Method for extracting fluorite from fluorite high-calcium ore

Abstract

The invention belongs to the field of mineral separation, and discloses a method for extracting fluorite from fluorite high-calcium ore, which comprises the following steps: step 1, desliming, crushing and grinding the fluorite high-calcium ore to obtain pulp ore; 2, the pulp ore is subjected to roughing operation, and roughed concentrate is obtained; 3, the roughing concentrate is subjected to concentration for at least five times, and fluorite concentrate is obtained; in the first five fine selection processes, two adjacent fine selection operations are respectively a dosing group and a blank group; the water glass and the inhibitor are added into the slurry corresponding to the dosing group, and the water glass and the inhibitor are not added into the slurry corresponding to the blank group. According to the method, the water glass and the inhibitor are combined, meanwhile, in the multiple concentration processes, the water glass and the inhibitor are alternately added or not added, and the high-grade fluorite concentrate can be efficiently and fully screened out.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing, and more specifically, relates to a method for extracting fluorite from high-calcium fluorite ore. Background Technology

[0002] With the large-scale development of fluorite resources, the problem of low quality and impurities has become increasingly prominent. Fluorite mainly coexists and interbeddes with gangue minerals such as calcite and barite. In calcite-type fluorite deposits, because calcite and fluorite have similar floatability, flotation separation is difficult, and acidified water glass or a combination of depressants is generally required to achieve selective inhibition of calcite.

[0003] Calcite is a calcium carbonate mineral widely found in fluorite ore. The calcium carbonate content in high-calcium fluorite ore is generally no less than 20 wt%. During fluorite flotation, we found that simply screening with depressants is far from sufficient for adequate and efficient separation of fluorite. This is because excessive depressant usage inhibits fluorite flotation and reduces flotation efficiency, while insufficient depressant usage prevents the fluorite and calcite from being adequately separated in the flotation froth, resulting in a low-grade fluorite concentrate.

[0004] The technical problem to be solved in this case is: how to conduct effective fluorite flotation for high-calcium fluorite ore. Summary of the Invention

[0005] The main objective of this invention is to provide a method for extracting fluorite from high-calcium fluorite ore. This method employs a combination of water glass and inhibitors, and through multiple screening processes, alternates between adding and not adding water glass and inhibitors, thereby efficiently and thoroughly screening out high-grade fluorite concentrate.

[0006] In a preferred embodiment of the present invention, the recovery rate of fluorite is improved by performing middlings reprocessing through a secondary process.

[0007] The specific solution of the present invention is as follows:

[0008] A method for extracting fluorite from high-calcium fluorite ore includes the following steps:

[0009] Step 1: The high-calcium fluorite ore is deslimed, crushed, and ground to obtain a pulp ore;

[0010] Step 2: The pulp ore is subjected to roughing operation to obtain roughing concentrate;

[0011] Step 3: Perform at least 5 fine-tuning processes on the rough concentrate to obtain fluorite concentrate;

[0012] In the first five selection processes, two adjacent selection operations were respectively the dosing group and the blank group; water glass and inhibitor were added to the slurry corresponding to the dosing group, while water glass and inhibitor were not added to the slurry corresponding to the blank group.

[0013] This invention uses water glass and inhibitors as reagents for the flotation operation. At the same time, by alternating the dosing group and the blank group, fluorite can be effectively floated out.

[0014] In the early stages of our experiments, we found that adding sufficient reagents to all the refining operations would significantly suppress the fluorite flotation yield; while not adding sufficient reagents would cause calcite and fluorite to float up, reducing the grade of the fluorite concentrate.

[0015] After thorough experimental verification, we conducted a selection process without adding reagents and surprisingly found that not only could calcite and fluorite be effectively separated, but the flotation of fluorite was not inhibited. The reason for this is that in the reagent-added group, the flotation foam contains a certain amount of reagent. This part of the foam continues to play a role after entering the next stage of flotation (i.e., the blank group). The calcite in the foam will settle, and the fluorite in the foam will be further enriched. After the blank group flotation, the amount of reagent in the foam is reduced. At this time, adding reagents again will further float the fluorite.

