A method for desulfurization of high-sulfur bauxite

Abstract

The application discloses a desulfurization method of high-sulfur bauxite, which comprises the following steps: A, ore is subjected to one-stage grinding operation, the proportion of the material with a fineness of 0.074 mm in the material obtained through one-stage grinding is 50%-70%, and one-stage grinding material is obtained; B, the one-stage grinding material is taken out and subjected to two-stage grinding operation, the proportion of the material with a fineness of 0.074 mm in the material obtained through two-stage grinding is 70%-90%; C, the material obtained through two-stage grinding and a flotation reagent are subjected to flotation operation in a flotation system; and D, the flotation aluminum concentrate is subjected to concentration, drying and dewatering, then is subjected to dispersion operation, and then is subjected to roasting operation, and the obtained roasting product is the final aluminum concentrate. The method can effectively dissociate the sulfur minerals in the ore and reduce the over-grinding phenomenon of the minerals, and can effectively remove the sulfur minerals in the bauxite and effectively reduce the sulfur content in the bauxite.

Description

Technical Field

[0001] This invention relates to the field of bauxite resource optimization and utilization technology, specifically to a desulfurization method for high-sulfur bauxite. Background Technology

[0002] Because of the high sulfur content in high-sulfur bauxite, the production of alumina is severely affected, especially the processes of leaching, sedimentation, and evaporation. The main effects are: (1) Sulfur minerals are decomposed by alkali during leaching, consuming some alkali and thus increasing alkali content; (2) Alumina production involves a large number of steel equipment such as tanks and evaporators, and the increased sulfur content of S2- in the solution causes iron to enter the solution in a colloidal state, resulting in corrosion of the steel equipment; (3) As evaporation proceeds, the concentration of the mother liquor gradually increases, and sulfates and their complex salts crystallize and adhere to the surface of the equipment, forming scale. The heat transfer coefficient of the scale is very small, hindering the heat transfer process and increasing steam consumption. Therefore, high-sulfur bauxite has not been effectively utilized. Summary of the Invention

[0003] The purpose of this invention is to provide a desulfurization method for high-sulfur bauxite. This method first uses staged grinding to effectively dissociate sulfur minerals in the ore and reduce over-grinding of the minerals. This not only effectively removes sulfur minerals from bauxite but also effectively reduces the sulfur content in bauxite.

[0004] To solve the above technical problems, the present invention adopts the following technical solution:

[0005] The desulfurization method for high-sulfur bauxite includes the following steps:

[0006] A. The ore undergoes a first-stage grinding operation. The material obtained from the first-stage grinding has a fineness of 0.074mm and accounts for 50%-70% of the material, which is then ground into first-stage material.

[0007] B. Take a section of grinding material and perform a second-stage grinding operation. The material obtained from the second-stage grinding has a fineness of 0.074mm and accounts for 70%-90% of the material.

[0008] C. The material obtained from the second-stage grinding and flotation reagents are subjected to flotation in the flotation system. The flotation operation includes roughing, scavenging and cleaning. The material and flotation reagents first undergo roughing. The froth from the roughing operation enters the scavenging operation. The froth obtained after scavenging is the flotation sulfur concentrate. The underflow from the roughing operation enters the cleaning operation. The underflow obtained after cleaning is the flotation aluminum concentrate.

[0009] D. The flotation aluminum concentrate is concentrated, dried and dehydrated, then dispersed and roasted to obtain the final aluminum concentrate.

[0010] The first stage of grinding operation uses a rod mill, and the second stage of grinding operation uses a ball mill.

[0011] In one stage of grinding, the grinding fineness of -0.074mm accounts for 50%-70%. This is because the grinding particle size is relatively uniform in rod mill operation, and the ore mudification phenomenon is low. If the grinding fineness is <50%, the degree of liberation of sulfur minerals in the ore is low, which increases the difficulty of the second stage ball mill operation. If the grinding fineness is >70%, it is easy to cause over-grinding, resulting in mineral mudification, especially in the second stage ball mill operation, where the over-grinding phenomenon is more serious.

