Treatment method for dissolving red mud out of gibbsite

Abstract

The invention relates to a treatment method for red mud dissolved out of gibbsite, the red mud dissolved out of gibbsite contains sodium-silicon slag and ferric oxide, the method comprises the following steps: under the condition of set temperature, mixing the red mud dissolved out of gibbsite with alkali liquor with set concentration and degassed carbide slag for chemical reaction, the red mud is dissolved out from the gibbsite to be converted into molten garnet, and dissolved-out slurry is obtained. According to the method, sodium oxide and aluminum oxide in the red mud dissolved out of gibbsite are effectively recycled.

Description

Technical Field

[0001] The present application relates to the technical field of red mud recovery from gibbsite ore dissolution, and in particular to a method for treating red mud from gibbsite ore dissolution. Background Art

[0002] At present, the main method for producing alumina is the Bayer process. Every ton of alumina produced will produce 1 to 2 tons of red mud. Currently, more than 100 million tons of red mud are produced each year. The red mud has a high alkali content, which has an adverse impact on the environment. Bayer red mud contains a large amount of aluminum oxide, silicon dioxide, sodium oxide and other substances. In order to recover the sodium and aluminum resources, lime can be added, but lime must be obtained by roasting, which consumes natural resources limestone and a lot of energy.

[0003] Currently, the main method for producing alumina is the Bayer process, especially the low-temperature dissolution of gibbsite ore, which accounts for more than half of the total. The A / S (weight ratio of aluminum oxide Al2O3 to silicon oxide SiO2) of red mud dissolved from gibbsite ore is 2-2.5, and the N / S (weight ratio of sodium oxide Na2O to silicon oxide SiO2) is about 0.45. The domestic output of this red mud exceeds 100 million tons per year, and the global output exceeds 200 million tons. Therefore, there is an urgent need to effectively recycle the red mud dissolved from gibbsite ore. Summary of the invention

[0004] The present application provides a method for treating red mud dissolved from gibbsite ore to solve the following technical problem: how to effectively recover sodium oxide and aluminum oxide from the red mud dissolved from gibbsite ore.

[0005] In a first aspect, the present application provides a method for treating red mud dissolved from gibbsite ore, wherein the red mud dissolved from gibbsite ore contains sodium silicate slag and iron oxide, and the method comprises:

[0006] Under the condition of set temperature, the gibbsite ore dissolved red mud is mixed with alkali solution with set concentration and degassed carbide slag to carry out chemical reaction, so that the gibbsite ore dissolved red mud is converted into iron hydrate garnet to obtain dissolved slurry.

[0007] Optionally, the set temperature T is 140°C≤T≤180°C, and the set concentration Nk is 160g / L~280g / L.

[0008] Optionally, the weight of the degassed carbide slag is 10% to 35% of the weight of the red mud dissolved from the gibbsite ore; and / or,

[0009] The red mud dissolved from the gibbsite ore is 100 g to 350 g relative to 1 L of the alkali solution; and / or

[0010] The chemical reaction time is 60 min to 240 min.

[0011] Optionally, the method further includes: performing solid-liquid separation on the leached slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.76 to 0.92, and N / S is 0.18 to 0.28.

[0012] Optionally, the set temperature T is 180°C < T ≤ 240°C, and the set concentration Nk is 140 g / L to 280 g / L.

[0013] Optionally, the weight of the degassed carbide slag is 10% to 40% of the weight of the diaspore ore digestion red mud; and / or,

[0014] Relative to 1 L of the alkali solution, the diaspore ore digestion red mud is 100 g to 400 g; and / or,

[0015] The time for the chemical reaction is 60 min to 180 min.

[0016] Optionally, the method further includes: performing solid-liquid separation on the leached slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.66 to 0.82, and N / S is 0.12 to 0.18.

[0017] Optionally, the set temperature T is 240°C < T ≤ 280°C, and the set concentration Nk is 100 g / L to 280 g / L.

