JPS6159182B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for enriching low-grade iron ore containing many types of quartz and other gangue minerals by flotation. Iron ore is cheaper than non-ferrous metal minerals and has been blessed with a relatively large amount of rich ore, so it has conventionally been used as a raw material for iron manufacturing without the need for special beneficiation. However, as rich ore reserves decrease, a situation has arisen in which even low-grade iron ore has to be used. For example, ore deposits (such as magnetite minerals) whose iron quality can be relatively easily increased through magnetic separation are given priority. development is progressing. In addition, in order to cope with the depletion of iron ore and promote the effective use of domestic resources, there is a growing momentum to effectively utilize low-grade hemtite minerals, which have abundant reserves. By the way, among low-grade iron ores, when the grain size of the iron ore is relatively coarse (approximately 2 to 3 mm or more), it is possible to improve the iron grade using relatively simple beneficiation methods such as water washing, heavy selection, and gravity beneficiation. However, in the case of low-grade hematite ores, which have small hematite particle sizes (usually less than 0.1 to 0.2 mmφ), it is not possible to separate the ore into individual pieces unless the ore is pulverized, and it is not easy to sort the ore after pulverization. At present, this objective has been achieved to some extent through the flotation method. In flotation of low-grade hematite ore, either the method of concentrating the hematite on the froth side or the method of concentrating it on the sink side is carried out, but in the early stages fatty acids or their salts were used as a scavenger. The former method used was the mainstream. However, this method has difficulty in selectivity and cannot achieve a sufficient effect of improving iron quality. On the other hand, the latter method can improve selectivity by using a scavenger such as an aliphatic amine and can obtain relatively high-grade concentrate, so the latter method is currently used. is becoming mainstream. In this case, a technique has also been established to further increase the iron quality by using starch as an inhibitor. However, even if the latest flotation technology as mentioned above is used, it is not easy to efficiently separate high-iron minerals from low-grade hematite ore, and currently the iron content is only about 60% by weight. Even the most preferable one has a limit of about 62 to 63% by weight, and if you try to increase the iron quality any further,
It is necessary to extend the ore beneficiation time or repeat the ore beneficiation several times, ignoring productivity, and as a result, the actual yield is extremely reduced. The present inventors focused on the above-mentioned circumstances and developed a mineral enrichment processing method that can efficiently separate high-grade ore concentrate from low-grade iron ore such as low-grade hematite minerals on an actual operational scale. We have been conducting research with this in mind. The present invention was completed as a result of such research, and
Its composition is dimer acid obtained by polymerizing unsaturated fatty acids as a scavenger when mineralizing low-grade iron ore containing many types of quartz and other gangue minerals by flotation. The gist lies in the use of aliphatic amines and/or salts thereof. The structure and effects of the present invention will be explained in detail below along with the research history leading to the completion of the present invention. First, in order to clarify the problems in the known flotation method, the present inventors investigated low-grade hematite ore with the chemical composition shown in Table 1 [minerals fixed by X-ray diffraction are hematite, firefly stone, quartz, aegirine (NaFeSi ₂ O ₆ ), apatite, barite, etc.] at 74μ
When the particles were crushed to a size of less than m and flotation was carried out using a known collector alone and starch as an inhibitor, the results shown in Table 2 were obtained.

【table】

[Table] As is clear from the results in Table 2, rich ore with an iron grade of less than 50% can be obtained in all cases. However, the above raw material ore has an extremely low iron content (30% or less) and is considered unsuitable as a raw material for flotation, so high-magnetic magnetic separation is used to increase the iron content to some extent through pretreatment. We considered this. That is, the raw material ore having the composition shown in Table 1 was pulverized to a particle size of 105 μm or less or 44 μm or less, and the magnetic separation effect was investigated when the magnetic flux density of the air-core magnetic field was varied in the range of 3000 to 9000 Gauss (the element 1/4'' expanded metal was used), and the results are shown in Table 3.

