CN1164368C - A kind of beneficiation method of bauxite - Google Patents

Abstract

The invention relates to a mineral processing method of bauxite, which relates to a mineral processing and desiliconization method of diaspore type bauxite. It is characterized in that: under coarse grinding conditions, the ground minerals are classified or re-selected to obtain two or three particle sizes, and the minerals with different particle sizes are separated by flotation or re-selection. Due to the difference in the flotation properties of coarse and fine particles, the separate sorting method can be used to create a flotation environment suitable for the coarse and fine flotation processes by adjusting the chemical system and the parameters of the sorting equipment, which improves the sorting efficiency. It greatly reduces the workload of fine grinding, reduces the cost of grinding and energy consumption, and effectively improves the recovery rate of alumina and the quality of concentrate.

Description

A kind of beneficiation method of bauxite

A method for beneficiation of bauxite, which relates to the beneficiation and desiliconization of bauxite used in the process of producing alumina from diaspore type bauxite, especially the use of diaspore and its rich associated A method for beneficiation and desiliconization of bauxite that is the object of separation.

As one of the raw materials for alumina production, diaspore bauxite has the characteristics of high alumina and silica content and low aluminum-silicon ratio. At present, most of the industrial alumina production using diaspore bauxite as raw material adopts hybrid method and sintering method. These methods have large investment, complicated process, high energy consumption and production cost; The production of alumina by the Bayer method has the advantages of low energy consumption, simple process and low production cost. However, the production of alumina by the Bayer process has relatively strict requirements on raw materials, and generally requires that the ratio of aluminum to silicon is greater than 10. With the depletion of diaspore-type ores with an aluminum-silicon ratio greater than 10 and the need to reduce energy consumption and production costs, it is becoming increasingly important to use the Bayer process to produce alumina. How to remove part of the silicon-containing minerals from raw materials with an aluminum-silicon ratio of less than 10 and increase the ratio of aluminum to silicon is the key to solving this problem.

The flotation process of diaspore-type bauxite is mainly the separation process of diaspore and silicon-containing minerals. There are many desiliconization methods of diaspore bauxite, and foam flotation desilication technology is one of the more economical and effective desilication technologies. Since the gangue minerals in diaspore-type bauxite are clay minerals such as kaolin, illite, pyrophyllite, etc., it is easy to muddy during the beneficiation process; the muddy gangue minerals are easier to float up mechanically, reducing the quality of the concentrate; During flotation, muddy gangue is more likely to absorb collectors, which increases the consumption of reagents; muddy gangue is easy to adhere to the surface of coarse-grained minerals, which seriously affects the floating of coarse grains, and affects the effect of beneficiation and the quality of concentrate.

At present, the flotation process of diaspore-type bauxite consists of finely grinding the bauxite once (with a particle size of about -0.074mm95% to 98%, or even finer particle size), and then using sodium carbonate, sodium sulfide, Sodium hexametaphosphate, etc. are used as regulators, and oxidized paraffin soap, tall oil, etc. are used as collectors for foam flotation. The process of grinding all the minerals at one time results in high energy consumption for grinding, and because most of the silicon-containing gangue minerals in the ore have low hardness, they are preferentially crushed in the grinding process to form ore slime, which is easy to be mixed and entrained during flotation, thus The foam flotation index is deteriorated, the selectivity of the collector is poor, and the flotation desilication effect is poor, which is difficult to meet the production needs, so this method is not actually used in industrial production.

In order to solve the above problems, in the patent application of a bauxite flotation method with the application number 98102900.0 in July 1998, according to the Mohs The hardness is about 2 and it is easy to crush, while the diaspore has high hardness (6.5-7) and is difficult to grind and has the characteristics of large specificity. Flotation is carried out after rough grinding of the raw ore to obtain the concentrate product. The shortcomings of poor sorting effect and high grinding energy consumption due to fine grinding of ore are solved, and an improved process of diaspore type bauxite is proposed. It is characterized in that the foam flotation is carried out under the condition that the bauxite is ground to a fineness of -0.074mm, which accounts for 40% to 88%, and the concentrate and medium ore mainly composed of diaspore joints are produced. Part of the alumina mineral components still contained in the middling ore after flotation is re-selected, and the effective components in the bauxite are recovered under the economical conditions as much as possible, and the income of the mineral processing process is improved. The medium ore can be re-grinded and re-selected with the raw ore in the mill, or can be combined with the primary flotation concentrate as the final concentrate according to the actual production requirements. Because of this process, the proportion of minerals with a grinding fineness of -0.074mm in flotation is reduced by 5% to 50%, which effectively saves grinding costs and energy consumption. At the same time, the recovery rate of alumina can be increased by more than 2%. The beneficiation and desiliconization process has been greatly improved.

