A cascade full-value utilization method for high-silicon iron tailings

Abstract

The present invention belongs to the field of solid waste treatment, and specifically relates to a method for cascade full-value utilization of high-silicon iron tailings, wherein the high-silicon iron tailings are subjected to graded desludging treatment to obtain fine mud and desludging sand; the desludging sand is subjected to weak magnetic separation to separate weak magnetic separation coarse concentrate and weak magnetic separation tailings; the weak magnetic separation coarse concentrate is subjected to ore grinding, closed-circuit fine grinding, and then weak magnetic separation to obtain iron concentrate and finely ground weak magnetic separation tailings; the fine mud and finely ground weak magnetic separation tailings are then used to prepare aerated concrete blocks; the weak magnetic separation tailings are subjected to strong magnetic separation treatment to obtain strong magnetic materials and non-magnetic materials; the non-magnetic materials are subjected to three-stage flotation treatment to obtain feldspar, quartz and three-stage flotation waste. The strong magnetic materials and the three-stage flotation waste are mixed and used for the preparation of ceramic microcrystalline linings. The present invention can achieve cascade full-value utilization of high-silicon iron tailings, and can obtain high-performance aerated concrete blocks and ceramic microcrystalline linings.

Description

Technical Field

[0001] The invention belongs to the field of mineral resource sorting and processing and mineral materials, and relates to a cascade full-value utilization method of high-silicon iron tailings. Background Art

[0002] Steel is the main metal material for national economic construction and is known as the "food of industry". It has high strength, good mechanical properties, abundant resources, and low comprehensive cost. It is widely used in all fields of social production and life and is an indispensable strategic basic industrial product. Due to the large amount of steel used, the iron raw materials consumed in its production are even greater. my country's steel production has ranked first in the world for many years. At present, it consumes about 1.5 billion tons of iron ore each year, and the import volume from abroad also exceeds 1 billion tons. The demand for iron ore is strong.

[0003] In order to achieve sustainable development of the steel industry, it is urgent to realize efficient resource utilization of iron tailings through technological creation and innovation.

[0004] However, there are relatively few existing resource recovery processes for high-silicon iron tailings, and the few technical means generally have problems such as difficulty in full resource utilization and unsatisfactory performance of co-produced products. Summary of the invention

[0005] In view of the problem that high-silicon iron tailings are difficult to fully utilize and the performance of co-produced products is still lacking, the purpose of the present invention is to provide a cascade full-value utilization method of high-silicon iron tailings, aiming to achieve full-value coordinated utilization of resources and co-produce high-performance aerated concrete and ceramic microcrystalline boards.

[0006] The composition of high-silicon iron tailings is complex and difficult to fully utilize, and the performance of the materials obtained by resource utilization still has a large room for improvement. In view of this problem, the inventors have conducted in-depth research and provide the following solutions:

[0007] A method for cascade full-value utilization of high-silicon iron tailings, comprising the following steps:

[0008] Step (1): Desludging-magnetic separation

[0009] The high silicon iron tailings are subjected to graded desludging treatment to obtain fine mud and desludging sand;

[0010] The desludging and settling sand is subjected to weak magnetic separation to obtain weak magnetic separation coarse concentrate and weak magnetic separation tailings;

[0011] Step (2):

[0012] In any order, the weak magnetic separation rough concentrate and weak magnetic separation tailings collected in step (1) are utilized as resources, the steps are as follows:

[0013] Step (2-a): Weak magnetic separation and resource processing of coarse concentrate

[0014] The weak magnetic separation coarse concentrate of step (1) is subjected to ore grinding, closed-circuit fine grinding and weak magnetic separation to obtain iron concentrate and finely ground weak magnetic separation tailings;

[0015] The fine mud and finely ground weak magnetic separation tailings from step (1) are used to prepare aerated concrete blocks;

[0016] Step (2-b): Weak magnetic separation tailings resource processing:

[0017] The weak magnetic separation tailings of step (1) are subjected to strong magnetic separation to obtain strong magnetic material and non-magnetic material;

[0018] The non-magnetic material is subjected to a first stage of flotation to obtain a first flotation foam material containing iron and impurities and a first purified material enriched with feldspar and quartz; the first purified material is subjected to a second stage of flotation to separate feldspar concentrate and a second flotation tailing; the second flotation tailing is subjected to a third reverse flotation to obtain quartz and a third flotation foam material;

[0019] Strong magnetic material and waste material from three-stage flotation (components other than quartz and feldspar from the three-stage flotation, specifically the first flotation foam material and the third flotation foam material) are mixed and used for the preparation of ceramic microcrystalline linings.

