Beneficiation system for efficiently recovering valuable elements from laterite type gold ore

Abstract

The utility model relates to an ore dressing system for efficiently recovering valuable elements from laterite type gold ore, which comprises a rod mill, a discharge port of the rod mill is connected to a feed port of a 1 # cyclone through an ore pulp pool and a slurry pump, and an overflow port of the 1 # cyclone is sequentially connected with a 1 # stirring barrel, a 1 # high-gradient medium magnetic separator and a 1 # high-gradient strong magnetic separator. A sand setting opening of the 1 # cyclone is connected to a feeding opening of the ball mill, a discharging opening of the ball mill is connected to a feeding opening of the 2 # cyclone through the ore pulp pool and the slurry pump, a sand setting opening of the 2 # cyclone is connected to the feeding opening of the ball mill, and an overflow opening of the 2 # cyclone is connected to a feeding opening of the thickener. And concentrate ports of the 1 # high-gradient medium-intensity magnetic separator and the 1 # high-gradient high-intensity magnetic separator are also connected to a feed port of the thickener through an ore pulp pool and a slurry pump. The primary slime is subjected to pre-selection and tailing discarding, so that a large amount of primary slime can be prevented from entering a cyanidation leaching process to generate adverse effects, the gold and silver leaching rate is improved, and the dosage of medicaments and activated carbon in the leaching process is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of comprehensive exploitation and utilization of low-grade iron ore and semi-processed ore, and particularly relates to a mineral processing system for efficiently recovering valuable metal gold, silver and iron minerals from laterite type gold ore with high clay content and strong viscosity. BACKGROUND

[0002] The most important feature of the laterite type gold ore is that the gold ore is distributed in the laterite, and the laterite is a red, ocher and brown soil formed by the oxidation and decomposition of silicate minerals containing Al and minerals containing Fe, and the ore is loose, and the crude ore is in the form of sandy soil, honeycomb, sandy clay structure, with high clay content and strong viscosity, and contains no or very little sulfide, and the main metal minerals are limonite and magnetite.

[0003] At present, the gold ore processing technology mainly adopts heap leaching, pelletizing heap leaching and full-mud cyanidation. Based on the composition and structural characteristics of the laterite type gold ore, the above three methods all have problems to different degrees. When the heap leaching method is used, the crude ore of the laterite type gold ore has fine particle size, high mud content and poor permeability, and it is difficult to directly heap leach, and direct heap leaching not only has low leaching rate but also long heap leaching period, and in serious cases, the ore heap is blocked, the leaching liquid cannot uniformly pass through the whole ore heap and flows away from the surface of the ore heap, and the heap leaching operation cannot be normally carried out. When the pelletizing heap leaching method is used to treat high-mud laterite type gold ore, there are the following shortcomings: no skeleton for pelletizing, great difficulty in granulation, poor stability and low gold and silver leaching rate. When the full-mud cyanidation method is used to treat high-mud laterite type gold ore, the mud covers and condenses on the surface of the mineral, increases the viscosity of the slurry and reduces the diffusion speed of CN - and Au(CN) 2- on the surface of the gold and silver containing mineral particles, affects the dissolution speed of gold and the leaching rate of gold. At the same time, the mud also adsorbs a large amount of CN - and Au(CN) 2- , consumes a large amount of leaching reagent and makes the dissolved gold lost in the tailings. In the active carbon adsorption process, a large amount of fine particle size mud is adsorbed and adhered to the active carbon and is difficult to desorb, which deteriorates the adsorption rate and desorption rate of the active carbon, causes the loss of gold and silver and high carbon loss.

[0004] Therefore, the existing gold ore processing technology cannot effectively recover the valuable metal elements in the laterite type gold ore, and the existing gold ore processing technology generally adopts a wet type cylinder type low-intensity magnetic separator for the comprehensive recovery of the iron minerals in the leaching residue. However, the recovery capacity of this magnetic separation method for the laterite type gold ore with high content of fine particle and micro-fine particle level magnetic minerals mainly in the form of limonite is insufficient, and it is difficult to recover the iron minerals. Therefore, it is necessary to study a mineral processing system suitable for the efficient recovery of valuable metal gold, silver and iron minerals from the laterite type gold ore. UTILITY MODEL CONTENTS

[0005] In order to overcome the existing red clay type gold ore dressing process in the production practice of primary slime caused by low gold leaching rate, low activated carbon adsorption rate, low total iron recovery rate, and the existing magnetic separation iron recovery process is not good and many other shortcomings, the utility model provides a kind of from red clay type gold ore high-efficiency recovery of valuable elements mineral processing system.