[0016] The above analysis shows that the blank group is not necessarily completely free of reagents. In some application scenarios, a small amount of the above-mentioned reagents can be added. For example, in the blank group, adding no more than 50g of water glass per ton of slurry and no more than 25g of inhibitor per ton of slurry can achieve the purpose of this invention.

[0017] The fluorite concentrate obtained by the method of this invention has a grade of 85-90% and a yield of 80-90%.

[0018] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the fine selection operation in step 3 is performed 5 to 9 times; the first, third, and fifth fine selection operations are the chemical addition group; the remaining fine selection operations are the blank group.

[0019] In some applications, the refining process is performed 6, 7, 8, or 9 times. Generally speaking, 7 refining operations are sufficient to obtain high-grade fluorite concentrate. Even if the number of refining operations is increased, the grade of fluorite concentrate will not be significantly improved.

[0020] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the inhibitor is one or more of sodium hexametaphosphate, tannic acid, tannin, sodium humate, modified starch, or dextrin.

[0021] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, during the roughing operation, the amount of water glass added per ton of pulp ore is 200-600g, the amount of inhibitor added per ton of pulp ore is 300-600g, and the fluorite collector is an oleic acid collector, with an amount of fluorite collector added per ton of pulp ore being 500-800g.

[0022] In the preliminary selection operation of some implementation cases, the amount of water glass added is 200g / ton, 250g / ton, 300g / ton, 350g / ton, 400g / ton, 500g / ton or 600g / ton;

[0023] In the preliminary selection process of some implementation cases, the amount of inhibitor added was 300g / ton, 350g / ton, 400g / ton, 450g / ton, 500g / ton, 550g / ton or 600g / ton;

[0024] In the preliminary screening operations of some implementation cases, the amount of fluorite collector added was 500g / ton, 550g / ton, 600g / ton, 650g / ton, 700g / ton, 750g / ton, or 800g / ton.

[0025] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, in the dosing group, the amount of water glass added per ton of slurry is 100-400g; the amount of inhibitor added per ton of slurry is 50-300g.

[0026] In some embodiments of the present invention, the amount of water glass added is 100g / ton, 150g / ton, 200g / ton, 250g / ton, 300g / ton, 350g / ton or 400g / ton;

[0027] The dosage of the inhibitor is 50g / ton, 100g / ton, 150g / ton, 200g / ton, 250g / ton, and 300g / ton;

[0028] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the tailings from the first cleaning operation, the tailings from the second cleaning operation, and the washing mud obtained after the desliming operation in step 1 are combined to obtain secondary slurry. The secondary slurry enters the secondary process for fluorite flotation, and secondary fluorite concentrate is obtained after the secondary process for flotation.

[0029] The tailings from the remaining selection operations are then incorporated into the previous selection operation.

[0030] During the production process, the tailings from the first and second cleaning operations are preferably fed into the secondary slurry because these tailings contain a large amount of calcium carbonate. If this calcium carbonate is returned to the previous stage in the traditional cleaning operation, it will lead to the accumulation of calcium carbonate in the slurry from the first cleaning operation, disrupting the fluorite-calcite balance in the slurry. Once this balance is disrupted, it will be difficult to effectively separate fluorite regardless of the type or amount of reagent used.

[0031] Research and analysis revealed that the calcium carbonate content in the tailings from the first and second beneficiation operations was quite similar to that in the washing slime. In high-calcium fluorite ore, the content of associated slime exceeded 20 wt%, which is a very large category of material.

[0032] Through repeated experiments, it was proven that the tailings from the first and second beneficiation operations can be centrally processed with the washing slime. A targeted process of one roughing, two scavenging, and four beneficiation steps was developed to obtain secondary fluorite concentrate with a grade of 70-75%.

[0033] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the secondary process specifically involves: subjecting the secondary slurry to one roughing and multiple cleaning processes to obtain secondary fluorite concentrate; and subjecting the tailings obtained from the roughing operation in the secondary process to a second scavenging process to obtain fluorite tailings.

