JPH05169036A - Method for concentrating gold ore - Google Patents

Abstract

PURPOSE:To automatically concentrate and remove only a pure country rock without mixing a middling having a low content of quartz contg. minute amts. of gold and silver with the country rock. CONSTITUTION:The ore contg. gold and silver is roughly crushed. The white part on the ore surface is calculated by using an image analyzer provided with a television camera, and the white part having less than a specified content is removed. The concentration accuracy is enhanced in this way, an evil influence of the component such as the clay material of the country rock is surely obviated, and the concentration accuracy is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beneficiation method of gold ore in which a mined gold-and-silver-containing ore is roughly crushed and then the mother rock containing no gold and silver is removed as waste stone before finely crushed.

[0002]

2. Description of the Related Art In the case of vein ore containing gold and silver, gold and silver are concentrated in the white quartz veins, and the gray or black host rock contains almost no gold and silver. It contains a large amount of clay minerals, which adversely affects the refining process. Therefore, by removing the black host rocks in advance, the processing cost can be reduced and the harmful effects of clay minerals in the subsequent refining process can be removed.

Therefore, conventionally, gold and silver ores have been crushed, then finely pulverized to an appropriate particle size, and suspended in an aqueous cyanide solution to leach gold and silver, whereby gold and silver are separated from gangue by a so-called bluing method. There are a method of concentrating, a method of using as a solvent for copper refining, and a method of separating and concentrating gold and silver minerals from gangue by a flotation method.

However, in order to carry out these methods, the ore must be crushed from several tens of microns to several hundreds of microns, which requires a huge amount of energy. In other words, the ore as it is mined contains a large amount of host rock mass that contains almost no gold and silver, and crushing such host rock into such fine particles wastes energy. Will be done.
In addition, since the host rock contains a large amount of clay minerals, it is generally well known that clay minerals have adverse effects in any of the bleaching method, copper refining solvent, and flotation method. Is.

Originally, quartz containing gold and silver is white, and can be easily visually distinguished from gray or black host rock. Therefore, as a method of removing the host rock from the coarsely crushed material, manual selection, so-called manual selection, or by detecting the color of the mass with a sensor or irradiating the mass with a laser beam and determining whether the mass is the host rock Automatic sorting by an ore sorter for distinguishing between is known.

[0006]

However, the manual selection is a method of manually removing the host rock visually selected by the operator. Therefore, it is troublesome when the size of the lump is small, so that the efficiency is extremely high. There is a problem of decrease. On the other hand, in the sorting using a machine, there is a problem that it is difficult to sort a so-called single-edged lump in which quartz containing gold and silver is vein-shaped in the host rock. That is, the color sensor sorter
Since the color of the whole mass is averaged and digitized, there is a problem that the mass containing vein-like quartz is easily confused with the host rock.
Also, the method using laser light has a narrow irradiation range,
Fine vein-shaped quartz may not be detected, and there is a problem that the single edge is easily confused with the host rock. For this reason, if a small amount of quartz-containing lumps is judged to be the host rock and is turned into waste rock and mixed, the actual yield of gold and silver decreases, and gold and silver are expensive. The actual yield is required, and the sorting machine according to the above method has not been put to practical use.

An object of the present invention is to provide an automated beneficiation method capable of selecting and removing only pure host rock without confusing it with the host rock even for a single-edged tool having quartz containing a small amount of gold and silver. To do.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems and achieve the above objects, the inventors of the present invention have found that the coarsely crushed ore is subjected to a white portion ratio using an image analyzer. The present invention has been completed by finding that the object can be achieved by calculating and removing those below a predetermined value. That is, the present invention, the ore mined from the quartz vein deposit containing gold and silver is photographed with a television camera, the percentage of the white portion of the ore surface is calculated using an image analyzer, and the percentage is less than or equal to a predetermined value. It is a method of selecting gold ore that removes things as host rocks that do not contain gold and silver.

The camera used in the present invention may be a monochrome camera because an ore mined from a general gold-silver quartz vein deposit can select quartz and host rock only by light and dark, and a monochrome image is sufficient. If a color camera is connected and color image processing is performed, it is possible to handle a wider variety of ores.