[0018] Optionally, the weight of the degassed carbide slag is 10% to 50% of the weight of the diaspore ore digestion red mud; and / or,

[0019] Relative to 1 L of the alkali solution, the diaspore ore digestion red mud is 100 g to 500 g; and / or,

[0020] The time for the chemical reaction is 30 min to 120 min.

[0021] Optionally, the method further includes: performing solid-liquid separation on the leached slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.28 to 0.72, and N / S is 0.01 to 0.12.

[0022] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0023] The embodiment of the present application provides a method for treating the red mud dissolved from gibbsite ore, wherein the red mud dissolved from gibbsite ore contains sodium silicate slag and iron oxide. The method comprises: under a set temperature, mixing the red mud dissolved from gibbsite ore with an alkali solution having a set concentration and degassed carbide slag to carry out a chemical reaction so as to convert the red mud dissolved from gibbsite ore into iron hydrate garnet to obtain a dissolved slurry. Generally, gibbsite ore is leached by Bayer process at a relatively low temperature of 145°C. A small amount of lime is added during the leaching process. The sodium silicate slag (Na2O·Al2O3·2SiO2·2H2O) in the red mud after the leaching process is observed through an electron microscope. The composition is incomplete and the combination is very loose. The red mud has a high iron oxide content, generally above 20%. Under the condition of a set temperature, the red mud leached from the gibbsite ore is mixed with an alkali solution with a set concentration and degassed carbide slag to carry out a chemical reaction, so that the red mud leached from the gibbsite ore is converted into iron hydrate garnet (CaO·Fe2O3·2SiO2·2H2O), and the aluminum oxide and sodium oxide in the sodium silicate slag are immersed in the solution, thereby effectively recovering the sodium oxide and aluminum oxide in the red mud leached from the gibbsite ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0026] Figure 1 A schematic flow chart of a method for treating red mud dissolved from gibbsite ore provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0029] In this application, unless otherwise specified, directional words such as "upper" and "lower" used refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of this application, the terms "include", "comprise", etc. mean "including but not limited to".

[0030] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0031] In a first aspect, the present application provides a method for treating red mud dissolved from gibbsite ore. Figure 1 A schematic diagram of a process for treating red mud from gibbsite ore provided in an embodiment of the present application; see Figure 1 The red mud dissolved from the gibbsite ore contains sodium silicate slag and iron oxide, and the method comprises:

[0032] S1. Under a set temperature, the red mud dissolved from the gibbsite ore is mixed with an alkali solution having a set concentration and degassed carbide slag to carry out a chemical reaction, so that the red mud dissolved from the gibbsite ore is converted into iron hydrate garnet to obtain a dissolved slurry.

[0033] In the present application embodiment, carbide slag is the waste residue produced after carbide hydrolysis in the process of industrial production of acetylene gas, polyvinyl chloride (PVC), polyvinyl alcohol (PVA), etc., and its main component is calcium hydroxide. Carbide slag is usually not properly handled, and is generally directly piled in the open air, occupying a large amount of land and polluting the surrounding soil and water sources. Acetylene is also left in the carbide slag. Although acetylene has utilization value, the economic benefit of degassing carbide slag to collect acetylene is very low. Acetylene is easy to be adsorbed on calcium hydroxide, and may be accumulated and cause potential safety hazards when it is released in the red mud dissolution process. Therefore, the present application adopts degassed carbide slag as an additive to treat the low-temperature Bayer process dissolution red mud of gibbsite ore, and the sodium oxide and aluminum oxide in the red mud can be effectively recovered at a lower temperature, and the aluminum oxide and sodium oxide recovery rate are more obvious when the higher temperature is processed.

[0034] Generally, gibbsite ore is leached by Bayer process at a relatively low temperature of 145°C. A small amount of lime is added during the leaching process. The sodium silicate slag (Na2O·Al2O3·2SiO2·2H2O) in the red mud after the leaching process is observed through an electron microscope. The composition is incomplete and the combination is very loose. The red mud has a high iron oxide content, generally above 20%. Under the condition of a set temperature, the red mud leached from the gibbsite ore is mixed with an alkali solution with a set concentration and degassed carbide slag to carry out a chemical reaction, so that the red mud leached from the gibbsite ore is converted into iron hydrate garnet (CaO·Fe2O3·2SiO2·2H2O), and the aluminum oxide and sodium oxide in the sodium silicate slag are immersed in the solution, thereby effectively recovering the sodium oxide and aluminum oxide in the red mud leached from the gibbsite ore.