[0006] Specific technical scheme: a kind of from red clay type gold ore high-efficiency recovery of valuable elements mineral processing system, including rod mill, the discharge outlet of the rod mill is connected to the feed inlet of 1# cyclone through slurry tank and slurry pump, the overflow outlet of 1# cyclone is sequentially connected with 1# stirring barrel, 1# high gradient medium magnetic separator, 1# high gradient high intensity magnetic separator, the sand outlet of 1# cyclone is connected to the feed inlet of ball mill, the discharge outlet of the ball mill is connected to the feed inlet of 2# cyclone through slurry tank and slurry pump, the sand outlet of 2# cyclone is connected to the feed inlet of ball mill, the overflow outlet of 2# cyclone is connected to the feed inlet of thickener, the concentrate outlet of 1# high gradient medium magnetic separator and 1# high gradient high intensity magnetic separator is also connected to the feed inlet of thickener through slurry tank and slurry pump;

[0007] The underflow outlet of the thickener is sequentially connected with 2# stirring barrel, leaching stirring barrel and leaching adsorption stirring barrel, the discharge outlet of the leaching adsorption stirring barrel is sequentially connected with 3# stirring barrel, 1# weak magnetic separator, 2# high gradient medium magnetic separator, 2# weak magnetic separator,

[0008] The concentrate outlet of 1# weak magnetic separator and 2# high gradient medium magnetic separator is connected to the feed inlet of 2# weak magnetic separator, the tailing outlet of 2# high gradient medium magnetic separator is connected to 2# high gradient high intensity magnetic separator through slurry tank and slurry pump, the middling outlet of 2# weak magnetic separator and the concentrate outlet of 2# high gradient high intensity magnetic separator are connected to the feed inlet of 3# high gradient high intensity magnetic separator through slurry tank and slurry pump.

[0009] Further, preferably, the leaching stirring barrel and or leaching adsorption stirring barrel are provided in multiple series.

[0010] Further, preferably, the magnetic field strength of the 1# high gradient medium magnetic separator is 0.35-0.6T, the magnetic field strength of the 1# high gradient high intensity magnetic separator is 0.7-1.3T, and the diameter of magnetic medium is 1-3mm.

[0011] Further, preferably, the magnetic field strength of the 1# weak magnetic separator is 0.3-0.4T, and the magnetic separation gap is 20-35mm.

[0012] Further, preferably, the magnetic field strength of the 2# high gradient medium magnetic separator is 0.35-0.6T.

[0013] Further, preferably, the magnetic field strength of the 2# weak magnetic separator is 0.1-0.3T

[0014] Further, preferably, the magnetic field strength of the 2# high gradient magnetic separator is 1.0-1.5T, and the rod medium wire diameter is 2-5mm.

[0015] Further, preferably, the magnetic field strength of the 3# high gradient magnetic separator is 0.7-1.1T, and the rod medium wire diameter is 2-5mm.

[0016] The present application has the following beneficial effects:

[0017] (1) The present application transforms the existing laterite type gold ore recovery equipment system, adds the raw ore stirring and pulp making-classification desliming-preliminary separation and tailings throwing process system, can preliminarily separate and throw tailings of the primary slurry, avoids the large amount of primary slurry from entering the cyanide leaching and magnetic separation main separation process to produce adverse effects, improves the gold and silver leaching rate of the "full slurry cyanidation-activated carbon adsorption leaching" process, reduces the amount of reagents and activated carbon in the leaching process, and improves the recovery capacity of iron minerals in the leaching residue.

[0018] (2) The present application uses two-stage magnetic separation of the high gradient medium and high magnetic separator, first uses the high gradient medium magnetic separator with high gradient and low magnetic field gap to strengthen the recovery of fine and micro fine particle grade magnetite, then uses the high gradient high impact and low stroke high gradient magnetic separator to strengthen the recovery of fine and micro fine particle grade limonite, effectively recovers the gold, silver and iron elements in the slurry, improves the comprehensive utilization rate of resources, and reduces the tailings storage volume.

[0019] (3) The present application sets up the five-stage magnetic separation iron separation equipment according to the composition and structural characteristics of the laterite type gold ore and the magnetic separation mechanism of the magnetic mineral, uses the low magnetic separation gap weak magnetic separator to recover most of the coarse, medium and part of the fine particle grade magnetite in one time, then uses the high gradient medium magnetic separator to sweep and strengthen the recovery of fine and micro fine particle grade magnetite, then uses the high field strength, large impact and small stroke high gradient magnetic separator to coarsely separate the fine and micro fine particle limonite particles, increases the possibility of being captured, further uses the high field strength, large impact and large stroke high gradient magnetic separator to finely separate and strengthen the recovery of fine and micro fine particle magnetic minerals, finally obtains the high recovery rate and high grade magnetite and limonite, solves the problem that the conventional wet type drum type magnetic separator is difficult to recover or has low recovery rate of weak magnetic limonite and fine and micro fine particle grade magnetic minerals, and improves the recovery index of iron minerals. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a beneficiation method flow chart of the present application for efficiently recovering valuable elements from the laterite type gold ore;

[0021] Figure 2 is a device correlation diagram of the beneficiation system of the present application for efficiently recovering valuable elements from the laterite type gold ore;

[0022] In the figure: 1 - rod mill, 3 - 1# cyclone, 4 - 1# stirring barrel, 5 - 1# high gradient medium magnetic separator, 6 - 1# high gradient strong magnetic separator, 7 - ball mill, 8 - 2# cyclone, 9 - thickener, 10 - 2# stirring barrel, 11 - leaching stirring barrel, 12 - leaching adsorption stirring barrel, 13 - 3# stirring barrel, 14 - 1# weak magnetic separator, 15 - 2# high gradient medium magnetic separator, 16 - 2# weak magnetic separator, 17 - 2# high gradient strong magnetic separator, 18 - 3# high gradient strong magnetic separator. DETAILED DESCRIPTION