The image analysis device is a device for processing and computing an image of ore taken by a television camera by a computer to determine whether or not the lump surface contains quartz. For example, Nireco Co., Ltd. Known devices such as Luzex (trade name) can be used. Further, the apparatus for sorting the ore after the discrimination can use the mechanical section of a general ore sorting machine.

The coarse crushing of the ore is carried out using a commonly used crusher for 10 to 100 mm, preferably
The particle size is about 20 to 50 mm.

[0012] It is preferable that the predetermined value of the ratio of the white portion of the ore surface to be removed as a host rock containing no gold and silver is 1 to 5%.

[0013]

In the present invention, the ore is photographed by the television camera by the image analysis device, and the ratio of the white portion on the lump surface is detected as the ratio of quartz. The color sensor method is
Since it measures the lightness and darkness of the average color of the whole mass,
Although it is not possible to distinguish between the gray host rock and the single edge containing quartz, in the present invention, it is possible to distinguish because the area of the quartz vein itself is measured. Further, in the method based on the reflectance of laser light, when the irradiation range of the laser light is smaller than the size of the lump, quartz veins outside the irradiation range may not be detected and may be mistaken as host rock. Since the ore is photographed in a plane and the area of the quartz veins is obtained for the entire individual lumps from the image, the quartz veins are not missed and accurate sorting is possible. In order to carry out this operation with high accuracy, coarse crushing of the ore is carried out within the above-mentioned particle size range. If the particle size is less than 10 to 20 mm, the number of particles per unit volume increases and the treatment amount decreases. 1
If the diameter exceeds 00 mm, the number of separated mother rocks decreases,
This is because the amount of waste stone decreases.

[0014]

EXAMPLES Next, examples of the present invention will be described. Example 1 Gold ore (mine 66.1 g / t, alumina 1
0.6 wt%) was coarsely crushed to a particle size of -50 mm to +30 mm at the ore feed, and a monochrome television camera connected to Luzex 5000 (trade name) manufactured by Nireco Corporation was used as an image analysis device. Sorting was performed by using the part of less than% as the host rock. In this example, the concentrate and the tailing were separated by manual selection based on the area ratio measurement value obtained by image analysis. However, L manufactured by Gunson's Sortex of Canada was used.
Similar results can be obtained by using a mechanical part such as an aser sorter.

The results are shown in Table 1. The results of the alumina content measurement are shown in Table 2.

From these results, by removing only the black portion of the ore as a tailing, the gold grade 66.
A 1g / t ore feed was processed to obtain a gold grade 98.8g / t concentrate, and the yield of the concentrate at this time was 66.8wt%.
It was confirmed that the alumina content was reduced from 10.6 wt% of the feed ore to 9.8 wt% of the concentrate. As a result, the burden of the subsequent treatment is reduced, and the adverse effects caused by the incorporation of clay minerals other than silica are reduced. Example 2 A beneficiation process was performed in the same manner as in Example 1 except that an ore having a gold grade of 55.4 g / t and alumina of 10.6 wt% was used, and the feed grain size was set to -30 mm to +18 mm. The results are shown in Tables 1 and 2.

[0017]

[Table 1]

[0018]

[Table 2]

From these results, a gold grade 55.4 g / t ore feed was processed to obtain a gold grade 117.4 g / t concentrate, and the concentrate yield was 47.0 wt%, and the alumina content was Was confirmed to have been reduced from 10.1 wt% of the ore supply to 7.4% of the concentrate, and the subsequent processing load was reduced, and the adverse effect of mixing clay minerals other than silica was reduced. It was

[0020]

According to the present invention, since the gold ore is photographed by the camera and processed by the image analyzer to remove the host rock,
It is possible to significantly reduce the amount of subsequent treatment, and at the same time, it is possible to remove or reduce the adverse effects of components such as clay substances in the host rock at the same time.

Claims (1)

[Claims] 1. An ore mined from a quartz vein deposit containing gold and silver is photographed by a television camera, and the percentage of the white portion of the ore surface is calculated by using an image analyzer, and the percentage is below a predetermined value. A method of beneficiating gold ore, which comprises removing as a host rock that does not contain gold and silver.