[0035] In some embodiments, the set temperature T is 140°C≤T≤180°C, and the set concentration Nk is 160 g / L to 280 g / L.

[0036] In some embodiments, the weight of the degassed carbide slag is 10% to 35% of the weight of the red mud dissolved from the gibbsite ore; and / or,

[0037] The red mud dissolved from the gibbsite ore is 100 g to 350 g relative to 1 L of the alkali solution; and / or

[0038] The chemical reaction time is 60 min to 240 min.

[0039] In some embodiments, the method further comprises: performing solid-liquid separation on the dissolution slurry to obtain solid waste; wherein the composition of the solid waste satisfies: A / S is 0.76 to 0.92, and N / S is 0.18 to 0.28.

[0040] In the embodiment of the present application, gibbsite ore is generally subjected to Bayer dissolution at a relatively low temperature of 145°C, and less lime is added during dissolution. The composition of the sodium silicate slag in the red mud after dissolution is incomplete and very loosely bonded, and the red mud has a high iron oxide content, generally above 20%. Under the condition of a relatively low set temperature, the addition of degassed carbide slag and an alkali solution with a set concentration can convert the red mud into iron hydrate garnet, thereby recovering the sodium oxide and aluminum oxide in the red mud. Exemplarily, the preset temperature can be 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, etc.; the caustic soda concentration N of the alkali solution kIt can be 160 g / L, 170 g / L, 180 g / L, 190 g / L, 200 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, 250 g / L, 260 g / L, 270 g / L, 280 g / L, etc.; the weight of the degassed carbide slag can be 10%, 15%, 20%, 25%, 30%, 35%, etc. of the weight of the bauxite ore digestion red mud; relative to 1 L of the alkali liquor, the bauxite ore digestion red mud can be 100 g, 150 g, 200 g, 250 g, 300 g, 350 g, etc.; the digestion time can be 60 min, 80 min, 100 min, 120 min, 140 min, 150 min, 180 min, 200 min, 230 min, 240 min, etc. In addition, in the degassed carbide slag, CaO is higher than 52% of the dry weight of the degassed carbide slag, and the content of organic carbon is lower than 0.5%.

[0041] In some embodiments, the set temperature T is 180 °C < T ≤ 240 °C, and the set concentration Nk is 140 g / L to 280 g / L.

[0042] In some embodiments, the weight of the degassed carbide slag is 10% to 40% of the weight of the bauxite ore digestion red mud; and / or,

[0043] Relative to 1 L of the alkali liquor, the bauxite ore digestion red mud is 100 g to 400 g; and / or,

[0044] The time of the chemical reaction is 60 min to 180 min.

[0045] In some embodiments, the method further includes: performing solid-liquid separation on the digested slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.66 to 0.82, and N / S is 0.12 to 0.18.

[0046] In the embodiments of the present application, when treating the Bayer red mud at a relatively high temperature (180 °C < T ≤ 240 °C), the A / S and N / S of the obtained solid waste are further reduced, A / S is 0.66 to 0.82, and N / S is 0.12 to 0.18. Exemplarily, the preset temperature can be 181 °C, 190 °C, 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, etc.; the caustic alkali concentration N of the alkali liquor kIt can be 140 g / L, 160 g / L, 180 g / L, 200 g / L, 220 g / L, 240 g / L, 260 g / L, 280 g / L, etc.; the weight of the degassed carbide slag can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc. of the weight of the bauxite ore digestion red mud; relative to 1 L of the alkali solution, the bauxite ore digestion red mud can be 100 g, 150 g, 200 g, 250 g, 300 g, 350 g, 400 g, etc.; the digestion time can be 60 min, 80 min, 100 min, 120 min, 140 min, 150 min, 180 min, etc. In addition, in the degassed carbide slag, CaO is higher than 52% of the dry weight of the degassed carbide slag, and the content of organic carbon is less than 0.5%.