[0020] The present invention proposes for the first time the idea of ​​converting high-silicon iron tailings into aerated concrete blocks and ceramic microcrystalline liners. The present invention has found that in order to realize this new utilization idea, it is necessary to face the problem of how to achieve full-value selective allocation of high-silicon iron tailings resources, and how to achieve full-value utilization while also improving the performance of co-produced aerated concrete blocks and ceramic microcrystalline liners. In response to this technical problem, the present invention has found that by using the desludging-magnetic separation process described in the present invention, further coordinating the various treatment processes of step 2 such as the control of the compatibility of resource raw materials, it is possible to achieve synergy and coordinate the resource allocation of high-silicon iron tailings, thereby achieving full resource recovery, and simultaneously improving the performance of regenerated aerated concrete blocks and ceramic microcrystalline liners. The method of the present invention is reasonably designed, technically effective, and economically feasible, and can fully utilize the valuable resources in the material in a tiered and classified manner to achieve the full-value utilization goal of iron tailings. It has the characteristics of strong applicability, green environmental protection, reliable operation, and economical and practical.

[0021] In the present invention, the iron (TFe) content in the high-silicon iron tailings is greater than or equal to 8wt.%, preferably 9-12wt.%; the SiO2 content is greater than or equal to 65wt.%, preferably 70-75wt.%.

[0022] In step (1) of the present invention, classification and desludging are performed based on a combined classification method, and the combined classification method includes a combination of a spiral classifier and a hydrocyclone; or a combination of a hydrocyclone and a high-frequency vibrating fine screen; or a combination of a spiral classifier, a hydrocyclone and a high-frequency vibrating fine screen.

[0023] In step (1) of the present invention, the intensity of the weak magnetic separation stage is ≤300 kA / m, preferably 80 to 240 kA / m.

[0024] The closed-circuit ground mineral material in step (2-a) of the present invention has a particle size of -0.045 mm after fine grinding, reaching more than 80%; research has found that within this preferred range, combined with the process of the present invention, it helps to further coordinate the full value utilization of high-silicon iron tailings resources, and in addition, it is also beneficial to improve the performance of the products obtained by co-production.

[0025] Preferably, the number of weak magnetic separations is greater than or equal to 2 times, preferably 2 to 4 times;

[0026] Preferably, the iron content (TFe) of the iron concentrate obtained by weak magnetic separation is greater than 60 wt.%.

[0027] In step (2-a) of the present invention,

[0028] The fine mud, finely ground weak magnetic separation tailings, lime, cement and gypsum in step (1) are mixed to obtain a mixture A, and then the mixture is mixed, poured, foamed and molded, and then autoclaved and cured to obtain an aerated concrete block;

[0029] Preferably, in mixture A, lime accounts for 16% to 25%, cement 8% to 15%, gypsum 1.0% to 5.0%, and the remainder is a mixture of fine mud and finely ground weak magnetic tailings in step (1). In the present invention, the recovered fine mud and finely ground weak magnetic tailings are fully used for the preparation of aerated concrete blocks. The present invention, thanks to the characteristics of the high-silicon iron tailings material and the combination of the recycling process ideas of steps 1 and 2-a, can achieve synergy and facilitate the acquisition of high-performance aerated concrete blocks.

[0030] In the present invention, the preparation conditions of aerated concrete are as follows: the water-to-material ratio of the slurry is 0.68-0.55, the foaming temperature is 60° C.-100° C., the steam curing temperature is 160° C.-220° C., and the steam curing time is 5-10 hours.

[0031] In the present invention, the processing order of step (2-a) and step (2-b) is not specific.

[0032] In step (2-b) of the present invention, the intensity of the strong magnetic separation treatment is greater than or equal to 400 kA / m, preferably 400 to 800 kA / m.

[0033] In the present invention, the non-magnetic components are subjected to three-stage flotation, and the process is, for example: the non-magnetic components are pulped for the first stage of flotation, the first stage of flotation foam (a small amount of residual iron and trace components) is collected, the ore pulp after the first stage of flotation is subjected to the second stage of flotation, the second stage of foam (feldspar) is collected, and then the pulp conditions are adjusted, such as adding a collector, and the third stage of flotation (reverse flotation) is carried out to collect the quartz bottom material. In the present invention, the three-stage flotation recovers feldspar and quartz, and the remaining material (the first flotation foam and the third flotation foam) is mixed with the strong magnetic material for preparing the ceramic microcrystalline lining.

[0034] In the present invention, based on existing means, feldspar and quartz can be recovered from the non-magnetic components, and the remaining materials can be used for the preparation of ceramic microcrystalline linings.