But above-mentioned improvement is to carry out sorting immediately after coarse grinding, that is to say, coarse grain and fine grain are mixed in the same sorting equipment and sorted together. Due to the special process mineralogy properties of diaspore bauxite, the minerals produced after grinding will have a wide range of particle sizes with more poles and less intermediate particle size. The typical particle size composition is shown in Table 1.

Table 1 Particle size composition of bauxite grinding products Ore sample size (mm) Sample 1 Sample 2 Yield Yield (%) (%) +0.150 5.69 4.88 -0.15+0.097 16.87 17.07 -0.097+0.075 3.46 5.28 -0.075+0.043 16.16 16.26 -0.043+0.037 6.91 8.23 -0.037+0.010 22.14 21.3626.92 -0.010 28.77 total 100 100

There are great differences in mineral composition and flotation properties between coarse and fine particles, which affect the effect of flotation. When the coarse and fine particles are mixed together for flotation, the fine particles are easily affected by the rising water flow and entrainment of air bubbles into the foam layer, resulting in a decrease in the quality of the concentrate; the specific surface energy of the coarse particles is lower than that of the fine particles, so the fine particles are usually The amount and speed of collectors adsorbed on the surface to make minerals hydrophobic are larger than that of coarse particles. However, generally the floating of coarse particles requires a higher degree of hydrophobization than fine particles, and sometimes neutral oil is added to increase the degree of hydrophobicity. Therefore, when coarse grains and fine grains are mixed together for flotation, it is usually necessary to add a sufficient amount or an excessive amount of collectors. At the same time, it is bound to increase the degree of hydrophobization of fine-grained gangue minerals and increase the amount of mechanical entrainment, resulting in an increase in the amount of reagents and fine grains. The quality of ore is reduced; coarse and fine flotation also require different pulp concentrations, and generally coarser ones require higher concentrations than finer ones. Coarse and fine flotation require different agitation intensities, with fines requiring strong agitation and turbulence. Coarse particles require lower stirring intensity and shorter buoyancy path of mineralized bubbles. For example: using shallow tank flotation machines, fast flotation machines, flash flotation machines, etc. The fine particles are mostly flotation by mechanical agitation flotation machine or flotation column. Fine particles are easy to coagulate, and dispersants are usually required.

In order to effectively flotation and separate minerals of different particle sizes at the same time and ensure the beneficiation yield, a large amount of collectors must be added to strengthen coarse particle capture, but a large amount of collectors reduces the separation efficiency of fine particles, so it is difficult to find A flotation environment is suitable for the separation of minerals with different particle sizes, which seriously affects the recovery of minerals and the flotation efficiency. Finding an effective method for beneficiation and desiliconization of diaspore bauxite is an effective way to improve the efficiency of bauxite separation.

The purpose of the present invention is to overcome the deficiencies of the prior art in the diaspore bauxite flotation process, to provide a method that can effectively reduce the energy consumption of ore grinding, reduce the impact of mineral muddy deterioration on the flotation process, A bauxite flotation method that overcomes the difficulty of creating a good flotation environment for mixed separation of minerals with different particle sizes, greatly reduces the amount of chemicals, improves the recovery rate of ore dressing, and improves the separation effect.

The method of the present invention is realized through the following technical solutions.

A bauxite beneficiation method, including the process of grinding ore finely, adding regulators and collectors to carry out froth flotation, characterized in that: when the bauxite is finely ground to a particle size of -0.074mm, it accounts for 30% to 80% %, the minerals are sorted by classification or gravity beneficiation method, and the fine particles with a fineness of -0.074% greater than 90% and the coarse particles with a fineness of -0.074mm accounting for 0% to 70% are separated and then floated respectively. Its process conditions are:

a. The beneficiation process conditions for flotation of the sorted coarse particles are: use sodium carbonate to adjust the pH value to 10, use oxidized paraffin soap, tall oil, fatty acid, oleic acid, and modified oleate for collection The dosage is 50g/t~400g/t, the flotation time is 1~5min, and some concentrate products are produced, and the sorted tailings are returned for grinding and re-election;

b. The process conditions for flotation of the sorted fine particles are: use sodium carbonate to adjust the pH value to 10, use modified oleate as collector, and the dosage is 50g/t~1000g/t, each operation The flotation time is 1 to 15 minutes, and the concentrate and tailings are produced.

