering must be used in order to ensure the requirements of operating conditions in the next process and make the process complicated and the operation difficult to control.
With the application of Knelson Concentrator, it has developed from one stage to two stagesKnelsongravity separation, and has been applied to the regrinding and classification process of gold concentrate in leachingoperation to recover the coarsegold, avoid the deposition loss of coarsegold in the leachingprocess and improve the recovery rate of gold.
2) The choice of different formis determined by the ore properties of the selected minerals. In actual production,the appropriate number of gravity separation operations should be selected according to the size distribution characteristics of the target minerals, so as to improve the recovery index of gravity separation as far as possible, and realize the principle of early recovery and more recovery.
3) The selection of the Knelsongravity separation process should be based on the selection index and the requirements of the next process, to minimize the use of the pump, to facilitate operation, to facilitate automatic control, and to maximize economic benefits.
Gravity separation process is the earliest method that applied in mineral processing. According to the density difference among mines and the difference of gravity, fluid power and mechanical force in moving medium, mines realizes mineral grains separation through density difference, gravity separation method still occupies an important position in the contemporary mineral processing.
Since founded in 1997, Xinhai Mining has constantly increased scientific research and technology of gravity concentration, innovated process system. During more than 20 years of exploration, Xinhai constantly improved gravity separation process, aims at providing customers with more environmental and efficient mineral processing.
Gravity separation process is widely applied in gold ore, tungsten ore, tin ore, manganese ore, mercury ore, titanium ore, lead ore, tantalum-niobium ores, galena, barite, fluorite ore, pyrite, limonite, hematite, antimony, chromium ore and ferrous metal.
Xinhai gravity separation process simplify the production process and avoid over-cycles; Tailings has less environmental pollution; Xinhai gravity separation equipment have simple manufacture, better stability, which saves energy and reduces cost.
Our Australian based head office houses the world's largest spiral manufacturing facility and produces over 20,000 starts annually. In 2010/11, we manufactured HC33 and WW6 spirals for ArcelorMittal's Mont Wright mining operations in Canada to deliver the largest single spiral order in our history.
Barite is a common mineral of barium, and the elements of barite are barium sulfate, the BaO accounts for 65.7% and SO3 accounts for 34.3%. It is an important industrial raw mineral material for making barium and barium compounds.
Taking the barite deposit in China as an example, it can be divided into four types: sedimentary deposit, volcano-sedimentary deposit, hydrothermal deposit, and residual deposit. According to ore types, raw ore properties, mine scale and application, the common barite mining processes mainly include handpicking, gravity separation, flotation, magnetic separation and combined barite mining process.
In general, the residual barite ore can be separated by the gravity separation method. The sedimentary barite ore and hydrothermal barite ore associated with sulfide ore and fluorite can be extracted by the gravity separation and flotation method. Below, we will explain to you one by one each barite mining process and barite mining equipment.
After the raw ore is extracted, simple handpicking is a common barite mining process for many small barite mines. Some barite mines have a high geological grade and stable quality, so the qualified barite products can be selected by handpicking according to the difference in the color and density between barite and associated minerals. For the rich barite ore selected by hand, the grain size shall be 30-150mm, and the BaSO4 shall be larger than 95%, generally larger than 92%. In general, the simple handpicking process is easy to operate and can be carried out without barite mining equipment. This barite mining process is suitable for the small-scale barite mining plant, but it also has the disadvantages of low productivity, high ore grade requirements and serious resource waste.
This barite mining process is mainly based on the density difference between barite and associated minerals, including ore washing, screening, desliming, jigging, shaking table, which is mostly used to treat residual barite ore.
After the raw ore is treated with washing, screening, crushing, classification and desliming, the high-quality barite concentrate can be obtained by jigging and shake table. The crushing stage adopts the jaw crusher and impact crusher, the fine crushing stage adopts the double roll crusher. The separation stage adopts a heavy medium rotary drum separator, cone classifier, jig or shake table. The heavy medium separation and jigging separation can be used when the particle size of barite is larger than 2mm, but the upper limit of particle size of heavy medium separation is 50mm, and the upper limit of wet and dry jigging separation is about 20mm. The shake table can be used for separation when the particle size of the barite is less than 2mm, but he hydrocyclone must be used to remove the mud before the separation, so as to improve the separation effect.