[0035] In step (2-b) of the present invention, the pH of the first flotation stage is 4.5-6.5, and the collector A used is at least one cationic amine collector selected from the group consisting of dodecylamine, hexadecylamine and octadecylamine; preferably, the amount of the collector A used is 50-200 g / t;

[0036] Preferably, the pH of the second stage of flotation is 2.5-3.5; the collector B used is at least one of a primary amine collector and a secondary amine collector. The primary amine is, for example, at least one of dodecylamine, hexadecylamine, and octadecylamine. In the second stage of flotation, the amount of collector B is 75-250 g / t. In the actual flotation process, after the first stage of flotation is completed, the pH of the remaining flotation slurry can be directly adjusted to 2.5-3.5, and the second stage of flotation can be directly carried out.

[0037] Preferably, the pH of the third flotation stage is 2.5-3.5, and the collector C used is at least one of a primary amine collector, a tertiary amine collector, and a quaternary amine collector; the collector C is a primary amine collector and a tertiary amine collector. Preferably, the amount of collector C is 100-300 g / t. In the actual operation of the present invention, after the second stage of flotation, the flotation foam (feldspar) can be separated, and then the collector is added to the remaining slurry to perform the third stage of flotation (reverse flotation), collect the quartz bottom material, and use the foam of the third stage of flotation for the preparation of ceramic microcrystalline linings.

[0038] In step (2-b) of the present invention, the ferromagnetic material, the first flotation foam material and the third flotation foam material are used as main raw materials to prepare the ceramic microcrystalline wear-resistant lining plate by a melting-calendering method.

[0039] In step (2-b) of the present invention, the ferromagnetic material, the first flotation foam material, the third flotation foam material are used as main raw materials, and the adjusting auxiliary agent is mixed and melted, rolled, crystallized annealed, cooled, cut and tailored to obtain a ceramic microcrystalline wear-resistant lining;

[0040] The adjustment aid is at least one of limestone, lime or soda ash;

[0041] Preferably, the adjustment auxiliary agent is 50-80% of the dry weight of the main raw material;

[0042] Preferably, the crystallization annealing condition is 1050° C. to 800° C. and the time is 10 to 150 min.

[0043] The beneficial effects of the present invention are:

[0044] (1) Through the new desludging combined classification process and grinding classification selection process, the high-silicon iron tailings can be efficiently and reasonably selected and fully utilized, which is conducive to the subsequent selection process to fully recover the valuable components of iron, feldspar and quartz as much as possible, and reduce the particle size of the residual materials and the adverse effects of residual metal minerals and impurities on the subsequent utilization of tailings.

[0045] (2) After high-silicon iron tailings are graded and sorted for valuable components, the material particle size characteristics and physical and chemical properties of multiple graded and sorted tailings are classified and used to prepare the main raw materials for aerated concrete blocks and ceramic linings. By adding some auxiliary raw materials and adjusting agents, aerated concrete blocks and ceramic linings are prepared to produce tiered products of different quality and value.

[0046] (3) The comprehensive method of tiered classification utilization in the present invention not only realizes the effective recovery of valuable components such as iron, feldspar, quartz, etc., and fully improves the resource utilization value of iron tailings, but also realizes the full-value comprehensive and efficient quality-based utilization of residual iron tailings, meets the quality requirements of building energy-saving wall materials and industrial wear-resistant materials, achieves the goal of high-value full-component utilization of iron tailings, and opens up a new way for the source of raw materials for new energy-saving building materials and industrial wear-resistant materials.

[0047] The method of the present invention has a high utilization rate of valuable components, a green and environmentally friendly utilization process, and a good cascade classification utilization effect. After treatment, sorting, quality improvement, and classification product preparation, the comprehensive utilization value of the iron tailings is high and the product quality is stable. Relevant experiments have confirmed that the iron concentrate, feldspar, and quartz products obtained by the present invention are of qualified quality, and the aerated concrete blocks and ceramic wear-resistant liners meet or exceed the standard requirements of building wall materials and wear-resistant liners, realizing the full value and efficient utilization of iron tailings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the principle of the processing method of the present invention. DETAILED DESCRIPTION

[0049] In order to make the technical scheme and technical effect of the present invention clearer, the technical scheme in the embodiment of the present invention will be described clearly and completely below. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The present invention provides a method for cascade full-value utilization of high-silicon iron tailings, comprising the following steps:

[0051] (1) The high silicon iron tailings are desludified after classification, the classified sediment is finely ground, and then subjected to weak magnetic separation to obtain a portion of the iron coarse concentrate, and the weak magnetic separation tailings are further subjected to strong magnetic separation to remove iron and impurities to obtain non-magnetic materials after iron and impurities are removed;

[0052] (2) The weak magnetic separation iron coarse concentrate obtained in step (1) is further subjected to closed-circuit grinding. The finely ground material is subjected to multiple weak magnetic separations to obtain an iron concentrate containing more than 60% iron (TFe) as a raw material for ironmaking;