The narrower and more uniform the particle size distribution of minerals after sorting, the more conducive to the control of the chemical industry conditions for mineral flotation and to increase the beneficiation yield. In order to make the distribution of mineral particle size uniform, the sorting level can be increased, and from an economic point of view, it is better to sort into two to three levels. When the minerals are classified or re-selected to produce three particle size grades, the fineness is -7μm accounting for 100%, -74μm greater than 90% and -74μm less than 70%.

Among them, -7μm can be directly used as tailings or separate separation; -74μm greater than 90% particle size separation conditions are the same as the above fine particles; -74μm smaller than 70% particle size separation conditions are the same as the above coarse particles.

The classification method is to use hydrocyclone classification, cone classifier classification, spiral classifier, cyclone screen, vibrating screen, water flow classifier and other classification.

The gravity beneficiation method uses spiral chute, jig, centrifuge, chute, centrifugal jig, etc. for separation.

The regrinding of coarse-grained sorted tailings is to return it to the original grinding machine or use a separate grinding machine for crushing.

The tailings re-selection of coarse-grained separation is to enter the classification or gravity beneficiation operation to form a cycle, or to combine with fine-grained products.

Fine particle flotation is sorted by flotation column flotation or conventional mechanical agitation type, inflatable agitation type flotation machine.

The process of the present invention increases the recovery rate of coarse grains (calculated at -0.074mm grain size) by 5% to 50%, and reduces the amount of fine grains (calculated in -0.020mm grain size) produced by ore grinding by 10% to 70%. Cost and energy consumption can be saved by 20% to 50%, while the recovery rate of alumina can be increased by 2% to 20%, the aluminum-silicon ratio of the total concentrate can be increased by more than 0.5, and the cost of chemicals can be reduced by more than 10%. Compared with technology, the economic benefit is remarkable.

Description of drawings

Fig. 1 is that the method of the present invention adopts closed-circuit grinding-coarse separation tailings to return to the principle flow of regrinding process;

Fig. 2 is the principle flow chart that the method of the present invention adopts open-circuit grinding-coarse separation tailings to return to the regrinding process;

Fig. 3 is the principle process of the method of the present invention adopting closed-circuit grinding-coarse separation tailings independent regrinding and reselection process;

Fig. 4 is that the method of the present invention adopts the principle flow of open circuit grinding-coarse separation tailings independent regrinding and reselection process;

The method of the present invention will be further described below in conjunction with the examples.

A new method for beneficiation and desiliconization of bauxite, including finely grinding the ore, adding regulators and collectors for foam flotation, characterized in that: after the bauxite is coarsely ground, it is obtained by classification or gravity separation. One or more products with different particle sizes. When divided into two kinds of particle size products, the fineness of -0.074mm is greater than 90% of fine grains and -0.074mm accounts for 0% to 70% of coarse grains; when divided into three kinds of grain size products, the fineness is -7μm respectively , -74μm is greater than 90% and -74μm is less than 70%. Coarse-grained products adopt flotation or gravity separation to recover coarse-grained diaspore rich conjoint organisms or monomers, and produce part of the concentrate, and the tailings of coarse-grained separation The ore is regrinded and re-selected; the flotation of the fine-grained product produces another part of the concentrate, and the final tailings of the mud (fine-grained) operation.

Coarse grinding means that the grinding fineness is 30%-80%-0.074mm.

The classification method is to use hydrocyclone classification, cone classifier classification, spiral classifier, cyclone screen, vibrating screen, water flow classifier and other equipment for classification.

The gravity beneficiation method uses spiral chute, jig, centrifuge, chute, and centrifugal jig to obtain two or more products.

The tailings regrinding of the coarse sorting refers to returning it to the original mill or using the mill alone for crushing.

The tailings re-selection of coarse-grained separation is to enter the classification or gravity beneficiation operation again to form a cycle, or to combine with fine-grained products for separation.

