Low-grade magnesite flotation process

Abstract

The invention relates to a low-grade magnesite flotation process which comprises the following steps: 1) crushing low-grade magnesite with the particle size range of less than or equal to 2mm; (2) feeding the crushed low-grade magnesite into a ball mill for ore grinding, and grinding the low-grade magnesite into fine powder; (3) water is added into the fine powder to form raw ore pulp, the raw ore pulp is added into a flotation machine, sulfuric acid is added under the stirring condition to enable the PH of the raw ore pulp to be 5-6, and then sodium hexametaphosphate and octadecylamine are sequentially added for reverse flotation; (4) after reverse flotation, a bottom layer material is reserved, water is added into the bottom layer material to prepare material ore pulp with the concentration being 15-25%, sodium hydroxide is added under the stirring condition to enable the PH of the material ore pulp to be 8-9, and then water glass, 2 # oil and oleic acid are sequentially added for direct flotation; and (5) concentrate obtained after flotation needs to be concentrated, filtered and dried. According to the method, the content of MgO in the low-grade magnesite can be increased, low-grade magnesite resources are fully utilized, and material waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, in particular to a flotation process for low-grade magnesite. Background Art

[0002] Magnesite is mainly used to produce various refractory products, such as magnesia bricks, chrome-magnesia bricks, alumina-magnesia bricks, etc. The refractoriness of these materials is as high as over 2000℃, and they are high-grade refractory materials.

[0003] my country is rich in magnesite resources and the mined ore is of high quality, so there has been relatively little research on magnesite beneficiation technology.

[0004] Therefore, at present, a large number of magnesite mines are mined arbitrarily, resulting in the abandonment of the poor and the exploitation of the rich. Due to the long-term mining method of exploiting the rich and abandoning the poor, my country's high-grade magnesite resources are decreasing, and a large number of low-grade magnesite is abandoned and stored without being fully utilized, resulting in a huge waste of resources. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem solved by the present invention is to provide a low-grade magnesite flotation process. The flotation process of the present invention can increase the MgO content in the low-grade magnesite, reduce the impurity content, make full use of the low-grade magnesite resources, and reduce material waste.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A low-grade magnesite flotation process comprises the following steps:

[0008] 1) Crushing low-grade magnesite to a particle size range of ≤2mm;

[0009] 2) Put the crushed low-grade magnesite into a ball mill for grinding into fine powder;

[0010] 3) Add the fine powder to water to form a raw ore pulp, add the raw ore pulp to the flotation machine, add sulfuric acid under stirring conditions to make the pH of the raw ore pulp 5-6, and then add sodium hexametaphosphate and octadecylamine in sequence to perform reverse flotation;

[0011] 4) After the above reverse flotation, the bottom material is retained, and water is added to the bottom material to prepare a material slurry with a concentration of 15-25%. Under stirring conditions, sodium hydroxide is added to make the pH of the material slurry 8-9, and then water glass, 2# oil, and oleic acid are added in sequence to perform positive flotation;

[0012] 5) The concentrate obtained after flotation needs to go through the processes of concentration, filtration and drying.

[0013] The part of the fine powder with a particle size of ≤0.074 mm accounts for 75-85% of the total weight of the whole material.

[0014] The concentration of the raw ore slurry is 25-35%.

[0015] In the step 3), the flotation temperature is 25-35° C., the stirring speed is 500-800 r / min, and the stirring time is 25-40 min.

[0016] In the step 3), the amount of sodium hexametaphosphate added is 80-150 g / t of raw ore pulp, and the amount of octadecylamine added is 200-250 g / t of raw ore pulp;

[0017] In the step 4), the flotation temperature is 25-30° C., the stirring speed is 500-800 r / min, and the stirring time is 20-30 min.

[0018] In the step 4), the amount of water glass added is 500-650 g / t of material slurry, the amount of 2# oil added is 80-130 g / t of material slurry, and the amount of oleic acid added is 1000-1500 g / t of material slurry.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention grinds low-quality magnesite into fine powder and reversely floats, so that quartz and silicate in the ore are effectively removed; the MgO content in the magnesite is increased through reverse flotation and direct flotation, the use value of the magnesite is increased, and the mineral resources are fully utilized; in addition, the pH of the reverse flotation is controlled at 5 to 6, and the pH of the direct flotation is controlled at 8 to 9, which is conducive to improving the purification effect. DETAILED DESCRIPTION

[0021] The specific implementation mode of the present invention is further described below:

[0022] Example 1

[0023] The present invention provides a low-grade magnesite flotation process, comprising the following steps:

[0024] 1) Crushing low-grade magnesite to a particle size range of ≤2mm;

[0025] 2) Put the crushed low-grade magnesite into a ball mill for grinding into fine powder;

[0026] 3) adding the fine powder to water to form a raw ore pulp, adding the raw ore pulp to a flotation machine, adding sulfuric acid under stirring conditions to make the pH of the raw ore pulp 5.5, and then adding sodium hexametaphosphate and octadecylamine in sequence for reverse flotation;

[0027] 4) After the above reverse flotation, the bottom material is retained, and water is added to the bottom material to prepare a material slurry with a concentration of 15-25%. Under stirring conditions, sodium hydroxide is added to make the pH of the material slurry 8, and then water glass, 2# oil, and oleic acid are added in sequence to perform positive flotation;

[0028] 5) The concentrate obtained after flotation needs to go through the processes of concentration, filtration and drying.

