A large-scale process method for a silicon-calcium phosphate ore spiral chute

Abstract

The present invention belongs to the technical field of phosphate ore beneficiation and relates to a large-scale process method for a siliceous-calcareous phosphate ore spiral chute. Specifically, it includes: (1) Raw ore desliming: The raw ore is deslimed, and the deslimed raw ore enters the next step; (2) Classification and gravity separation: The deslimed raw ore is classified into several relatively narrower particle sizes according to certain conditions, and the products of each particle size are respectively subjected to gravity separation using a chute (with a diameter greater than 1200 mm). The concentrates and tailings after gravity separation of the products of each particle size are respectively combined into gravity separation concentrates and gravity separation tailings; (3) Flotation of gravity separation products. The present invention adds desliming and classification and gravity separation operations, which can effectively reduce the problem of entrainment of fine particle sizes in each strip in the chute (with a diameter greater than 1200 mm) and the problem of poor separation accuracy of the chute (with a diameter greater than 1200 mm) caused by equal-settling particles, improve the grade difference between the concentrates and tailings separated by the chute (with a diameter greater than 1200 mm), enhance the adaptability of the reagents in the subsequent flotation process, and improve the fluidity of the flotation foam.

Description

Technical Field

[0001] The present invention belongs to the technical field of phosphate ore beneficiation, and particularly relates to a process method for the large-scale spiral chute of siliceous-calcareous phosphate ore. Background Art

[0002] China's phosphate ore resources are rich in reserves, but mainly low-grade siliceous-calcareous collophanite. Due to the fine dissemination size and poor dissociation of collophanite, it is difficult to efficiently recover and utilize it by simple flotation method. At present, positive and reverse flotation and double reverse flotation are mainly used for separation, but there are problems such as poor effect at low temperature and sticky foam, making industrialization difficult; in recent years, the method of combined gravity and flotation separation of siliceous-calcareous collophanite has gradually attracted people's attention. The combined gravity and flotation method uses a spiral chute to pre-separate phosphate ore to obtain high-grade phosphate ore products and low-grade phosphate ore products, and then the two products are respectively post-treated by flotation method, which can effectively recover phosphate minerals.

[0003] Phosphate ore is a mineral that is difficult to separate by gravity separation because the density of useful minerals and gangue minerals is relatively close. Spiral chute gravity separation is currently mainly used for pre-treatment before flotation of phosphate ore to recover most of the concentrate in the gravity separation situation in advance. According to research, reducing the distance-diameter ratio of the spiral chute can improve the sensitivity of the chute to density in the radial direction, and then improve the separation accuracy of the spiral chute. Therefore, most of the spiral chutes used in phosphate ore at present are ultra-small distance-diameter ratio chutes. The current spiral chutes for phosphate ore are mainly small chutes with a diameter of 600 mm, and the single-unit processing capacity is limited. Under the condition that other parameters remain unchanged, as the diameter increases, the separation accuracy of the spiral chute for phosphate ore decreases rapidly, and it cannot effectively separate the original minerals into two products with a large difference in grade. Also, because there is a minimum limit for the distance-diameter ratio of the spiral chute, otherwise the spiral chute will cause stacking during separation, so it is also impossible to improve the separation accuracy of the spiral chute by further reducing the distance-diameter ratio, which restricts the industrial application of the combined gravity and flotation method. Therefore, combined with the current development status of the combined gravity and flotation beneficiation technology, it is particularly important to develop a process flow that can improve the separation accuracy of large chutes.

[0004] The patent technology of "A Process for Combined Gravity-Flotation Beneficiation of Phosphate Ore (CN 110369120 A)" discloses a process for combined gravity-flotation beneficiation of phosphate ore. This process is a three-stage spiral chute gravity separation process to obtain gravity separation concentrate and gravity separation tailings. The distance-diameter ratio of the spiral chute used is 0.32 - 0.45. This method can obtain good technical indicators when the chute diameter is small, but the distance-diameter ratio of the spiral chute used is close to the limit. In the process of industrial scale-up, under the condition of limited distance-diameter ratio, it will inevitably lead to the deterioration of the separation effect of the chute.