Fine particle flotation is sorted by flotation column flotation or conventional mechanical agitation type, inflatable agitation type flotation machine.

The bauxite trapping object of the present invention is a diaspore and its rich associated body, which is different from the usual trapping object; The diaspore in the particle size exists in the form of a monomer or a richer joint. Due to the difference in mineral composition and relative content between coarse particles and fine particles, their flotation characteristics are not completely the same, so the required flotation agent system, type of flotation machine, flotation time, and pulp concentration are not completely the same, so coarse Particles and fine particles are separated for flotation, and the respective flotation environments can be optimized respectively, so as to perform economical and effective flotation. It overcomes the special requirement for the flotation environment that requires simultaneous flotation when coarse grains and fine grains are floated together. Owing to the beneficiation and desiliconization method of bauxite of the present invention, a kind of suitable flotation environment is built specially for coarse-grained diaspore-rich conjunctivities or monomers, thereby improving the collection capacity of coarse grains, while fine grains are separately separated It is beneficial to optimize the separation conditions and lay the foundation for the process of obtaining high-alumina-silicon ratio concentrates.

Due to the particle size classification after grinding, the coarse particles produced adopt fast or flash flotation, which shortens the flotation time; the total amount of collector can be reduced by more than 10%; the fine-grained flotation concentrate has high quality (aluminum-silicon ratio At about 18), the fine-grained gangue is reduced to enter the concentrate, and the filtration and dehydration performance of the concentrate is greatly improved. Under the same conditions, the moisture content of the concentrate can be reduced by 2%-5%, the aluminum-silicon ratio of the total concentrate can be increased by more than 0.5, and the coarse particle collection effect can be increased by 5%-50%. Because the coarse particles are recovered as much as possible, the amount of finely ground ore is reduced, so the energy consumption and consumption of grinding are reduced by 20%-50%, and the effect is very obvious.

Example 1

Raw material: a mine sample in Henan, its chemical composition is (%) Al ₂ O ₃ SiO _{2 Fe2O3 _} Al-Si Ratio 63.90 10.96 6.12 5.83

The process is as follows: the grinding fineness is -0.074mm, accounting for 60%, and the spiral classifier is used to classify the minerals into two grades, and the fineness is -74μm accounting for 95% and -74μm accounting for 50%. In mine 1, the coarse-grain flotation tailings are returned to the original mill for regrinding, and the fine-grained flotation machines are used for one roughing, one sweeping, and three beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 53.05%, the ratio of aluminum to silicon is 11.53, and the recovery rate of Al ₂ O ₃ is 57.65%. The yield of concentrate 2 is 29.12%, the ratio of aluminum to silicon is 18.45, and the recovery rate of Al ₂ O ₃ is 32.76%.

Example 2

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 30%. The spiral chute machine is used to separate the coarse and fine products. The fineness is -74μm accounting for 90% and -74μm accounting for 20%. Concentrate 1, the coarse flotation tailings are returned to the original mill for regrinding, the fine particles are separated by flotation columns, the first roughing and the second beneficiation produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 250g/t of modified oleate is added for coarse-grain flotation operation, 350g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 58.05%, the ratio of aluminum to silicon is 11.08, and the recovery rate of Al ₂ O ₃ is 61.77%. The yield of concentrate 2 is 24.72%, the ratio of aluminum to silicon is 19.84, and the recovery rate of Al ₂ O ₃ is 27.06%.

Example 3

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 80%, and the cone classifier is used for classification. The fineness is -74μm accounting for 95% and -74μm accounting for 30%. The selected tailings are returned to be reground separately, and combined with the fine particles using an inflatable stirring flotation machine for flotation, one roughing, one sweeping, three times of beneficiation, and the concentrate 2 and tailings are produced respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 15.05%, the ratio of aluminum to silicon is 11.12, and the recovery rate of Al ₂ O ₃ is 16.02%. The yield of concentrate 2 is 67.45%, the ratio of aluminum to silicon is 16.27, and the recovery rate of Al ₂ O ₃ is 72.95%.

Example 4

Raw material and other conditions are with embodiment 1.