[Table] As is clear from Table 3, high-magnetic magnetic separation is extremely effective as a method of raising extremely low-grade materials to medium-grade materials. However, it is not easy to obtain high-grade rich ore through high-magnetic separation alone. By the way, the first
The figure shows the relationship between the actual iron yield and iron grade (Fe content) when high magnetic force magnetic separation is repeated once or twice using the same method as above. If the iron grade is lowered and the iron grade is increased, the actual yield will be extremely reduced. Also, the actual yield rate is 60%
Even if it is suppressed to a certain degree, the iron quality is limited to about 60%, and it is extremely difficult to increase the iron quality to more than 60% using only high-magnetic separation. Based on these results, when processing low-grade iron ore to enrich it, it is necessary to increase the iron quality to a certain level by using high-magnetic magnetic separation, etc., and then to convert high-grade refined iron ore by flotation. The method of obtaining ore is considered to be effective. Therefore, we targeted the crude concentrate obtained by high-magnetic magnetic separation as shown in Table 4, and used the aliphatic amine (beef tallow diamine acetate) that obtained the best results in the supplementary experiment as a collector and the collector in a preliminary experiment. This was the first time we confirmed its performance. The flotation effect was investigated when dimer acids or their salts obtained by polymerizing unsaturated fatty acids (particularly Versadime (trademark: manufactured by Henkel Japan Co., Ltd.)) were used alone.

[Table] In this experiment, an MS-type flotation machine (impeller rotation speed 2140 rpm, capacity 200 c.c.) was used, and the pulp concentration was 7.5% and the flotation time was 5 minutes. Using an appropriate amount of pine oil as a foaming agent, the pH of the pulp is adjusted to 10~10 with HCl or NaOH.
Adjusted to 11.5. The PH of the pulp was determined based on the following preliminary experimental results. In other words, Fig. 2 shows the use of Versadime as a collecting agent to collect pulp.
This is an experimental graph showing the effect on the iron quality of the sink when the pH is changed in the range of 8 to 12.
Concentrates with the highest iron grade can be obtained around 10 to 11.5. The results are shown in Table 5.