[0047] In some embodiments, the set temperature T is 240 °C < T ≤ 280 °C, and the set concentration Nk is 100 g / L to 280 g / L.

[0048] In some embodiments, the weight of the degassed carbide slag is 10% to 50% of the weight of the bauxite ore digestion red mud; and / or,

[0049] Relative to 1 L of the alkali solution, the bauxite ore digestion red mud is 100 g to 500 g; and / or,

[0050] The time of the chemical reaction is 30 min to 120 min.

[0051] In some embodiments, the method further includes: performing solid-liquid separation on the digestion slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.28 to 0.72, and N / S is 0.01 to 0.12.

[0052] In the embodiments of the present application, since the iron oxide content of the red mud (generally above 20%) is relatively high, and it can be treated at a high temperature of 240 °C < T ≤ 280 °C, the A / S of the obtained solid waste can reach 0.28 to 0.72, N / S is 0.01 to 0.12, the sodium oxide content is less than 1%, calculated as sodium oxide, the recovery rate of sodium resources can reach up to more than 90%, calculated as alumina, the recovery rate of aluminum resources can reach about 70%. The iron in the red mud can be enriched, which is beneficial to the recovery of iron, and the red mud is conducive to comprehensive utilization. The requirements for the degassed carbide slag are lower. During high-temperature digestion, the CaO content in the degassed carbide slag is greater than 46%, and the organic C content is less than 0.7%. Exemplarily, the preset temperature can be 241 °C, 245 °C, 250 °C, 255 °C, 260 °C, 265 °C, 270 °C, 275 °C, 280 °C, etc.; the caustic alkali concentration N of the alkali solution kIt can be 100g / L, 120g / L, 140g / L, 160g / L, 180g / L, 200g / L, 220g / L, 240g / L, 260g / L, 280g / L, etc.; the weight of the degassed carbide slag can be 10%, 20%, 30%, 40%, 50%, etc. of the weight of the red mud dissolved from the gibbsite ore; relative to 1L of alkali solution, the red mud dissolved from the gibbsite ore can be 100g, 150g, 200g, 250g, 300g, 350g, 400g, 450g, 500g, etc.; the dissolution time can be 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, etc.

[0053] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0054] Example 1

[0055] The degassed carbide slag has a CaO content of 62% and an organic C content of 0.2% based on dry weight.

[0056] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0057] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0058] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution, red mud and degassed carbide slag is 220g / L, alkali solution is mixed with 200g red mud per liter of alkali solution, the weight of degassed carbide slag accounts for 25% of the weight of red mud, the temperature of dissolution treatment is 160℃, the time of dissolution treatment is 3h, and the A / S of the obtained solid waste is 0.86 and the N / S is 0.24. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 60.9% and the recovery rate of sodium oxide is 46.7%.

[0059] Example 2

[0060] The degassed carbide slag has a CaO content of 62% and an organic C content of 0.2% based on dry weight.

[0061] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0062] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0063] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution is 200g / L, alkali solution, red mud and degassed carbide slag are mixed, 280g of red mud is mixed with each liter of alkali solution, the weight of degassed carbide slag accounts for 35% of the weight of red mud, the temperature of dissolution treatment is 180℃, the time of dissolution treatment is 2h, and the A / S of the obtained solid waste is 0.80 and the N / S is 0.22. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 63.6% and the recovery rate of sodium oxide is 51.1%.

[0064] Example 3

[0065] The degassed carbide slag has a CaO content of 62% and an organic C content of 0.2% based on dry weight.

[0066] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0067] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0068] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution, red mud and degassed carbide slag is 260g / L, alkali solution, red mud and degassed carbide slag are mixed, 220g of red mud is mixed with each liter of alkali solution, the weight of degassed carbide slag accounts for 25% of the weight of red mud, the temperature of dissolution treatment is 160℃, the time of dissolution treatment is 4h, and the A / S of the obtained solid waste is 0.78 and N / S is 0.20. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 64.5%, and the recovery rate of sodium oxide is 55.6%.