The process is: the grinding fineness is -0.074mm, which accounts for 70%, and the coarse and fine products are obtained by jig separation. The fineness is -74μm, which accounts for 95% and -74μm, which accounts for 40%. Concentrate 1, coarse-grain flotation tailings return to the original mill for grinding and re-election, and fine-grained flotation machines are used for flotation separation, one roughing, one sweeping, three beneficiation, respectively output concentrate 2 and tailings.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 230g/t of modified oleate is added for coarse-grain flotation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 21.15%, the ratio of aluminum to silicon is 11.71, and the recovery rate of Al ₂ O ₃ is 22.51%. The yield of concentrate 2 is 61.72%, the ratio of aluminum to silicon is 16.89, and the recovery rate of Al ₂ O ₃ is 65.92%.

Example 5

The process is as follows: the grinding fineness is -0.074mm, which accounts for 65%. The centrifuge is used to separate the coarse and fine products. The fineness is -74μm, which accounts for 95% and -74μm, which accounts for 50%. Mine 1, the coarse-grain flotation tailings are returned to the original mill for grinding and re-election, and the fine-grained flotation machines are flotation-selected, with one roughing, one sweeping, and three selections to produce concentrate 2 and tailings respectively. mine.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 200g/t of modified oleate is added for coarse-grain flotation, 350g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 45.75%, the ratio of aluminum to silicon is 11.32, and the recovery rate of Al ₂ O ₃ is 49.14%. The yield of concentrate 2 is 37.12%, the ratio of aluminum to silicon is 18.36, and the recovery rate of Al ₂ O ₃ is 38.87%.

Example 6

The process is as follows: the grinding fineness is -0.074mm, which accounts for 50%, and the secondary product is obtained by hydrocyclone classification. The fineness is -74μm, which accounts for 95% and -74μm, which accounts for 40%. , Coarse flotation tailings are returned to the original mill for regrinding and re-election, and fine particles are flotation by stirring flotation machine, one roughing, one sweeping, three times of beneficiation, and output concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 260g/t of modified oleate is added for coarse-grain flotation, 380g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 58.49%, the ratio of aluminum to silicon is 10.43, and the recovery rate of Al ₂ O ₃ is 62.43%. The yield of concentrate 2 is 24.53%, the ratio of aluminum to silicon is 19.26, and the recovery rate of Al ₂ O ₃ is 27.72%.

Example 7

Raw material: a mine sample in Shanxi, its chemical composition is (%) Al ₂ O ₃ SiO ₂ Fe Al-Si Ratio 65.50 9.93 3.50 6.59

Other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 55%, and the secondary product is obtained by grading with a 38μm sieve. The fineness is -38μm accounting for 100% and -38μm accounting for 8%. The flotation tailings are returned to the original mill for re-grinding and re-election, and the fine particles are separated by agitation flotation machine flotation, one roughing, one sweeping, and three times of beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 50.23%, the ratio of aluminum to silicon is 11.47, and the recovery rate of Al ₂ O ₃ is 52.94%. The yield of concentrate 2 is 33.74%, the ratio of aluminum to silicon is 18.29, and the recovery rate of Al ₂ O ₃ is 37.14%.

Example 8

Raw material is with embodiment 7. Other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, which accounts for 45%, and the secondary product is obtained by grading with a 45μm sieve. The fineness is -45μm, accounting for 100% and -45μm, accounting for 5%. The flotation tailings are returned to the original mill for re-grinding and re-election, and the fine particles are separated by agitation flotation machine flotation, one roughing, one sweeping, and three times of beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 50.26%, the ratio of aluminum to silicon is 10.41, and the recovery rate of Al ₂ O ₃ is 55.17%. The yield of concentrate 2 is 31.74%, the ratio of aluminum to silicon is 18.47, and the recovery rate of Al ₂ O ₃ is 36.84%.

Example 9

Raw material: a mine sample in Shanxi, its chemical composition is (%) Al ₂ O ₃ SiO ₂ Fe Al-Si Ratio 60.43 13.51 4.12 4.47

Other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, which accounts for 58%, and the secondary product is obtained by grading with a 45μm sieve. The fineness is -45μm, accounting for 100% and -45μm, accounting for 5%. The flotation tailings are returned to the original mill for re-grinding and re-election, and the fine particles are separated by agitation flotation machine flotation, one roughing, one sweeping, and three times of beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 180g/t of modified oleate is added for coarse-grain flotation, 350g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 30.83%, the ratio of aluminum to silicon is 12.14, and the recovery rate of Al ₂ O ₃ is 34.70%. The yield of concentrate 2 is 44.05%, the ratio of aluminum to silicon is 14.71, and the recovery rate of Al ₂ O ₃ is 60.81%.

