JPH0487648A - Method for refining molybdenum ore - Google Patents

Abstract

PURPOSE:To rapidly and efficiently remove the copper sulfide ore from molybdenite by applying high-gradient magnetic separation to the molybdenite contg. the copper sulfide ore obtained by copper roughing, copper cleaning and molybdenum flotation when the copper content decreases below about 10wt.%. CONSTITUTION:The copper concentrate obtained by copper-roughing and copper- cleaning a copper ore is molybdenum-floated one to three times to obtain molybdenite contg. <= about 10wt.% copper. The molybdenite is crushed, and the molybdenite grains and copper sulfide ore grains are liberated. The granular molybdenite and copper sulfide ore are pulped and passed through the net (matrix) of a high-gradient magnetic separator, hence the copper sulfide ore is magnetically to the matrix, and the molybdenum ore (molybdenite) as a nonmagnetic material is separated as a non-adhered material. When one-stage high-gradient magnetic flotation is not sufficient for the separation and concentration, plural-stage high-gradient magnetic separation and concentration is applied, or the high-gradient magnetic separation and scavenging are combined to conduct high-gradient magnetic concentration.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for refining molybdenum minerals, in which molybdenum concentrate is beneficiated from molybdenum ore (molybdenum disulfide) containing copper sulfide minerals as impurities. Regarding.

[Conventional technology]

In porphyry copper mines, molybdenum concentrate is generally made from molybdenum ore contained in copper sulfide ore as a main raw material, and is recovered as a by-product in the concentrate and refining process of copper sulfide minerals through flotation (hereinafter referred to as flotation). . Since molybdenum is of high value, it is possible to operate even if the raw material ore is of low grade in terms of general beneficiation of base metal minerals, but the concentrate must be of high quality with extremely few impurities.

To explain the conventional beneficiation method for molybdenum concentrate, raw ore consisting of copper ore is crushed, flotated and separated into tailings and froth, and the resulting froth is further subjected to the same treatment. By repeating the above steps and performing copper rough selection and copper selection, copper sulfide mineral containing molybdenite is obtained as copper concentrate.

Luminite is known as one of the minerals that floats the most, and it floats even without special treatment.

By further performing preferential flotation of molybdenum on the copper concentrate obtained in this way, final copper concentrate is obtained as tailings, and by repeating molybdenum screening on the froth, final molybdenum can be obtained. Concentrate is obtained.

As mentioned above, molybdenite itself has strong buoyancy, so it can easily float to the surface by adding kerosene or other fuel oil and the necessary amount of foaming agent. 1. Since major copper sulfide minerals such as bornite and chalcocite all have strong floating properties, these copper sulfide minerals inevitably become mixed into the floss.

[Problem to be solved by the invention]

Therefore, when refining molybdenite, it is necessary to suppress the flotation of copper sulfide minerals by adding a copper mineral inhibitor such as cyanide. Since the added scavenger remained on the particle surface, the selection had to be repeated several times to more than ten times while adding the inhibitor. As a result, the loss of molybdenum caused by flotation or suppression at each stage of refining is accumulated each time the refining is repeated, and the final molybdenum yield is 80% to 40% of the content in the copper concentrate. In some cases, copper removal may be insufficient. As described above, the refining of molybdenite by flotation has problems in that the actual yield is low despite the operating costs such as reagents, energy, and equipment maintenance costs, and it is time-consuming and inefficient. Particularly at the molybdenum preferential flotation stage, it was extremely inefficient because it was necessary to repeat the flotation 10 to 10-odd times. Furthermore, conventionally, copper sulfide minerals such as chalcopyrite 9 bornite mixed into the final molybdenum concentrate have weak magnetism, so it has been considered impossible to separate them by magnetic separation in the refining stage.

In view of these problems, an object of the present invention is to provide a method for refining molybdenum minerals that can quickly and efficiently remove copper sulfide minerals mixed in molybdenite.

[Means to solve the problem]

The method for refining molybdenum minerals according to the present invention is to refine molybdenum minerals containing copper sulfide minerals obtained by rough copper separation, copper refinement, and molybdenum flotation until the copper content reaches about 10% by weight or less. The molybdenum concentrate is refined using gradient magnetic beneficiation.

