Iron removal process for potassium feldspar containing micro-fine particle crystals and iron impurities
Through dry grinding, multi-gradient magnetic separation, sulfide flotation and other processes, the problem that the existing technology cannot effectively remove high iron-containing impurities in potassium feldspar, and the reduction of Fe2O3 content and the improvement of whiteness in potassium feldspar concentrate were achieved, and high-end potassium feldspar powder was prepared.
Patent Information
- Application Number
- CN202411892359.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-03-21
AI Technical Summary
The existing potassium feldspar ore iron removal process cannot effectively remove high iron-containing impurities containing fine crystal structures such as pyrite, pyrite, hematite, and pyroxene. It is impossible to reduce the Fe2O3 content to below 0.1%, and the whiteness reaches more than 60%, so as to prepare high-purity mid-to-high-end potassium feldspar products.
The dry grinding and powder making process are used to control the particle size of potassium feldspar powder between 180 and 250 mesh to account for more than 80%. Combined with multi-gradient magnetic separation and sulfide flotation processes, it includes three-stage flat plate magnetic separation, two iron concentrate recovery, two coarse selection and two sweep selection. Further, the iron content in potassium feldspar concentrate is reduced through pyroxene and other ferrosilicate flotations.
The Fe2O3 content in potassium feldspar concentrate has been reduced to below 0.1%, the whiteness is above 60%, and the concentrate yield is above 70%. High-end potassium feldspar powder has been prepared, which has increased the added value of the product and is suitable for the mid-to-high-end market.
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Figure CN119657328A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of comprehensive utilization of mineral resources, and in particular to an actual production and iron removal beneficiation process of potassium feldspar, which is mainly suitable for removing iron from potassium feldspar containing high iron impurities and high potassium content, such as pyrite, pyrrhotite, hematite, pyroxene and other fine crystalline impurities. Background Art
[0002] Potassium feldspar is used as a ceramic body ingredient and ceramic glaze in the ceramic industry, accounting for 30%, and the rest is used in other industries such as chemicals, glass flux, enamel raw materials, abrasives, glass fibers, and welding rods. With the development of the economy and the improvement of people's living standards, the demand for potassium feldspar in the fields of construction, ceramics, glass, chemicals, and electronics has continued to increase. Especially in the fields of construction and ceramics, with the acceleration of urbanization and consumption upgrades, the demand for medium and high-end potassium feldspar materials has shown a rapid growth trend. However, the low-end and medium-end ceramic and glass products have gradually shrunk, and the low-end and medium-end potassium feldspar materials have become increasingly in excess, and the medium and high-end product materials have become the main selling products.
[0003] From 2018 to 2023, the market size of my country's potassium feldspar industry increased from 637 million yuan to 1.381 billion yuan, with a compound annual growth rate of 16.73%; it is estimated that from 2024 to 2028, the market size of my country's potassium feldspar industry will increase from 1.581 billion yuan to 2.715 billion yuan, with a compound annual growth rate of 14.48%.
[0004] China has abundant potassium feldspar resources, but the iron content exceeds the standard, which limits the application of potassium feldspar. When potassium feldspar and iron impurities are closely related and widely distributed, it is difficult to separate the iron impurities in potassium feldspar. At this time, the commonly used process methods such as ore washing and magnetic separation cannot obtain high-purity potassium feldspar products. Especially for potassium feldspar containing iron impurities such as pyroxene, hematite, pyrite, pyrrhotite and other fine-grained structures (for specific structure and micromorphology, see the reference attachment Figure 5 , Attachment Figure 6 , Attachment Figure 7 As shown in a), under the premise of not significantly reducing the concentrate yield, the Fe2O3 content of the raw ore is reduced from 3.2% to below 0.1%, and high-end potassium feldspar with high purity is prepared, which cannot be achieved with existing mineral processing technology.
[0005] At present, potassium feldspar beneficiation and iron removal usually adopt flotation + magnetic separation or magnetic separation + flotation process. When the process of flotation first and magnetic separation later is adopted, the floatability of pyrrhotite is poor during flotation, and it is easy to follow the target mineral into the tailings. In addition, pyrrhotite is easy to form mud and oxidize, and it will consume a lot of oxygen during the flotation process, resulting in insufficient oxygen for pyrite flotation and incomplete flotation, causing pyrrhotite and pyrite to be retained in the potassium feldspar flotation concentrate, and it is difficult to remove pyrite in the subsequent magnetic separation; when the process of magnetic separation first and flotation later is adopted, some weakly magnetic iron-containing impurities such as pyroxene are also difficult to remove due to factors such as the type of iron-containing minerals and the fine crystal particle size.
[0006] After reviewing previous patent materials and repeated laboratory experiments, it is found that there is currently no mineral processing process that can reduce the Fe2O3 content in the potassium feldspar ore rich in fine-crystalline impurities of pyrrhotite, pyrite, hematite and pyroxene described in the present invention from 3.2% to below 0.1% and the whiteness to above 60% while ensuring a suitable yield of potassium feldspar.