[0012] In the two-stage grinding operation, the grinding fineness of -0.074mm accounts for 70%-90%. This is because ball mills are suitable for fine grinding operations. After the ore is ground by the ball mill, the processing capacity of the ball mill can be improved, the grinding time can be shortened, and the mudding phenomenon of the grinding product can be reduced. If the grinding fineness is <70%, the two-stage grinding operation time will increase, the mudding phenomenon of the ore will increase, and the processing capacity will decrease. If the grinding fineness is >90%, the residence time of easily liberated ore in the mill will be prolonged, which will lead to severe mudding of the ore, reduce the flotation effect, and increase the grinding cost.

[0013] In step C, the flotation operation uses a non-drive flotation cell, wherein the roughing operation is performed once, the cleaning operation is performed 2-3 times, and the scavenging operation is performed 1-2 times.

[0014] The feed pressure for each process in the flotation operation is as follows: 0.14MPa-0.2MPa for roughing, 0.18MPa-0.24MPa for cleaning, and 0.12MPa-0.16MPa for scavenging.

[0015] In step D, the equipment used for concentration is a thickener or a settling tank.

[0016] In step D, the equipment used for drying and dehydration is a low-temperature belt dryer or a rotary dryer.

[0017] The low-temperature belt dryer has a feeding and discharging time of 80s-120s and a feeding interval of 200s-400s during the drying process. The moisture content of the dried material is less than 8%.

[0018] The rotary dryer has a rotation speed of less than 5 revolutions per minute, and the moisture content of the dried material is less than 8%.

[0019] In step D, the equipment used for decentralized operations is a dry grinding mill with a ball-to-material ratio of 1.0-1.2:1.

[0020] In step D, the equipment used for the roasting operation is one of a suspension roasting furnace, a rotary kiln, or a fluidized bed.

[0021] The roasting operation is carried out at a temperature of 400℃-1000℃. If the roasting temperature is below 400℃, the sulfur content in the bauxite is high, and the sulfur removal effect is poor. If the roasting temperature is above 1000℃, the desulfurization effect is only slightly improved. Moreover, the higher the temperature, the greater the energy consumption, the higher the equipment requirements, and the higher the production cost.

[0022] The present invention has the following advantages:

[0023] The method of this invention adopts a combined process of "gravity separation-dispersion-roasting", which can effectively reduce the sulfur content in sedimentary bauxite, making it usable for alumina production.

[0024] The method of this invention employs a combined process of "flotation-dispersion-roasting" to reduce the sulfur content in sedimentary bauxite, making it usable for alumina production. Based on the dissemination characteristics of sulfur minerals in high-sulfur bauxite, firstly, a rod mill is used in the first stage of grinding to reduce over-grinding of the minerals. Then, a second stage of grinding further refines the minerals, reducing the proportion of small balls added in the second stage ball mill, thus minimizing over-grinding while simultaneously meeting the requirements for mineral liberation and improving grinding output and efficiency. Secondly, the concentrated, dried, and dehydrated flotation aluminum concentrate is dispersed to break up any agglomerated material from the drying process, improving roasting efficiency and reducing the sulfur content in the aluminum concentrate. Detailed Implementation

[0025] To facilitate a better understanding of the present invention, the following examples are provided. These examples fall within the scope of protection of the present invention, but do not limit the scope of protection of the present invention.

[0026] Example 1

[0027] A desulfurization method for high-sulfur bauxite, the method comprising:

[0028] The high-sulfur bauxite has a sulfur content of 8%. After primary grinding, the grinding product is classified, resulting in a slurry with 50% of particles at -0.074mm. This slurry then enters the secondary grinding stage, where the coarse particles are returned to the primary grinding stage for regrinding. The secondary grinding product, after further classification, yields a slurry with 70% of particles at -0.074mm, which enters the flotation system. The coarse particles are returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage returns to the roughing stage. The froth from the second scavenging stage is sulfur concentrate, which is then further processed by flotation and scavenging. The underflow from the second flotation roughing operation is returned to the first flotation scavenging operation; the underflow from the first flotation roughing operation is returned to the first flotation cleaning operation; the underflow from the first cleaning operation is returned to the second cleaning operation; the froth from the second cleaning operation is returned to the first flotation cleaning operation; the underflow from the second cleaning operation is returned to the third cleaning operation; the froth from the third cleaning operation is returned to the second flotation cleaning operation; the underflow from the third cleaning operation is the flotation aluminum concentrate; after being concentrated and dehydrated by a thickener, the flotation aluminum concentrate is dried using a low-temperature belt dryer; the dried material is dispersed using a dry grinding mill; the dispersed material is roasted in a suspension roaster at a roasting temperature of 400℃; the roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.37%.