[0053] (3) The non-magnetic material in the above step (1) is further subjected to flotation separation to remove iron and impurities, and then feldspar and quartz are separated by flotation to obtain feldspar products and quartz products;

[0054] (4) mixing the classified overflow fine-grained material obtained in the above step (1) with the finely ground weak magnetic separation tailings, and using them as raw materials for producing aerated concrete blocks, and using them to produce aerated concrete blocks as energy-saving building material products;

[0055] (5) The magnetic product obtained by the strong magnetic separation to remove iron and impurities in the above step (3), the flotation foam product obtained by the flotation separation to remove iron and impurities, and the flotation tailings for the subsequent extraction of feldspar and quartz, are concentrated, filtered and dehydrated as raw materials for the production of ceramic microcrystalline wear-resistant linings by the melt-calendering method.

[0056] The graded desludging in the present invention adopts combined classification, such as: a combination of a spiral classifier and a hydrocyclone, or a combination of a hydrocyclone and a high-frequency vibrating fine screen, or a combination of a spiral classifier, a hydrocyclone and a high-frequency vibrating fine screen, which is beneficial to improving the desludging efficiency and adapting to the material characteristics of different particle sizes and mud contents.

[0057] Preferably, the sand settling fine grinding in step (2) adopts a closed-circuit grinding inspection and classification process;

[0058] Preferably, the particle size of the reground material in step (2) is -0.045 mm and reaches more than 80%, which is beneficial to the monomer dissociation of iron tailings in the iron tailings, as well as the silicon content and particle size requirements of the subsequent raw materials used as aerated concrete blocks;

[0059] Preferably, the multiple weak magnetic separation processes in step (2) are one roughing and one fine separation, one roughing and two fine separations, or one roughing and three fine separations, to obtain an iron concentrate containing more than 60% iron (TFe) as a raw material for ironmaking.

[0060] In the present invention, non-magnetic materials of high-silicon iron tailings are further ironed and impurities removed by flotation separation. Sulfuric acid is used as an adjusting agent in the flotation operation, the pH value is controlled at 4.5-6.5, and cationic amine collectors are used for positive flotation; then, sulfuric acid is used to control the pH value at 2.5-3.5, and cationic amine collectors are used as flotation agents to extract feldspar; amine collectors are added to continue flotation, and finally quartz products and some intermediate ore products containing feldspar and quartz are obtained; feldspar and quartz products are obtained, and high-value utilization of iron tailings is realized. At the same time, flotation tailings containing iron and impurities of different levels, such as metal impurities such as iron, titanium, and manganese, and flotation intermediates containing silicon, aluminum, potassium, and sodium are obtained, which is conducive to obtaining docking materials with strong adaptability according to the requirements and grades of different ceramic linings, fully exploring the chemical composition characteristics of high-silicon iron tailings materials, and achieving the requirements of reasonable, accurate, and tiered utilization.

[0061] Preferably, sulfuric acid is used as a regulator in the flotation in step (3), and the pH value for iron and impurity removal is controlled at 4.5 to 6.5.

[0062] Preferably, the collector used for flotation in step (3) is a cationic amine collector for positive flotation.

[0063] Preferably, in the flotation operation of feldspar in step (3), sulfuric acid is used to control the pH value to be between 2.5 and 3.5.

[0064] In the present invention, after high-silicon iron tailings are graded and valuable components are separated, the material particle size characteristics and physical and chemical properties of multiple graded and sorted tailings are mixed with graded overflow fine-grained materials and finely ground weak magnetic separation tailings as raw materials for producing aerated concrete blocks, and the particle size characteristics and silicon content characteristics thereof are utilized, and part of lime, cement and a small amount of gypsum are added to produce aerated concrete blocks as energy-saving building material products;

[0065] Preferably, in the step (4), the mixed raw material of the classified overflow fine-grained material and the finely ground weak magnetic separation tailings accounts for 55% to 75%, and the added auxiliary raw materials include 16% to 25% lime, 8% to 15% cement, and 1.0% to 5.0% gypsum.

[0066] In the present invention, the magnetic product of strong magnetic separation for removing iron and impurities, the flotation foam product obtained by flotation separation for removing iron and impurities, and the flotation tailings for subsequent extraction of feldspar and quartz, three kinds of separation intermediate products are concentrated, filtered and dehydrated, and used as raw materials for producing ceramic microcrystalline wear-resistant linings by melt-calendering method; the high silicon material characteristics and the flux-assisting characteristics of part of feldspar therein are utilized, and part of the iron minerals and a small amount of metal minerals contained in the iron and impurity removal products of strong magnetic separation and flotation operations are utilized as nucleating agents; and a small amount of adjusting agent, such as limestone, lime or soda ash, is added, and the ceramic microcrystalline wear-resistant linings are produced by melt-calendering method.