[0007] Different iron-containing minerals in potassium feldspar require different beneficiation methods. It is necessary to develop suitable potassium feldspar beneficiation technology to produce qualified products. In short, the current potassium feldspar beneficiation and iron removal technology is not suitable for the beneficiation and iron removal of potassium feldspar containing iron impurities such as pyroxene, hematite, pyrite, and pyrrhotite, and it is impossible to reduce its Fe2O3 content to less than 0.1% and produce a high-grade potassium feldspar product with a whiteness of more than 60%. Summary of the invention
[0008] The present invention aims at the deficiencies of the prior art and provides a potassium feldspar ore iron removal and beneficiation process. The potassium feldspar ore with high iron impurities and high potassium content, such as pyrite, pyrrhotite, hematite, pyroxene and other fine crystal structures, is iron removed by beneficiation, and the Fe2O3 content in the potassium feldspar concentrate is reduced to less than 0.1%, the whiteness is more than 60%, the K2O is more than 13%, and the concentrate yield is more than 70%, so as to prepare high-end potassium feldspar powder. In order to achieve the above purpose, the following technical scheme is adopted:
[0009] The present application is a process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities, comprising the following steps:
[0010] (1) Crushing of potassium feldspar ore: After the potassium feldspar ore leaves the crushing system, the particle size of potassium feldspar is controlled below 30 mm;
[0011] (2) Dry grinding and powder selection of potassium feldspar:
[0012] The potassium feldspar is crushed into potassium feldspar raw powder. The particle requirements of the potassium feldspar raw powder are: all 180 meshes pass through, and 180-250 mesh powder accounts for more than 80%;
[0013] (3) Multi-gradient magnetic separation: including three-stage flat plate magnetic separation and two iron ore concentrate recovery;
[0014] (4) Sulfide flotation: including two roughing separations and two scavenging separations;
[0015] (5) Flotation of iron-containing silicate aluminates such as pyroxene: including two roughing selections and one scavenging selection;
[0016] (6) Drying: obtaining the final potassium feldspar concentrate product.
[0017] Furthermore, in the multi-gradient magnetic separation step, the 180-250 mesh potassium feldspar powder from the potassium feldspar powder making system is made into a potassium feldspar slurry with a slurry concentration of 20%-30%, and the slurry is sent to the magnetic separator through a pipeline. After completing three-stage flat plate magnetic separation and two iron ore concentrate recovery, the slurry is thickened into a 35% slurry by a thickener and enters the flotation system.
[0018] Furthermore, in step (3), the magnetic field strengths of the three-stage flat-plate magnetic separation are 1500 Gs, 8000 Gs, and 18000 Gs, respectively; and the magnetic separation strengths of the two iron ore concentrate recovery steps are 5000 Gs and 1600 Gs, respectively.
[0019] Furthermore, in the sulfide flotation step, the potassium feldspar concentrate from the magnetic separation system is fed by a metering feeder to a tubular screw conveyor according to a set value and enters a stirred slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the added mineral processing agent enter the stirring mixing tank together and enter the flotation system through siphon diversion.
[0020] Furthermore, in step (4), the slurry is controlled at a pH of 5-6 in the sulfide flotation process by adding sulfuric acid as an adjusting agent; the mineral processing reagent includes a black medicine + yellow medicine combination reagent and an activator; the combination reagent is a combination reagent prepared by mixing butylamine black medicine and ethyl yellow medicine in a mass ratio of 1:3, and the activator is copper sulfate.
[0021] Furthermore, in step (4), the order of the two roughing selections and the two scavenging selections in the sulfide flotation process is: first roughing selection, second roughing selection, first scavenging selection, and second scavenging selection.
[0022] Furthermore, in step (4), 70-100 g / t of the combined reagent is added in the first roughing process, and the flotation time is 10-15 min; 70-100 g / t of the combined reagent is added in the second roughing process, and the flotation time is 5-10 min; 40-60 g / t of the combined reagent and 5-10 g / t of the activator are added in the first scavenging process, and the scavenging time is 5-10 min; 40-60 g / t of the combined reagent and 5-10 g / t of the activator are added in the second scavenging process, and the scavenging time is 5-10 min.
[0023] Furthermore, in the flotation step of pyroxene and other iron-containing silicate aluminates, the slurry after the sulfide flotation step is tempered by adding a regulating agent, sulfuric acid or sodium carbonate, to control the pH of the slurry in the flotation process of pyroxene and other iron-containing silicate aluminates to 7-7.5, and a collector and a dispersant are added to complete the flotation of pyroxene and other iron-containing silicate aluminates; the collector includes sodium oleate and dodecylamine, and the dispersant is water glass.