[0023] In order to make the technical problems and technical solutions solved by the utility model more clear and understandable, the utility model is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0024] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown based on the drawings, and is only used to facilitate the description of the utility model, and is not used to indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0025] In the description of the utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "setting", "mounting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0026] As Figure 2As shown, the embodiment provides a beneficiation system for efficiently recovering valuable elements from laterite gold ore, which comprises a rod mill 1. A feeding device such as a belt conveyor can be arranged at the front end of the rod mill 1 to facilitate feeding of the ore into the rod mill 1. The discharge port of the rod mill 1 is connected to the feed inlet of a 1# cyclone 3 through an ore slurry tank and a slurry pump. The overflow port of the 1# cyclone 3 is connected to a 1# stirring barrel 4, a 1# high-gradient medium magnetic separator 5, and a 1# high-gradient high-intensity magnetic separator 6 in sequence. The sand outlet of the 1# cyclone 3 is connected to the feed inlet of a ball mill 7. The discharge port of the ball mill 7 is connected to the feed inlet of a 2# cyclone 8 through an ore slurry tank and a slurry pump. The sand outlet of the 2# cyclone 8 is connected to the feed inlet of the ball mill 7. The overflow port of the 2# cyclone 8 is connected to the feed inlet of a thickener 9. The concentrate outlets of the 1# high-gradient medium magnetic separator 5 and the 1# high-gradient high-intensity magnetic separator 6 are also connected to the feed inlet of the thickener 9 through an ore slurry tank and a slurry pump.

[0027] The underflow port of the thickener 9 is connected to a 2# stirring barrel 10, a leaching stirring barrel 11, and a leaching adsorption stirring barrel 12 in sequence. The discharge port of the leaching adsorption stirring barrel 12 is connected to a 3# stirring barrel 13, a 1# low-intensity magnetic separator 14, a 2# high-gradient medium magnetic separator 15, and a 2# low-intensity magnetic separator 16 in sequence. The concentrate outlets of the 1# low-intensity magnetic separator 14 and the 2# high-gradient medium magnetic separator 15 are connected to the feed inlet of the 2# low-intensity magnetic separator 16. The tailing outlet of the 2# high-gradient medium magnetic separator 15 is connected to a 2# high-gradient high-intensity magnetic separator 17 through an ore slurry tank and a slurry pump. The middlings outlet of the 2# low-intensity magnetic separator 16 and the concentrate outlet of the 2# high-gradient high-intensity magnetic separator 17 are connected to the feed inlet of a 3# high-gradient high-intensity magnetic separator 18 through an ore slurry tank and a slurry pump.

[0028] The leaching stirring barrel 11 and / or the leaching adsorption stirring barrel 12 are provided in multiple series. The number of the barrels can be flexibly set according to the ore processing capacity and processing capacity requirements. It should be noted that the above-mentioned devices are all existing devices, and the utility model does not involve the modification of the devices, but only involves the use of the above-mentioned existing devices.

[0029] In combination Figure 1 As shown in the beneficiation method, the working principle of the beneficiation system is as follows:

[0030] (1) The laterite gold ore is fed into the rod mill 1 through the feeding device. The rod mill 1 stirs and grinds the ore into an ore slurry with a concentration of 15% to 30%. The ore slurry is transported to the 1# cyclone 3 through a slurry pump for classification to obtain +0.037mm size fraction and -0.037mm size fraction.

[0031] (2) The -0.037 mm particle size material classified out is transferred from the overflow port of the 1# cyclone 3 to the 1# stirring barrel 4, stirred and then transported to the 1# high gradient medium magnetic separator 5 for a first-stage medium magnetic pre-concentration, to obtain a coarse iron concentrate I and a tailing I; the tailing I is transported to the 1# high gradient strong magnetic separator 6 through a tailing port for a second-stage strong magnetic pre-concentration, to obtain a coarse iron concentrate II and a tailing II, and the coarse iron concentrate I and the coarse iron concentrate II are pumped to the thickener 9 after being adjusted in a slurry tank. In this process, the magnetic field strength of the 1# high gradient medium magnetic separator 5 is 0.35-0.6 T, and the operating concentration is controlled at 15%-30%; the magnetic field strength of the 1# high gradient strong magnetic separator 6 is 0.7-1.3 T, the magnetic medium diameter is 1-3 mm, and the operating concentration is controlled at 15%-30%.

[0032] (3) The +0.037 mm particle size material classified out is transferred from the sand port of the 1# cyclone 3 to the ball mill 7 for fine grinding, the fine grinding product is classified by the 2# cyclone 8, the fineness is more than 85% of -200 mesh, the sand (+200 mesh particle size material) is returned to the ball mill 7 for recycling and regrinding, and the overflow is fed into the thickener 9.

