Method for beneficiation of low-grade petalite ore

Abstract

The present invention relates to a method for beneficiating low-grade petalite ore, and belongs to the technical field of lithium ore beneficiation. The method for beneficiating low-grade petalite ore of the present invention comprises: a. uniformly crushing the lithium feldspar ore to obtain ore powder, wherein the ore particle size of the ore powder is 4 mm, accounting for 55% to 95%; b. mixing the ore powder with a heavy suspension, and performing heavy medium beneficiation to obtain a floating phase of petalite concentrate containing a heavy medium, and a sinking phase of tailings containing a heavy medium; c. performing ultrasonic pre-cleaning treatment on the floating phase obtained in step b; d. performing de-mediation screening on the floating phase after the pre-cleaning treatment in step c, wherein the material on the screen is the petalite concentrate, and the material under the screen is a mixture of the heavy medium and the ore mud. The petalite of the present invention has good separation indexes, high grade and high recovery rate. By adopting the process of the present invention, the loss of the heavy medium is reduced, and the recovery rate of the heavy medium is ≥99%.

Description

Technical Field

[0001] The invention relates to a method for beneficiating low-grade petalite ore, belonging to the technical field of lithium ore beneficiation. Background Art

[0002] Lithium is the lightest metal element in nature. It is known as the "energy metal of the 21st century" and "white oil". It is widely used in emerging fields such as batteries, medicine, nuclear industry, aerospace, and new energy vehicles. The current global lithium supply and demand situation is difficult to ease in the short term. The slow growth of new production capacity and the unstable political situation overseas have led to a continuous increase in domestic demand. The proportion of lithium extraction from ore will continue to increase in the future. At present, domestic lithium resources mainly come from spodumene, lepidolite and lithium salt lakes. With the rapid development of the lithium battery industry, the demand for lithium resources has also risen sharply. Because petalite ore can be used for lithium extraction like spodumene and lepidolite, petalite ore with relatively small reserves has also received more and more attention. Many companies have begun to deploy petalite ore for lithium extraction.

[0003] Petalite, spodumene, lepidolite, eucryptite, and pyroxenite are common lithium-containing minerals in nature. The chemical composition of petalite is Li[ALSi4O 10 ], specific gravity 2.3-2.5, petalite has lower density than spodumene.

[0004] After searching the literature, there are few studies on petalite beneficiation. Occasionally, it is mentioned that the method of flotation feldspar is used for petalite beneficiation, mainly using cationic collectors, such as amine collectors, to flotate petalite under acidic conditions. The use of cationic collectors to flotate petalite often requires the addition of hydrofluoric acid for activation, but hydrofluoric acid seriously pollutes the environment and equipment, and the Li2O grade and recovery rate of the petalite concentrate obtained by flotation are also low, and the petalite separation effect is poor.

[0005] Invention patent CN101147888A discloses a heavy medium beneficiation method for spodumene ore, a heavy medium-strong magnetic beneficiation process for spodumene ore, the first step of crushing: crushing the spodumene ore into spodumene ore with most monomers dissociated; the second step of washing: washing the crushed spodumene ore to remove the ore mud; the third step of beneficiation: the washed spodumene ore is mixed with a heavy medium, and fed into a heavy medium cyclone at a pressure of 0.05-0.20MPa for separation, and the light product of the ore is removed by a de-mediation screen to become tailings; the heavy product is removed by a de-mediation screen to become a concentrate spodumene. The process method of the present invention is simple and reasonable, low in cost, reduces the crushing particle size requirements, saves investment in crushing equipment, avoids the pollution caused by the use of chemical reagents for separation, and separates spodumene from other gangue minerals in an environmentally friendly manner. The heavy medium beneficiation method described in CN101147888A is mainly used for the separation of spodumene ore. This method uses ferrosilicon as the heavy medium, and the stability of the prepared heavy suspension is often poor, and the density of the heavy suspension fluctuates greatly, which affects the separation effect; only the removal of the medium by the removal screen causes serious heavy medium entrainment, large heavy medium loss, and high cost. This heavy medium beneficiation method is used for the separation of minerals with small specific gravity differences, and it is difficult to obtain better separation indicators. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for beneficiating low-grade petalite ore.

[0007] In order to solve the above-mentioned first technical problem, the method for beneficiating low-grade petalite ore of the present invention comprises:

[0008] a. The lithium feldspar ore is uniformly crushed to obtain ore powder, wherein the ore particle size of the ore powder is -4mm, accounting for 55% to 95%;

[0009] b. mixing the ore powder with the heavy suspension, and performing heavy medium beneficiation to obtain a floating phase of petalite concentrate containing a heavy medium, and a sinking phase of tailings containing a heavy medium;

[0010] c. The floating phase obtained in step b is subjected to ultrasonic pre-cleaning treatment;

[0011] d. The floating phase after the pre-cleaning treatment in step c is subjected to a de-mediating sieve, the over-sieve material is the petalite concentrate, and the under-sieve material is a mixture of heavy medium and sludge.