[0024] Furthermore, in step (5), the order of the two rough selections and the one sweep selection is: one rough selection, two rough selections, and sweep selection.
[0025] Furthermore, in step (5), in the primary roughing process, 900-1200 g / t of dispersant, 50-80 g / t of sodium oleate and 40-60 g / t of dodecylamine are added, and the flotation time is 8-15 min; in the secondary roughing process, 600-800 g / t of dispersant, 30-60 g / t of sodium oleate and 20-50 g / t of dodecylamine are added, and the flotation time is 8-15 min; in the scavenging process, 600-800 g / t of dispersant, 30-60 g / t of sodium oleate and 20-50 g / t of dodecylamine are added, and the mixture is stirred for 2-3 min and then air is supplied, and the flotation time is 8-15 min.
[0026] It can be seen from the above technical solutions that the embodiments of the present invention have the following effects:
[0027] (1) The present invention is aimed at removing iron from high-iron impurities and high-potassium potassium feldspar containing fine-grained crystalline impurities such as pyrite, pyrrhotite, hematite, pyroxene, etc., and adopts a process of first magnetic separation and then flotation to select magnetic pyrrhotite, weakly magnetic mica-based aluminum silicate minerals, and granular hematite. Among them, the selection of pyrrhotite in advance effectively avoids the influence of oxidation and hydrolysis of the mineral on the selection of pyrite in the subsequent flotation process, and improves the selection rate of magnetic pyrite in the subsequent flotation.
[0028] (2) The present invention adopts dry grinding and powder making technology to dry grind, grind and classify potassium feldspar, which has a simple process flow, a large processing capacity, a narrow potassium feldspar particle size distribution range, is not prone to over-grinding, and has low energy consumption; it avoids the problem of easy over-grinding of iron-containing impurities, which makes ore dressing and separation difficult.
[0029] (3) The present invention controls the grinding particle size to -180 mesh, of which 180-250 mesh accounts for 80%. Before entering the mineral processing system, the fine particles with a high iron content of -250 mesh are removed, which is beneficial to the subsequent mineral processing and iron removal, and greatly improves the quality of the potassium feldspar product.
[0030] (4) The present invention uses a permeable screen after flotation to remove the easily muddy and iron-containing fine impurities, thereby further reducing the iron content in the potassium feldspar concentrate.
[0031] (5) The ore dressing and iron removal process of the present invention can reduce the Fe2O3 in potassium feldspar to below 0.1%, with a whiteness of more than 60% and a concentrate yield of more than 70%. It greatly improves the added value of potassium feldspar concentrate and enables the product to enter the mid-to-high-end market. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 This is a schematic diagram of the overall process flow of the embodiment provided in this application;
[0033] Figure 2 This is a process flow chart of the potassium feldspar magnetic separation according to the embodiment of the present application;
[0034] Figure 3 This is a flow chart of the potassium feldspar sulfide flotation process provided in the embodiment of this application;
[0035] Figure 4 This is a flotation process flow chart of iron-containing aluminosilicates such as pyroxene in potassium feldspar provided in the embodiment of this application;
[0036] Figure 5 SEM analysis of iron-bearing minerals in potassium feldspar;
[0037] Figure 6 EDS analysis of iron-bearing minerals in potassium feldspar;
[0038] Figure 7 Comparison of microscopic photos of potassium feldspar before and after beneficiation. DETAILED DESCRIPTION
[0039] The present invention will be further described below in conjunction with specific embodiments.
[0040] The key to potassium feldspar beneficiation and iron removal lies in the accurate analysis of the iron-bearing minerals in potassium feldspar, so that the beneficiation process can be configured in a targeted manner.
[0041] According to the research and analysis of the applicant, the iron-containing minerals in potassium feldspar applicable to the present invention are easier to grind than potassium feldspar. After grinding, it is found through research and testing that pyroxene and pyrite with high content are easy to be enriched in powders below 250 mesh. For specific data, please refer to the following Table 1. Therefore, choosing a suitable grinding process is very important for subsequent mineral processing operations.
[0042] Table 1 Iron content of each particle size after potassium feldspar 180 mesh fully passed the original ore powder wet sieve
[0043] Sample fineness Mass / g Proportion / % <![CDATA[Fe2O3 / %]]> -180～+200 45.35 45.35 4.12 -200～+250 38.19 38.19 3.85 -250 15.95 15.95 5.75 Suspended matter 0.51 0.51 5.63
[0044] At present, potassium feldspar beneficiation is mostly wet grinding, which has the disadvantages of wide distribution of powder particle size, long beneficiation process, easy over-grinding leading to difficulty in beneficiation separation, increased use of flotation reagents, increased costs, etc. Therefore, the potassium feldspar powder in this application selects dry powder making process, controls the powder particle size of 180 mesh to pass all, of which 180-250 mesh powder accounts for 80%, and screens out fine powder below 250 mesh before entering the beneficiation system, which can effectively improve product quality.