[0033] (4) The coarse iron concentrate I, the coarse iron concentrate II and the fine grinding material are thickened by the thickener 9 to obtain underflow slurry and overflow water. The overflow water does not contain cyanide and can be reused in the front process system; the underflow slurry is thickened to a concentration of 25%-40% and then transferred to the 2# stirring barrel 10, lime milk (2-5 kg / t) is added for stirring and slurry adjustment to pH 10-12, and then the slurry is transported to the leaching stirring barrel 11, sodium cyanide (3-5 kg of sodium cyanide is added per ton of ore) is added for stirring and leaching, and then the slurry is continuously transferred to the series-connected leaching and adsorption stirring barrel 12, activated carbon is added for adsorption leaching, and after multiple cyanide leaching and activated carbon adsorption leaching, gold-loaded carbon and leaching residue are obtained.

[0034] (5) The leaching residue is transferred to the 3# stirring barrel 13 for slurry adjustment and then transported to the 1# weak magnetic separator 14 for weak magnetic roughing, to obtain a weak magnetic roughing coarse concentrate (magnetite) and a weak magnetic roughing tailing; in this process, the magnetic field strength of the 1# weak magnetic separator 14 is 0.3-0.4 T, the magnetic separation gap is 20-35 mm, and the operating concentration is controlled at 20%-30%.

[0035] (6) The weak magnetic roughing tailing is transferred to the 2# high gradient medium magnetic separator 15 for high gradient medium magnetic scavenging, to recover fine and micro-fine particle magnetite in the tailing, to obtain a medium magnetic scavenging middling and a medium magnetic scavenging tailing; in this process, the magnetic field strength of the 2# high gradient medium magnetic separator 15 is 0.35-0.6 T, and the operating concentration is controlled at 18%-28%.

[0036] (7) Weak magnetic roughing rough concentrate (magnetite) and medium magnetic scavenging medium ore is transferred to the 2# weak magnetic separator 16 for weak magnetic cleaning, and the magnetite concentrate and weak magnetic cleaning medium ore are obtained; in this process, the magnetic field strength of the 2# weak magnetic separator 16 is 0.1-0.3T, and the operating concentration is controlled at 15%-25%.

[0037] (8) The medium magnetic scavenging tailings are transferred to the 2# high gradient magnetic separator 17 for high gradient magnetic roughing, and the high gradient magnetic roughing rough concentrate and the high gradient magnetic roughing tailings are obtained; in this process, the magnetic field strength of the 2# high gradient magnetic separator 17 is 1.0-1.5T, the rod medium wire diameter is 2-5mm, and the operating concentration is controlled at 15%-25%.

[0038] (9) The weak magnetic cleaning medium ore and the high gradient magnetic roughing rough concentrate are transferred to the 3# high gradient magnetic separator 18 for high gradient magnetic cleaning, and the limonite concentrate and the high gradient magnetic cleaning tailings are obtained. The high gradient magnetic roughing tailings and the high gradient magnetic cleaning tailings constitute the tailings III (containing cyanide). In this process, the magnetic field strength of the 3# high gradient magnetic separator 18 is 0.7-1.1T, the rod medium wire diameter is 2-5mm, and the operating concentration is controlled at 8%-20%.

[0039] The process of the beneficiation system mainly includes three stages: raw ore grading desliming-preliminary selection tailing throwing, preselected concentrate and coarse sand full mud cyanidation-leaching, and iron selection of leaching residue. The specific research mechanism is as follows:

[0040] (I) Analysis of the mechanism of the preselected tailing throwing and the iron selection of the leaching residue

[0041] The necessary condition for magnetic separation: the magnetic force F acting on the target mineral particles 1磁 Must be greater than all the mechanical forces ∑F opposite to the direction of the magnetic force 机 And the magnetic force F acting on the non-target mineral particles 2磁 Must be less than all the mechanical forces ∑F opposite to the direction of the magnetic force 机 (Including gravity, viscous resistance, centrifugal force, attraction and repulsion between particles and particles, etc.), that is:

[0042] F 1磁 >∑F 机 >F 2磁 (1)

[0043] In the process of magnetic separation, F 1磁 <∑F 机 , which means that the target mineral cannot be effectively captured and is lost in the tailings, F 1磁 , F 2磁 >∑F 机 , which means that the target mineral and the non-target mineral are both captured, resulting in high impurity content of the concentrate.

[0044] Because of the great difference in magnetism between weakly magnetic minerals and strongly magnetic minerals, the separation equipment and the mechanism of the magnetic force acting on the particles are different, which are described separately.

[0045] 1. Approximate calculation of the magnetic force of strongly magnetic mineral particles in the permanent magnetic drum magnetic separation process

[0046] Strongly magnetic minerals such as magnetite, titanomagnetite, and maghemite are usually recovered by wet low-intensity magnetic separators, and the most representative one is the permanent magnetic drum separator. The magnetic force acting on the strongly magnetic mineral particles is:

[0047] (2)

[0048] In the above formula, k is the approximate calculation coefficient; B is the magnetic induction intensity of the permanent magnet, T; A is the effective adsorption area of the permanent magnet, m 2 ; μ 0－ is the vacuum permeability, a constant; μ r is the permeability, dimensionless; d is the distance between the permanent magnet and the adsorbed particles, m.