[0012] In a specific embodiment, the ore particle size in step a is -4 mm, accounting for 55% to 95%.

[0013] In a specific embodiment, the heavy suspension in step b is obtained by uniformly mixing magnetic powder, water, and a dispersant, and the dispersant is preferably at least one of silicates, phosphates, polycarboxylates, and polyethers.

[0014] In a specific embodiment, the content of magnetic powder in the heavy suspension is 1768g-1875g / L; the added amount of the dispersant is 0.01%-0.1% of the weight of the magnetic powder.

[0015] In a specific embodiment, the density of the magnetic powder is 4.8 g / cm 3 ~5g / cm 3 ; The content of the magnetic powder with a particle size less than 0.048 mm is 100%.

[0016] In one embodiment, the density of the resuspension is 2.3 g / cm 3 ~2.5g / cm 3 ; preferably 2.4g / cm 3 ~2.5g / cm 3 .

[0017] In a specific embodiment, the heavy medium beneficiation equipment is a heavy medium vibration chute, a column-type heavy medium separator, a deep trough cone-type heavy medium separator or a heavy medium cyclone.

[0018] In a specific embodiment, the frequency of the ultrasonic pre-cleaning treatment is 20KHz to 50KHz.

[0019] In a specific embodiment, the mesh size of the de-mesh sieve in step d is 0.1 mm to 0.5 mm.

[0020] In a specific embodiment, the method further includes: subjecting the undersize material in step d to magnetic separation to obtain heavy medium and ore slime; preferably, the precipitate obtained in step b is also processed according to steps c and d, the precipitate is subjected to ultrasonic pre-cleaning treatment, and then subjected to de-mediating screening, the oversize material is tailings, and the undersize material is subjected to magnetic separation to obtain heavy medium and ore slime.

[0021] In a specific embodiment, the magnetic separation is at least one of weak magnetic separation or strong magnetic separation, and the magnetic separation field strength is preferably 500Gs to 3000Gs; preferably, the heavy medium obtained after magnetic separation is returned to be prepared into a heavy suspension for recycling.

[0022] Beneficial effects:

[0023] 1. The present invention successfully uses heavy medium beneficiation technology to treat low-grade petalite ore for the first time. The petalite separation index is good, the grade and recovery rate are high, and the obtained petalite concentrate has a Li2O grade of 3.5% to 4.5% and a recovery rate of 70% to 85%.

[0024] 2. The heavy medium beneficiation technology used to treat low-grade petalite ore still faces the problems of high loss of heavy medium and low recovery rate of heavy medium. Generally, the recovery rate of heavy medium is below 95%, the medium loss is large, and the beneficiation cost is increased. However, by adopting the process of the present invention, the loss of heavy medium is reduced, and the recovery rate of heavy medium is ≥99%, which is very beneficial to reduce costs and large-scale industrial production.

[0025] 3. The process of the present invention is simple, the dielectric loss is low, the sorting accuracy is high, and it is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a low-grade petalite ore dressing process flow chart. DETAILED DESCRIPTION

[0027] In order to solve the above-mentioned first technical problem, the method for beneficiating low-grade petalite ore of the present invention comprises:

[0028] a. The lithium feldspar ore is uniformly crushed to obtain ore powder, wherein the ore particle size of the ore powder is -4mm, accounting for 55% to 95%;

[0029] b. mixing the ore powder with the heavy suspension, and performing heavy medium beneficiation to obtain a floating phase of petalite concentrate containing a heavy medium, and a sinking phase of tailings containing a heavy medium;

[0030] c. The floating phase obtained in step b is subjected to ultrasonic pre-cleaning treatment;

[0031] d. The floating phase after the pre-cleaning treatment in step c is subjected to a de-mediating sieve, the over-sieve material is the petalite concentrate, and the under-sieve material is a mixture of heavy medium and sludge.

[0032] In a specific embodiment, the ore particle size in step a is -4 mm.

[0033] In a specific embodiment, the heavy suspension in step b is obtained by uniformly mixing magnetic powder, water, and a dispersant, and the dispersant is preferably at least one of silicates, phosphates, polycarboxylates, and polyethers.

[0034] In a specific embodiment, the content of magnetic powder in the heavy suspension is 1768g-1875g / L; the added amount of the dispersant is 0.01%-0.1% of the weight of the magnetic powder.

[0035] In a specific embodiment, the density of the magnetic powder is 4.8 g / cm 3 ~5g / cm 3 ; The content of the magnetic powder with a particle size less than 0.048 mm is 100%.

[0036] In one embodiment, the density of the resuspension is 2.3 g / cm 3 ~2.5g / cm 3 ; preferably 2.4g / cm 3 ~2.5g / cm 3 .