[0045] In addition, the present application is applicable to potassium feldspar containing a certain amount of pyroxene, which has weak magnetic properties and is difficult to be selected by high gradient magnetic separation with a magnetic field strength of 3000-18000Gs. Therefore, flotation requires two stages of flotation to remove it.
[0046] In summary, the present application targets potassium feldspar with high iron content and high potassium content, which contains fine crystalline impurities such as pyrite, pyrrhotite, hematite, pyroxene, etc. By adopting dry powder making and screening process, the particle size of 180 mesh is controlled to pass through, and the powder of 180-250 mesh accounts for more than 80%. The mineral processing process of magnetic separation followed by flotation is adopted, in which the magnetic separation adopts high gradient magnetic separation and the flotation adopts two-stage flotation, which can reduce Fe2O3 in potassium feldspar to less than 0.1%, the whiteness is more than 60%, and the concentrate yield is more than 70%, so as to prepare high-end potassium feldspar powder. The overall process flow is shown in the attached Figure 1 , the specific technical scheme adopted is as follows.
[0047] (1) Crushing of potassium feldspar ore
[0048] The potassium feldspar ore is crushed by jaw crusher and cone crusher, and the particle size of potassium feldspar out of the crushing system is controlled below 30mm.
[0049] (2) Dry grinding and powder selection of potassium feldspar
[0050] After leaving the crushing system, the potassium feldspar is conveyed by the conveying system to the vertical mill for dry powder making. The particle size requirements of potassium feldspar powder leaving the vertical mill system are: 180 meshes all pass, and 180-250 meshes account for more than 80%. After the potassium feldspar powder is screened, the high-iron fine particles below -250 mesh are removed, and the remaining 180-250 mesh powders enter the mineral processing system.
[0051] (3) Multi-gradient magnetic separation
[0052] The 180-250 mesh potassium feldspar powder from the potassium feldspar powder making and storage system is slurried in a slurry tank at a certain solid-liquid ratio to make potassium feldspar slurry with a slurry concentration of 20%-30%. The slurry is sent to the magnetic separator through a pipeline. After completing three-stage flat plate magnetic separation and two iron ore concentrate recovery, the slurry is thickened into 35% slurry by a thickener and enters the flotation system.
[0053] The magnetic separation configuration includes three-stage flat plate magnetic separation and two iron concentrate recovery: the magnetic field strength of the three-stage flat plate magnetic separation is 1500Gs, 8000Gs, and 18000Gs; the magnetic field strength of the two-stage iron concentrate recovery is 5000Gs and 1600Gs. For detailed process flow, please see the attached Figure 2 .
[0054] Specifically, first, the first magnetic separation (magnetic separation 1 in the figure) uses a magnetic field strength of 1500Gs to remove iron, the main purpose of which is to remove strong magnetic substances such as magnetite in the potassium feldspar ore; then the obtained potassium feldspar is subjected to the second magnetic separation (magnetic separation 2 in the figure), using a magnetic field strength of 8000Gs to remove iron, the main purpose of which is to remove weak magnetic substances such as hematite and pyrrhotite in the potassium feldspar ore.
[0055] Simultaneously, the magnetic minerals selected in the first and second magnetic separation processes are subjected to the first iron concentration recovery at a magnetic field strength of 5000 Gs (selection 1 in the figure) to obtain iron-containing concentrate, which can be directly sold as a by-product, and the non-magnetic potassium feldspar minerals are returned to the second magnetic separation.
[0056] The third magnetic separation (magnetic separation 2 in the figure) uses a magnetic field strength of 18000Gs to remove iron, with the purpose of removing a portion of the pyroxene iron-containing silicate materials in the potassium feldspar ore. The magnetically separated magnetic minerals enter the second iron concentration recovery (concentration 2 in the figure), and the recovered weakly magnetic materials are stored in the warehouse, and the non-magnetic potassium feldspar returns to the third magnetic separation.
[0057] The potassium feldspar minerals from the second magnetic separation continue to undergo the third magnetic separation (magnetic separation 3 in the figure).
[0058] After the third stage of magnetic separation, the potassium feldspar minerals pass through a permeable screen and after removing the suspended solids with high iron content, they enter the next stage of the flotation system.
[0059] The first and second concentrating of iron-containing minerals are aimed at improving the recovery rate of potassium feldspar and selecting the by-product iron concentrate.
[0060] In summary, the main purpose of multi-gradient magnetic separation is to select magnetic pyrrhotite, granular hematite, and a part of pyroxene. The selection of pyrrhotite effectively avoids the influence of oxidation and hydrolysis of the mineral on the selection of pyrite in the subsequent flotation process.
[0061] (4) Sulfide flotation
[0062] The sulfide flotation system configuration consists of 2 roughing separations and 2 scavenging separations.