[0049] The above formula shows that the magnetic force acting on the strongly magnetic minerals such as magnetite, titanomagnetite, and maghemite in the magnetic field of the permanent magnetic drum separator is proportional to the magnetic induction intensity B of the permanent magnet and the effective adsorption area A of the permanent magnet; and inversely proportional to the permeability μ r of the strongly magnetic minerals and the distance d between the permanent magnet and the adsorbed particles. The magnetic force acting on the strongly magnetic mineral particles in the magnetic field decays exponentially with the distance d, that is, only within a certain range from the surface of the magnetic pole, a larger magnetic force can be obtained. Therefore, under the condition that other conditions remain unchanged, the use of medium-high field strength (0.35-0.6 T) and the reduction of the magnetic separation gap (the distance d between the permanent magnet and the adsorbed particles) can effectively enhance the magnetic force between the permanent magnet and the magnetite particles, and compared with the ordinary permanent magnetic drum separator, it has a higher probability of separation and enrichment of fine and micro-fine particles of magnetite.

[0050] 2. Calculation of the magnetic force of weakly magnetic mineral particles

[0051] The potential energy obtained by the magnetization of the magnetic mineral particles is:

[0052] (3)

[0053] The magnetic force acting on the magnetic mineral particles can be calculated by the negative gradient value of the particle potential energy, that is:

[0054] (4)

[0055] In the above formula, μ0 is the vacuum permeability, a constant; k is the volume susceptibility of the mineral particles, a dimensionless constant; H is the external magnetic field strength, A / m; V is the volume of the mineral particles, m 3 .

[0056] When the particle is small, the volume susceptibility of the mineral particle, the magnetic force HgradH in the volume it occupies, can be regarded as a constant, then:

[0057] (5)

[0058] In the above formula, gradH is the magnetic field gradient, describing the rate of change of the magnetic field intensity in space, mT / m.

[0059] To eliminate the influence of the actual existing voids in the mineral particles on the calculation of the magnetic force, the specific magnetic force concept is introduced, that is, the magnetic force acting on the unit mass of the particle:

[0060] (6)

[0061] (7)

[0062] f m - specific magnetic force, N / kg; - specific magnetization coefficient of the mineral particle, m3 / kg; p - weakly magnetic mineral particle, kg / m3, and the others are the same as above.

[0063] During magnetic separation, the capture of the mineral particle is closely related to the dispersion and agglomeration behavior of the fine particle system. Two effective measures to improve the separation index of fine mineral are to increase the apparent particle size of the fine mineral (selective magnetic agglomeration method and magnetic seed method) and to increase the magnetic force on the particles of the target mineral to overcome the direct separation of fine materials by mechanical force. The magnetic force acting on the mineral particle depends on the specific magnetization coefficient of the particle and the magnetic field force HgrandH.

[0064] For weakly magnetic minerals such as limonite and siderite, most of the pure minerals belong to paramagnetic substances (hematite belongs to antiferromagnetic substances), and the magnetism comes from the rotation of part of the atomic magnetic moment. The specific magnetization coefficient is small, and the magnetism is independent of the shape and size of the particle, but related to the mineral composition. The same kind of mineral has certain differences due to different ore deposit genesis and ore formation conditions, and the theoretical analysis can be regarded as a constant. Therefore, the size of the magnetic force acting on the weakly magnetic mineral particle depends on the magnetic field intensity H and the magnetic field gradient grandH. The use of high-gradient high-intensity magnetic separators can realize the efficient recovery of fine and micro-fine grade weakly magnetic minerals (limonite, siderite, etc.).

[0065] And magnetite belongs to ferrimagnetic substance, and the magnetism comes from the movement of magnetic domain. The specific magnetization coefficient The numerical value is large, before reaching the magnetic saturation, its specific magnetization coefficient increases with the increase of magnetic field intensity H, decreases with the decrease of particle size, but the coercive force increases, especially when the particle size is less than 37 microns, the specific magnetization coefficient decreases sharply. It can be seen that for a specific particle size and particle shape, fine and micro-fine magnetite particles, because the magnetite particles reach magnetic saturation under a lower external magnetic field, after reaching magnetic saturation, if the magnetic force on the particles is to be increased, simply increasing the magnetic field strength cannot meet the separation purpose, and a certain magnetic field gradient needs to be increased. Therefore, the high gradient permanent magnet medium magnetic separator can realize the effective recovery of fine and micro-fine magnetite.