Example 10

Raw material is with embodiment 9. Other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, which accounts for 60%, and the chute separation is used to produce coarse and fine products. Mine 1, the coarse-grain flotation tailings are returned to the original mill for grinding and re-election, and the fine-grained flotation machines are flotation-selected, with one roughing, one sweeping, and three selections to produce concentrate 2 and tailings respectively. mine.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 200g/t of modified oleate is added for coarse-grain flotation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 31.15%, the ratio of aluminum to silicon is 11.34, and the recovery rate of Al ₂ O ₃ is 35.58%. The yield of concentrate 2 is 44.03%, the ratio of aluminum to silicon is 16.21, and the recovery rate of Al ₂ O ₃ is 50.18%.

Example 11

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, which accounts for 55%, and the spiral chute machine is used to separate the three products of coarse, fine and mud. %, coarse-grain flotation produces concentrate 1, coarse-grain flotation tailings are returned to the original mill for re-grinding, fine-grained flotation columns are used for separation, primary roughing and secondary beneficiation produce concentrate 2 respectively, The mud is directly used as tailings.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 50.47%, the ratio of aluminum to silicon is 12.04, and the recovery rate of Al ₂ O ₃ is 54.10%. The yield of concentrate 2 is 30.74%, the ratio of aluminum to silicon is 18.61, and the recovery rate of Al ₂ O ₃ is 32.78%.

Example 12

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 45%, and the spiral chute machine is used to separate the three products of coarse, fine and mud, and the fineness is -74μm accounting for 30%, -74μm accounting for 95% and -7μm accounting for 100 %, the coarse tailings are sorted by spiral chute to produce concentrate 1, the coarse tailings are returned to the original mill for regrinding, and the fine grains are sorted by flotation column, one roughing and three times of beneficiation, respectively output concentrate 2 , mud directly as tailings.

Chemical system: the pulp is adjusted to pH 10 with sodium carbonate, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grained roughing, and 50g/t of modified oleate is added for sweeping.

In the closed-circuit process, the yield of concentrate 1 is 15.39%, the ratio of aluminum to silicon is 9.07, and the recovery rate of Al ₂ O ₃ is 15.90%. The yield of concentrate 2 is 65.02%, the ratio of aluminum to silicon is 16.73, and the recovery rate of Al ₂ O ₃ is 70.04%.

Example 13

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 55%, and the cyclone screen is used to classify the output of secondary products, the fineness is -74μm accounting for 40% and -74μm accounting for 95%, and the coarse-grained flotation produces concentrate 1 , the coarse tailings are returned to the original mill for regrinding, and the fine ones are sorted by flotation columns, with one roughing and three beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 280g/t of modified oleate is added for coarse-grain flotation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 55.09%, the ratio of aluminum to silicon is 11.07, and the recovery rate of Al ₂ O ₃ is 57.91%. The yield of concentrate 2 is 28.76%, the ratio of aluminum to silicon is 17.47, and the recovery rate of Al ₂ O ₃ is 33.05%.

Example 14

Raw material and other conditions are with embodiment 1.

The process is: the grinding fineness is -0.074mm, which accounts for 55%, and the centrifugal jig machine is used to separate the coarse and fine products. Concentrate 1 is produced. Coarse tailings are returned to the original mill for regrinding. Fine particles are separated by flotation columns. One roughing and three beneficiation are used to produce concentrate 2 respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 230g/t of modified oleate is added for coarse-grain flotation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 45.78%, the ratio of aluminum to silicon is 9.07, and the recovery rate of Al ₂ O ₃ is 48.19%. The yield of concentrate 2 is 37.12%, the ratio of aluminum to silicon is 17.63, and the recovery rate of Al ₂ O ₃ is 40.32%.

Example 15

Raw material and other conditions are with embodiment 1.