[0037] In a specific embodiment, the heavy medium beneficiation equipment is a heavy medium vibration chute, a column-type heavy medium separator, a deep trough cone-type heavy medium separator or a heavy medium cyclone.

[0038] In a specific embodiment, the frequency of the ultrasonic pre-cleaning treatment is 20KHz to 50KHz.

[0039] In a specific embodiment, the mesh size of the de-mesh sieve in step d is 0.1 mm to 0.5 mm.

[0040] In a specific embodiment, the method further includes: subjecting the undersize material in step d to magnetic separation to obtain heavy medium and ore slime; preferably, the precipitate obtained in step b is also processed according to steps c and d, the precipitate is subjected to ultrasonic pre-cleaning treatment, and then subjected to de-mediating screening, the oversize material is tailings, and the undersize material is subjected to magnetic separation to obtain heavy medium and ore slime.

[0041] In a specific embodiment, the magnetic separation is at least one of weak magnetic separation or strong magnetic separation, and the magnetic separation field strength is preferably 500Gs to 3000Gs; preferably, the heavy medium obtained after magnetic separation is returned to be prepared into a heavy suspension for recycling.

[0042] The heavy medium obtained after magnetic separation is returned to be prepared into a heavy suspension for recycling. The heavy medium obtained after magnetic separation includes the floating phase being removed by a removal screen, the undersize being subjected to magnetic separation to obtain the heavy medium, and the sinking phase being removed by a removal screen, the undersize being subjected to magnetic separation to obtain the heavy medium.

[0043] The specific implementation modes of the present invention are further described below in conjunction with embodiments, but the present invention is not limited to the scope of the embodiments.

[0044] Example 1

[0045] The Li2O content of a petalite mine in Australia is 1.70%. The mineral composition of the mine is mainly quartz, albite, petalite, muscovite, etc. Figure 1 The process shown in the figure crushes the petalite ore, controls the crushing particle size, and evenly crushes it to a -4mm particle content of 55% as the selected material. Water is used as the dispersion medium and high-purity magnetic powder is used as the dispersed phase. 1859g of particle size is less than 0.048mm and the density is 4.9g / cm 3High-purity magnetic powder is added to the suspension, and 0.01% of the weight of the magnetic powder is added as dispersant sodium silicate, and the density is 2.48g / cm 3 The selected material and the heavy suspension are pumped into the heavy medium dressing equipment respectively for lithium feldspar beneficiation. The floating phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 20KHz, and then the lithium feldspar concentrate, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment; the sinking phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 20KHz, and then the heavy medium, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment. The magnetic separation field strength is 500Gs. The heavy medium is recycled by preparing a qualified heavy suspension, and the tailings and sludge in this embodiment are combined into a comprehensive tailings. The lithium feldspar concentrate and the comprehensive tailings obtained by the heavy medium beneficiation are filtered, dried, weighed, and sampled for testing, and the beneficiation indicators are shown in Table 1 below.

[0046] Table 1 Example 1 Ore dressing index

[0047]

[0048] Example 2

[0049] The Li2O content of a petalite mine in Xinjiang is 1.08%. The mineral composition of the mine is mainly quartz, albite, petalite, muscovite, microcline, tantalum-niobate, etc. The petalite ore is crushed, the crushing particle size is controlled, and the -4mm particle content is evenly crushed to 95% as the selected material. Water is used as the dispersion medium and high-purity magnetic powder is used as the dispersed phase. 1875g of particle size is less than 0.048mm and the density is 5.0g / cm 3 High-purity magnetic powder is added to the suspension, and 0.05% of the weight of the magnetic powder is added to the dispersant sodium hexametaphosphate to prepare a density of 2.5g / cm 3 The selected material and the heavy suspension are pumped into the heavy medium dressing equipment respectively for lithium feldspar beneficiation. The floating phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 20KHz, and then the lithium feldspar concentrate, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment; the sinking phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 30KHz, and then the heavy medium, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment, and the magnetic separation field strength is 1000Gs. The heavy medium is recycled by preparing a qualified heavy suspension, and the tailings and sludge in this embodiment are combined into a comprehensive tailings. The lithium feldspar concentrate and the comprehensive tailings obtained by the heavy medium beneficiation are filtered, dried, weighed, and sampled for testing, and the beneficiation indicators are shown in Table 2 below.