[0066] In summary, the strong magnetic minerals are separated by the low intensity magnetic separator, and the weak magnetic minerals are separated by the high gradient high intensity magnetic separator, so that the magnetic force F 磁 >∑F 机 on the mineral particles can be effectively increased, and the separation is carried out. The red soil type gold ore targeted by the utility model is usually limonite type gold ore, and the main iron ore is limonite, followed by magnetite and other iron oxides and iron silicates. Limonite is a weakly magnetic mineral and also a main gold-bearing mineral, and magnetite is a strongly magnetic mineral. Therefore, in the pre-selection tailing and leaching residue iron separation, the low intensity magnetic separator is used to recover magnetite, and the high gradient high intensity magnetic separator is used to recover limonite and fine and micro-fine magnetite; and in the separation of magnetite in the leaching residue, the low intensity magnetic separator is used while the magnetic separation gap (20-35 mm) of the operation area is reduced, which can effectively increase the specific magnetic force f m on the strongly magnetic minerals, so that f m is greater than the resultant force ∑F 机 of the reverse mechanical force on the particles, and most of the coarse, medium and part of the fine magnetite particles can be effectively recovered by one-time low intensity rough separation.

[0067] (II) Analysis of the influence of primary slime on the main separation process

[0068] 1. Influence on the whole slime cyanidation-activated carbon adsorption leaching process

[0069] When the primary slime enters the whole slime cyanidation-activated carbon adsorption leaching process, the slime will cover and condense on the surface of the mineral, increase the viscosity of the slurry, and reduce the diffusion speed of CN - and Au(CN) 2- on the gold and silver-containing mineral particles, affect the dissolution speed of gold and the leaching rate of gold. At the same time, due to the fine particle size and large specific surface area, the slime will adsorb a large amount of CN - and Au(CN) 2-, consume a large amount of leaching reagent while losing the dissolved gold in the tailings. In addition, in the activated carbon adsorption process, a large amount of fine particle slime is adsorbed and adhered to the activated carbon, which is difficult to desorb, thus deteriorating the adsorption rate and desorption rate of activated carbon, resulting in gold and silver loss and high carbon loss. In production practice, when the ore blending ratio of laterite type gold ore and rock gold type oxidized ore reaches 1:3, the indexes such as the processing capacity of the concentrator, the cyanide leaching rate, the adsorption rate and the desorption rate are greatly reduced. Therefore, while ensuring the comprehensive and efficient recovery of resources, how to avoid the influence of clay on cyanide leaching, activated carbon adsorption and desorption is the key to improving the indexes of the whole slime cyanide-activated carbon adsorption leaching process of laterite type gold ore.

[0070] 2. Influence on magnetic separation process

[0071] The primary slime has fine particle size, large specific surface area and surface activity. In the magnetic separation, the primary slime is adhered to the surface of the magnetic particles in the form of covering or heterogeneous agglomeration, or is non-selectively agglomerated with each other, a large amount of argillaceous slurry enters the cleaning operation, resulting in serious inclusions in the concentrate product and a decrease in grade.

[0072] For the above influences, the utility model sets up the "raw ore grading desliming-preliminary separation and tailing throwing" process system before the main separation process, can carry out the preliminary separation and tailing throwing treatment to the primary slime, removes the slime in the primary ore, so as to avoid the adverse influence of the slime on leaching and magnetic separation in the main separation process, and can recover the valuable metal elements rich in the slime, improves the comprehensive utilization rate of resources.

[0073] Application Example 1:

[0074] Raw material 1#: a kind of laterite type gold ore, raw ore Au grade 1.70g / t, TFe 28% (mFe content 11%), the laterite type oxidized ore is a primary ore, which is a supergene ore body caused by weathering and erosion-transportation and deposition, the ore is mostly sandy soil, honeycomb, and the rock mass is kaolinized. The laterite ore has low gold grade, mainly fine-grained native gold, and the iron ore is mainly magnetite and limonite, and the iron ore is the main gold-bearing mineral. The gold content in magnetite is about 40%, the gold content in limonite is about 30%, the bare gold content is about 15%, and the gold content in other minerals is 15%. The gangue minerals are mainly quartz, kaolin, feldspar, chlorite and sericite.

[0075] The beneficiation system and beneficiation method are used for valuable metal recovery of raw material 1#, and the recovery steps are summarized as follows:

[0076] Firstly, the raw ore is treated by the process of "mixing and slurry-making-grading desliming (-0.037 mm)-preliminary separation and tailing throwing", the preliminary separation and tailing throwing is treated by the process of "one-stage high-gradient medium magnetic separation + two-stage high-gradient strong magnetic separation", 20.42% of the pre-separation tailings II can be thrown out, and the Fe and Au grades in the tailings are 10.27% and 0.219 g / t respectively, the loss rates of Fe and Au are 7.49% and 2.63% respectively.

[0077] Secondly, the two-stage pre-separation coarse concentrates are mixed and slurried (the concentration is 30%, the lime is 2.5 kg / t, and the slurry pH is 10), and then treated by the process of "full mud cyanidation-activated carbon adsorption leaching", under the condition that the stirring leaching time is 42 h and the sodium cyanide dosage is 3 kg / t, the gold operation leaching rate is 66.56%; the coarse sand (+0.037 mm) of the grading desliming is re-ground and classified (the proportion of -200 mesh is more than 85%, the concentration is 35%, the lime is 3 kg / t, and the slurry pH is 11), and then treated by the process of "full mud cyanidation-activated carbon adsorption leaching", under the condition that the stirring leaching time is 36 h and the sodium cyanide dosage is 3 kg / t, the gold operation leaching rate is 92.49%;

[0078] Finally, the pre-separation coarse concentrate leaching residue and the grading desliming coarse sand leaching residue are mixed and stirred uniformly, and then treated by the process of "weak magnetic rough separation-high-gradient medium magnetic scavenging-high-gradient strong magnetic rough separation-weak magnetic separation-high-gradient strong magnetic separation", the iron concentrate with the Fe grade of 61.57% and the Fe recovery rate of 35%, the brown iron concentrate with the Fe grade of 48.41% and the Fe recovery rate of 24%, and the tailings III containing cyanide can be obtained.