[0034] More specifically, the secondary process is as follows: after the secondary slurry undergoes one roughing and multiple fine selections, it is then concentrated by a thickener and filtered by a filter press. The filter residue is the secondary fluorite concentrate.

[0035] In the first roughing operation of the secondary process, 100-300g of water glass is added per ton of secondary slurry; 50-300g of inhibitor is added per ton of secondary slurry; the inhibitor in the roughing operation can be the same inhibitor used in the cleaning operation.

[0036] In some embodiments of the present invention, the amount of water glass added during a single roughing operation is 100g / ton, 150g / ton, 200g / ton, 250g / ton, or 300g / ton;

[0037] The amount of inhibitor added is 50g / ton, 100g / ton, 150g / ton, 200g / ton, 250g / ton or 300g / ton;

[0038] During a single roughing operation, 200–400 g of fluorite collector is added to each ton of slurry.

[0039] In the secondary scavenging process of this process, 100-200g of fluorite collector is added to each ton of slurry.

[0040] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, during the first roughing process of the secondary process, the concentration of the secondary slurry is 25-30 wt%, and the pH is 8-10.5.

[0041] During the secondary scavenging process in this flow, the slurry is adjusted to a concentration of 16-20 wt%.

[0042] In the above-described method for extracting fluorite from high-calcium fluorite ore, during the roughing operation in step 2, the pH of the slurry is adjusted to 8–10.5, then water glass and depressant are added, and finally a fluorite collector is added. After the roughing operation, a roughing concentrate and roughing tailings are obtained. The roughing tailings undergo a secondary scavenging operation to obtain fluorite tailings. During the secondary scavenging operation, a fluorite collector is added to the slurry. In the above-described main flotation process, in each scavenging operation, the roughing tailings slurry is adjusted to a concentration of 17–22%; the collector addition amount is 100–200 g / ton.

[0043] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the fluorite collector is an oleic acid collector, and more specifically, the oleic acid collector is YB.

[0044] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, step 1 specifically involves: washing and desliming the high-calcium fluorite ore, with the ore larger than 0.5 mm entering the crushing system; crushing the ore through one or more stages to obtain fine crushed material with a particle size less than or equal to 10 mm; grinding the fine crushed material through one or more stages to obtain a slurry with a diameter less than or equal to 200 mesh; adjusting the slurry to a solid content of 25-30 wt% and using it as the slurry for roughing.

[0045] In the above-mentioned method for extracting fluorite from high-calcium fluorite ore, the calcium carbonate content in the high-calcium fluorite ore is not less than 20 wt%.

[0046] In some preferred embodiments of the present invention, in step 3, after the rough concentrate is subjected to at least 5 fine-tuning processes, the fine-tuned material is fed into a thickener for concentration processing. The thickener is used to concentrate the material, the overflow liquid is fed into a wastewater treatment system, and the concentrated material is fed into a filter press for filtration to obtain fluorite concentrate.

[0047] One of the above-described technical solutions of the present invention has at least one of the following advantages or beneficial effects:

[0048] This invention uses water glass and inhibitors as reagents for the flotation process. By alternating between the dosing group and the blank group, fluorite can be effectively floated out. In the dosing group, the flotation foam contains a certain amount of reagent. This part of the foam continues to play a role after entering the next flotation operation (i.e., the blank group). The calcite in the foam will settle, and the fluorite in the foam will be further enriched. After the blank group flotation, the amount of reagent in the foam is reduced. At this time, reagent is added again to further float fluorite.

[0049] The fluorite concentrate obtained by the method of this invention has a grade of 70-90% and a yield of 70-90%. Attached Figure Description

[0050] Figure 1 This is a flowchart of Embodiment 1 of the present invention. Detailed Implementation

[0051] The embodiments of the present invention are described in detail below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0052] Before describing the specific embodiments of the present invention, the materials involved in the present invention will be explained first:

[0053] High-calcium fluorite ore: This ore contains 25-35% calcium fluoride, 20-30% calcium carbonate, 20-30% fine mud, with 15-25% calcium fluoride and 20-30% calcium carbonate in the fine mud, and a moisture content of 15-25%.