[Table] As is clear from Table 5, by using aliphatic amine or Versadime as a collector, the iron grade of the concentrate can be increased to about 61 to 62%. However, it was not possible to achieve an iron quality of about 65% or higher, which is the current goal of the present inventors. The reason why the above results were obtained is not necessarily clear, but one reason is that aliphatic amines have high selectivity for quartz in gangue minerals, as is clear from the above additional test results. However, the selectivity for other gangue minerals cannot necessarily be said to be sufficient, and therefore, in cases where many kinds of gangue minerals other than quartz are contained, as in this example, It is thought that improvement of iron quality is hindered due to insufficient separation of iron. By the way, as is clear from the following experiment, Versadime does not necessarily have sufficient selectivity for quartz, but it has been confirmed that it exhibits high selectivity for other gangue minerals such as fluorite. That is, using crude concentrate having the chemical composition shown in Table 4 above, maintaining the pulp PH at 10.5 to 11.3, adding starch (22.5 mg/) as an inhibitor, and varying the amount of Versadime added. When flotation was carried out and the contents of Fe, SiO ₂ and F derived from fluorite in the sink were investigated, the results shown in Figure 3 were obtained. As is clear from Figure 3, Versadime hardly contributes to the selective removal of SiO ₂ (i.e. quartz), but it has an extremely excellent selective removal effect on gangue minerals other than quartz (especially fluorite). There is. From these results, we found that by using Versadime and aliphatic amine in combination as scavengers, and removing gangue minerals other than quartz with Versadime and removing quartz with aliphatic amine, the iron grade can be effectively reduced. It is thought that it can be improved. Therefore, we used the sink fraction obtained by using Versadime (amount used: 22.5 mg/) in the above flotation process, aliphatic amine (amount added: 1 to 20 mg/) as a scavenger, and starch (amount added: Pulp PH is 10.5 using 22.5mg/)
Flotation was carried out with the adjustment to ~11.3. The results are shown in Figure 4. As is clear from Figure 4, the iron content in the final sink fraction is 65% because the quartz contained in the sink fraction obtained using Versadime as a collection agent is removed by the aliphatic amine. increase to a certain extent. In addition, in the above, a procedure was adopted in which gangue components other than quartz were first removed using Versadigm, and then quartz was removed using an aliphatic amine, but the results are almost the same even if the reverse procedure is adopted, In some cases, it is also possible to add both collectors at the same time to remove quartz and other gangue components at once. However, in order to utilize the functions of each scavenger to the maximum extent possible, a sequential flotation method in which each scavenger is added individually is preferable. In flotation to suspend quartz,
It has been confirmed that the suspension of quartz can be made easier by adding an appropriate amount of soluble Ca salt such as CaCl ₂ as an activator, and in the present invention, it is extremely difficult to use soluble Ca salt in combination at the quartz removal stage. Effective. In addition, if the iron content of the raw ore is extremely low,
As explained at the beginning, it is operationally and economically disadvantageous to increase the iron quality by flotation alone.
For extremely low-grade ores, it is best to increase the iron grade to about 40% or more through preliminary treatment such as high-magnetic separation, and then perform the mineral enrichment treatment of the present invention, so that the iron grade of the raw ore is 40 to 50%. If the mineral is of a certain extent, the mineral enrichment treatment of the present invention may be directly performed. For example, Figure 5 shows a flow sheet for mineral enrichment processing applied to raw material ores with a relatively high iron content, and Figure 6 shows a flow sheet for mineral enrichment processing applied to raw material ores with extremely low iron grades. It is. However, the present invention is not limited by these flow sheets, and it is of course possible to carry out the present invention with appropriate changes within the scope that can comply with the spirit described above and below. The present invention is roughly constructed as described above, and by using dimer acid and/or its salt obtained by polymerizing unsaturated fatty acids and an aliphatic amine together as a scavenger, it is possible to remove quartz from other types of quartz. It has become possible to efficiently obtain high-grade iron concentrate even from low-grade iron ore containing gangue minerals. Therefore, the practical value of the present invention is extremely great now and in the future, when the depletion of high-grade iron ore makes it inevitable to utilize low-grade iron ore. Next, examples will be shown. Example A low-grade hematite ore containing quartz, fluorite, aegirine, barite, amphibole, etc. as gangue minerals and having an iron content of 26.60% was crushed to a particle size of 44 μm or less,
Preliminary ore beneficiation was performed using a high-magnetic magnetic separator (magnetic flux density of air-core magnetic field: 5000 Gauss), and crude concentrate with an iron grade of 54.58% was obtained. Using this coarse concentrate, the first stage of flotation uses Versadime as a collection agent (sodium oleate or aliphatic sulfonate is also used for comparison), starch as a suppressor, and the second stage collects Sequential flotation was performed using an aliphatic amine (tallow diamine acetate) as an agent and starch as an inhibitor. The results are shown in Table 6. Even if aliphatic amine is used in combination with other known collectors, it is not possible to obtain concentrate with an iron content of 65% or more, but aliphatic amine and Versadime When used in combination,
It is possible to stably obtain concentrate with an iron grade of approximately 65% or higher.

【table】 [Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between actual iron yield and iron grade of concentrate when high magnetic force magnetic separation method is adopted, Figure 2 is a graph showing the relationship between pulp PH and iron grade, and Figure 3 is a graph showing the relationship between pulp PH and iron grade.
The figure shows the amount of Versadime added, Fe in the sink,
Graph showing the relationship between SiO ₂ and F content, 4th
The figure is a graph showing the relationship between the amount of aliphatic amine added and the content of Fe, SiO ₂ and F in the sink in the second stage flotation after the first stage flotation using Versadime. Figures 5 and 6 are flow sheets illustrating the mineral enrichment treatment method of the present invention.

Claims (1)

[Claims] 1. A dimer obtained by polymerizing unsaturated fatty acids as a scavenger when mineralizing low-grade iron ore containing quartz and other gangue minerals by flotation. A method for mineral enrichment processing of low-grade iron ore, characterized by using an acid and/or a salt thereof and an aliphatic amine. 2. The mineralization treatment method according to claim 1, in which starch is also used as an inhibitor. 3. The mineralization treatment method according to claim 1 or 2, which is carried out by maintaining the PH of the pulp at 9.5 to 11.5. 4. The mineralization enrichment method according to any one of claims 1 to 3, in which a soluble Ca salt is used as an activator. 5. The mineral enrichment processing method according to any one of claims 1 to 4, using low-grade iron ore having an iron grade of 40 to 50% by weight. 6. The mineral enrichment processing method according to claim 5, which uses low-grade iron ore whose iron quality has been increased by magnetic separation.