[0005] The patented technology of "A combined gravity and flotation process for high sesquioxide phosphate rock spiral chute (CN 109453891 B)" discloses a combined gravity and flotation process for sesquioxide phosphate rock spiral chute. This process includes the spiral chute separation of the ground phosphate rock, and the obtained gravity separation concentrate and tailings are respectively subjected to double reverse flotation and positive and reverse flotation. This process can avoid the negative impact on flotation separation caused by the inclusion of coarse and fine particles during the flotation process, has high separation efficiency, can effectively reduce impurities such as iron, aluminum, and magnesium in the concentrate, and has low separation cost. However, this process is applicable to a relatively narrow range of original ore particle sizes and cannot solve the problem of poor separation effect of the spiral chute caused by the entrainment of fine particles. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a combined gravity separation, classification and double reverse flotation and positive and reverse flotation process for phosphate rock chute, which improves the recovery rate of phosphate concentrate and the grade of phosphate concentrate, and reduces the loss of phosphate resources.

[0007] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0008] A large-scale process method for silica-calcium phosphate rock spiral chute, comprising the following steps:

[0009] (1) Raw ore desliming: The phosphate rock raw ore with a P2O5 grade of 18.0 - 27.5 wt% and a fineness of 40 - 80% is subjected to desliming treatment to remove the fine particle fraction with a particle size less than 0.020 mm. The fine particle part is treated by a conventional fine particle flotation method, and the deslimed raw ore enters the next step.

[0010] (2) Classification gravity separation: The deslimed raw ore is classified, and according to the different particle size distributions of the deslimed raw ore, it is divided into three relatively narrower particle size grades. The products of each grade are respectively subjected to gravity separation using a special spiral chute; the concentrates and tailings after the gravity separation of the products of each grade are respectively combined into gravity separation concentrates and gravity separation tailings;

[0011] (3) Flotation of gravity separation products: The gravity separation concentrate is treated by double reverse flotation, and the gravity separation tailings are treated by positive and reverse flotation; the double reverse flotation is one-time reverse flotation for magnesium removal and one-time reverse flotation for silicon removal; the positive and reverse flotation is one-time positive flotation for silicon removal and one-time reverse flotation for magnesium removal.

[0012] Preferably, the particle size range of the classified product needs to be adjusted according to the fineness of the raw phosphate ore. If the fineness range of the phosphate ore particle size is 40%-50%, the deslimed raw ore is divided into three particle sizes according to the following two particle size boundaries: particle size boundary one 0.15±0.01 mm, particle size boundary two 0.09±0.01 mm; if the fineness range of the phosphate ore particle size is 50%-70%, the deslimed raw ore is divided into three particle sizes according to the following two particle size boundaries: particle size boundary one 0.1±0.01 mm, particle size boundary two 0.075±0.01 mm; if the fineness range of the phosphate ore particle size is 70%-80%, the deslimed raw ore is divided into three particle sizes according to the following two particle size boundaries: particle size boundary one 0.09±0.01 mm, particle size boundary two 0.04±0.01 mm.

[0013] Preferably, the spiral chute is a spiral chute with a diameter greater than 1200 mm.

[0014] Preferably, the equipment used for the desliming treatment is a vibrating screen, a desliming hopper or a hydrocyclone, and preferably a hydrocyclone.

[0015] More preferably, for the special spiral chutes of each particle size, the requirements for the pitch-diameter ratio are as follows. The pitch-diameter ratio of the gravity separation spiral chute used for the products in the coarse particle size part is 0.4-0.6, and the pitch-diameter ratio of the gravity separation spiral chute used for the products in the fine particle size part is 0.36-0.45. The pitch-diameter ratio varies according to the particle size of the classified product.

[0016] Preferably, in the step (3), the flotation collectors used in the double reverse flotation for magnesium removal process, the normal and reverse flotation for silicon removal process, and the normal and reverse flotation for magnesium removal process are all fatty acid flotation collectors, and their dosages are 0.1-0.3 kg / t (calculated based on the gravity separation concentrate), 0.7-1.0 kg / t (calculated based on the gravity separation tailings), 0.1-0.3 kg / t (calculated based on the gravity separation tailings) respectively. The flotation collector used in the double reverse flotation for silicon removal process is an amine flotation collector, and its dosage is 50-150 g / t (calculated based on the gravity separation concentrate).