[0067] Preferably, the adjusting agent added in step (5) is: limestone, lime or soda ash, and a mixture of two or three thereof;

[0068] Preferably, in the method for producing the ceramic microcrystalline wear-resistant lining plate in step (5), the melt-calendering method is preferred, which is beneficial to improving the compressive strength and wear resistance of the ceramic microcrystalline wear-resistant lining plate, reducing the porosity of the ceramic microcrystalline wear-resistant lining plate, and extending the service life of the ceramic microcrystalline wear-resistant lining plate.

[0069] In the following typical implementation cases of the present invention, the magnetic field strength of the weak magnetic separation is, for example, 100 to 150 kA / m.

[0070] Example 1

[0071] Firstly, the iron tailings containing 10.5% of iron (TFe) and 72.5% of silicon (SiO2) were classified by a combination of a spiral classifier and a hydrocyclone to obtain fine mud and desludging sand with a yield of 17.8%. The desludging sand was separated by weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings (desludging sand weak magnetic separation tailings);

[0072] The weak magnetic coarse concentrate adopts the grinding inspection and grading closed-circuit grinding process to obtain a slurry of -0.045mm accounting for 82%. The magnetic separation process is selected as a roughing selection and a scavenging selection magnetic separation process to obtain an iron concentrate with an iron content of 61.9%, as well as finely ground weak magnetic separation tailings.

[0073] The desludging and sanding weak magnetic separation tailings were subjected to strong magnetic separation with a magnetic field strength of 480 kA / m to obtain magnetic products and strong magnetic tailings. The strong magnetic tailings were used as flotation feed for the first stage of flotation to remove iron and impurities. Sulfuric acid was added to control the pH value to 5.5-6.5. Dodecylamine (dodecylamine in this case, the dosage was 160 g / t) was added as a collector. After flotation operation, the flotation separation method iron and impurity removal product (a first stage flotation foam, containing only 0.36% TFe) was obtained. Sulfuric acid was added to the first stage flotation slurry to adjust The pH value is 2.5-3.0. After the second stage flotation, the obtained foam is feldspar concentrate (Na2O+K2O content is 8.48%). N,N-dimethyldodecylamine and N,N-dimethyltetradecylamine (mass ratio is 1:1, total addition amount is 150g / t, flotation time condition is 10min) are added to the second stage flotation slurry for the third stage flotation to obtain the quartz product of the bottom product (quartz concentrate containing SiO2 of 99.56%) and the reverse flotation tailings (three-stage flotation foam).

[0074] The fine-grained material (fine mud) overflowed from the classification and the finely ground weak magnetic tailings were passed through an efficient thickener, and the weight content of the material was 67% as the raw material for producing aerated concrete blocks. The auxiliary raw materials included 20% lime, 10% cement, and 3.0% gypsum. After slurry mixing, pouring, and foaming, the preparation conditions of aerated concrete were: the water-to-material ratio of the slurry was 0.55, the foaming temperature was 70°C, the steam curing temperature was 190°C, and the steam curing time was 8h. After autoclaving and curing in an autoclave, the compressive strength was 3.57MPa and the dry volume density was 622kg / m 3 , products that meet the requirements of A5.0B06 grade qualified products.

[0075] The magnetic products of strong magnetic separation for iron and impurity removal, the products of flotation separation for iron and impurity removal (first stage flotation foam) and the flotation tailings of reverse flotation quartz (third stage flotation foam), after concentration-filtration and dehydration, are used as the main raw materials for the production of ceramic microcrystalline wear-resistant linings by melt rolling method, and 7% limestone is added. After mixing and melting, the mixture is rolled 5 times by a calender, crystallized and annealed at 1050℃~900℃, and then cut to obtain ceramic microcrystalline wear-resistant lining products, which finally realizes the full-value utilization of high-silicon iron tailings. The product has low porosity, high hardness and good wear resistance. Its apparent porosity is 0.28% and its Rockwell hardness is HRA80.

[0076] Example 2

[0077] Step (1) firstly, the iron tailings containing 9.3% of iron (TFe) and 74.9% of silicon (SiO2) are subjected to a combined classification method of a hydrocyclone and a high-frequency vibrating fine screen to obtain fine mud and desludging sand with a yield of 16.5%, and the desludging sand is separated by weak magnetic separation to obtain weak magnetic coarse concentrate and weak magnetic tailings (desludging sand weak magnetic separation tailings);

[0078] Step (2) The weak magnetic coarse concentrate adopts a grinding inspection and grading closed-circuit grinding process to obtain a slurry of -0.045 mm accounting for 85%, and a magnetic separation process is selected as a magnetic separation process of primary roughing and secondary scavenging to obtain an iron concentrate with an iron content of 61.6%, as well as finely ground weak magnetic separation tailings.