[0063] The potassium feldspar concentrate from the magnetic separation system is fed by the metering feeder at the bottom of the silo to the tubular screw conveyor according to the set value and enters the stirring slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the mineral processing reagent added by the dosing machine enter the stirring mixing tank together, and enter the SF type flotation machine of the flotation system through siphon diversion to complete flotation. The detailed process flow chart is attached Figure 3 .
[0064] Slurry pH: add sulfuric acid as an adjusting agent to control the slurry pH of the sulfide flotation process to 5-6; stir for 2-3 minutes; prepare a black medicine + yellow medicine combination reagent by mixing butylamine black medicine and ethyl xanthate in a ratio of 1:3 (mass ratio), and use copper sulfate as the activator.
[0065] Primary roughing: add butylamine black medicine: ethyl xanthate 1:3 combination reagent 70-100g / t; flotation time 10-15min;
[0066] Secondary roughing: According to the yield of the foam product of the primary roughing and the potassium feldspar carrying condition, 70-100g / t of black powder + yellow powder combination reagent is added in the secondary roughing; the flotation time is 5-10min;
[0067] Primary scavenging: Add 40-60g / t of black medicine + yellow medicine combination reagent and 5-10g / t of activator copper sulfate to the slurry after roughing; scavenging time is 5-10min;
[0068] Secondary scavenging: Add 40-60g / t of black medicine + yellow medicine combination reagent and 5-10g / t of activator copper sulfate to the slurry from the first scavenging; scavenging time is 5-10min;
[0069] The potassium feldspar to which the present application is applied contains a large amount of non-magnetic pyrite, which is an important reason for the high iron content in potassium feldspar. The main purpose of sulfide flotation is to select the non-magnetic pyrite.
[0070] (5) Flotation of iron-containing silicate aluminates such as pyroxene
[0071] The potassium feldspar applicable to this application contains iron-containing aluminosilicate minerals such as pyroxene. Such minerals have high iron content and weak magnetic properties. The multi-gradient magnetic separation is not effective. Therefore, targeted flotation is required for removal. The detailed process flow chart is attached. Figure 4 .
[0072] The flotation system configuration of this section consists of 2 roughing separations and 1 scavenging separation.
[0073] Slurry pH: add sulfuric acid or sodium carbonate as an adjusting agent to adjust the slurry pH to 7-7.5 during the flotation process of pyroxene and other iron-containing silicate aluminates; stir for 2-3 minutes; the collectors are sodium oleate and dodecylamine, and the dispersant is water glass.
[0074] Primary roughing: adding dispersant water glass 900-1200g / t, sodium oleate 50-80g / t, dodecylamine 40-60g / t; flotation time 8-15min;
[0075] Secondary roughing: add dispersant water glass 600-800g / t, sodium oleate 30-60g / t, dodecylamine 20-50g / t; flotation time 8-15min;
[0076] Sweeping: Add dispersant water glass 600-800g / t, sodium oleate 30-60g / t, dodecylamine 20-50g / t; stir for 2-3 minutes and then send air; flotation time 8-15 minutes.
[0077] Finally, the potassium feldspar concentrate slurry discharged from the flotation machine is filtered through water permeability, and the sieve is 180-250 mesh potassium feldspar concentrate with a moisture content of 25-35%, which can be packaged and sold after subsequent drying. The fine impurities that are easy to be muddy and contain iron under the sieve are settled, and the water is recycled. The muddy iron-containing impurities are enriched and uniformly sent to the pickling treatment system for further iron removal.
[0078] (6) Drying and testing
[0079] The potassium feldspar concentrate after water permeability filtration is dried to obtain the final potassium feldspar concentrate product. After testing, the finished product can achieve Fe2O3 reduced to below 0.1%, whiteness above 60%, and concentrate yield above 70%.
[0080] Embodiment 1:
[0081] The potassium feldspar mine in Daping, Song County, Henan Province is used.
[0082] (1) Crushing of potassium feldspar ore
[0083] The potassium feldspar ore is crushed by jaw crusher and cone crusher, and the particle size of potassium feldspar out of the crushing system is controlled below 30mm.
[0084] (2) Dry grinding and powder selection of potassium feldspar
[0085] After leaving the crushing system, the potassium feldspar is conveyed by the conveying system to the vertical mill for dry powder making. The particle size requirements of potassium feldspar powder leaving the vertical mill system are: 180 meshes all pass, and 180-250 meshes account for more than 80%. After the potassium feldspar powder is screened, the high-iron fine particles below -250 mesh are removed, and the remaining 180-250 mesh powders enter the mineral processing system.
[0086] (3) Multi-gradient magnetic separation
[0087] The potassium feldspar powder coming out of the potassium feldspar powder making and storage system is slurried in a slurry tank at a certain solid-liquid ratio to make potassium feldspar slurry with a slurry concentration of 20%-30%. The slurry is sent to the magnetic separator through a pipeline. After completing three-stage flat plate magnetic separation and two iron ore concentrate recovery, the slurry is thickened into 35% slurry by a thickener and enters the flotation system.