In addition, molybdenite containing copper sulfide minerals with a copper content of about 1
When the concentration becomes 0% by weight or less, the molybdenum concentrate is purified by cyanide aqueous solution treatment and high gradient magnetic beneficiation.

[Effect]

If the copper concentrate obtained by rough separation and copper separation of copper ore is subjected to molybdenum flotation 1 to 3 times, the copper content will be approximately 1.
If less than 0% by weight of molybdenite is obtained and this molybdenite is subjected to high-gradient magnetic beneficiation, or if the copper sulfide mineral contained in the molybdenite contains a substance that is difficult to magnetize, cyanide is removed. By combining aqueous treatment,
Copper sulfide minerals can be separated with fewer processing steps, and molybdenum concentrate can be purified quickly and effectively.

〔Example〕

Hereinafter, the purification method according to the present invention will be explained in detail.

As mentioned above, chalcocite, chalcopyrite, bornite, and the like are known as main copper sulfide minerals contained in molybdenite obtained by flotation of copper concentrate for molybdenum.

Among these, in the case of molybdenite which mainly contains chalcopyrite and bornite as copper sulfide minerals, high gradient magnetic beneficiation is performed.

Here, to explain high gradient magnetic ore beneficiation, a high gradient magnetic separator (High
h GraclientMagnetic 5ep
arater) is valid. This high-gradient magnetic separator places a strong magnetic wire or mesh (matrix) in a uniform magnetic field inside a solenoid coil, and uses the high magnetic field gradient generated around the wire or mesh to attract magnetic materials and convert them into magnetic materials. It separates non-magnetic materials. Even bornite, which has the strongest magnetism among copper sulfide minerals, has a magnetic susceptibility of II ~
55rr? /kg, or it is possible to magnetize it with this high gradient magnetic separator. The high gradient magnetic separation rough separation, fine selection, cleaning separation (HGMS rough selection, fine selection, cleaning separation), etc. using this separator are referred to as high gradient magnetic separation.

In addition, when performing high gradient magnetic beneficiation, it is necessary to crush the molybdenite and separate it into particles of the molybdenite itself and copper sulfide mineral particles. The degree of particles in this case varies depending on the origin of the ore (due to differences in refining conditions and crystal size, etc.); for example, copper sulfide ore made from American dust has a particle size of 45 μm.
The average diameter is 75 μm or less for ores produced in China. In fact, the particle size can be easily determined by crushing the ore to be treated and observing it under a microscope. However, if the particle size becomes smaller than 2 to 3 μm, the magnetizing force will be weakened, which is not preferable.

Furthermore, in consideration of processing efficiency in the high gradient magnetic beneficiation stage, it is appropriate that the copper grade of molybdenite is 10% by weight or less. In order to make the content of copper in the molybdenum ore 10% by weight or less, molybdenum flotation with respect to the copper concentrate may be carried out about 1 to 3 times. If the copper content exceeds 10% by weight, it is not preferable because the efficiency of high gradient magnetic beneficiation decreases.

Then, by making these particulate molybdenite and copper sulfide minerals of a predetermined particle size into pulp and passing them through the matrix of a high gradient magnetic separator, the copper sulfide minerals are magnetically attached to the matrix, and the non-magnetic molybdenum minerals are (molybumite) can be separated as a non-magnetic substance. Moreover, the pulp flow rate at this time is preferably 50 to 200 m/h. If there are many fine particles, the flow rate is reduced to improve the magnetic adhesion of the copper sulfide mineral, but if the flow rate is too low, molybdenum will be mixed into the magnetized material, which is not preferable.

The magnetic field strength at the time of air core is 1°9~ under the pulp flow rate conditions mentioned above.
Approximately 22.2 kOe is appropriate. If the magnetic field strength is too strong, molybdenum will also mix into the magnetic object.