[0079] Step (3) The desludging and sanding weak magnetic separation tailings are subjected to strong magnetic separation, and the magnetic field strength is 540 kA / m to obtain magnetic products and strong magnetic tailings. The strong magnetic tailings are used as flotation feed for the first stage of flotation to remove iron and impurities, sulfuric acid is added, and the pH value is controlled to be 5.0-6.0. Octadecylamine (the dosage is 120 g / t) is added as a collector. After flotation operation, a flotation separation method iron removal and impurity removal product (first stage flotation foam) is obtained. Sulfuric acid is added to the first stage flotation slurry to adjust the pH value to 3. 0~3.5, carry out the second stage flotation, the obtained foam is feldspar concentrate (Na2O+K2O content is 8.25%), add N,N-dimethyldodecylamine and N,N-dimethyltetradecylamine (mass ratio is 1:1, the total addition amount is 100g / t) to the second stage flotation pulp, carry out three stage flotation, the flotation time condition is 8min, and obtain the quartz product of the bottom product (quartz concentrate containing SiO2 is 99.63%) and reverse flotation tailings (three stage flotation foam).

[0080] Step (4) The fine-grained material (fine mud) overflowed from the classification and the finely ground weak magnetic tailings are passed through an efficient thickener, and the weight content of the material is 75% as the raw material for producing aerated concrete blocks. The auxiliary raw materials include 16% lime, 8% cement, and 1.0% gypsum. After slurry mixing, pouring, and foaming molding, the preparation conditions of aerated concrete are as follows: the water-to-material ratio of the slurry is 0.61, the foaming temperature is 100°C, the steam curing temperature is 160°C, the steam curing time is 10h, and after autoclave curing, the compressive strength is 3.65MPa and the dry volume density is 628kg / m 3 , products that meet the requirements of A3.5B06 grade qualified products.

[0081] Step (5) The magnetic product of strong magnetic separation for iron and impurity removal, the product of flotation separation for iron and impurity removal (first stage flotation foam) and the flotation tailings of reverse flotation quartz (third stage flotation foam), the three intermediate products of separation are concentrated, filtered and dehydrated, and used as the main raw materials for producing ceramic microcrystalline wear-resistant linings by melt rolling method, 6% lime is added, mixed and melted, rolled four times by a rolling machine, crystallized and annealed at 950°C to 800°C, and then cut to obtain ceramic microcrystalline wear-resistant lining products, thus finally realizing the full-value utilization of high-silicon iron tailings. The product has low porosity, high hardness and good wear resistance. Its apparent porosity is 0.29% and its Rockwell hardness is HRA75.

[0082] Example 3

[0083] Firstly, the iron tailings containing 10.8% iron (TFe) and 71.3% silicon (SiO2) were classified by a combination of spiral classifier, hydrocyclone and high-frequency vibrating fine screen to obtain fine mud and desludging sand with a yield of 19.6%.

[0084] After desludging and sanding, weak magnetic separation is used to obtain weak magnetic coarse concentrate and weak magnetic tailings (desludging and sanding weak magnetic separation tailings); the weak magnetic coarse concentrate adopts a grinding inspection and grading closed-circuit grinding process to obtain a slurry of -0.045mm accounting for 90%, and the magnetic separation process is selected as a magnetic separation process with a primary roughing selection and a secondary scavenging selection to obtain an iron concentrate with an iron content of 62.7%, as well as finely ground weak magnetic separation tailings.

[0085] The desludging and sanding weak magnetic separation tailings are subjected to strong magnetic separation with a magnetic field strength of 640 kA / m to obtain magnetic products and strong magnetic tailings. The strong magnetic tailings are used as flotation feed for the first stage of flotation to remove iron and impurities (add sulfuric acid, control the pH value to 4.5-5.0, add cationic mixed amine (specifically hexadecylamine, the amount is 200 g / t) as a collector), and then a stage of flotation is performed to obtain a flotation method for removing iron and impurities (a stage of flotation foam). Sulfuric acid is added to the flotation slurry to adjust pH. The H value is 2.5-3.0. After the second stage flotation, the foam obtained is feldspar concentrate (Na2O+K2O content is 8.31%), and then N,N-dimethyldodecylamine and N,N-dimethyltetradecylamine are added to the second stage flotation slurry (mass ratio is 1:1, the total addition amount is 200g / t, and the flotation time condition is 9min) to obtain the bottom product quartz product (quartz concentrate containing SiO2 of 99.78%) and reverse flotation tailings (three-stage foam).