[0029] The part of the fine powder with a particle size of ≤0.074 mm accounts for 75-85% of the total weight of the whole material.

[0030] The concentration of the raw ore slurry is 25-35%.

[0031] In the step 3), the flotation temperature is 25-35° C., the stirring speed is 500-800 r / min, and the stirring time is 25-40 min.

[0032] In the step 3), the amount of sodium hexametaphosphate added is 120 g / t of raw ore pulp, and the amount of octadecylamine added is 220 g / t of raw ore pulp;

[0033] In the step 4), the flotation temperature is 25-30° C., the stirring speed is 500-800 r / min, and the stirring time is 20-30 min.

[0034] In the step 4), the amount of water glass added is 550 g / t of material slurry, the amount of 2# oil added is 90 g / t of material slurry, and the amount of oleic acid added is 1200 g / t of material slurry.

[0035] Example 2

[0036] The present invention provides a low-grade magnesite flotation process, comprising the following steps:

[0037] 1) Crushing low-grade magnesite to a particle size range of ≤2mm;

[0038] 2) Put the crushed low-grade magnesite into a ball mill for grinding into fine powder;

[0039] 3) adding the fine powder to water to form a raw ore pulp, adding the raw ore pulp to a flotation machine, adding sulfuric acid under stirring conditions to make the pH of the raw ore pulp 6, and then adding sodium hexametaphosphate and octadecylamine in sequence to perform reverse flotation;

[0040] 4) After the above reverse flotation, the bottom material is retained, and water is added to the bottom material to prepare a material slurry with a concentration of 15-25%. Under stirring conditions, sodium hydroxide is added to make the pH of the material slurry 9, and then water glass, 2# oil, and oleic acid are added in sequence to perform positive flotation;

[0041] 5) The concentrate obtained after flotation needs to go through the processes of concentration, filtration and drying.

[0042] The part of the fine powder with a particle size of ≤0.074 mm accounts for 75-85% of the total weight of the whole material.

[0043] The concentration of the raw ore slurry is 25-35%.

[0044] In the step 3), the flotation temperature is 25-35° C., the stirring speed is 500-800 r / min, and the stirring time is 25-40 min.

[0045] In the step 3), the amount of sodium hexametaphosphate added is 150 g / t of raw ore pulp, and the amount of octadecylamine added is 250 g / t of raw ore pulp;

[0046] In the step 4), the flotation temperature is 25-30° C., the stirring speed is 500-800 r / min, and the stirring time is 20-30 min.

[0047] In the step 4), the amount of water glass added is 600 g / t of material slurry, the amount of 2# oil added is 130 g / t of material slurry, and the amount of oleic acid added is 1350 g / t of material slurry.

[0048] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A low-grade magnesite flotation process, characterized in that: The steps include: 1) Crushing low-grade magnesite to a particle size range of ≤2mm; 2) Put the crushed low-grade magnesite into a ball mill for grinding into fine powder; 3) Add the fine powder to water to form a raw ore pulp, add the raw ore pulp to the flotation machine, add sulfuric acid under stirring conditions to make the pH of the raw ore pulp 5-6, and then add sodium hexametaphosphate and octadecylamine in sequence to perform reverse flotation; 4) After the above reverse flotation, the bottom material is retained, and water is added to the bottom material to prepare a material slurry with a concentration of 15-25%. Under stirring conditions, sodium hydroxide is added to make the pH of the material slurry 8-9, and then water glass, 2# oil, and oleic acid are added in sequence to perform positive flotation; 5) The concentrate obtained after flotation needs to go through the processes of concentration, filtration and drying.

2. A low-grade magnesite flotation process according to claim 1, characterized in that: The part of the fine powder with a particle size of ≤0.074 mm accounts for 75-85% of the total weight of the whole material.

3. A low-grade magnesite flotation process according to claim 1, characterized in that: The concentration of the raw ore slurry is 25-35%.

4. A low-grade magnesite flotation process according to claim 1, characterized in that: In the step 3), the flotation temperature is 25-35° C., the stirring speed is 500-800 r / min, and the stirring time is 25-40 min.

5. A low-grade magnesite flotation process according to claim 1 or 4, characterized in that: In the step 3), the amount of sodium hexametaphosphate added is 80-150 g / t of raw ore pulp, and the amount of octadecylamine added is 200-250 g / t of raw ore pulp.

6. A low-grade magnesite flotation process according to claim 1, characterized in that: In the step 4), the flotation temperature is 25-30° C., the stirring speed is 500-800 r / min, and the stirring time is 20-30 min.

7. A low-grade magnesite flotation process according to claim 1 or 6, characterized in that: In the step 4), the amount of water glass added is 500-650 g / t of material slurry, the amount of 2# oil added is 80-130 g / t of material slurry, and the amount of oleic acid added is 1000-1500 g / t of material slurry.