If sufficient separation and beneficiation cannot be achieved with one-stage high-gradient magnetic separation, high-gradient magnetic separation can be performed by performing multiple stages of HGMS (high-gradient magnetic separation) sorting or by combining HGMS (high-gradient magnetic separation) cleaning. Let's do it.

Note that HGMS cleaning and selection refers to a process for separating molybdenum minerals mixed into the magnetic substances separated by HGMS rough selection or fine selection and feeding them back to the non-magnetized substances.

As mentioned above, when beneficializing molybdenite containing mainly chalcopyrite and bornite as copper sulfide minerals, the copper concentrate is flotated with molybdenum 1 to 3 times to reduce the copper content to 10% by weight or less. (And since this molybdenite has the property that chalcopyrite and bornite are easily magnetically attached, high-gradient magnetic beneficiation is performed without pretreatment, and chalcopyrite and bornite are easily attached to the magnet. It is possible to separate and refine molybdenum concentrate with a low content of copper sulfide minerals.

Next, in the case of molybdenite, which contains molybdenite, oxycopperite, or a mixture thereof in addition to chalcopyrite and bornite as copper sulfide minerals, beneficiation is performed by combining high-gradient magnetic beneficiation and cyanide aqueous solution treatment. Do this. This is because chalcocite is difficult to attract magnetism, but has the property of being dissolved by an aqueous cyanide solution.

Here, to explain the cyanide aqueous solution treatment, the cyanide aqueous solution is preferably sodium cyanide or potassium cyanide, and the cyanide aqueous solution only needs to have a concentration of 200 ppm or more. Further, when pulp is prepared by mixing molybdenum with an aqueous cyanide solution, the pulp concentration is preferably 60% by weight or less, and the treatment time is preferably several hours to about 48 hours. This pulp has a pH of 9 or more, and its temperature is preferably room temperature.

Moreover, in this case, it is more preferable to perform pulp agitation, so either the cyanide aqueous solution treatment or the high gradient magnetic beneficiation can be performed first, or both can be performed simultaneously. Get results.

When the cyanide aqueous solution treatment is performed first, the grain size of molybdenite obtained through the copper selection process may be used as it is, but it is preferable to use it after crushing it to 210 μm or less.

As mentioned above, when beneficent ore containing chalcocite, copper oxide ore, or a mixture thereof as a copper sulfide mineral, the copper concentrate is flotated with molybdenum 1 to 3 times to reduce the copper content to 10% by weight or less. This molybdenite is treated with a cyanide aqueous solution to dissolve the chalcocite into the liquid phase and separate it.In high-gradient magnetic beneficiation, molybdenite and copper sulfide minerals are separated as a single substance. Chalcopyrite, bornite, etc. are separated by crushing them into particles of the desired particle size and passed through a high-gradient magnetic separator, and if necessary, they are beneficent by combining multiple stages of HGMS sorting or cleaning sorting. Do this.

In this way, a purified molybdenum or molybdenum concentrate with a low content of copper sulfide minerals is obtained.

As described above, according to the present invention, the number of processing steps such as the number of times of molybdenum flotation can be significantly reduced, so copper sulfide minerals contained in molybdenite can be quickly and efficiently removed, making it possible to reduce the number of operations. It is possible to reduce costs.

Next, a specific example of the method for refining molybdenum minerals according to the present invention will be described based on the flow sheets shown in FIGS. 1 and 2.

Copper concentrate containing mainly chalcopyrite and bornite was purified by 1 to 3 cycles of molybdenum preferential flotation, and the resulting molybdenite (A ) was processed according to the flow sheet shown in FIG.

The molybdenite (A) is crushed and sieved with a particle size of 45 μm, and only the particles under the sieve, that is, particles of 45 μm or less, are mixed with water to make pulp, and the pulp is subjected to high gradient magnetic beneficiation at a pulp concentration of 10 to 20% by weight. did. The high gradient magnetic separator used in high gradient magnetic beneficiation is SAL AHGMS (registered trademark) 10-1.
This is a 5-20 type testing machine, and since this testing machine is a hatch processing type, there is a limit to the amount of ore that can be processed at one time, and here the processing was carried out with the initial amount of ore fed at 200-500 g. In addition, a capture matrix called FX was used.