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Before gravity separation, desliming and classification are added to separate the fine-grained part of the original ore with very poor separation effect by sluice, and then the deslimed original ore is classified. Due to the certain difference in grindability of various gangue minerals and useful minerals during the grinding process, the content of different gangue minerals in different particle sizes is different. The easily ground dolomite minerals are mostly distributed in the fine particle size, and the difficult-to-grind feldspar minerals are mostly distributed in the coarse particle size. After classification, the products of each particle size are respectively subjected to gravity separation using a targeted spiral chute, which can expand the density difference of the minerals to be separated, eliminate the adverse effects of equal-settling particles on the separation of the spiral chute, improve the separation effect of the large-diameter chute, and at the same time, effectively improve the separation accuracy of the large-diameter spiral chute for phosphate ore, enabling the large-diameter spiral chute to effectively separate the original minerals into two products with a large difference in grade, enhancing the adaptability of the medicament in the subsequent flotation process, and improving the fluidity of the flotation foam. It can promote the industrial application of the gravity-flotation combined separation method. Description of the Drawings

[0019] Figure 1 It is the process flow diagram of the process method for the large-scale spiral chute of siliceous-calcareous phosphate ore of the present invention. Detailed Embodiments

[0020] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments and drawings. However, in order to enable those of ordinary skill in the art to fully understand the technical solutions and beneficial effects of the present invention, the following is further described in conjunction with specific embodiments. The embodiments are merely simple examples of the present invention and do not represent or limit the scope of the rights protected by the present invention. The scope of protection of the present invention is subject to the claims.

[0021] Example 1

[0022] A process method for the large-scale spiral chute of siliceous-calcareous phosphate ore, the specific steps are as follows:

[0023] (1) Grind the original phosphate ore with a P2O5 grade of 25.5 wt% to a proportion of -0.074 mm accounting for 65.3%, then adjust the pulp concentration to 20%, and then use a 600-mesh sieve to remove the fine-grained part less than 0.023 mm. The yield of the fine-grained part is 13.5%. The fine-grained part uses the positive flotation method to remove the siliceous gangue minerals therein, and then uses the reverse flotation method to remove the magnesium-containing gangue minerals therein.

[0024] (2) The raw ore that has undergone screening and desliming in the previous step is classified again using 150-mesh and 200-mesh vibrating screens, and the deslimed raw ore is divided into three particle size grades: +0.106 mm, +0.074 - 0.106 mm, and +0.023 - 0.074 mm; the yields of the three particle size grades are 8.12%, 26.58%, and 51.8% respectively; the +0.106 mm particle size grade is separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.5 to obtain concentrate and tailings; the +0.074 - 0.106 mm particle size grade is separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.45 to obtain concentrate and tailings; the +0.023 - 0.074 mm particle size grade is separated using a spiral chute with a diameter of 1200 mm and a pitch-diameter ratio of 0.42 to obtain concentrate and tailings. The concentrates and tailings obtained by gravity separation of the three particle size grades are respectively combined into gravity separation concentrate and gravity separation tailings.

[0025] (3) The gravity separation concentrate is treated for silicon and magnesium removal using double reverse flotation, and the gravity separation tailings are treated for silicon and magnesium removal using forward and reverse flotation.

[0026] The gravity separation effects of the three particle size products are shown in the following table (the products are each strip distributed radially along the spiral chute):

[0027] Table 1 Partial separation effect of +0.106 mm particle size grade

[0028] Product Yield Grade / % Positive cumulative grade / % Negative cumulative grade / % Recovery rate Positive cumulative recovery rate Negative cumulative recovery rate 1 2.93％ 32.82 32.82 25.82 3.72％ 3.72％ 100.00％ 2 13.28％ 33.72 33.56 25.61 17.35％ 21.07％ 96.28％ 3 18.30％ 32.18 32.83 24.32 22.81％ 43.88％ 78.93％ 4 21.75％ 28.26 31.06 22.13 23.80％ 67.68％ 56.12％ 5 19.18％ 17.97 27.73 19.08 13.35％ 81.03％ 32.32％ 6 7.09％ 18.66 26.95 19.95 5.12％ 86.15％ 18.97％ 7 6.49％ 20.45 26.48 20.47 5.14％ 91.29％ 13.85％ 8 7.01％ 20.26 26.03 20.48 5.50％ 96.79％ 8.71％ 9 3.97％ 20.87 25.82 20.87 3.21％ 100.00％ 3.21％ Total 100.00％ 25.82 100.00％

[0029] Table 2 Separation effect of +0.074 - 0.106 mm particle size grade

[0030]

[0031] Table 3 Separation effect of +0.023 - 0.074 mm particle size grade

[0032]