[0054] YZ-4: Changsha Lifu Resources and Environment Technology Co., Ltd.

[0055] YB: Changsha Lifu Resources and Environment Technology Co., Ltd., which contains tannins and other inhibitor raw materials, and is a mixed inhibitor.

[0056] Unless otherwise specified, % in the examples and comparative examples represent weight percentages.

[0057] Example 1

[0058] The method for extracting fluorite from high-calcium fluorite ore, and its process flow steps are as follows: Figure 1 The details are as follows:

[0059] (1) Using fluorite-calcite associated mineral (high-calcium fluorite mineral) as raw material, the raw ore is fed into a cylindrical washing machine for washing and desliming. The raw ore larger than 0.5mm enters the crushing system, and the ore smaller than or equal to 0.5mm is the washing mud that enters the secondary process for fluorite flotation.

[0060] More preferably, the fluorite content of the washed ore slime is tested in advance. If the fluorite content in the washed ore slime exceeds 8%, it can be considered to enter the subsequent first grinding process; if it is less than or equal to 8%, it enters the second process. This can improve the yield of fluorite concentrate to a certain extent.

[0061] (2) Raw ore larger than 0.5mm enters the crushing system and is crushed into coarse crushed material, medium crushed material and fine crushed material through a three-stage closed-circuit process. The coarse crushed material has a particle size of <143mm, the medium crushed material has a particle size of <40.8mm, and the fine crushed material has a particle size of <10mm. The raw ore is finally crushed into fine crushed material of <10mm.

[0062] (3) Fine crushed material enters the ball mill. The ball mill adopts a two-stage closed-loop process to break down the crushed ore into individual pieces.

[0063] First stage ball milling: Fine crushed material and water are fed into the mill at a weight ratio of 2:1, and the material is ground until the proportion of particles with a size of <0.075mm is 40-45%.

[0064] Two-stage ball milling: The slurry from the first-stage ball mill is sieved through a 200-mesh sieve. Material smaller than 200 mesh is used as flotation feed, while material larger than 200 mesh enters the ball mill for the second-stage grinding. It is fed into the ball mill with water at a weight ratio of 2:1. The grinding process results in 82.6% of the particles being <0.075mm.

[0065] The material with a particle size of less than 200 mesh from the first-stage ball mill and the material from the second-stage mill are combined into a flotation feed with a flotation concentration of 28.5 wt%.

[0066] (4) The main flotation process consists of one roughing, two sweeping, and seven cleaning processes;

[0067] Specifically, the main flotation process includes the following steps:

[0068] Step 41: Sodium carbonate is first added to the slurry with a concentration of 28.5 wt% after two-stage ball milling to adjust the pH to 10; then water glass and inhibitor YZ-4 are added; 300g of water glass and 400g of YZ-4 are added per ton of slurry; finally, collector YB is added, 600g of collector YB is added per ton of slurry.

[0069] After roughing, rough concentrate and rough tailings are obtained; the rough concentrate proceeds to step 42, and the rough tailings proceed to step 43.

[0070] Step 42: The refining process involves seven refining operations: Refining I, Refining II, Refining III, Refining IV, Refining V, Refining VI, and Refining VII. The material obtained from Refining VII is then concentrated in a thickener and filtered in a filter press to obtain fluorite concentrate.

[0071] Tailings from Selected I and Selected II are then fed into the next process.

[0072] Tailings from Selected III, Selected IV, Selected V, Selected VI, and Selected VII are then selected at the next higher level. For example, tailings from Selected V are selected again at Selected IV.

[0073] In the above 7 selection processes, the slurry concentration was 25%; the pH did not require separate adjustment.

[0074] For Selective Process I, Selective Process III, and Selective Process V, water glass and inhibitor YZ-4 are added. In the corresponding operations, 250g of water glass and 150g of YZ-4 are added to each ton of slurry. Selective Process II, Selective Process IV, Selective Process VI, and Selective Process VII are blank processes with no added reagents.