[0029] The experimental indicators in the above process are shown in Table 1.

[0030] Table 1 Desulfurization test indicators for high-sulfur bauxite ore / %

[0031]

[0032]

[0033] Example 2

[0034] A desulfurization method for high-sulfur bauxite, the method comprising:

[0035] The high-sulfur bauxite has a sulfur content of 8%. After primary grinding, the grinding product is classified and the resulting slurry (55% of which is -0.074mm) enters the secondary grinding stage. The coarse-grained material is returned to the primary grinding stage for regrinding. After secondary grinding, the product is classified and the resulting slurry (75% of which is -0.074mm) enters the flotation system. The coarse-grained material is returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses a non-driven flotation cell. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage is returned to the roughing stage. The froth from the second scavenging stage is sulfur concentrate, which is then floated. The underflow from scavenging stage II is returned to flotation stage I; the underflow from flotation roughing stage I enters flotation stage I, the froth from flotation stage I is returned to flotation roughing stage, the underflow from flotation stage I enters flotation stage II, the froth from flotation stage II is returned to flotation stage I, the underflow from flotation stage II enters flotation stage III, the froth from flotation stage III is returned to flotation stage II, and the underflow from flotation stage III is flotation aluminum concentrate; after concentration and dewatering in settling tanks, the flotation aluminum concentrate is dried using a rotary dryer, and the dried material is dispersed using a dry mill, and the dispersed material is roasted in a rotary kiln at a roasting temperature of 600℃. The roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.33%.

[0036] The experimental indicators in the above process are shown in Table 2.

[0037] Table 2 Desulfurization test indicators for high-sulfur bauxite ore / %

[0038] raw ore 100.00 8.00 100.00 Aluminum concentrate 70.35 0.33 2.90 Sulfur concentrate 17.33 40.39 87.49 <![CDATA[SO₂ gas]]> 12.32 6.24 9.60

[0039] Example 3

[0040] A desulfurization method for high-sulfur bauxite, the method comprising:

[0041] The high-sulfur bauxite ore has a sulfur content of 8%. After primary grinding, the grinding product is classified and the resulting slurry (60% of which is -0.074mm) enters the secondary grinding stage. The coarse-grained material is returned to the primary grinding stage for regrinding. After secondary grinding, the product is classified and the resulting slurry (80% of which is -0.074mm) enters the flotation system. The coarse-grained material is returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage is returned to the roughing stage. The froth from the second scavenging stage is sulfur concentrate. The underflow from the second flotation stage is returned to the first flotation stage; the underflow from the roughing stage enters the first flotation stage, the froth from the first flotation stage is returned to the roughing stage, the underflow from the first flotation stage enters the second flotation stage, the froth from the second flotation stage is returned to the first flotation stage, the underflow from the second flotation stage enters the third flotation stage, the froth from the third flotation stage is returned to the second flotation stage, and the underflow from the third flotation stage is the flotation aluminum concentrate; after being concentrated and dehydrated by a thickener, the flotation aluminum concentrate is dried using a low-temperature belt dryer, and the dried material is dispersed using a dry mill, and the dispersed material is roasted in a fluidized bed at a roasting temperature of 800℃. The roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.27%.

[0042] The experimental indicators in the above process are shown in Table 3.

[0043] Table 3 Desulfurization test indicators for high-sulfur bauxite / %

[0044] raw ore 100.00 8.00 100.00 Aluminum concentrate 69.45 0.27 2.34 Sulfur concentrate 17.68 39.53 87.36 <![CDATA[SO₂ gas]]> 12.87 6.40 10.29

[0045] Example 4

[0046] A desulfurization method for high-sulfur bauxite, the method comprising:

[0047] The high-sulfur bauxite ore has a sulfur content of 8%. After primary grinding, the grinding product is classified, resulting in a slurry with 65% of particles at -0.074mm. This slurry then enters the secondary grinding stage, where the coarse particles are returned to the primary grinding stage for regrinding. The secondary grinding product, after further classification, yields a slurry with 85% of particles at -0.074mm, which enters the flotation system. The coarse particles are returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage returns to the roughing stage. The froth from the second scavenging stage is sulfur concentrate, which is then further processed by flotation and scavenging. The underflow from the second flotation roughing operation is returned to the first flotation scavenging operation; the underflow from the first flotation roughing operation is returned to the first flotation cleaning operation; the underflow from the first cleaning operation is returned to the second cleaning operation; the froth from the second cleaning operation is returned to the first flotation cleaning operation; the underflow from the second cleaning operation is returned to the third cleaning operation; the froth from the third cleaning operation is returned to the second flotation cleaning operation; the underflow from the third cleaning operation is the flotation aluminum concentrate; after being concentrated and dehydrated in the settling tank, the flotation aluminum concentrate is dried using a low-temperature belt dryer; the dried material is dispersed using a dry grinding mill; the dispersed material is roasted in a suspension roasting furnace at a roasting temperature of 900℃; the roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.25%.

[0048] The experimental indicators in the above process are shown in Table 4.

[0049] Table 4 Desulfurization test indicators for high-sulfur bauxite ore / %

[0050] raw ore 100.00 8.00 100.00 Aluminum concentrate 68.81 0.25 2.15 Sulfur concentrate 18.04 38.54 86.91 <![CDATA[SO₂ gas]]> 13.15 6.66 10.94

[0051] Example 5

[0052] A desulfurization method for high-sulfur bauxite, the method comprising:

[0053] The high-sulfur bauxite has a sulfur content of 8%. After a primary grinding process, the grinding product is classified, resulting in a slurry with 70% of particles being -0.074mm. This slurry then enters the secondary grinding stage, where the coarse particles are returned to the primary grinding stage for regrinding. The secondary grinding product, after further classification, yields a slurry with 90% of particles being -0.074mm, which enters the flotation system. The coarse particles are returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage is returned to the roughing stage. The froth from the second scavenging stage is sulfur concentrate. The underflow from the second flotation stage is returned to the first flotation stage; the underflow from the roughing stage enters the first flotation stage, the froth from the first flotation stage is returned to the roughing stage, the underflow from the first flotation stage enters the second flotation stage, the froth from the second flotation stage is returned to the first flotation stage, the underflow from the second flotation stage enters the third flotation stage, the froth from the third flotation stage is returned to the second flotation stage, and the underflow from the third flotation stage is the flotation aluminum concentrate; after being concentrated and dehydrated by a thickener, the flotation aluminum concentrate is dried using a rotary dryer, and the dried material is dispersed using a dry mill, and the dispersed material is roasted in a rotary kiln at a roasting temperature of 1000℃. The roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.23%.

[0054] The test indicators in the above process are shown in Table 5.

[0055] Table 5 Desulfurization test indicators for high-sulfur bauxite ore / %

[0056]

[0057]

[0058] Comparative Example 1

[0059] A desulfurization method for high-sulfur bauxite, the method comprising:

[0060] The high-sulfur bauxite ore has a sulfur content of 8%. After primary grinding, the grinding product is classified and the resulting slurry (40% of which is -0.074mm) enters the secondary grinding stage. The coarse-grained material is returned to the primary grinding stage for regrinding. After secondary grinding, the product is classified and the resulting slurry (60% of which is -0.074mm) enters the flotation system. The coarse-grained material is returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage is returned to the roughing stage. The froth from the second scavenging stage is sulfur concentrate, which is then further processed by flotation and scavenging. The underflow from the second flotation roughing operation is returned to the first flotation scavenging operation; the underflow from the first flotation roughing operation enters the first flotation cleaning operation; the froth from the first flotation cleaning operation returns to the first flotation roughing operation; the underflow from the first flotation cleaning operation enters the second flotation cleaning operation; the froth from the second flotation cleaning operation returns to the first flotation cleaning operation; the underflow from the second flotation cleaning operation enters the third flotation cleaning operation; the froth from the third flotation cleaning operation returns to the second flotation cleaning operation; the underflow from the third flotation cleaning operation is the flotation aluminum concentrate; after the flotation aluminum concentrate is concentrated and dehydrated by a thickener, it is dried by a low-temperature belt dryer; the dried material is dispersed by a dry mill; the dispersed material is roasted in a suspension roaster at a roasting temperature of 400℃; the roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 0.91%.