The process is as follows: the grinding fineness is -0.074mm, accounting for 55%, and the secondary product is obtained by vibrating screen classification, the fineness is -74μm accounting for 40% and -74μm accounting for 95%. The tailings are returned to the original mill for regrinding, and the fine particles are separated by flotation columns, with one roughing and three beneficiation to produce concentrate 2 and tailings respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 200g/t of modified oleate is added for coarse-grain flotation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing, and Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 43.17%, the ratio of aluminum to silicon is 11.39, and the recovery rate of Al ₂ O ₃ is 46.82%. The yield of concentrate 2 is 39.26%, the ratio of aluminum to silicon is 18.17, and the recovery rate of Al ₂ O ₃ is 33.51%.

Example 16

Raw material and other conditions are with embodiment 1.

The process is: the grinding fineness is -0.074mm, which accounts for 55%, and the water flow classifier is used to classify coarse and fine products. The fineness is -74μm, which accounts for 40% and -74μm, which accounts for 95%. Concentrate 1, coarse tailings are returned to the original mill for regrinding, fine particles are separated by flotation columns, one roughing, three times of beneficiation, and concentrate 2 and tailings are produced respectively.

Chemical system: pulp is adjusted to pH 10 with sodium carbonate, 300g/t of modified oleate is added for coarse-grain flotation operation, 400g/t of modified oleate and 30g/t of sodium hexametaphosphate are added for fine-grain roughing operation, Add 50g/t of modified oleate to the selection operation.

In the closed-circuit process, the yield of concentrate 1 is 50.32%, the ratio of aluminum to silicon is 11.28, and the recovery rate of Al ₂ O ₃ is 53.27%. The yield of concentrate 2 is 32.16%, the ratio of aluminum to silicon is 17.82, and the recovery rate of Al ₂ O ₃ is 36.05%.

Claims (7)

1. A method for beneficiation of bauxite, comprising grinding the ore, adding regulators and collectors to carry out foam flotation, characterized in that the bauxite is ground to a particle size of -0.074mm after accounting for 30% to 80%, The minerals are sorted by classification or gravity separation, and the fine particles with a fineness of -0.074mm greater than 90% and the coarse particles with a fineness of -0.074mm accounting for 0% and 70% are separated and then flotation is carried out respectively. The process conditions are: a. The beneficiation process conditions for the flotation of the sorted coarse particles are as follows: use sodium carbonate to adjust the pH value to 10, use modified oleate as a collector, and the dosage is 50g/t~400g/t. The time is 1 to 5 minutes, and some concentrate products are produced, and the sorted tailings are re-grinded and re-selected; b. Carry out flotation on the sorted fine particles, the process conditions are: use sodium carbonate to adjust the pH value to 10, use modified oleate as collector, the dosage is 50g/t～1000g/t, the flotation time It takes 1 to 15 minutes to produce concentrate and tailings. 2. A method for beneficiation of bauxite according to claim 1, characterized in that after the bauxite is ground to a particle size of -0.074mm and accounts for 30% to 80%, the minerals are classified by grading or gravity beneficiation. When three particle size levels are produced, the fineness is -7μm accounting for 100%, -74μm is more than 90% and -74μm is less than 70%; the fineness is -0.074mm and the fineness is -0.074mm mm accounts for 0% to 70% of coarse particles to be flotation separately, wherein -7μm can be directly used as tailings; -74μm is greater than 90% particle size sorting conditions are the same as the fine particle level flotation process conditions described in claim 1; -74μm The classification conditions of greater than 70% particle size are the same as the coarse particle size flotation process described in the claims. 3. The mineral processing method of a kind of bauxite according to claim 1, characterized in that: the classification method after grinding is to adopt hydrocyclone, cone classifier, spiral classifier, cyclone screen, vibrating screen, Water flow classifier and other classification. 4. The mineral processing method of a kind of bauxite according to claim 1, characterized in that: the gravity mineral processing method after grinding is to adopt spiral chute, jig, centrifuge, chute, centrifugal jig and other separations . 5. The mineral processing method of a kind of bauxite according to claim 1, characterized in that: the regrinding of the coarsely separated tailings is to return it to the original mill or use the mill alone for crushing. 6. The mineral processing method of a kind of bauxite according to claim 1, characterized in that: the re-selection of the tailings of coarse-grained separation is to enter the classification or gravity separation operation to form a cycle, or to form a cycle with fine-grained products Merge elections. 7. A method for beneficiation of bauxite according to claim 1, characterized in that: the fine particle flotation is sorted by flotation column flotation or conventional mechanical agitation type, inflatable agitation type flotation machine.

Images