[0088] First, the first magnetic separation uses a magnetic field strength of 1500Gs to remove iron, the purpose is to remove strong magnetic substances such as magnetite in potassium feldspar ore; then the potassium feldspar obtained is subjected to the second magnetic separation, and the magnetic field strength of 8000Gs is used to remove iron, the purpose is to remove weak magnetic substances such as hematite and pyrrhotite in potassium feldspar ore. Simultaneously, the magnetic minerals selected in the first and second magnetic separation processes are subjected to the first iron concentration recovery with a magnetic field strength of 5000Gs to obtain iron-containing concentrate, which can be sold directly as a by-product, and the non-magnetic potassium feldspar minerals are returned to the second magnetic separation. The third magnetic separation uses a magnetic field strength of 18000Gs to remove iron, the purpose is to remove a part of the pyroxene iron-containing silicate substances in the potassium feldspar ore, the magnetic minerals selected by the magnetic separation enter the second iron concentration recovery, the recovered weak magnetic substances are stored in the warehouse, and the non-magnetic potassium feldspar returns to the third magnetic separation. The potassium feldspar minerals selected in the second magnetic separation continue to be subjected to the third magnetic separation. After the third stage of magnetic separation, the potassium feldspar minerals pass through a permeable screen to remove suspended solids with high iron content before entering the next stage of the flotation system.
[0089] (4) Sulfide flotation
[0090] The potassium feldspar concentrate from the magnetic separation system is fed by the metering feeder at the bottom of the silo to the tubular screw conveyor according to the set value and enters the stirring slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the mineral processing reagent added by the dosing machine enter the stirring mixing tank together, and enter the SF type flotation machine of the flotation system through siphon diversion to complete flotation.
[0091] Add sulfuric acid as an adjusting agent to control the pH of the slurry in the sulfide flotation process to 5-6; stir for 3 minutes;
[0092] First roughing: adding 95g / t of butylamine black medicine and ethyl xanthate 1:3 combination reagent; flotation time 15min;
[0093] Secondary roughing: add 72g / t of black powder + yellow powder combination reagent in the second stage roughing; flotation time 10min;
[0094] First sweeping: Add 60g / t of black medicine + yellow medicine combination reagent and 10g / t of activator copper sulfate to the pulp after roughing; sweeping time is 10min;
[0095] Secondary scavenging: Add 45g / t of black medicine + yellow medicine combination reagent and 9.5g / t of activator sulfuric acid to the slurry from the first scavenging; the scavenging time is 6min.
[0096] (5) Flotation of iron-containing silicate aluminates such as pyroxene
[0097] Add sulfuric acid or sodium carbonate as a conditioning agent to control the pH of the slurry in the flotation process of pyroxene and other iron-containing silicate aluminates to 7-7.5; stir for 3 minutes;
[0098] Primary roughing: adding dispersant water glass 1000g / t, sodium oleate 80g / t, dodecylamine 55g / t; flotation time 14min;
[0099] Secondary roughing: add dispersant water glass 800g / t, sodium oleate 45g / t, dodecylamine 25g / t; flotation time 8.5min;
[0100] Sweep selection: add 690g / t of dispersant water glass, 30g / t of sodium oleate and 35g / t of dodecylamine; stir for 2 minutes and then supply air; flotation time is 11 minutes.
[0101] Finally, the potassium feldspar concentrate slurry discharged from the flotation machine is filtered through water permeability, and the potassium feldspar concentrate on the sieve has a moisture content of 25.6%, which is tested after drying.
[0102] Embodiment 2:
[0103] Example 2 uses the potassium feldspar mine in Daping, Song County, Henan Province. The first three steps are the same as those in Example 1, except for steps 4 and 5.
[0104] (4) Sulfide flotation
[0105] The potassium feldspar concentrate from the magnetic separation system is fed by the metering feeder at the bottom of the silo to the tubular screw conveyor according to the set value and enters the stirring slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the mineral processing reagent added by the dosing machine enter the stirring mixing tank together, and enter the SF type flotation machine of the flotation system through siphon diversion to complete flotation.
[0106] Add sulfuric acid as an adjusting agent to control the pH of the slurry in the sulfide flotation process to 5-6; stir for 2.5 minutes;
[0107] First roughing: add butylamine black medicine: ethyl xanthate 1:3 combination reagent 80g / t; flotation time 12min;
[0108] Secondary roughing: add 83g / t of black powder + yellow powder combination reagent in the second stage roughing; flotation time 7min;
[0109] First sweeping: Add 50g / t of black medicine + yellow medicine combination reagent and 8g / t of activator copper sulfate to the slurry after roughing; sweeping time is 7min;
[0110] Secondary scavenging: Add 55g / t of black powder + yellow powder combination reagent and 8g / t of activator sulfuric acid to the slurry from the first scavenging; the scavenging time is 10min.