[0061] The experimental indicators in the above process are shown in Table 6.

[0062] Table 6 Desulfurization test indicators for high-sulfur bauxite ore / %

[0063] raw ore 100.00 8.00 100.00 Aluminum concentrate 70.65 0.91 8.04 Sulfur concentrate 16.48 40.11 82.63 <![CDATA[SO₂ gas]]> 12.87 5.80 9.34

[0064] Comparative Example 2

[0065] A desulfurization method for high-sulfur bauxite, the method comprising:

[0066] The high-sulfur bauxite has a sulfur content of 8%. After primary grinding, the grinding product is classified and the resulting slurry (70% of which is -0.074mm) enters the secondary grinding stage. The coarse-grained material is returned to the primary grinding stage for regrinding. After secondary grinding, the product is classified and the resulting slurry (80% of which is -0.074mm) enters the flotation system. The coarse-grained material is returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process consists of one roughing, one cleaning, and two scavenging stages. The flotation equipment uses a non-driven flotation cell. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The flotation process involves several steps: the underflow from scavenging stage 1 is returned to the roughing stage; the froth from scavenging stage 2 is used to obtain sulfur concentrate; the underflow from scavenging stage 2 is returned to flotation stage 1; the underflow from the roughing stage enters the cleaning stage 1; the froth from cleaning stage 1 is returned to the roughing stage; and the underflow from cleaning stage 1 is used to obtain flotation aluminum concentrate. After thickening and dehydration in a thickener, the flotation aluminum concentrate is dried using a low-temperature belt dryer. The dried material is then dispersed using a dry mill, and the dispersed material is roasted in a suspension roaster at 300℃. The roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product. The sulfur content in the final aluminum concentrate is 2.14%.

[0067] The experimental indicators in the above process are shown in Table 7.

[0068] Table 7 Desulfurization test indicators for high-sulfur bauxite ore / %

[0069] raw ore 100.00 8.00 100.00 Aluminum concentrate 76.32 2.14 20.42 Sulfur concentrate 15.37 38.96 74.85 <![CDATA[SO₂ gas]]> 8.31 4.56 4.73

[0070] Comparative Example 3

[0071] A desulfurization method for high-sulfur bauxite, the method comprising:

[0072] The high-sulfur bauxite has a sulfur content of 8%. After primary grinding, the grinding product is classified, resulting in a slurry with 80% of particles being -0.074mm. This slurry then enters the secondary grinding stage, where the coarse particles are returned to the primary grinding stage for regrinding. The secondary grinding product, after further classification, yields a slurry with 95% of particles being -0.074mm, which enters the flotation system. The coarse particles are returned to the secondary grinding stage for regrinding. The secondary grinding product reacts with flotation reagents and enters the flotation process. The flotation process employs one roughing, three cleaning, and two scavenging stages. The flotation equipment uses non-driven flotation cells. The froth from the roughing stage enters the first scavenging stage, and the froth from the first scavenging stage enters the second scavenging stage. The underflow from the first scavenging stage returns to the roughing stage. The froth from the second scavenging stage is sulfur concentrate, which is then further processed by flotation and scavenging. The underflow from the second flotation roughing operation is returned to the first flotation scavenging operation; the underflow from the first flotation roughing operation is returned to the first flotation cleaning operation; the underflow from the first cleaning operation is returned to the second cleaning operation; the froth from the second cleaning operation is returned to the first flotation cleaning operation; the underflow from the second cleaning operation is returned to the third cleaning operation; the froth from the third cleaning operation is returned to the second flotation cleaning operation; the underflow from the third flotation cleaning operation is the flotation aluminum concentrate; after being concentrated and dehydrated by a thickener, the flotation aluminum concentrate is dried by a low-temperature belt dryer; the dried material is dispersed by a dry mill; the dispersed material is roasted in a suspension roaster at a roasting temperature of 500℃; the roasted product is roasted aluminum concentrate, which is the final aluminum concentrate product, and the sulfur content in the final aluminum concentrate is 1.27%.

[0073] The experimental indicators in the above process are shown in Table 8.