[0033] As shown in the above table, after classification, the tailing grade of the +0.106mm particle size fraction can reach as low as 17.97wt% after gravity separation, the concentrate grade can reach 31.06wt%, and the concentrate recovery rate can reach 67.68%; the tailing grade of the +0.074 - 0.106mm particle size fraction can reach as low as 19.85wt% after gravity separation, the concentrate grade can reach 31.54wt%, and the concentrate recovery rate can reach 50.39%; the tailing grade of the +0.023 - 0.074mm particle size fraction can reach as low as 21.6 after gravity separation, the concentrate grade can reach 30.92wt%, and the concentrate recovery rate can reach 44.02%. The overall concentrate grade of gravity separation is 31.13wt%, the overall tailing grade is 20.71wt%, and the overall recovery rate is 56.1%; the large-diameter chute can be used for the tailings to effectively pre-treat the phosphate rock and pre-recover most of the phosphate rock into the gravity separation concentrate.

[0034] The gravity separation overall concentrate is used to remove the silica and magnesium-containing gangue minerals by the double reverse flotation method. The specific process is one-time reverse flotation for magnesium removal and one-time reverse flotation for silicon removal. First, the concentration of the gravity separation overall concentrate is adjusted to 25%, phosphoric acid is added to adjust the pH to 5.0, and 0.1kg / t of magnesium removal collector (the magnesium removal collector is the saponified product of oleic acid) is added for magnesium removal operation. The flotation time is 2 minutes. Then, 100g / t of silicon removal collector (the silicon removal collector is an amine collector, and the component is dodecylamine) is added for silicon removal operation. The flotation time is 3 minutes. Finally, the concentrate grade can reach 33.25wt%, and the operation recovery rate can reach 95.7%.

[0035] The gravity separation overall tailings are used to remove the silica and magnesium-containing gangue minerals by the positive and reverse flotation method. The specific process is one-time positive flotation for silicon removal and one-time reverse flotation for magnesium removal. First, the concentration of the gravity separation overall tailings is adjusted to 20%, sodium carbonate is added to adjust the pH to 9.5, and 0.8kg / t of positive flotation silicon removal collector (the positive flotation silicon removal collector is the saponified product of oleic acid) is added for silicon removal operation. The flotation time is 3 minutes. Then, phosphoric acid is added to adjust the pH to 5.0, and 0.1kg / t of magnesium removal collector (the magnesium removal collector is the saponified product of oleic acid) is added for magnesium removal operation. The flotation time is 2 minutes. Finally, the concentrate grade can reach 30.03wt%, and the operation recovery rate can reach 84.1%.

[0036] Example 2

[0037] A process method for the large-scale spiral chute of siliceous-calcareous phosphate rock is as follows:

[0038] (1) Grind the phosphate rock raw ore with a P2O5 grade of 25.5 wt% to a proportion of -0.074 mm accounting for 45.6%, then adjust the pulp concentration to 20%, and then use a 600-mesh sieve to remove the fine particle part less than 0.023 mm. The yield of the fine particle part is 7.31%. The fine particle part uses the positive flotation method to remove the siliceous gangue minerals therein, and then uses the reverse flotation to remove the magnesium-containing gangue minerals therein.

[0039] (2) The raw ore that has been screened and deslimed in the previous step is classified again using 100-mesh and 180-mesh vibrating screens, and the deslimed raw ore is divided into three particle sizes: +0.15 mm, +0.088 - 0.15 mm, and +0.023 - 0.088 mm; the yields of the three particle sizes are 9.33%, 41.15%, and 42.21% respectively; the +0.15 mm particle size is sorted using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.55 to obtain concentrate and tailings; the +0.088 - 0.15 mm particle size is sorted using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.5 to obtain concentrate and tailings; the +0.023 - 0.088 mm particle size is sorted using a spiral chute with a diameter of 1200 mm and a pitch-diameter ratio of 0.42 to obtain concentrate and tailings. The concentrates and tailings obtained by gravity separation of the three particle sizes are respectively combined into gravity separation concentrate and gravity separation tailings.

[0040] (3) The gravity separation concentrate is treated for silicon and magnesium removal using double reverse flotation, and the gravity separation tailings are treated for silicon and magnesium removal using positive and reverse flotation.