[0069] Example 4

[0070] The degassed carbide slag has a CaO content of 60% and an organic C content of 0.2% based on dry weight.

[0071] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0072] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0073] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution is 180g / L, alkali solution, red mud and degassed carbide slag are mixed, 300g of red mud is mixed with each liter of alkali solution, the weight of degassed carbide slag accounts for 25% of the weight of red mud, the temperature of dissolution treatment is 200℃, the time of dissolution treatment is 2h, and the A / S of the obtained solid waste is 0.78 and the N / S is 0.18. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 64.5%, and the recovery rate of sodium oxide is 60%.

[0074] Example 5

[0075] The degassed carbide slag has a CaO content of 60% and an organic C content of 0.2% based on dry weight.

[0076] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0077] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0078] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution, red mud and degassed carbide slag is 220g / L, alkali solution is mixed with 350g red mud per liter of alkali solution, the weight of degassed carbide slag accounts for 25% of the weight of red mud, the temperature of dissolution treatment is 220℃, the time of dissolution treatment is 2h, and the A / S of the obtained solid waste is 0.74 and N / S is 0.18. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 66.4% and the recovery rate of sodium oxide is 60%.

[0079] Example 6

[0080] The degassed carbide slag has a CaO content of 60% and an organic C content of 0.2% based on dry weight.

[0081] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0082] Alkali liquor, red mud and degassed carbide slag are mixed and subjected to dissolution treatment to obtain dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation and liquid products and solid wastes are collected.

[0083] Wherein, the caustic soda concentration N of the alkali solution is KThe concentration of alkali solution, red mud and degassed carbide slag is 240g / L, alkali solution, red mud and degassed carbide slag are mixed, 350g of red mud is mixed with each liter of alkali solution, the weight of degassed carbide slag accounts for 35% of the weight of red mud, the temperature of dissolution treatment is 240℃, the time of dissolution treatment is 2h, and the A / S of the obtained solid waste is 0.68 and the N / S is 0.16. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 69.1%, and the recovery rate of sodium oxide is 64.4%.

[0084] Example 7

[0085] The degassed carbide slag has a CaO content of 60% and an organic C content of 0.2% based on dry weight.

[0086] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0087] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0088] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution, red mud and degassed carbide slag is 120g / L, alkali solution is mixed with 300g red mud per liter of alkali solution, the weight of degassed carbide slag accounts for 40% of the weight of red mud, the temperature of dissolution treatment is 260℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.58 and the N / S is 0.08. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 73.6% and the recovery rate of sodium oxide is 82.2%.

[0089] Example 8

[0090] The degassed carbide slag has a CaO content of 58% and an organic C content of 0.4% based on dry weight.

[0091] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0092] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0093] Wherein, the caustic soda concentration N of the alkali solution is KThe concentration of alkali solution, red mud and degassed carbide slag is 160g / L, alkali solution is mixed with 350g red mud per liter of alkali solution, the weight of degassed carbide slag accounts for 30% of the weight of red mud, the temperature of dissolution treatment is 260℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.70 and the N / S is 0.06. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 68.2% and the recovery rate of sodium oxide is 86.7%.

[0094] Example 9

[0095] The degassed carbide slag has a CaO content of 58% and an organic C content of 0.4% based on dry weight.

[0096] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0097] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0098] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution is 200g / L, alkali solution, red mud and deaerated carbide slag are mixed, 380g of red mud is mixed per liter of alkali solution, the weight of deaerated carbide slag accounts for 40% of the weight of red mud, the temperature of dissolution treatment is 270℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.64, N / S is 0.08, and the sodium oxide content is 0.72%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 70.9%, and the recovery rate of sodium oxide is 82.2%.

[0099] Example 10

[0100] The degassed carbide slag has a CaO content of 56% and an organic C content of 0.2% based on dry weight.