[0111] (5) Flotation of iron-containing silicate aluminates such as pyroxene
[0112] Add sulfuric acid or sodium carbonate as a conditioning agent to control the pH of the slurry in the flotation process of pyroxene and other iron-containing silicate aluminates to 7-7.5; stir for 3 minutes;
[0113] Primary roughing: adding dispersant water glass 1200g / t, sodium oleate 65g / t, dodecylamine 40g / t; flotation time 9min;
[0114] Secondary roughing: add dispersant water glass 600g / t, sodium oleate 35g / t, dodecylamine 48g / t; flotation time 12min;
[0115] Sweep selection: add 770g / t of dispersant water glass, 45g / t of sodium oleate and 20g / t of dodecylamine; stir for 2 minutes and then supply air; flotation time is 8 minutes.
[0116] Finally, the potassium feldspar concentrate slurry discharged from the flotation machine is filtered through water permeability, and the potassium feldspar concentrate on the sieve has a moisture content of 30.8%, which is tested after drying.
[0117] Embodiment 3:
[0118] Example 3 uses the potassium feldspar mine in Daping, Song County, Henan Province. The first three steps are the same as those of Examples 1 and 2, except for steps 4 and 5.
[0119] (4) Sulfide flotation
[0120] The potassium feldspar concentrate from the magnetic separation system is fed by the metering feeder at the bottom of the silo to the tubular screw conveyor according to the set value and enters the stirring slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the mineral processing reagent added by the dosing machine enter the stirring mixing tank together, and enter the SF type flotation machine of the flotation system through siphon diversion to complete flotation.
[0121] Add sulfuric acid as an adjusting agent to control the pH of the slurry in the sulfide flotation process to 5-6; stir for 2 minutes;
[0122] First roughing: add butylamine black medicine: ethyl xanthate 1:3 combination reagent 70g / t; flotation time 10min;
[0123] Secondary roughing: Add 98g / t of black powder + yellow powder combination reagent in the second stage roughing; flotation time 5min;
[0124] First sweeping: Add 42g / t of black medicine + yellow medicine combination reagent and 5.5g / t of activator copper sulfate to the slurry after roughing; sweeping time 5min;
[0125] Secondary scavenging: Add 58g / t of black powder + yellow powder combination reagent and 5g / t of activator sulfuric acid to the slurry from the first scavenging; the scavenging time is 8min.
[0126] (5) Flotation of iron-containing silicate aluminates such as pyroxene
[0127] Add sulfuric acid or sodium carbonate as a conditioning agent to control the pH of the slurry during the flotation of pyroxene and other iron-containing silicate aluminates to 7-7.5; stir for 2 minutes;
[0128] Primary roughing: adding dispersant water glass 900g / t, sodium oleate 50g / t, dodecylamine 50g / t; flotation time 10min;
[0129] Secondary roughing: add dispersant water glass 700g / t, sodium oleate 60g / t, dodecylamine 40g / t; flotation time 15min;
[0130] Sweep selection: add 620g / t of dispersant water glass, 60g / t of sodium oleate and 50g / t of dodecylamine; stir for 3 minutes and then supply air; flotation time is 15 minutes.
[0131] Finally, the potassium feldspar concentrate slurry discharged from the flotation machine is filtered through water permeability, and the potassium feldspar concentrate on the sieve has a moisture content of 33.9%, which is tested after drying.
[0132] The finished product test data of Examples 1-3 are shown in Table 3 below.
[0133] Table 2 Iron content and whiteness of potassium feldspar products after beneficiation
[0134] Example Fineness <![CDATA[Fe2O3 / %]]> Whiteness Concentrate yield / % <![CDATA[K2O / % in Concentrate]]> Example 1 -180～+250 0.087 69 72 13.8 Example 2 -180～+250 0.092 63 76 13.5 Example 3 -180～+250 0.095 65 75 13.2
[0135] In addition, the comparison of microscopic photos of potassium feldspar before and after beneficiation can be found in the attached Figure 7 .
[0136] It can be seen from the above embodiments that through the scheme of the present application, for high-iron and high-potassium fine-grained potassium feldspar containing pyrite, pyrrhotite, hematite, and pyroxene, a high-quality potassium feldspar concentrate product can be achieved, the Fe2O3 in the potassium feldspar can be reduced to below 0.1%, the whiteness is above 60%, and the concentrate yield is above 70%, which meets the needs of the mid-to-high-end market. The effect of the process method of the present application is obvious.
[0137] The above is only a detailed description of the preferred implementation methods of the present application. Technicians in the technical field to which the present application belongs can make various changes and additions to the described specific implementation methods or replace them in a similar manner. The technical scope of the present application should be determined by the claims, and should also include the meaning equivalent to the contents recorded in the claims and all changes within the scope thereof.