The specific gravity of the barite is large, generally 4-4.6, and it also has a good floatability. The barite flotation process is mainly used to separate the sedimentary barite and hydrothermal barite ore associated with sulfide ore and fluorite based on the difference of surface physical and chemical properties between barite and associated minerals.
Taking the barite ore in China as an example, the barite deposits are featured with more lean ore and less rich ore. More than 80% of the proven reserves are associated with other minerals. The flotation method must be used for the separation of fine barite ore and gravity separation tailings. The main barite flotation processes are positive flotation process and reverse flotation process, in which the purpose of the reverse flotation process is to remove the alkali sulfide.
As a common salt mineral, the barite flotation process can be divided into two types according to the form of adsorption: one is to use fatty acid alkyl sulfate, alkyl sulfonate and other anion collectors to adsorb on the surface of barite mineral in the form of chemical adsorption, so as to separate from the other associated minerals. Another is to use an amine collector to float barite in the form of physical adsorption. The amines collector has low efficiency and is very sensitive to the influence of slime, so it is suggested to adopt the anionic collector in this barite mining process. In general, add the NaOH to the ball mill, adjust the pH value to 8-10, and add the sodium silicate to the slurry as the regulator, then use the oleic acid collector in the barite flotation process under the condition of 40%-50% solid concentration.
The barite magnetic separation process is mainly based on the surface magnetic difference between barite and iron oxide minerals, which is widely used to separate the iron-containing barite. The magnetic separation process is often used as the combined process with gravity separation, which can produce the barite a material of barium-based drugs requiring very low iron content.
The combined barite mining process of gravity separation and flotation is often used for the barite associated with sulfide ores. For the flotation-gravity separation process used to treat the barite-quartz-calcite ore, add the sodium silicate and collector into the flotation tank of flotation machine for removing the quartz, and obtain the barite-calcite mixed ore, and adopt jig, shake table to obtain the barite concentrate based on the density difference between gangue minerals (such as calcite) and barite.
The early mining barite ore is mostly high-grade ore, which is usually separated by the low-cost and low technical handpicking or gravity separation process. However, with the low grade of barite ore and the complex ore properties, magnetic separation, flotation and combined barite mining processes have been widely used in barite mining. It is suggested that each mine owner should make a scientific and reasonable barite mining process according to the beneficiation test report, avoiding unnecessary economic losses.
The major methods of recovering gold are gravity separation, gold flotation, cyanide. In fact, traditional gravity separators, such as jig machine, spiral chute, gold shaker table, have the shortages of low beneficiation ratio and low productivity. In addition, the flotation process is difficult to work on the coarse grain gold minerals which with heavy density. Considering environmental protection, the application of gold cyanide method is also greatly limited. Compared with the commonly used gold recovery methods, Knelson concentrator is an efficient centrifugal mineral processing equipment, has great advantages of capable to recovering coarse, medium, fine grain gold, high beneficiation ratio and no pollution.
Mine is a typical porphyry type gold-copper deposit, with low-grade gold-bearing refractory ore. as shown in the processing result, the efficiency of recovering associated gold is very poor. In this experiment, we carry out the gravity separation experimental of the knelson concentrator, trying to provide the technical basis for improving the recovery efficiency of associated gold ore.
Copper and iron are the two main elements in the raw ore, and exist in the forms of alpha chalcocite, covelline, enargite, iron pyrite. The gangue minerals are mainly quartz, dickite, alunite and a small amount of iron oxide, etc. Gold symbiosis with other minerals closely, that is the raw ore is multi-metal gold-bearing refractory ore.
Based on the analysis of the occurrence state and distribution of gold in the overflow ore, it is found that a large part of the gold is dissociated from the raw ore, the visible gold in the overflow ore accounts for 36%. It can be seen from the distribution of gold in the ore that improving the recovery of visible gold is the key to increase the recovery rate.