[0101] The gibbsite ore is dissolved into red mud at 145°C. The iron oxide content in the red mud is 48%. The A / S of the red mud is 2.2 and the N / S is 0.45.

[0102] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0103] Wherein, the caustic soda concentration N of the alkali solution is kThe concentration of alkali solution is 240g / L, alkali solution, red mud and deaerated carbide slag are mixed, 450g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 40% of the weight of red mud, the temperature of dissolution treatment is 260℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.68, N / S is 0.05, and the sodium oxide content is 0.38%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 69.1%, and the recovery rate of sodium oxide is 88.9%.

[0104] Embodiment 11

[0105] The degassed carbide slag has a CaO content of 47% and an organic C content of 0.6% based on dry weight.

[0106] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0107] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0108] Wherein, the caustic soda concentration N of the alkali solution is k The concentration of alkali solution is 220g / L, alkali solution, red mud and deaerated carbide slag are mixed, 350g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 35% of the weight of red mud, the temperature of dissolution treatment is 280℃, the time of dissolution treatment is 30min, the A / S of the obtained solid waste is 0.58, the N / S is 0.07, and the sodium oxide content is 0.56%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 73.6%, and the recovery rate of sodium oxide is 84.4%.

[0109] Example 12

[0110] The degassed carbide slag has a CaO content of 47% and an organic C content of 0.65% based on dry weight.

[0111] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0112] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0113] Wherein, the caustic soda concentration N of the alkali solution is KThe concentration of alkali solution is 260g / L, alkali solution, red mud and deaerated carbide slag are mixed, 350g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 45% of the weight of red mud, the temperature of dissolution treatment is 270℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.28, N / S is 0.01, and the sodium oxide content is 0.16%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 87.3%, and the recovery rate of sodium oxide is 97.8%.

[0114] Example 13

[0115] The degassed carbide slag has a CaO content of 48% and an organic C content of 0.65% based on dry weight.

[0116] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0117] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0118] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution is 160g / L, alkali solution, red mud and deaerated carbide slag are mixed, 350g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 35% of the weight of red mud, the temperature of dissolution treatment is 260℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.58, N / S is 0.03, and the sodium oxide content is 0.48%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 73.6%, and the recovery rate of sodium oxide is 93.3%.

[0119] Embodiment 14

[0120] The degassed carbide slag has a CaO content of 52% and an organic C content of 0.2% based on dry weight.

[0121] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0122] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0123] Wherein, the caustic soda concentration N of the alkali solution is KThe concentration of alkali solution is 180g / L, alkali solution, red mud and deaerated carbide slag are mixed, 450g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 45% of the weight of red mud, the temperature of dissolution treatment is 270℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.48, N / S is 0.06, and the sodium oxide content is 0.53%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 78.2%, and the recovery rate of sodium oxide is 86.7%.

[0124] Embodiment 15

[0125] The degassed carbide slag has a CaO content of 47% and an organic C content of 0.65% based on dry weight.

[0126] The gibbsite ore is dissolved into red mud at 145°C, the iron oxide content in the red mud is 52%, the A / S of the red mud is 2.2, and the N / S is 0.45.

[0127] The alkali solution, red mud and the degassed carbide slag are mixed and subjected to dissolution treatment to obtain a dissolution slurry, and the dissolution slurry is subjected to solid-liquid separation to collect liquid products and solid wastes.

[0128] Wherein, the caustic soda concentration N of the alkali solution is K The concentration of alkali solution is 260g / L, alkali solution, red mud and deaerated carbide slag are mixed, 460g of red mud is mixed with each liter of alkali solution, the weight of deaerated carbide slag accounts for 45% of the weight of red mud, the temperature of dissolution treatment is 270℃, the time of dissolution treatment is 1h, and the A / S of the obtained solid waste is 0.50, N / S is 0.02, and the sodium oxide content is 0.37%. Alumina and sodium oxide are recovered through liquid products, and the recovery rate of aluminum oxide is 77.3%, and the recovery rate of sodium oxide is 95.5%.