[0075] After seven rounds of refining, a fluorite concentrate with a grade of 88.9% was obtained, with a yield of 82.5%.

[0076] Step 43: The roughing tailings are subjected to a secondary scavenging operation to obtain fluorite tailings;

[0077] In each scavenging operation, the roughing tailings slurry is adjusted to a concentration of 20.5%, and collector YB is added, with 150g of collector YB added to each ton of slurry.

[0078] The grade of the fluorite tailings is 5%.

[0079] Furthermore, the above process consists of one coarse selection, two sweep selections, and four fine selections, specifically:

[0080] Primary roughing: The tailings and washing slime from Cleaning I and Cleaning II are combined to obtain secondary slurry, which is adjusted to a concentration of 26.5%. Sodium carbonate is used to adjust the pH to 10. Water glass and inhibitor YZ-4 are then added, with 250g of water glass and 150g of YZ-4 added per ton of slurry. Finally, collector YB is added, with 300g of collector YB added per ton of slurry. The secondary slurry undergoes primary roughing to obtain secondary roughing concentrate and secondary roughing tailings. The secondary roughing concentrate enters the fourth cleaning stage, and the secondary roughing tailings enter the second scavenging stage.

[0081] Secondary scavenging: During each scavenging process, the slurry is adjusted to a concentration of 18.5%, and collector YB is added, with 150g of collector YB added per ton of slurry; after scavenging, fluorite tailings are obtained; this fluorite tailings can be combined with the fluorite tailings obtained in step 43. If the fluorite content of the tailings is too low, such as below 8%, it is combined with the mud.

[0082] Four selections: The four selections are Secondary Selection I, Secondary Selection II, Secondary Selection III, and Secondary Selection IV;

[0083] Similar to the seven rounds of selection mentioned above, secondary selection I and secondary selection III are supplemented with water glass and the inhibitor YZ-4, while secondary selection II and secondary selection IV are supplemented without any reagents. The types and amounts of reagents added are the same as those in the seven rounds of selection.

[0084] In the above four refining processes, the slurry concentration is 24.5%; the pH does not need to be adjusted separately; in the four refining processes of this process, the tailings from each stage of secondary refining can be reused in the next stage of secondary refining.

[0085] In the above four refining processes, the tailings from each refining process enter the next stage. If the calcium carbonate content in the tailings is too high or the fluorite content is too low, they will enter the tailings concentration process of scavenging or be merged into the slurry.

[0086] After four rounds of fine selection, and after thickening and filtration by a filter press, secondary fluorite concentrate was obtained with a grade of 73.5% and a yield of 70.5%.

[0087] Example 2

[0088] The process is largely the same as in Example 1, except that dextrin is used instead of inhibitor YZ-4 in the coarsening and cleaning operations in the main flotation process and in the coarsening and cleaning operations in the secondary process; the other parameters remain unchanged.

[0089] After the above adjustments, the grade of fluorite concentrate is 83.6% and the yield is 75.9%; the grade of secondary fluorite concentrate is 71.9% and the yield is 69.8%.

[0090] Example 3

[0091] The process is largely the same as in Example 1, except that tannin is used instead of inhibitor YZ-4 in the roughing and cleaning operations of the main flotation process and the roughing and cleaning operations of the secondary process; the other parameters remain unchanged.

[0092] After the above adjustments, the grade of fluorite concentrate is 86.9% and the yield is 70.9%; the grade of secondary fluorite concentrate is 72.6% and the yield is 65.8%.

[0093] Example 4

[0094] Generally the same as Example 1, except that:

[0095] In the main flotation process, in step 41, the amount of water glass added per ton of slurry is 600g / ton; the amount of inhibitor added per ton of slurry is 600g / ton; and the collector YB is adjusted to 800g / ton.

[0096] In step 42, the amount of water glass added per ton of slurry is 400g / ton; the amount of inhibitor added per ton of slurry is 300g / ton.