[0086] The fine-grained materials from the overflow of classification and the finely ground weak magnetic tailings are passed through a high-efficiency thickener and used as raw materials for the production of aerated concrete blocks according to the weight content of the materials of 55%. The auxiliary raw materials include 25% lime, 15% cement and 5.0% gypsum. After slurry mixing, pouring and foaming, the preparation conditions of aerated concrete are as follows: the water-to-material ratio of the slurry is 0.68, the foaming temperature is 80℃, the steam curing temperature is 220℃, the steam curing time is 6h, and after autoclave curing, the compressive strength is 5.08MPa and the dry volume density is 619kg / m 3 , products that meet the requirements of A5.0B06 grade qualified products.

[0087] The magnetic products of strong magnetic separation for iron and impurity removal, the products of flotation separation for iron and impurity removal, and the flotation tailings of reverse flotation quartz, three kinds of sorting intermediate products, after concentration-filtration and dehydration, are used as the main raw materials for producing ceramic microcrystalline wear-resistant linings by melt rolling method, 4.5% lime and 1.0% soda ash are added, after mixing and melting, they are repeatedly rolled by a rolling machine, crystallized and annealed, and then cut to obtain ceramic microcrystalline wear-resistant lining products, finally realizing the full-value utilization of high-silicon iron tailings (rolling and crystallization conditions are the same as in Example 1). The product has low porosity, high hardness and good wear resistance. Its apparent porosity is 0.27% and Rockwell hardness is HRA85.

[0088] Comparative Example 1

[0089] Compared with Example 3, the only difference is that the preparation process of aerated concrete blocks is changed. The difference in step 4 is that only fine-grained materials (fine mud) from graded overflow are used as raw materials, and the content of fine mud in the aerated concrete raw materials is still 75%, that is, the recovered raw materials are completely replaced by weak magnetic separation tailings with fine mud. The other operations and parameters are the same as those in Example 3. As a result, it is found that the strength of the aerated concrete obtained is 2.8 to 3.0 MPa, which is not as good as the full value method of the present invention.

[0090] Comparative Example 2

[0091] Compared with Example 3, the only difference is that the preparation process of aerated concrete blocks is changed. The difference in step 4 is that only finely ground weak magnetic tailings are used as raw materials, and the content of the finely ground weak magnetic tailings in the aerated concrete raw materials is still 75%, that is, the fine mud in the recovered raw materials is replaced by finely ground weak magnetic tailings. The other operations and parameters are the same as those in Example 3. As a result, it is found that the strength of the aerated concrete obtained is 2.9 to 3.1 MPa, which is not as good as the full value method of the present invention.

[0092] It can be seen from Example 3 and Comparative Examples 1 to 2 that the method of the present invention can not only achieve a better waste utilization effect, but also unexpectedly achieve combined synergy to obtain better performance of the treated product.

[0093] Comparative Example 3

[0094] Compared with Example 3, the only difference is that in step (5), the magnetic product of strong magnetic separation of iron and impurities in the raw material uses the first flotation foam and the third flotation foam as the recovered raw material, and the other operations and parameters are the same as those in Example 3. The study found that the apparent porosity of the obtained ceramic microcrystalline wear-resistant lining product is 0.55% and the Rockwell hardness is HRA65. The performance is not as good as the method of the present invention.

[0095] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the full-value utilization of high-silicon iron tailings, characterized in that: include: Step (1): Desludging-magnetic separation The high silicon iron tailings are subjected to graded desludging treatment to obtain fine mud and desludging sand; The desludging and settling sand is subjected to weak magnetic separation to obtain weak magnetic separation coarse concentrate and weak magnetic separation tailings; Step (2): In any order, the weak magnetic separation rough concentrate and weak magnetic separation tailings collected in step (1) are utilized as resources, the steps are as follows: Step (2-a): Weak magnetic separation and resource processing of coarse concentrate The weak magnetic separation coarse concentrate of step (1) is subjected to ore grinding, closed-circuit fine grinding and weak magnetic separation to obtain iron concentrate and finely ground weak magnetic separation tailings; The fine mud and finely ground weak magnetic separation tailings from step (1) are used to prepare aerated concrete blocks; Step (2-b): Weak magnetic separation tailings resource processing: The weak magnetic separation tailings of step (1) are subjected to strong magnetic separation to obtain strong magnetic material and non-magnetic material; The non-magnetic material is subjected to a first stage of flotation to obtain a first flotation foam material containing iron and impurities and a first purified material enriched with feldspar-quartz; The first purified material is subjected to a second stage flotation treatment to separate feldspar concentrate and a second flotation tailing, and the second flotation tailing is subjected to a third reverse flotation to obtain quartz and a third flotation foam material; The strong magnetic material, the first flotation foam material and the third flotation foam material are mixed and used for preparing the ceramic microcrystalline lining plate.

2. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 1, characterized in that: The iron content in the high-silicon iron tailings is greater than or equal to 8wt.%; the SiO2 content is greater than or equal to 65wt%.

3. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 2, characterized in that: The high-silicon iron tailings contain 9-12wt% iron and 70-75wt% SiO2.

4. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 1, characterized in that: In step (1), classification and desludging are performed based on a combined classification method, wherein the combined classification method includes a combination of a spiral classifier and a hydrocyclone; or a combination of a hydrocyclone and a high-frequency vibrating fine screen; or a combination of a spiral classifier, a hydrocyclone and a high-frequency vibrating fine screen.

5. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 1, characterized in that: In step (1), the intensity of the weak magnetic separation stage is ≤300 kA / m.

6. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 5, characterized in that: In step (1), the intensity of the weak magnetic separation stage is 80~240kA / m.

7. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 1, characterized in that: The closed-circuit ground mineral material in step (2-a) has a particle size of -0.045 mm after fine grinding reaching more than 80%.

8. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 1, characterized in that: The number of weak magnetic selections is greater than or equal to 2 times.

9. The cascade full-value utilization method of high-silicon iron tailings as claimed in claim 8, characterized in that: The number of weak magnetic selections is 2 to 4 times.

10. The cascade full-value utilization method of high-silicon iron tailings according to claim 1, characterized in that: The iron content of the iron concentrate obtained by weak magnetic separation is greater than 60wt.%.

11. The cascade full-value utilization method of high-silicon iron tailings according to claim 1, characterized in that: In step (2-a), the fine mud, finely ground weak magnetic separation tailings, lime, cement and gypsum of step (1) are mixed to obtain a mixture A, which is then slurried, poured, foamed and then autoclaved to obtain aerated concrete blocks.

12. The method for full-value utilization of high-silicon iron tailings according to claim 11, characterized in that: In mixture A, lime accounts for 16% to 25%, cement accounts for 8% to 15%, gypsum accounts for 1.0% to 5.0%, and the remainder is a mixture of fine mud and finely ground weak magnetic separation tailings in step (1).

13. The cascade full-value utilization method of high-silicon iron tailings according to claim 11, characterized in that: Preparation conditions of aerated concrete: water-to-material ratio of slurry is 0.68~0.55, foaming temperature is 60℃~100℃, steaming temperature is 160℃~220℃, and steaming time is 5~10 h.

14. The cascade full-value utilization method of high-silicon iron tailings according to claim 1, characterized in that: In step (2-b), the intensity of the strong magnetic separation treatment is greater than or equal to 400 kA / m.

15. The method for full-value utilization of high-silicon iron tailings according to claim 14, characterized in that: In step (2-b), the intensity of the strong magnetic separation treatment is 400~800kA / m.

16. The cascade full-value utilization method of high-silicon iron tailings according to claim 1, characterized in that: In step (2-b), the pH of the first flotation stage is 4.5-6.5, and the collector A used is at least one cationic amine collector selected from the group consisting of dodecylamine, hexadecylamine and octadecylamine; the amount of the collector A used is 50-200 g / t.

17. The method for full-value utilization of high-silicon iron tailings according to claim 1, characterized in that: The pH value of the second flotation is 2.5-3.5; the collector B used is at least one of a primary amine collector and a secondary amine collector; and the amount of the collector B used in the second flotation stage is 75-250 g / t.

18. The method for full-value utilization of high-silicon iron tailings according to claim 1, characterized in that: The pH value of the third flotation stage is 2.5-3.5, and the collector C used is at least one of a primary amine collector, a secondary amine collector, a tertiary amine collector, and a quaternary amine collector, and the amount of the collector C used is 100-300 g / t.

19. The method for full-value utilization of high-silicon iron tailings according to claim 1, characterized in that: In step (2-b), the ceramic microcrystalline lining is produced by a melting-calendering method.

20. The method for full-value utilization of high-silicon iron tailings according to claim 19, characterized in that: The ferromagnetic material, the first flotation foam material, the third flotation foam material are used as main raw materials, and the adjusting auxiliary agent is mixed and melted, rolled, crystallized annealed, cooled, cut and tailored to obtain a ceramic microcrystalline lining plate; The adjustment auxiliary agent is at least one of limestone, lime or soda ash.

21. The method for full-value utilization of high-silicon iron tailings according to claim 20, characterized in that: The adjusting auxiliary agent is 50-80% of the dry weight of the main raw material.

22. The method for full-value utilization of high-silicon iron tailings according to claim 20, characterized in that: The crystallization annealing conditions are 1050℃~800℃ and the time is 10~150 min.

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