Taking enrichment and gold mineral scanning processes for the part of overflow ore, obtain 80 gold minerals. According to the count of grain ore size, the visible gold is mainly fine-grained grade, in which, 10 ~ 80 m account for 80%, few are less than 10m. In view of the previous research, gold particles over 37 m can be recovered by gravity separation, while 10 ~ 37 m is more suitable for flotation processing. click to find more info about Fine gold recovery equipment.
The ore sample is a low-grade gold bearing refractory copper ore, in which, gold is closely associated with copper-sulfur minerals, the gold( mainly in nature gold) are distributed in the gaps. After the ore was dissociated, a large part of gold became granular gold, and it was difficult to achieve effective recovery by flotation, so the Knelson is used to pre-recover the granular gold.
The Knelson centrifugal concentrator is often arranged at the outlet of the ball mill, we analysis the ball mill discharge firstly, to know the metal distribution of different particle sizes. As can be seen in the above table, the major particle size is 0.045mm-0.6mm, with 75.26% of productivity, and the distribution rate of gold is up to 83.76%. The recovery result of this grain size will directly affect the recovery effect of the final gold metal.
Machine: KC-MD3 Knelson concentrator and shaker table for gold recovery Experimental variable: gravity, fluidized water, fluidized water, feeding rate. Sample ore size: -1mm Content of gold: 0.55 g/t 2.2.1 Gravity Experiment condition: pulp density 30%, feeding rate 1 kg/min, fluidized water 3.0-3.3 L/min, enrichment time 25min, gravity range 40-120G. From the experimental results, with the increase of gravity value, the concentrate gold grade and recovery rate of Knelson gravity decreased. The lower gravity value is beneficial to Knelson to concentrate gold. When the gravity value is 40G, the grade of gold concentrate is 107.28 g/t, and the recovery rate is 67.49%. 2.2.2 Fluidized water Experiment condition: pulp density 30%, feeding rate 1 kg/min, gravity value 40G, enrichment time 25min, fluidized water have 2L/min, 3L/min, 4L/min, 5L/min. The result shows that with the increase of fluidization water flow, the grade of gold concentrate tends to rise, the recovery rate is changed slightly. When the water flow is 5.0 L/min, the concentrate is 100.56 g / t, and the recovery rate is 64.35%.
2.2.3 Enrichment time Experimental conditions: pulp density 30%, ore feeding speed 1 kg/min, gravity value is 40G, fluidization water 5.0 L/ min, enrichment time have 20 minutes, 25 minutes,30 minutes and 35 minutes. With the increase of enrichment time, the grade of concentrate increases gradually, and the recovery rate increases at first and then decreases. When the enrichment time is 30 min, the maximum value is 68.23%, and the concentration level is 114.63%.
2.2.4 Feeding speed Experimental conditions: pulp density 30%, gravity value is 40G, fluidization water 5.0 L/ min, enrichment time 30min. As the feeding rate is increased, the grade of concentrate has a tendency to rise, and the beneficiation effect is gradually enhanced, the recovery rate is increasing at first and then decreased. when the feeding rate at 1 kg/min, the recovery rate up to the max value of 70.70%, the grade is 137.12g/t. Considering the stability of Knelson concentrator, the most suited feeding speed is 1 kg/min.
2.2.5 Enlarged experimental of combined variables On the basis of the preliminary experiments, researcher adopt KC-MD 7.5 Knelson concentrator to carry on combined variables experimental of discharged ore of ball mill. Experimental condition: process ore 600 kg, particle size -2mm, pulp density 30%, feeding rate 300-400kg/h, gravity value 40G, fluidization water pressure 0.2-0.3 Mpa.
Knelson gravity concentrator has a good effect on gold enrichment, and obtain a high grade of concentrate. The gold content of the concentrate is 251.30 g/t, the recovery rate is 53.70%, and the Knelson has not affected the recovery of copper.
2.3.2 Granular gold recovery The grain size range of gold minerals is 0 ~ 800 m, and the particle size distribution of gold particles is mainly concentrated in the range of 20 ~ 100 m( 69%). The gold particles less than 30 m account for only about 8%, the recovery rate of that is low. The gold particles larger than 150 m in the concentrate account for 13%, of which only about 1% are more than 360 m. This part of the particulate gold is difficult to be recovered by flotation. Recovering the great mass of gold by Knelson gravity separation can effectively reduce the sedimentary gold in the flotation machine, and avoid the repeated grinding.