[0079] The products in the above implementation process are detected and analyzed to obtain the following results, as shown in Table 1:

[0080] Table 1: Indexes of the products in the recovery process of the raw material 1#

[0081]

[0082] Application Example 2:

[0083] Raw material 2#: a kind of laterite type gold ore, the raw ore Au grade is about 1.40 g / t, the associated Ag grade is about 18.50 g / t, and the TFe is 25% (the mFe content is 8%). The ore is loose, the raw ore is sandy and clay, honeycomb, sandy clay structure, high clay content, strong viscosity, and contains no or little sulfide. The main metallic minerals are limonite and magnetite, and the gold mainly exists in the form of native gold, and the gold in the form of micro-inclusion in the magnetite and limonite accounts for more than 80% of the total amount of the raw ore; the silver mineral species are various, and the occurrence state is complex, resulting in low full mud cyanidation leaching rate in production; the iron minerals are mainly magnetite and limonite. The gangue minerals are mainly carbonate minerals such as dolomite and calcite, followed by clay minerals such as chlorite, kaolin and sericite.

[0084] The mineral separation system and the mineral separation method are used for valuable metal recovery of the raw material 2#, and the recovery steps are summarized as follows:

[0085] Firstly, the raw ore is subjected to the process of "stirring pulp making-classification desliming (-0.037mm)-preliminary separation and tailing throwing", the preliminary separation and tailing throwing adopts "one-stage high gradient medium magnetic separation + two-stage high gradient strong magnetic separation", 27.5% of the preliminary separation tailings II can be thrown out, and the Fe, Au and Ag grades in the tailings are 12.5%, 0.2g / t and 12.3g / t respectively, and the loss rates of Fe, Au and Ag are 13.75%, 3.93% and 18.28% respectively.

[0086] Secondly, the coarse sand (+0.037mm) of the classification desliming is subjected to regrinding classification (more than 85% of -200 mesh), and then is combined with the two-stage preliminary separation coarse concentrate to be stirred and thickened (the concentration is 40%, and 5kg / t of lime is added to adjust the pH of the thickening to 12), and then is subjected to "full mud cyanidation-activated carbon adsorption leaching", under the condition that the amount of sodium cyanide is 5kg / t and the stirring leaching time is 32h, the leaching rate of gold is 86.14%, and the leaching rate of Ag is 35%;

[0087] Finally, the preliminary separation coarse concentrate leaching residue and the classification desliming coarse sand leaching residue are stirred and uniformly mixed, and then are subjected to the five-stage magnetic separation process of "weak magnetic rough separation-high gradient medium magnetic scavenging-high gradient strong magnetic rough separation-weak magnetic separation-high gradient strong magnetic separation" for iron leaching from the leaching residue, so that the magnetite concentrate with the iron grade of 62% and the iron recovery rate of 37.5%, the brown iron concentrate with the iron grade of 48% and the iron recovery rate of 28%, and the cyanide-containing tailings III can be obtained.

[0088] The products in the above implementation process are detected and analyzed to obtain the following results, as shown in Table 2:

[0089] Table 2: Indexes of each product in the recovery process of the raw material 2#

[0090]

[0091] According to the comprehensive application examples 1 and 2, the mineral separation system and the mineral separation method can efficiently recover valuable elements gold, silver and iron minerals from the laterite type gold ore with high clay content and strong viscosity, and the gold and silver leaching rates are high, and the magnetite and brown iron ore in the leaching residue can also be recovered with high grade.

[0092] The system is used for the transformation of the existing laterite type gold ore recovery equipment system, and the "raw ore stirring pulp making-classification desliming-preliminary separation and tailing throwing process system" is added, the raw ore slurry can be subjected to preliminary separation and tailing throwing, more than 20% of the cyanide-free tailings can be thrown out, the adverse effects caused by a large amount of raw ore slurry entering the cyanidation leaching and magnetic separation main separation process can be avoided, the gold and silver leaching rates of the "full mud cyanidation-activated carbon adsorption leaching" process are improved, the dosages of reagents and activated carbon in the leaching process are reduced, and the recovery capacity of iron minerals in the leaching residue is improved.

[0093] Meanwhile, the utility model discloses " one section high gradient medium magnetic separator + two section high gradient high intensity magnetic separator " two section magnetic separation, first adopt high gradient, low magnetic field gap medium magnetic preselection intensification recovery fine particle, fine particle grade magnetite, again adopt high gradient, high stroke ( benefit loose ore grain), low stroke ( reduce inertia force) high intensity preselection intensification recovery fine particle, fine particle grade limonite, effectively recover gold silver iron element in slurry, improve resource comprehensive utilization, reduce tailing stock.