[0050] Table 2 Example 2 Ore dressing index

[0051]

[0052] Example 3

[0053] The Li2O content of a petalite ore in Africa is 1.61%. The mineral composition of the ore is mainly quartz, albite, calcium feldspar, petalite, muscovite, microcline, cesium garnet, etc. The petalite ore is crushed, the crushing particle size is controlled, and the -4mm particle content is evenly crushed to 80% as the selected material. Water is used as the dispersion medium and high-purity magnetic powder is used as the dispersed phase. 1768g of particle size is less than 0.048mm and the density is 4.8g / cm 3 High-purity magnetic powder was added to the suspension at the same time, and 0.1% of the dispersant polyethylene glycol ether was added to prepare a density of 2.4g / cm 3 The selected material and the heavy suspension are pumped into the heavy medium dressing equipment respectively for lithium feldspar beneficiation. The floating phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 20KHz, and then the lithium feldspar concentrate, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment; the sinking phase of the heavy medium beneficiation is treated with ultrasonic pre-cleaning at a frequency of 50KHz, and then the heavy medium, tailings and sludge are obtained after the de-mediation sieve + magnetic separation de-mediation treatment, and the magnetic separation field strength is 3000Gs. The heavy medium is recycled by preparing a qualified heavy suspension, and the tailings and sludge in this embodiment are combined into a comprehensive tailings. The lithium feldspar concentrate and the comprehensive tailings obtained by the heavy medium beneficiation are filtered, dried, weighed, and sampled for testing, and the beneficiation indicators are shown in Table 3 below.

[0054] Table 3 Ore dressing index of Example 3

[0055]

Claims

1. A method for beneficiating low-grade petalite ore, characterized in that: The method comprises: a. The petalite ore is uniformly crushed to obtain ore powder, wherein the ore particle size of the ore powder is -4mm, accounting for 55% to 95%; b. The ore powder is mixed with a heavy suspension, and the floating phase obtained by heavy medium beneficiation is a petalite concentrate containing a heavy medium, and the sinking phase is a tailing containing a heavy medium; the heavy suspension is obtained by uniformly mixing magnetic powder, water, and a dispersant; the content of magnetic powder in the heavy suspension is 1768g / L to 1875g / L; c. The floating phase obtained in step b is subjected to ultrasonic pre-cleaning treatment; d. The floating phase after the pre-cleaning treatment in step c is subjected to a de-mediating sieve, the over-sieve material is the petalite concentrate, and the under-sieve material is a mixture of heavy medium and sludge.

2. The method for beneficiating low-grade petalite ore according to claim 1, characterized in that: The dispersant in step b is at least one of silicate, phosphate, polycarboxylate and polyether.

3. The method for beneficiating low-grade petalite ore according to claim 2, characterized in that: The added amount of the dispersant is 0.01% to 0.1% of the weight of the magnet powder.

4. The method for beneficiating low-grade petalite ore according to claim 2, characterized in that: The density of the magnet powder is 4.8 g / cm 3 ~5g / cm 3 ; The content of the particle size of the magnetic powder less than 0.048mm is 100%.

5. The method for beneficiating low-grade petalite ore according to claim 2, characterized in that: The density of the resuspension is 2.3 g / cm 3 ~2.5g / cm 3 .

6. The method for beneficiating low-grade petalite ore according to claim 5, characterized in that: The density of the resuspension is 2.4 g / cm 3 ~2.5g / cm 3 .

7. The method for beneficiating low-grade petalite ore according to claim 1 or 2, characterized in that: The equipment for heavy medium separation is a heavy medium vibration chute, a column-type heavy medium separator, a deep trough cone-type heavy medium separator or a heavy medium cyclone.

8. The method for beneficiating low-grade petalite ore according to claim 1 or 2, characterized in that: The frequency of the ultrasonic pre-cleaning treatment is 20 KHz to 50 KHz.

9. The method for beneficiating low-grade petalite ore according to claim 1 or 2, characterized in that: The mesh size of the de-mesh sieve in step d is 0.1 mm to 0.5 mm.

10. The method for beneficiating low-grade petalite ore according to claim 1 or 2, characterized in that: The method further comprises: subjecting the undersize material in step d to magnetic separation to obtain heavy medium and ore slime.

11. The method for beneficiating low-grade petalite ore according to claim 1 or 2, characterized in that: The method further comprises: treating the sediment phase obtained in step b according to steps c and d, performing ultrasonic pre-cleaning treatment on the sediment phase, and then performing de-mediating screening to remove the media, wherein the material on the screen is tailings, and the material under the screen is subjected to magnetic separation to obtain heavy medium and ore mud.

12. The method for beneficiating low-grade petalite ore according to claim 10, characterized in that: The magnetic separation field strength is 500Gs to 3000Gs.

13. The method for beneficiating low-grade petalite ore according to claim 11, characterized in that: The magnetic separation field strength is 500Gs to 3000Gs.

14. The method for beneficiating low-grade petalite ore according to claim 10, characterized in that: The heavy medium obtained after magnetic separation is returned to be prepared into a heavy suspension for recycling.

15. The method for beneficiating low-grade petalite ore according to claim 11, characterized in that: The heavy medium obtained after magnetic separation is returned to be prepared into a heavy suspension for recycling.

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