Using Nielsen concentrator which obtains synthetic recovery of -0.6+0.038 mm gold. Nielsen concentrator, the pre-recovery of most of the particles of gold, can reduce the loss of gold in flotation operations, achieving the goal of the income received early.
About JXSC JXSC starts the mining equipment manufacturing since 1985 have great advantages in mining equipment among various minerals and professional solutions for mineral processing plant, is a reliable provider of gold separator machine and gold recovery equipment. Follow us to receive updates of the gold extraction process.
Mining Equipment Manufacturers, Our Main Products: Gold Trommel, Gold Wash Plant, Dense Media Separation System, CIP, CIL, Ball Mill, Trommel Scrubber, Shaker Table, Jig Concentrator, Spiral Separator, Slurry Pump, Trommel Screen.
Gravity ore dressing/ gravity beneficiation/ gravity separation is one of the main ore beneficiation methods, includes heavy medium separation( DMS/ HMS), jigging, shaker concentrator, spiral chute concentrator. HMS and mineral jigs suit for the coarse ore particle, shaker has a high dressing accuracy, can be used in the weak magnetic iron mineral recovery plant, the spiral chute is very popular in the iron ore processing plant, besides, mineral centrifugal concentrators applied in the fine particle dressing. Specification of gravity separation method: low operating cost, little pollution. Main gravity separators machine as following.
put crushed ore material into the heavy medium fluid( density greater than waters), separate the two different materials under the flotation and sedimentation process of the buoyancy force. HMS/ DMS has a good effect on the little density difference, thus a high separation accuracy. besides, large production capacity is also a great advantage. heavy medium separation machines include a vibrating chute, ore dressing machine, cyclone, vortex, min particle low to 0.55mm.
Chinese mining machine manufacturers can provide several types of jig concentrators like trapezoid jig, rectangular jig, Remer vibratory jig, hydraulic press jig, sawtooth Pulsation Jig, pan American jig, circular mineral jig, eccentric jig, plunger jig, duplex gold jigs, moving sieve jig, Harz jig, etc. The working principle of the mineral jig: the ore particles in the jigging machine are mainly layered by means of the density differences, the bigger the gravity difference is, the higher the gravity separation efficiency is. it is necessary to keep layers with a certain shatter condition, if the material layer is very full and compaction, it will count against the jigging process, prolong the loose condition to improve the separation effect and capability.
Generally, the particle size of ore dressing in the shaking table is in the range of 0.037 ~ 3 mm. in recent years, the shaker table as the ancillary equipment to recover the weak magnetic iron mineral. whats more, shaking tables are widely used to separate tungsten, tin, niobium, tantalum and gold-bearing ores. The shaking table surface is the working platform, the surfaces material types include wood, glass fiber reinforced polyester resin and aluminum alloy, shaker surface with a wear protection layer and providing corrosion resistant layer, greatly prolong the service life. JXSC customers tin processing plant, 16 sets of shakers combine with the spiral separator, get a 60% tin concentrate.
Chute dressing machines include a spiral separator, spiral chute, vibrating chute, belt separator, centrifugal concentrator, etc. spiral separator is very popular in ore processing plants, meanwhile, an important and the widest used gravity separator machine. 4.1 Spiral separator mainly for coarse size ore, take Wabush iron ore dressing plant as an example. Material: quartz-type weakly magnetic iron ore Feed size: 0. 84 ~0mm 5 sets of spiral separators Effect: original ore degree 35%, concentrate %64. Chinese ore dressing machine manufacturers start to develop spiral dressing equipment since 1950, practice shows that it has a good performance with 75.36% recovery rate( run mine 41%, concentrate 56%). 4.2 Centrifugal concentrator We produce a fine particle cent concentrator for 0. 037 ~0. 010mm, I recent years, the gold centrifugal concentrator has a great development, plays a core role in the dressing plant of fine particle weak magnetic iron ore. Gold centrifuge combines with the chute, shaker improves the concentrate accuracy. JXSC mining machinery factory provides gravity separator since 1985, contact us to know the latest price of gravity separator machine.
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