[0097] The collector YB in step 43 is adjusted to 400g / ton;

[0098] In the flotation process, during the first roughing operation, the amount of water glass added per ton of slurry is 300g / ton; the amount of inhibitor added per ton of slurry is 300g / ton; and the collector YB is adjusted to 400g / ton.

[0099] In the flotation process, during the secondary scavenging operation, the collector YB is adjusted to 200g / ton;

[0100] After the above adjustments, the grade of fluorite concentrate is 89.2%, and the yield is 83.7%; the grade of secondary fluorite concentrate is 73.3%, and the yield is 75.4%.

[0101] Example 5

[0102] Generally the same as Example 1, except that:

[0103] In the main flotation process, in step 41, the amount of water glass added per ton of slurry is 200g / ton; the amount of inhibitor added per ton of slurry is 300g / ton; and the collector YB is adjusted to 500g / ton.

[0104] In step 42, the amount of water glass added per ton of slurry is 100g / ton; the amount of inhibitor added per ton of slurry is 50g / ton.

[0105] The collector YB in step 43 is adjusted to 100g / ton;

[0106] In the flotation process, the amount of water glass added per ton of slurry is 100g / ton; the amount of inhibitor added per ton of slurry is 50g / ton; and the collector YB is adjusted to 200g / ton.

[0107] In the flotation process, during the secondary scavenging operation, the collector YB is adjusted to 100g / ton;

[0108] After the above adjustments, the grade of fluorite concentrate is 86.6%, and the yield is 78.5%; the grade of secondary fluorite concentrate is 74.8%, and the yield is 75.2%.

[0109] Example 6

[0110] It is largely the same as Example 1, except for step 42, which specifically includes 5 selections.

[0111] Step 42: The selection process involves five rounds of selection: Selection I, Selection II, Selection III, Selection IV, and Selection V.

[0112] Tailings from Selected I and Selected II are then fed into the next process.

[0113] Tailings from Selected III, Selected IV, and Selected V are then moved to the next higher level of selection.

[0114] Selective I, Selective III, and Selective V processes involved the addition of water glass and the inhibitor YZ-4; Selective II and Selective IV processes served as blank processes without the addition of any reagents.

[0115] The remaining parameters are the same as step 42 in Example 1;

[0116] After five rounds of refining, a fluorite concentrate with a grade of 78.9% was obtained, with a yield of 89.1%.

[0117] Example 7

[0118] The process is largely the same as in Example 1, except for step 42, which specifically includes six selections.

[0119] Step 42: The selection process involves six rounds of selection: Selection I, Selection II, Selection III, Selection IV, Selection V, and Selection VI.

[0120] Tailings from Selected I and Selected II are then fed into the next process.

[0121] Tailings from Selected III, Selected IV, Selected V, and Selected VI are then moved to the next level of selection.

[0122] Selected processes I, III, and V involved the addition of water glass and the inhibitor YZ-4; Selected processes II, IV, and VI served as blank processes without the addition of any reagents.

[0123] The remaining parameters are the same as step 42 in Example 1;

[0124] After six rounds of refining, fluorite concentrate with a grade of 83.3% was obtained, with a yield of 86.6%.

[0125] Example 8

[0126] The process is largely the same as in Example 1, except for step 42, which specifically includes eight selections.

[0127] Step 42: The selection process involves 8 rounds of selection, namely Selection I, Selection II, Selection III, Selection IV, Selection V, Selection VI, Selection VII, and Selection VIII;

[0128] Tailings from Selected I and Selected II are then fed into the next process.

[0129] Tailings from Selected III, Selected IV, Selected V, Selected VI, Selected VII, and Selected VIII are then moved to the next higher level of selection.

[0130] Selected processes I, III, and V were performed with the addition of water glass and the inhibitor YZ-4; Selected processes II, IV, VI, VII, and VIII were performed as blank processes without the addition of any reagents.

[0131] The remaining parameters are the same as step 42 in Example 1;

[0132] After eight rounds of refining, a fluorite concentrate with a grade of 89% was obtained, with a yield of 81.9%.