[0094] Secondly, the utility model discloses according to the composition and structural characteristics of laterite type gold deposit and the magnetic separation mechanism of magnetic mineral, sets up five stage magnetic separation iron separation equipment of leaching residue, adopts low magnetic separation gap weak magnetic separator one-time rough separation recovery most coarse, medium particle grade and part fine particle grade magnetite, again adopts high gradient medium magnetic sweep selection intensification recovery fine particle, fine particle grade magnetite, after that, adopt high field intensity, big stroke, small stroke high gradient high intensity rough separation and make fine particle, fine particle limonite particle be in dispersed state all the time, increase its possibility of being captured, further adopt high field intensity, big stroke, big stroke high gradient high intensity concentration intensification fine particle, fine particle magnetic mineral recovery, finally obtain high recovery rate, high grade magnetite and limonite, solve the problem that conventional wet type cylinder type magnetic separator is difficult to recover or recovery rate is low to weak magnetic limonite and fine particle, fine particle grade magnetic mineral, improve the recovery index of iron mineral.

[0095] The utility model is described in detail through specific and preferred embodiments, but the person skilled in the art should understand that the utility model is not limited to the above-mentioned embodiments, and any modification, equivalent replacement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A beneficiation system for efficient recovery of valuable elements from lateritic gold ores, characterised in that, The rod mill (1) is connected to the feeding port of the 1# cyclone (3) through a slurry tank and a slurry pump, the overflow port of the 1# cyclone (3) is connected to the 1# stirring barrel (4), the 1# high-gradient medium magnetic separator (5) and the 1# high-gradient strong magnetic separator (6) in sequence, the sand outlet of the 1# cyclone (3) is connected to the feeding port of the ball mill (7), the discharging port of the ball mill (7) is connected to the feeding port of the 2# cyclone (8) through a slurry tank and a slurry pump, the sand outlet of the 2# cyclone (8) is connected to the feeding port of the ball mill (7), the overflow port of the 2# cyclone (8) is connected to the feeding port of the thickener (9), and the concentrate outlets of the 1# high-gradient medium magnetic separator (5) and the 1# high-gradient strong magnetic separator (6) are also connected to the feeding port of the thickener (9) through a slurry tank and a slurry pump. The underflow port of the thickener (9) is connected to the 2# stirring barrel (10), the leaching stirring barrel (11) and the leaching adsorption stirring barrel (12) in sequence, the discharging port of the leaching adsorption stirring barrel (12) is connected to the 3# stirring barrel (13), the 1# weak magnetic separator (14), the 2# high-gradient medium magnetic separator (15) and the 2# weak magnetic separator (16) in sequence, the concentrate outlets of the 1# weak magnetic separator (14) and the 2# high-gradient medium magnetic separator (15) are connected to the feeding port of the 2# weak magnetic separator (16), the tailing outlet of the 2# high-gradient medium magnetic separator (15) is connected to the 2# high-gradient strong magnetic separator (17) through a slurry tank and a slurry pump, and the middling outlet of the 2# weak magnetic separator (16) and the concentrate outlet of the 2# high-gradient strong magnetic separator (17) are connected to the feeding port of the 3# high-gradient strong magnetic separator (18) through a slurry tank and a slurry pump.

2. A beneficiation system for efficient recovery of valuable elements from lateritic gold ores as claimed in claim 1, wherein, The leaching stirring barrel (11) and / or the leaching adsorption stirring barrel (12) are provided in multiple series.

3. A beneficiation system for efficient recovery of valuable elements from lateritic gold ores as claimed in claim 1, wherein, The magnetic field strength of the 1# high-gradient medium magnetic separator (5) is 0.35-0.6T, and the magnetic field strength of the 1# high-gradient strong magnetic separator (6) is 0.7-1.3T, and the diameter of the magnetic medium is 1-3mm.

4. The beneficiation system for efficient recovery of valuable elements from lateritic gold ore according to claim 1, characterized in that, The magnetic field strength of the 1# weak magnetic separator (14) is 0.3-0.4T, and the magnetic separation gap is 20-35mm.

5. The beneficiation system for efficient recovery of valuable elements from lateritic gold ore according to claim 1, characterized in that, The magnetic field strength of the 2# high-gradient medium magnetic separator (15) is 0.35-0.6T.

6. A mineral separation system for efficient recovery of valuable elements from lateritic gold ores as claimed in claim 1, wherein, The magnetic field strength of the 2# weak magnetic separator (16) is 0.1-0.3T.

7. The mineral separation system of claim 1, wherein, The magnetic field strength of the 2# high-gradient strong magnetic separator (17) is 1.0-1.5T, and the wire diameter of the rod medium is 2-5mm.

8. A mineral separation system for efficient recovery of valuable elements from lateritic gold ores as claimed in claim 1, wherein, The magnetic field strength of the 3# high-gradient strong magnetic separator (18) is 0.7-1.1T, and the wire diameter of the rod medium is 2-5mm.

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