[0129] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0130] (1) For the low-temperature Bayer process of gibbsite ore dissolution red mud, it is proposed that a relatively low temperature of 140-180°C can be used to recover most of the aluminum oxide and sodium oxide in it. The A / S of the solid waste obtained after treatment is 0.78-0.92, and the N / S is 0.12-0.28;

[0131] (2) Due to the relatively high iron oxide content in the red mud (generally above 20%), and it can be treated at a high temperature of 240°C < T ≤ 280°C. The A / S of the solid waste obtained can reach 0.28 - 0.72, N / S is 0.01 - 0.12, and the sodium oxide content is less than 1%. Calculated by sodium oxide, the recovery rate of sodium resources can reach up to over 90%. Calculated by alumina, the recovery rate of aluminum resources can reach about 70%. The iron in the red mud can be enriched, which is beneficial to the recovery of iron, and the red mud is conducive to comprehensive utilization. Lower requirements are imposed on the degassed carbide slag. During high-temperature digestion, the CaO content in the degassed carbide slag is greater than 46%, and the organic C content is less than 0.7%. The A / S of the solid waste obtained after treatment is 0.28 - 0.72, N / S is 0.01 - 0.12, and the sodium oxide content is less than 1%;

[0132] (3) For the bauxite digestion red mud with A / S of 2.2 and N / S of 0.45, calculated by sodium oxide, the recovery rate of sodium resources can reach 37.8% - 97.8%, and calculated by alumina, the recovery rate of aluminum resources can reach 58.2% - 87.3%.

[0133] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for treating red mud dissolved from gibbsite ore, characterized in that: The digestion red mud of the gibbsite ore contains sodium silicate slag and iron oxide, and the method includes: Under the condition of a set temperature, mixing the digestion red mud of the gibbsite ore with an alkali solution having a set concentration and degassed carbide slag for a chemical reaction to convert the digestion red mud of the gibbsite ore into calcium ferrite garnet, obtaining a digestion slurry.

2. The method according to claim 1, characterized in that The set temperature T is 140°C ≤ T ≤ 180°C, and the set concentration Nk is 160 g / L to 280 g / L.

3. The method according to claim 2, characterized in that The weight of the degassed carbide slag is 10% to 35% of the weight of the digestion red mud of the gibbsite ore; and / or, Relative to 1 L of the alkali solution, the digestion red mud of the gibbsite ore is 100 g to 350 g; and / or, The time of the chemical reaction is 60 min to 240 min.

4. The method according to claim 2, characterized in that: The method further includes: Performing solid-liquid separation on the digestion slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.76 to 0.92, and N / S is 0.18 to 0.

28.

5. The method according to claim 1, characterized in that The set temperature T is 180°C < T ≤ 240°C, and the set concentration Nk is 140 g / L to 280 g / L.

6. The method according to claim 5, characterized in that The weight of the degassed carbide slag is 10% to 40% of the weight of the digestion red mud of the gibbsite ore; and / or, Relative to 1 L of the alkali solution, the digestion red mud of the gibbsite ore is 100 g to 400 g; and / or, The time of the chemical reaction is 60 min to 180 min.

7. The method according to claim 5, characterized in that The method further includes: Performing solid-liquid separation on the digestion slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.66 to 0.82, and N / S is 0.12 to 0.

18.

8. The method according to claim 1, characterized in that: The set temperature T is 240°C < T ≤ 280°C, and the set concentration Nk is 100 g / L to 280 g / L.

9. The method according to claim 8, characterized in that The weight of the degassed carbide slag is 10% to 50% of the weight of the digestion red mud of the gibbsite ore; and / or, Relative to 1 L of the alkali solution, the digestion red mud of the gibbsite ore is 100 g to 500 g; and / or, The time of the chemical reaction is 30 min to 120 min.

10. The method according to claim 8, characterized in that The method further includes: Performing solid-liquid separation on the digestion slurry to obtain solid waste; wherein, the composition of the solid waste satisfies: A / S is 0.28 to 0.72, and N / S is 0.01 to 0.12.

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