Then, the magnetic field strength (at the time of air core) is 4.7 with molybdenite (A)
kOe, the ore was fed to a high gradient magnetic separator set at a valve flow rate of 100 m/h above the matrix, and HGMS rough selection 101
Magnetized materials (such as chalcopyrite and bornite) and non-magnetized materials (
It was separated into molybdenite) and molybdenite. In this case, since the removal of copper sulfide minerals in the molybdenum ore was incomplete in the -degree treatment, two more rounds of selection 102 and 103 were performed. Furthermore, since the copper sulfide minerals remaining in the non-magnetized material during the selection stage are considered to be very fine particles or single-edged particles, the magnetic field strength was increased to 20 kOe in the final selection 103. Also, rough selection 101 and 1
In order to recover molybdenum mixed in due to factors other than magnetic force from the magnetic material separated in the second selection 102, cleaning selection 104 was performed with the pulp flow rate increased to 200 m/h, and it was possible to separate it as a single edge.

The processing results are shown in Table 1.

To explain according to the flow sheet shown in Table 1 and Figure 2, copper concentrate was subjected to molybdenum preferential flotation 1 to 3 times in the same manner as in Example-1.
Copper sulfide content of molybdenite (B) containing chalcocite, copper oxide ore, etc., refined by 0.00 is extremely low at 0.31% by weight. For this reason, regarding high gradient magnetic beneficiation, after HGMS rough selection 106) (GMS fine selection 107)
] times, and the combined magnetically attracted materials of the rough selection 106 and the fine selection 107 were subjected to three HGMS cleaning selections 108.10.
9. Repeat 110, cleaning selection I08, 1 twice.
The non-magnetic material separated in 09 was recovered as molybdenum concentrate in order to improve its actual yield. In addition, rough selection 106
．． In the selection 107 and the first and second cleaning selections 108 and 109, the magnetic field strength was 9 kOe.

The pulp flow rate was 100 m/h, and the final cleaning step 11O had a magnetic field strength of 20 kOe and a pulp flow rate of 200 m/h.
Processing was performed with the setting set to h.

The processing results are shown in Table 2.

HGMS treatment test results for 2nd surface molybdenite (B) (no pretreatment) Example-2 (a) In the flow sheet shown in FIG. 2, the copper sulfide content of molybdenite (B) is 0. It is 38% by weight. In addition, molybdenite (B) contains chalcocite and copper oxide ore, which are difficult to attract magnetically, as in Example 2 (a), and in order to treat this, cyanide was added before the HGMS rough selection 106. Aqueous solution treatment 11
1 step has been added. By pre-treating with a 1g/z cyanide aqueous solution for 48 hours, chalcopyrite is easily dissolved in hydrocyanic acid, so it is eluted together with copper oxide, and after this pretreatment, chalcopyrite, which is easily magnetized, is dissolved in chalcopyrite. It is thought that only bornite and bornite remain. Therefore, as shown in Table 3, the copper sulfide mineral content decreased to 0.38% by weight. The following treatment was carried out in the same manner as in Example-2(a). Example-2
Actual yield of molybdenum concentrate (88.8% compared to (a)
) losses were small.

Table 3 Cyanide aqueous solution treatment (leaching) of molybdenite (B) and H
GMS processing test results FIGS. 1 and 2 are flow sheets showing a specific example of the method for refining molybdenum minerals according to the present invention.

Claims (2)

[Claims] (1) When the molybdenite containing copper sulfide minerals obtained by rough copper separation, fine copper separation, and molybdenum flotation is reduced to about 10% by weight or less, the high gradient A method for refining molybdenum minerals by magnetic beneficiation to obtain molybdenum concentrate. (2) Cyanide of molybdenum containing copper sulfide minerals obtained by coarse copper separation, fine selection of copper, and flotation of molybdenum is obtained when the copper content in the molybdenite becomes approximately 10% by weight or less. A method for refining molybdenum minerals by performing aqueous solution treatment and high gradient magnetic beneficiation to obtain molybdenum concentrate.