[0041] After classification treatment, for the +0.15 mm particle size part, the tailing grade after gravity separation can reach as low as 19.35 wt%, the concentrate grade can reach 31.22 wt%, and the concentrate recovery rate can reach 60.41%; for the +0.088 - 0.15 mm particle size part, the tailing grade after gravity separation can reach as low as 19.75 wt%, the concentrate grade can reach 30.91 wt%, and the concentrate recovery rate can reach 63.38%; for the +0.023 - 0.088 mm particle size part, the tailing grade after gravity separation can reach as low as 20.31 wt%, the concentrate grade can reach 31.08 wt%, and the concentrate recovery rate can reach 62.20 wt%. The comprehensive concentrate grade of gravity separation is 31.02, the comprehensive tailing grade is 19.96 wt%, and the comprehensive recovery rate is 62.23%.

[0042] Example 3

[0043] To better illustrate the improvement of the classification treatment under certain conditions on the separation effect of the spiral chute, the same process flow as in Example 1 is adopted in this embodiment. In step 2, the deslimed raw ore is not classified, and the deslimed raw ore is directly separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.4. The separation results are as follows: After gravity separation, the lowest tailing grade can only reach 23.25 wt%, the concentrate grade can only reach 29.33 wt%, and the concentrate recovery rate can reach 39.66%; compared with Example 1, after desliming and without classification treatment, it is very difficult to achieve a good pretreatment effect using a 1500 mm chute.

[0044] Under the above gravity separation conditions, for the subsequent flotation operation, to achieve the same flotation effect as in Example 1, the dosage of the agent during the magnesia removal process of the gravity separation combined concentrate will increase to 0.3 kg / t, and the flotation time needs to be extended to 4 minutes; the dosage of the desilication agent will increase to 300 g / t, and the flotation time needs to be extended to 5 minutes. The foam phenomenon is also worse than that under the conditions of Example 1. Therefore, 10 g / t of defoamer needs to be added during the flotation process to increase the fluidity of the foam, increasing the agent cost.

[0045] Example 4

[0046] To better illustrate the improvement effect of the desliming treatment on the separation accuracy of the spiral chute, the same process as in Example 1 is used, the desliming treatment in step 1 is removed, and the deslimed raw ore is not classified in step 2. The deslimed raw ore is directly separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.4. The separation results are as follows: After gravity separation, the lowest tailing grade can reach 24.89 wt%, the concentrate grade can reach 28.97 wt%, and the concentrate recovery rate can reach 34.79%; compared with Example 1 and Example 3, without desliming and without classification treatment, it is even more difficult to achieve a good pretreatment effect using a 1500 mm chute.

[0047] Example 5

[0048] To illustrate that there are significant differences in spiral chutes with different diameters under the condition that other structural parameters are the same, the process flow of Example 4 is adopted, and in step 2, a spiral chute with a diameter of 600 mm and a pitch-diameter ratio of 0.4 is directly used for gravity separation treatment. The separation results are as follows: After gravity separation, the lowest tailing grade can reach 21.89 wt%, the concentrate grade can reach 29.32 wt%, and the concentrate recovery rate can reach 66.25%; compared with Example 4, the 600 mm diameter spiral chute is easier to achieve the required separation accuracy.

[0049] Example 6

[0050] To illustrate the influence of classification conditions on the separation of spiral chutes, the same process as in Example 1 was adopted. In the second step, a 100-mesh and 180-mesh sieve were used to divide the deslimed raw ore into three particle size grades: +0.15 mm, +0.088 - 0.15 mm, and +0.023 - 0.088 mm; the yields were 6.54%, 20.36%, and 59.6% respectively; the +0.15 mm particle size grade was separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.55 to obtain concentrate and tailings; the +0.088 - 0.15 mm particle size grade was separated using a spiral chute with a diameter of 1500 mm and a pitch-diameter ratio of 0.5 to obtain concentrate and tailings; the +0.023 - 0.088 mm particle size grade was separated using a spiral chute with a diameter of 1200 mm and a pitch-diameter ratio of 0.42 to obtain concentrate and tailings. The concentrates and tailings obtained by gravity separation of the three particle size grades were respectively combined into gravity separation concentrate and gravity separation tailings. The gravity separation concentrate was subjected to desilication and demagnesium treatment using double reverse flotation, and the gravity separation tailings were subjected to desilication and demagnesium treatment using forward and reverse flotation.

[0051] After classification treatment, the tailing grade of the +0.15 mm particle size grade after gravity separation was 22.21, the concentrate grade was 29.87 wt%, and the concentrate recovery rate could reach 54.52%; the lowest tailing grade of the +0.088 - 0.15 mm particle size grade after gravity separation could reach 22.55 wt%, the concentrate grade could reach 29.56 wt%, and the concentrate recovery rate could reach 44.94%; the lowest tailing grade of the +0.023 - 0.088 mm particle size grade after gravity separation could reach 23.18 wt%, the concentrate grade could reach 29.77 wt%, and the concentrate recovery rate could reach 41.26%. The comprehensive concentrate grade of gravity separation was 29.73 wt%, the comprehensive tailing grade was 22.96 wt%, and the comprehensive recovery rate was 42.33%.