[0133] Comparative Example 1

[0134] The general process is the same as in Example 1, except for step 42:

[0135] Step 42: The selection process involves 7 selections, namely Selection I, Selection II, Selection III, Selection IV, Selection V, Selection VI, and Selection VII;

[0136] Tailings from Selected I and Selected II are then fed into the next process.

[0137] Tailings from Selected III, Selected IV, Selected V, Selected VI, and Selected VII are then moved to the next higher level of selection.

[0138] Water glass and inhibitor YZ-4 are added in the processing of Selected I, Selected II, Selected III, Selected IV and Selected V, with 250g of water glass and 150g of YZ-4 added per ton of slurry; no water glass and inhibitor are added in Selected VI and Selected VII.

[0139] The remaining parameters are the same as step 42 in Example 1;

[0140] After seven rounds of refining, a fluorite concentrate with a grade of 93.8% was obtained, with a yield of 54.7%.

[0141] Comparative Example 2

[0142] The process is largely the same as in Example 1, except that in step 42, water glass and inhibitor YZ-4 are added in the processes of refinement I, refinement II, refinement III, refinement IV and refinement V, with 150g of water glass and 100g of YZ-4 added per ton of slurry; water glass and inhibitor are not added in refinement VI and refinement VII.

[0143] After seven rounds of refining, a fluorite concentrate with a grade of 91.7% was obtained, with a yield of 68.5%.

[0144] Comparative Example 3

[0145] The general process is the same as in Example 1, except for step 42:

[0146] Step 42: The selection process involves 7 selections, namely Selection I, Selection II, Selection III, Selection IV, Selection V, Selection VI, and Selection VII;

[0147] Tailings from Selected I, Selected II, Selected III, Selected IV, Selected V, Selected VI, and Selected VII are all sent to the next higher level of selection.

[0148] The remaining parameters are the same as step 42 in Example 1;

[0149] After seven rounds of refining, a fluorite concentrate with a grade of 78.6% was obtained, with a yield of 74.8%.

[0150] Results analysis:

[0151] 1. As can be seen from Examples 1 to 3, using YZ-4 as an inhibitor results in higher grade and yield of fluorite concentrate; other inhibitors can also achieve higher yield and grade.

[0152] 2. As can be seen from Examples 4 and 5, using different amounts of inhibitors and collectors has a certain impact on the yield and grade of the product, but the impact is not decisive.

[0153] 3. As can be seen from Examples 6 to 8, the optimal number of selections is 7 times. If the number of selections is less than this, the product quality will be relatively lower. If the number of selections reaches 8 times, there is no obvious advantage in yield or quality.

[0154] 4. As can be seen from Comparative Example 1, if equal amounts of water glass and inhibitors are added in the first five selection processes, the product yield is significantly reduced and the grade is significantly increased; in Comparative Example 2, if the total amount of water glass and YZ-4 is kept approximately the same as in Example 1 and water glass and inhibitors are added in the first five selection processes, the product yield is significantly reduced and the grade is significantly increased.

[0155] The results of Comparative Examples 1 and 2 show that if no blank group is set in the first five flotation stages, the grade will be significantly higher and the yield will be significantly lower. This is because each flotation stage contains reagents, which inhibit the floating of fluorite. The present invention uses an intermittent reagent addition method. In the blank group, the material still contains a small amount of reagents. The material obtained from the previous stage flotation will retain more fluorite in the product of this stage flotation. By alternately setting the reagent addition group and the blank group, the fluorite can be prevented from sinking with calcite in the flotation operation corresponding to the blank group, thus preventing material waste.

[0156] As can be seen from Comparative Examples 1 and 2, even if the total amount of reagent is controlled within the range commonly used in the art, it is impossible to achieve the goal of retaining more fluorite without a blank group. That is, as long as the reagent is controlled within the range of conventional dosage, the present invention can significantly improve the yield and maintain a relatively high product quality by setting a blank group.

[0157] Although the fluorite grade of the present invention is slightly lower than that of Comparative Examples 1 and 2, the yield is significantly higher. From an economic and industrialization perspective, the solution of the present invention is the only feasible solution.