Claims
1. A process for removing iron from potassium feldspar containing fine-grained crystalline iron impurities, characterized in that: The following steps are involved: (1) Crushing of potassium feldspar ore: After the potassium feldspar ore leaves the crushing system, the particle size of potassium feldspar is controlled below 30 mm; (2) Dry grinding and powder selection of potassium feldspar: The potassium feldspar is crushed into potassium feldspar raw powder. The particle requirements of the potassium feldspar raw powder are: all 180 meshes pass through, and 180-250 mesh powder accounts for more than 80%; (3) Multi-gradient magnetic separation: including three-stage flat plate magnetic separation and two iron ore concentrate recovery; (4) Sulfide flotation: including two roughing separations and two scavenging separations; (5) Flotation of iron-containing silicate aluminates such as pyroxene: including two roughing selections and one scavenging selection; (6) Drying: obtaining the final potassium feldspar concentrate product.
2. The iron removal process of potassium feldspar containing fine-grained crystalline iron impurities according to claim 1 is characterized in that: In the multi-gradient magnetic separation step, 180-250 mesh potassium feldspar powder from the potassium feldspar powder making system is made into potassium feldspar slurry with a slurry concentration of 20%-30%, and the slurry is sent to the magnetic separator through a pipeline. After completing three-stage flat plate magnetic separation and two iron ore concentrate recovery, the slurry is thickened into 35% slurry by a thickener and enters the flotation system.
3. A process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities according to claim 1 or 2, characterized in that: The magnetic field strengths of the three-stage flat-plate magnetic separation are 1500Gs, 8000Gs, and 18000Gs respectively; the magnetic separation strengths of the two iron ore concentrate recovery processes are 5000Gs and 1600Gs respectively.
4. The iron removal process of potassium feldspar containing fine-grained crystalline iron impurities according to claim 1, characterized in that: In the sulfide flotation step, the potassium feldspar concentrate from the magnetic separation system is fed by a metering feeder to a tubular screw conveyor according to a set value and enters a stirred slurry tank to form a slurry with a slurry concentration of 35%. The slurry and the added mineral processing agent enter the stirring mixing tank together and enter the flotation system through siphon diversion.
5. The iron removal process of potassium feldspar containing fine-grained crystals and iron impurities according to claim 4 is characterized in that: The slurry is controlled to have a pH of 5-6 in the sulfide flotation process by adding sulfuric acid as an adjusting agent; the mineral processing reagents include a combination of black medicine + xanthate and an activator; the combination reagent is a combination reagent made of butylamine black medicine and ethyl xanthate in a mass ratio of 1:3, and the activator is copper sulfate.
6. A process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities according to claim 1, 4 or 5, characterized in that: The order of the two roughing selections and the two scavenging selections in the sulfide flotation process is: first roughing selection, second roughing selection, first scavenging selection, and second scavenging selection.
7. A process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities according to claim 6, characterized in that: In the first roughing process, 70-100 g / t of combined reagent is added, and the flotation time is 10-15 min; in the second roughing process, 70-100 g / t of combined reagent is added, and the flotation time is 5-10 min; in the first scavenging process, 40-60 g / t of combined reagent and 5-10 g / t of activator are added, and the scavenging time is 5-10 min; in the second scavenging process, 40-60 g / t of combined reagent and 5-10 g / t of activator are added, and the scavenging time is 5-10 min.
8. The iron removal process of potassium feldspar containing fine-grained crystalline iron impurities according to claim 1, characterized in that: In the flotation step of iron-containing silicate aluminates such as pyroxene, the slurry after the sulfide flotation step is tempered by adding a regulating agent, sulfuric acid or sodium carbonate, to control the pH of the slurry in the flotation process of iron-containing silicate aluminates such as pyroxene to be 7-7.5, and a collector and a dispersant are added to complete the flotation of iron-containing silicate aluminates such as pyroxene; the collector includes sodium oleate and dodecylamine, and the dispersant is water glass.
9. A process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities according to claim 1 or 8, characterized in that: In the flotation step of pyroxene and other iron-containing silicate aluminates, the order of two roughing selections and one scavenging selection is: one roughing selection, two roughing selections, and scavenging selection.
10. A process for removing iron from potassium feldspar containing fine-grained crystals and iron impurities according to claim 9, characterized in that: In the primary roughing process, 900-1200 g / t of dispersant, 50-80 g / t of sodium oleate and 40-60 g / t of dodecylamine are added, and the flotation time is 8-15 min. In the secondary roughing process, 600-800 g / t of dispersant, 30-60 g / t of sodium oleate and 20-50 g / t of dodecylamine are added, and the flotation time is 8-15 min. In the scavenging process, 600-800 g / t of dispersant, 30-60 g / t of sodium oleate and 20-50 g / t of dodecylamine are added, and the mixture is stirred for 2-3 min and then air is supplied, and the flotation time is 8-15 min.