[0052] As can be seen from Example 6, different classification conditions have a great influence on the subsequent gravity separation. Under the condition that other conditions remain unchanged, the particle size boundaries selected in the classification process will affect the subsequent spiral chute gravity separation process. Therefore, in the implementation of this process, appropriate particle size boundaries need to be determined according to the particle size of the raw ore.

[0053] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and the features in the embodiments in this application can be arbitrarily combined with each other without conflict. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A large-scale process method for a silica-calcium phosphate ore spiral chute, characterized in that It includes the following steps: (1) Raw ore desliming: Deslime the raw phosphate ore with a P2O5 grade of 18.0 - 27.5 wt% and a fineness of 40 - 80%, removing the fine particle fraction with a particle size less than 0.020 mm. The fine particle part is treated using conventional fine particle flotation methods, and the deslimed raw ore enters the next step; (2) Classification gravity separation: Classify the deslimed raw ore. According to the different particle size distributions of the deslimed raw ore, it is divided into three relatively narrower particle size grades. The particle size range of the classified product needs to be adjusted according to the fineness of the raw phosphate ore. If the fineness range of the raw phosphate ore is 40% - 50%, the deslimed raw ore is divided into three grades according to the following two particle size grade boundaries: Particle size grade boundary one is 0.15 ± 0.01 mm, and particle size grade boundary two is 0.09 ± 0.01 mm; if the fineness range of the phosphate ore is 50% - 70%, the deslimed raw ore is divided into three grades according to the following two particle size grade boundaries: Particle size grade boundary one is 0.1 ± 0.01 mm, and particle size grade boundary two is 0.075 ± 0.01 mm; if the fineness range of the phosphate ore is 70% - 80%, the deslimed raw ore is divided into three grades according to the following two particle size grade boundaries: Particle size grade boundary one is 0.09 ± 0.01 mm, and particle size grade boundary two is 0.04 ± 0.01 mm. The products of each grade are separately subjected to gravity separation using a special spiral chute; the concentrates and tailings after gravity separation of the products of each grade are respectively combined into gravity separation concentrates and gravity separation tailings; (3) Flotation of gravity separation products: The gravity separation concentrates are treated using double reverse flotation, and the gravity separation tailings are treated using positive and reverse flotation; the double reverse flotation is one - time reverse flotation for magnesium removal and one - time reverse flotation for silicon removal; the positive and reverse flotation is one - time positive flotation for silicon removal and one - time reverse flotation for magnesium removal.

2. The large-scale process method of a silicon-calcium phosphate ore spiral chute according to claim 1, characterized in that, The spiral chute is a spiral chute with a diameter greater than 1200 mm.

3. A large-scale process method for a silicon-calcium phosphate ore spiral chute according to claim 1, characterized in that, The equipment used for the desliming treatment is a vibrating screen, a desliming hopper or a hydrocyclone.

4. A large-scale process method for a silicon-calcium phosphate ore spiral chute according to claim 3, characterized in that The equipment used for the desliming treatment is a hydrocyclone.

5. A large-scale process method for a silicon-calcium phosphate ore spiral chute according to claim 1, characterized in that In step (3), the flotation collectors used in the double reverse flotation magnesium removal process are all fatty acid collectors, and their dosage is 0.1 - 0.3 kg / t.

6. The large-scale process method of a silica-calcium phosphate ore spiral chute according to claim 1, characterized in that, In step (3), the flotation collectors used in the positive and reverse flotation silicon removal process are all fatty acid collectors, and their dosage is 0.7 - 1.0 kg / t.

7. A large-scale process method for a silicon-calcium phosphate ore spiral chute according to claim 1, characterized in that In step (3), the flotation collectors used in the positive and reverse flotation magnesium removal process are all fatty acid collectors, and their dosage is 0.1 - 0.3 kg / t.

8. A large-scale process method for a silicon-calcium phosphate ore spiral chute according to claim 1, characterized in that, In step (3), the flotation collector used in the double reverse flotation silicon removal process is an amine collector, and its dosage is 50 - 150 g / t.

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