[0158] 5. As can be seen from Comparative Example 3, if the tailings from the first and second cleaning processes do not enter the next process, the grade and yield will be significantly affected. This is because the tailings from the first and second cleaning processes contain a large amount of calcium carbonate. This calcium carbonate will cause calcium carbonate to accumulate in the slurry from the first cleaning process, disrupting the fluorite-calcite balance of the slurry and reducing the yield and grade of fluorite.

[0159] The applicant declares that the present invention is illustrated by the above embodiments, but the present invention is not limited to the above process steps, nor does it mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for extracting fluorite from high-calcium fluorite ore, characterized in that, Includes the following steps: Step 1: The high-calcium fluorite ore is deslimed, crushed, and ground to obtain a pulp ore; Step 2: The pulp ore is subjected to roughing operation to obtain roughing concentrate; Step 3: Perform at least 5 fine-tuning processes on the rough concentrate to obtain fluorite concentrate; In the roughing operation, the pH value is adjusted first, then water glass and inhibitor are added, and finally fluorite collector is added; in the first 5 cleaning processes, the two adjacent cleaning operations are respectively the dosing group and the blank group; water glass and inhibitor are added to the slurry corresponding to the dosing group, and no water glass and inhibitor are added to the slurry corresponding to the blank group.

2. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, The selection operation in step 3 is performed 5 to 9 times; the first, third, and fifth selection operations are for the drug-adding group; the remaining selection operations are for the blank group.

3. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, The inhibitor is one or more of the following: sodium hexametaphosphate, tannic acid, tannin, sodium humate, modified starch, dextrin, and YZ-4.

4. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, In the roughing operation, the amount of water glass added per ton of pulp is 200-600g, the amount of inhibitor added per ton of pulp is 300-600g, and the fluorite collector is an oleic acid collector, with the amount of fluorite collector added per ton of pulp being 500-800g. In the dosing group, the amount of water glass added per ton of slurry was 100-400g; the amount of inhibitor added per ton of slurry was 50-300g.

5. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, The tailings from the first cleaning operation, the tailings from the second cleaning operation, and the washed sludge obtained after the desliming operation in step 1 are combined to obtain secondary slurry. The secondary slurry enters the secondary process for fluorite flotation, and after secondary process flotation, secondary fluorite concentrate is obtained. The tailings from the remaining selection operations are then incorporated into the previous selection operation.

6. The method for extracting fluorite from high-calcium fluorite ore according to claim 5, characterized in that, The secondary process specifically involves: after the secondary slurry undergoes one roughing and multiple cleaning processes, a secondary fluorite concentrate is obtained; the tailings obtained from the roughing operation in the secondary process are then subjected to a second scavenging to obtain fluorite tailings.

7. The method for extracting fluorite from high-calcium fluorite ore according to claim 6, characterized in that, In the first roughing operation of the secondary process, the amount of water glass added per ton of secondary slurry is 100-300g, the amount of inhibitor added per ton of secondary slurry is 50-300g, and the amount of fluorite collector added per ton of secondary slurry is 200-400g.

8. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, In the roughing operation of step 2, the pH of the slurry is adjusted to 8-10.5, then water glass and inhibitor are added, and finally fluorite collector is added. After the roughing operation, roughing concentrate and roughing tailings are obtained. The roughing tailings are subjected to a secondary scavenging operation to obtain fluorite tailings. In the secondary scavenging operation, fluorite collector is added to the slurry.

9. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, Step 1 specifically involves: washing and desliming the high-calcium fluorite ore, with the ore larger than 0.5 mm entering the crushing system; crushing the ore through one or more stages to obtain fine crushed material with a particle size of less than or equal to 10 mm; grinding the fine crushed material through one or more stages to obtain a slurry with a diameter of less than or equal to 200 mesh; adjusting the slurry to a solid content of 25-30% before using it as the slurry for roughing.

10. The method for extracting fluorite from high-calcium fluorite ore according to claim 1, characterized in that, The calcium carbonate content in the high-calcium fluorite ore is not less than 20 wt%.

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