[0074] Table 8 Desulfurization test indicators for high-sulfur bauxite ore / %

[0075] raw ore 100.00 8.00 100.00 Aluminum concentrate 72.02 1.27 11.43 Sulfur concentrate 17.52 37.26 81.60 <![CDATA[SO₂ gas]]> 10.46 5.33 6.97

[0076] Comparative Example 4

[0077] This comparative example uses a desulfurization method for sulfur-containing bauxite provided by Chinese invention patent CN117225584A to treat high-sulfur bauxite with a sulfur content of 8%, resulting in a bauxite concentrate with a sulfur content of 0.74%.

[0078] The experimental indicators in the above process are shown in Table 9.

[0079] Table 9 Desulfurization test indicators for high-sulfur bauxite ore / %

[0080] raw ore 100.00 8.00 100.00 Aluminum concentrate 70.68 0.74 6.54 Sulfur concentrate 29.32 25.50 93.46

[0081] Comparative Example 5

[0082] This comparative example uses a sorting method for high-sulfur bauxite provided by Chinese invention patent CN117101856A to process high-sulfur bauxite with a sulfur content of 8%, resulting in a bauxite concentrate with a sulfur content of 0.92%.

[0083] The experimental indicators in the above process are shown in Table 10.

[0084] Table 10 Desulfurization test indicators for high-sulfur bauxite mines / %

[0085] raw ore 100.00 8.00 100.00 Aluminum concentrate 73.15 0.92 8.41 Sulfur concentrate 26.85 27.29 91.59

[0086] The desulfurization test results of each embodiment and comparative example are shown in Table 11:

[0087] Table 11 Summary of Test Indicators

[0088]

[0089] As can be seen from the table above, the method provided in the embodiments of this application can effectively reduce the sulfur content in aluminum concentrate.

[0090] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has 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., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0091] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A desulfurization method for high-sulfur bauxite, characterized in that, Includes the following steps: A. The ore undergoes a first-stage grinding operation. The material obtained from the first-stage grinding has a fineness of 0.074mm and accounts for 50%-70% of the material, which is then ground into first-stage material. B. Take the first stage of grinding material and perform a second stage of grinding. The material obtained from the second stage of grinding has a fineness of 0.074mm and accounts for 70%-90% of the total material. C. The material obtained from the second-stage grinding and flotation reagents are subjected to flotation in the flotation system. The flotation operation includes roughing, scavenging and cleaning. The material and flotation reagents first undergo roughing. The froth from the roughing operation enters the scavenging operation. The froth obtained after scavenging is the flotation sulfur concentrate. The underflow from the roughing operation enters the cleaning operation. The underflow obtained after cleaning is the flotation aluminum concentrate. D. The flotation aluminum concentrate is concentrated, dried and dehydrated, and then dispersed before being roasted to obtain the final aluminum concentrate. The first stage of grinding operation uses a rod mill, and the second stage of grinding operation uses a ball mill. In step C, the flotation operation uses a non-drive flotation cell, wherein the roughing operation is performed once, the cleaning operation is performed 2-3 times, and the scavenging operation is performed 1-2 times. The feed pressure for each process in the flotation operation is as follows: 0.14MPa-0.2MPa for roughing, 0.18MPa-0.24MPa for cleaning, and 0.12MPa-0.16MPa for scavenging.

2. The desulfurization method for high-sulfur bauxite according to claim 1, characterized in that: In step D, the equipment used for concentration is a thickener or a settling tank.

3. The desulfurization method for high-sulfur bauxite according to claim 1, characterized in that: In step D, the equipment used for drying and dehydration is a low-temperature belt dryer or a rotary dryer. The low-temperature belt dryer described above has a feeding and discharging time of 80s-120s, a feeding interval of 200s-400s, and the moisture content of the dried material is less than 8%. The rotary dryer has a rotation speed of less than 5 revolutions per minute, and the moisture content of the dried material is less than 8%.

4. The desulfurization method for high-sulfur bauxite according to claim 1, characterized in that: In step D, the equipment used for decentralized operations is a dry grinding mill with a ball-to-material ratio of 1.0-1.2:

1.

5. The desulfurization method for high-sulfur bauxite according to claim 1, characterized in that: In step D, the equipment used for the roasting operation is one of a suspension roasting furnace, a rotary kiln, or a fluidized bed.

6. The desulfurization method for high-sulfur bauxite according to claim 5, characterized in that: The roasting process is carried out at a temperature of 400℃-1000℃.

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